Search

Excessive production of biomass, in times of intensification of agriculture and climate change, is again becoming one of the biggest environmental issues. Identification of sources and effects of this phenomenon in a river catchment in the space–time continuum has been supported by advanced environmental modules combined on a digital platform (Macromodel DNS/SWAT). This tool enabled the simulation of nutrient loads and chlorophyll “a” for the Nielba River catchment (central-western Poland) for the biomass production potential (defined here as a TN:TP ratio) analysis. Major differences have been observed between sections of the Nielba River with low biomass production in the upper part, controlled by TN:TP ratios over 65, and high chlorophyll “a” concentrations in the lower part, affected by biomass transport for the flow-through lakes. Under the long and short-term RCP4.5 and RCP8.5 climate change scenarios, this pattern will be emphasized. The obtained results showed that unfavorable biomass production potential will be maintained in the upper riverine sections due to a further increase in phosphorus loads induced by precipitation growth. Precipitation alone will increase biomass production, while precipitation combined with temperature can even enhance this production in the existing hot spots., Modeling approach assists in current and future water eutrophication analysis in a river under climate change scenarios.

International audience; Aim: The roles of geodynamics, climatic variability and landscape evolution in shaping aquatic biodiversity patterns on the African continent remain poorly understood. We studied the geographical origin and phylogenetic relationships of an Afrotropical freshwater snail genus to examine the role of drainage evolution on diversification and range evolution. The relevance of fish provinces in bio-regionalization of invertebrates was explored, as well as the evolution of habitat specificity.Location: Africa including Madagascar. Taxon: Lanistes (Gastropoda: Ampullariidae).Methods: Based on a sampling covering the entire geographical range, we reconstructed a fossil-calibrated multi-locus molecular phylogeny using maximum likelihood and Bayesian inference approaches. After applying species delimitation methods, we estimated ancestral areas and habitats and examined rates of diversification through time using lineage through time plots.Results: RAxML and MrBayes analyses resulted in highly congruent topologies and a strongly supported phylogeny. Our BEAST analysis indicate that Lanistes probably originated in the Eocene about 50 Ma and the most recent common ancestor (MRCA) of all 23 Lanistes OTUs in our study may have inhabited an area including the Central African and adjacent Lower Guinean biogeographical regions. A steeper increase in species accumulation from the middle Miocene (c. 15 to 10 Ma), followed by a decrease towards the present was found. Sympatry and jump dispersal were the common cladogenetic events and only a single anagenetic dispersal event was detected. The biogeographical analyses further suggest that Madagascar was colonized from East Africa and that the Zambezi River was colonized at least twice independently. Seven species are confined to rivers and three live exclusively in lakes. The estimation of ancestral habitats suggested that the MRCA of all Lanistes probably evolved in ariverine habitat.Main conclusions: The diversification of Lanistes started in the Eocene and occurred at a constant pace apart from a possible climate-related increase in the Miocene. This study highlights the significance of temporal geographical isolation of river systems and subsequent reconnection in clade diversification and of jump dispersal in range evolution. More comparative analyses across various taxa are needed to obtain a betterunderstanding of African freshwater biodiversity.

Water management is assuming more and more importance as freshwater resources are becoming scarce, both in quality and in quantity, across many developed and developing countries. This trend can be attributed to population growth, industrialization, growing agricultural demand, poor water management practices and climate change. In attempting to deal with the intensification of water quality- and quantity-related problems in recent decades, many countries have revised their water resource management policies and legislation, introducing new institutional frameworks and management instruments. Considering regional geographic and cultural distinctions, the present article aims at comparing the models of water resource management in the European Union (EU) and in Brazil. Institutional and legal arrangements currently in place, water planning and management instruments currently in use, assessments of water body status and watershed diagnoses were analysed. Main strengths and weaknesses of each water management system are pointed out in the conclusion. Main challenges for the water sector, and highlights of the converging and diverging points concerning water resource management systems, in each region, are discussed. Highlights Management of tropical and temperate water resources are distinct.; Management differences are due to cultural and geographic characteristics of basins.; Drainage basins were shown to be the efficient management units in both regions.; More efficient management tools are developed with comprehensive basin monitoring.; Regardless of the region, management targets are difficult to be attained.

Change in climate and land use is the main cause of increasing streamflow and soil erosion. However, very few studies have investigated these changes on a basin scale. Thus, this study used the Soil and Water Assessment Tool (SWAT) method to evaluate the effects of both land use and climate change effects on streamflow, sediment yield, and soil loss in the Nam Rom River Basin, Northwest of Vietnam. The outputs of the SWAT model demonstrated it to be a strong tool in predicting catchment hydrology, sediment transport, and soil loss. Meanwhile, based on SWAT model simulation, it was found that reforestation and management practices executed between 1992 and 2015 strongly contributed to the decreased sediment yield. The potential for climate change clearly leads to an increase to sediment yield and significantly more soil loss. The combined climate and land use change analysis indicated that land use planning could be adopted to mitigate streamflow (16.9%) and sediment load (4.9%) in the future, in conjunction with the projected direct impact of climate change. In conclusion, the findings in the present study contribute useful knowledge, methods, and techniques that could be reapplied to other regions in Vietnam and the world in terms of land and water conservation.

Soil and water are the two main natural resources that sustain human existence on earth. Proper monitoring and maintenance of these resources are done on basin level. The IRB drains an area of 7,951.03 km2. The basin has a mean annual discharge of 120m3/sec and generates significant surface runoff and sediment. The study aim was to evaluate the sediment yield across IRB using the Soil and Water Assessment Tool (SWAT) model. SWAT is a watershed-based, semi-distributed hydrologic model for simulating hydrological processes at different spatial scales. The model utilized digital elevation model DEM to extract the river network, basin delineation, and sub-basin division. The sub-basins were further divided into hydrological response unit HRU at a threshold of 5% slope, 5% the land use and 5% soil. Harmonized soil data and two land-use data of 1995 and 2010 were used to simulate the sediment yield across IRB. The study result shows an increase in sediment yield of 0.73 t/ha from1995 to 2010. Sub-basin 10 has the highest sediment yield during the two periods; September and October are the months with the highest sediment yield.

The article describes the steps for organizing and conducting ecological monitoring of surface water in order to move Ukraine to the European standards in the field of water use and protection. The main water users-pollutants of the Western Bug River basin in the Lviv region were identified. The results of the water samples taken from the control bodies in 2018 were analyzed. A promising way to improve the work of the water basin management of the Western Bug River is proposed.

The sustainable management of river basins is a comprehensive problem involving not only environmental quality but also socio-economic aspects. The primary objective of the study is to propose a sustainable management model of a river basin based on a clear identification of the good water quality in the river basin applicable for any river basin. The proposal is based on a monitoring of the quality of surface water in the basin, a quantitative and qualitative analysis of pollution, a questionnaire survey on the sewer systems and wastewater treatment in the basin and the diffuse sources of water pollution. For a better outline, a case study of Hornád river basin, Slovakia, was carried out. Two methodologies were applied: SWOT analysis for identification of indicators and the priorities and AHP analysis for a prioritization of the decisions. These analyses can be carried out for any activity based on identification of indicators and the priorities of the defined indicators to promote sustainable development. Based on the findings and the results of the analyses the model for managing the development of surface water quality in the basin was proposed. Generally applicable principles of sustainable development, accepting legislation in the field of water management, considering the quality of surface water in the basin, the impacts of wastewater discharges into the recipient, the identification and evaluation of positive and negative aspects of surface water quality, and the implementation of the proposed measures and post-implementation monitoring of qualitative development were covered in and by the proposed model.

What would happen in Mediterranean rivers and streams if warming but not drying occurred? We examined whether the delivery of environmental flows within a warming climate can maintain suitable macroinvertebrate habitats despite warming. A two-dimensional ecohydraulic model was used to (1) simulate the influence of water temperature and flow on macroinvertebrates by calculating habitat suitability for 12 climate change scenarios and (2) identify the mechanism by which macroinvertebrate assemblages respond to warming. The results suggest that not all watersheds will be equally influenced by warming. The impact of warming depends on the habitat conditions before warming occurs. Watersheds can, thus, be categorized as losing (those in which warming will degrade current optimal thermal habitat conditions) and winning ones (those in which warming will optimize current sub-optimal thermal habitat conditions, until a given thermal limit). Our models indicate that in losing watersheds, the delivery of environmental flows can maintain suitable habitats (and, thus, healthy macroinvertebrate assemblages) for up to 1.8–2.5 °C of warming. In winning watersheds, environmental flows can maintain suitable habitats when thermal conditions are optimal. Environmental flows could, thus, be used as a proactive strategy/tool to mitigate the ecological impacts of warming before more expensive reactive measures within a changing climate become necessary.

The past two decades have witnessed increasing global concern about the need for sustainable water and land management in an era of rapid change, and persistent water insecurity. Good water governance is a prerequisite to improve water management all over the world. The OECD Water Governance Initiative developed Water Governance Principles to enhance the process from water policy design to implementation. This contribution aims to examine how the OECD Water Governance Principles fit actual water governance on the local scale. Therefore a Dutch case is employed here to almost serve as a benchmark test for the framework of the OECD water governance principles.

An assessment of Varuna river basin of India was performed to study the various drainage parameters in GIS platform. The delineation of drainage network is possible either physically from topographic sheets or with the help data of Digital Elevation Model (DEM) by methods for calculation techniques. Extraction of the basin and sub-basins, stream network has been produced to evaluate the drainage characteristics in the study zone. The entire Varuna river basin has been subdivided into 3 sub-watersheds and 41 morphometric parameters have been computed under four broad categories i.e. drainage network, basin geometry, drainage texture, and relief characteristics. The morphometric analysis has been performed and different parameters have been correlated with each other to understand their underlying connection and their role over the basin hydro geomorphology. The study discloses different types of morphometric analysis and how they influence the soil and topography of the basin. The investigation and estimation of basin morphometry and relief parameters in GIS will be of massive utility in catchment area advancement, understanding the watershed for natural resource evaluation, planning and administration at any scale. The outcomes thus generated equip us with significant knowledge and may also provide an input that are essential in decision making for watershed planning and drainage development of the watershed.

Nowadays, the increasing intensity of extreme rainfall and changes in land use have triggered massive floods in various regions of Indonesia. Changes in the characteristics of these two parameters cause an raising in the peak and duration of the flood over time. Peak and duration of flood estimation might be very useful for national and local government because it is closely related to the effectiveness of prevention and mitigation plan in the future. One approach for estimating them simultaneously is a hydrograph-based model. The objective of this research is to examine the application of ITS-2— a synthetic unit hydrograph (SUH) model which developed at Sepuluh Nopember Institute of Technology (ITS) in 2017— for estimating peak flood discharge as a basis for planning disaster mitigation programs. This study was carried out by testing the reliability of the ITS-2 Model using Nash–Sutcliffe Efficiency (NSE) indicator by comparing the measured unit hydrograph and synthetic unit hydrograph derived using the model, optimizing the parameters of the model, and then analyzing the transformation of rainfall-flood discharge in the Gumbasa Watershed, one of the major watersheds in Central Sulawesi Province, Indonesia. This catchment is part of the Palu watershed, which is largely a tropical rainforest conservation area known as the Lore Lindu National Park. The input model is based on design rainfall with a certain return period using frequency analysis where the data was obtained from rainfall stations in the study area. The results of the research showed that the performance of the ITS-2 model was still very good with NSE above 80%. The difference in peak discharge of these two unit hydrographs is relatively low with a deviation below 10%. The optimal values of the ITS-2 Model parameter coefficients consisting of C1 C2, and C3 were achieved at 1.29, 0.33 and 1.88 values respectively. The results of hydrograph analysis based on a 1-year to 100-year return period indicate that peak flood discharge ranges from 100 m3/sec to 550 m3/sec. From a series of analyzes and tests that have been conducted in previous research and current research, it can be concluded that the ITS-2 Model can be applied to various watershed sizes especially in Indonesia

A pilot investigation is being conducted to evaluate the current hydroclimatological condition of the Jawi River Basin, Malaysia. The river basin is reported to face physical changes in the near future. The basin area is located in the northern part of Peninsular Malaysia, which lies near to the equator. In this analysis, local climatology information was used since 1990 until 2010 from the Meteorological Office. The design rainstorm intensity was derived from DID Hydrological Procedure No.1, while the Hydrological Procedure No. 12 was used to compute low flows based on regional frequency analysis. The climate of the river basin reflects the equatorial climate with some monsoonal effects. Generally, the highest mean rainfall occurs in the month of October and the lowest rainfall occurs in the month of January. The 7 day low flow value for the basin is about 0.062 cubic meter per second cumecs . This means that the river basin should maintain the stream discharge at least 0.062 cumecs or above to prevent any adverse ecological impacts on the waterbody and its ecosystem. Noorazuan Md Hashim | Mohd. Azlan Abdullah "Hydroclimatological assessment of Jawi River Basin, Malaysia" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23725.pdf

Environmental research addresses ecosystems of various hierarchical levels. One of the ecosystem types is the river basin. The basin approach has been applied in the research. We consider the river basin as a single ecosystem of complex landscape structure. The research objective was to assess the biological processes in various landscapes within a holistic natural geosystem – a catchment area. The Klyazma River Basin (a part of the Volga River of 40 thousand km2 area) was the research object. It is a complex combination of different landscapes, each marked by a diverse composition of geomorphological and soil-vegetation structures. According to the geomorphological structure and soil and vegetation cover, four landscape provinces and eight key sites have been identified in the studied catchment area where the ecosystem parameter have been measured. The study is based on remote sensing data and the Trends. Earth Land Degradation Monitoring. The calculation of productivity indicators (GPP, NPP) in carbon units and the land use structure analysis are based on Modis data. The soil organic carbon pool was determined by the UN FAO’s data, based on Trends. Earth and QGIS 2.18. The two-factor variance analysis ANOVA has been used for the data statistic processing. The cartographic analysis of the land use structure dynamics of the entire Klyazma Basin resulted in revealing the areas where various land transitions from one category to another have been identified. They are basically associated with the agricultural land overgrowth. The forest area increased by 9% during the period from 2001 to 2017. Considerable increase in the waterlogged, wetlands areas was observed in the eastern part of the Basin, in the Volga-Klyazma Province. The landscapes react differently to changes in climatic parameters and land use. Thus, the active revegetation of farmland by forests gives the increased rate of carbon accumulation in the soil. Landscapes covered with grasses and shrubs are more productive those covered with forest. On the other hand, woody biotopes are more stable in their development over time. Statistical analysis using the two-factor variation analysis ANOVA method resulted in demonstrating that phytoproductivity dynamics of the key sites does not depend on their productivity parameters nor on the site landscape structure, but is mainly determined by a time factor. In different landscapes the biological processes, characterising the organic matter dynamics in the form of plant production, organic matter accumulation and others are shown to differ both in rate and intensity and ambiguously respond to changes in climate parameters and land use. The river basin, as a single ecosystem, showed sufficient stability of the dynamic processes. This suggests that holistic natural ecosystems, such as catchment areas, have internal compensatory mechanisms that maintain the development stability for a long time, while unplanned land use remains the main damaging factor.

Hydrological modeling is an important tool used for basin management and studying the impacts of extreme events in a river basin. In streamflow simulations, precipitation plays an essential role in hydrological models. Meteorological satellite precipitation measurement techniques provide highly accurate rainfall information with high spatial and temporal resolution. In this analysis, the tropical rainfall monitoring mission (TRMM) 3B42 V7 precipitation products were employed for simulating streamflow by using the soil water assessment tool (SWAT) model. With India Metrological Department and TRMM data, the SWAT model can be used to predict streamflow discharge and identify sensitive parameters for the Mahi basin. The SWAT model was calibrated for 2 years and then independently validated for 2 years by comparing observed and simulated streamflow. A strong correlation was observed between the calibration and validation results for the Paderdibadi station, with a Nash­–Sutcliffe efficiency of &gt, 0.34 and coefficient of determination (R2) of &gt, 0.77. The SWAT model was used to adequately simulate the streamflow for the Upper Mahi basin with a satisfactory R2 value. The analysis indicated that TRMM 3B42 V7 is useful in SWAT applications for predicting streamflow and performance and for sensitivity analysis. In addition, satellite data may require correction before its utilization in hydrological modeling. This study is helpful for stakeholders in monitoring and managing agricultural, climatic, and environmental changes.

In regions under development and facing recurrent droughts, increasing the area of irrigated agriculture may create additional disruption in water resources management. The present study was focused on three river sub-basins with the highest agricultural intensity (S. Miguel, Ribeira Seca and S. Domingos) in Santiago Island (Cape Verde). Sets of wells were selected to evaluate the influence of salinization and agriculture practices on the hydrochemistry. This assessment was performed by using data from the bibliography (2003) and a recent campaign (2016). The water chemistry indicates lower mineralization in the S. Miguel sub-basin. Nitrates and nitrites, typically associated with diffuse pollution, are present in all sub-basins, but with varying patterns. Additionally, sodium chloride waters occur in all the three sub-basins, especially those closest to the coastline. In turn, a bicarbonate-magnesium facies was identified in S. Domingos, at the furthest point from the coast, indicating a geological control. The comparison between the two periods suggests a decrease in water quality. The rising extension of the irrigation area associated with aridity should intensify the already observed soil salinization. Thus, the present review highlights the strategic importance of water monitoring at the basin level as a management tool for resources preservation in insular arid and developing regions., This research was funded by the Gulbenkian Scholarship Service from FCG (CALOUSTE GULBENKIAN FOUNDATION), for the granted individual scholarship, under the program of Postgraduate Scholarships for students of PALOP and East Timor - Stimulating research and professional appreciation, process Nº. 139758, and co-funded by FCT through projects with references UIDB/04683/2020 and UIDP/04683/2020.

Although planktonic algae are a basic component of freshwater ecosystems, studies on their diversity and species distribution are still not in satisfactory numbers. This study aims to contribute to Turkish freshwater algal flora particularly with the new records reported. A total of 158 Charophyta taxa were determined in the study conducted from 2017 to 2019 in 25 river basins of Turkey. In this study, while the highest Charophyta taxon was found in Sakarya and Batı Akdeniz basins with 50 and 42 taxa, respectively, Burdur basin was the only basin where we did not find the Charophyta species. The highest Charophyta diversity was observed in Girdev Lake (Batı Akdeniz basin) and Işık Dağı Karagöl Lake (Sakarya basin) among the lakes of Turkey’s 25 river basins. Thirty-one of these Charophyta taxa represent new records for the freshwater algal flora of Turkey. Of these, 13 species are commonly distributed, while 18 species have rare distribution areas. Morphology, ecology, and distribution of each taxon were also discussed in details., Planktonik algler tatlı su ekosistemlerinin temel bir bileşeni olmasına rağmen, onların çeşitliliği ve tür dağılımları konusundaki çalışmalar hala tatmin edici sayılarda değildir. Bu çalışma, özellikle raporlanan yeni kayıtlarla Türkiye tatlı su alg florasına katkıda bulunmayı amaçlamaktadır. 2017-2019 yılları arasında Türkiye'nin 25 nehir havzasında yapılan bu çalışmada toplam 158 Charophyta taksonu tespit edilmiştir. Bu çalışmada, en yüksek Charophyta taksonuna sırasıyla 50 ve 42 takson sayısıyla Sakarya ve Batı Akdeniz havzalarında rastlanırken, Charophyta türüne rastlamadığımız tek havza Burdur olmuştur. Türkiye'nin 25 akarsu havzasındaki göller arasında en fazla Charophyta çeşitliliği Girdev Gölü (Batı Akdeniz havzası) ve Işık Dağı Karagöl (Sakarya havzası)’de görülmüştür. Tespit edilen bu Charophyta taksonlarının 31’i Türkiye'deki tatlısu alg florası için yeni kayıt niteliğindedir. Bunlardan 13 tür yayılış alanı olarak yaygın iken, 18 tür nadir yayılış alanına sahiptir. Her bir taksonun morfolojisi, ekolojisi ve dağılımı da ayrıntılı olarak verilmiştir.

Almost a decade ago, the Mexican government targeted to establish environmental water reserves (EWR)—a volume of water allocated for ecological protection based on the Environmental Flow Mexican Norm (eflows, NMX-AA-159-SCFI-2012, ratified in 2017)—in strategic low-pressured for water use and high conservation importance river basins throughout the country. To date, 12 EWRs have been declared for up to 50 years, which encompass 295 river basins and ~55% of the national mean annual runoff (MAR). In this article, we conducted a quality evaluation of the EWRs established. First, the EWR level was analyzed against the MAR and according to wider hydrological conditions. The EWR fulfillment was evaluated by comparing the volumes enacted against the theoretical (Norm implementation). Our findings revealed that independently of individual and regional water use and conservation merits context, ~75% of the EWRs met theoretical volumes at least at an acceptable level, of which medians ranged from 24% to 73% MAR (natural parametrization and A–D environmental objectives). These outcomes prove the usefulness and consistency of the Mexican strategic hierarchical approach for eflow assessments. We aim for them to be considered as the baseline for future on-site eflow implementation and environmental water policy assessments, to show the nationwide potential benefits for protecting free-flowing rivers and to encourage a regional escalation of the strategy.

Made available in DSpace on 2022-04-28T19:41:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Socioenvironmental indexes are important mechanisms for the communication of information in a summary form. They may also be a sound source on the quality of life of human beings. In this sense, the objective of this research is to create a socioenvironmental sustainability index (SSI) applied to river basins that integrate socioenvironmental information from the river basin of the Una River in São Paulo (Brazil) by creating a fuzzy inference system in a geographic information system environment. From the results obtained, only two sub-river basins of the Una River are classified as regular. They are in the urban area to the north of the study area. The other sub-river basins are classified as in poor conditions, that is, with high socioenvironmental vulnerability. They correspond to 81% of the study area. This poor classification is justified by the low income and the high rate of illiteracy in the study area. Both factors presented very poor values. The urban area, compared to the rural area, showed a better socioenvironmental performance. It is partly justified by the access of the population in these areas to education and better work opportunities. Institute of Science and Technology São Paulo State University (UNESP) Institute of Science and Technology São Paulo State University (UNESP)

Tropical rivers such as the Rio Negro constitute a major portion of the global aquatic flux of dissolved organic carbon (DOC) entering the ocean, but the exact amount, source contributions and fate of terrestrial DOC remain unknown. We investigated the role of valley and upland whitesand ecosystems (WSEs) and terra firme plateaus in forming blackwater tributaries in the Rio Negro basin to develop novel constraints for the terrestrial export of carbon. 5709 molecular markers from ground- and surface waters of two contrasting valley and upland sites feeding Rio Negro tributaries were identified by ultrahigh resolution mass spectrometry (FT-MS), analyzed by multivariate statistics and compared to known Rio Negro markers. In a Principal Coordinates Analysis, valley and upland DOC molecular composition differed by 78% from plateau DOC, which was characterized by reworked, aliphatic and unsaturated N- and S-containing molecules, while valley and upland DOC contained mainly condensed aromatics, aromatics and oxidized unsaturated structures. Valley and upland samples differed by 10% in molecular DOC composition and by their isotopic content (14C of SPE-DOC, 18O and 2H of water) which indicated differences in hydrology and C turnover. Against expectation, markers of widespread whitesand valleys did not emerge as a major source of Rio Negro markers, but specific upland markers did. Pubchem suggested chromene and benzofuran structures as promising candidates for further study. Our findings indicate that the export of molecular markers diverges from expected transport-limited DOC behavior, and thereby opens new avenues for source annotation beyond DOC quantity. Terrestrial DOC from upland whitesand areas is a major source of specific blackwater molecules missing in the regional ecosystem C balance, whereas C export from the whitesand valleys and especially from terra firme plateaus represents mainly recycled and transformed carbon not directly affecting the ecosystem C balance and possibly, the watersheds downstream molecular signature. Our study highlights the potential of high-resolution techniques to constrain carbon balances of ecosystems and landscapes by novel molecular markers. A comparison with other terrestrial DOM datasets indicated molecular similarities with temperate acidic soils and tropical rivers that warrant further analysis of common DOM markers. Implications, limitations, and future challenges are discussed in the light of potential applications of diagnostic molecular links for DOC source annotation and estimation of terrestrial DOM export in the land-to-ocean continuum., Geochimica et Cosmochimica Acta, 311, ISSN:0016-7037, ISSN:1872-9533

Ensuring adequate freshwater quality is an important aspect of integrated environmental management and sustainable development. One contribution towards this end is to monitor the water quality of river basins. An important issue in constructing a water quality monitoring network is how to allocate the stations. This is usually done by using in situ measurements of pollutants together with other information. A stage-based optimization approach has been developed to find the optimal sites to allocate the monitoring stations. The proposed approach constructs a network in a sequence of stages without the need for in situ pollution measurements. Instead, it uses pollutant estimates from the WorldQual model together with other social and hydrological criteria. The approach is computationally efficient and provides an ordered list of stations that can be used to initialize or augment a water quality network. This is especially relevant for consideration by developing countries since, with this approach, they can get an overview of their river basins, and then prioritize the initial distributions of the networks. The approach was applied successfully to the 741,751 km2 of the Jubba River basin, but it is applicable to river basins of any size.

Study region Benin-Owena and Ogun Oshun river basins, Nigeria Study focus Nigeria is a signatory to the United Nations 2030 Agenda and its Sustainable Development Goals (SDGs). Target 6.1 of Goal 6 has requested member nations to achieve universal and equitable access to safe and affordable drinking water for all by 2030. To meet this target as the country population reaches 257.8 million by 2030 in the face of limited freshwater resource will require collecting water resource, water use, socio-economic and environmental data in accordance with the provision of the River Basin Development Authority Act CAP 396 LFN 1990 (section 4(1)(e)). Implementing data collection at the river basin level will help inform and support action towards the realisation of Nigeria’s drinking water target. This study therefore explores the situation of data collection in Nigeria and exposes the factors constraining its full implementation. New hydrological insights Evidence distilled from data gathering sources revealed that: (a) only hydrological and meteorological data were being collected by the River Basin Development Authorities (RBDAs), (b) even with that, inadequate financial resources constrained its full implementation, and (c) the inability of the RBDAs to collect hydrogeological, water use, socio-economic, and environmental data was traced to institutional factors. This study offers proposals on measures which might help to improve the situation towards a better data collection implementation at the river basin level in Nigeria.

Reductions in water availability and increasing rainfall variability are generating a narrative of growing competition for water in the Mediterranean basin. In this article, we explore the distribution and importance of water resources in the Muga River Basin (Catalonia, Spain) based on key stakeholders&rsquo, perceptions. We performed a sociocultural evaluation of the main water ecosystem services in the region through stakeholder interviews and participatory mapping. The basin was generally perceived as a hotspot of ecosystem services, but we detected varying opinions and considerable differences in the perceptions of importance and spatial distribution of water ecosystem services. These discrepancies were linked to the varying levels of stakeholders&rsquo, dependence on water. Our findings are important for contributing to correct water planning and management in the river basin, which is a complex water social system marked by conflicts between different stakeholder groups vying for the same resource. This complex situation requires bottom-up strategies to create transparent, participatory decision-making models.

This study describes an economic model in the Guadalquivir river basin (Southern Spain) that considers inter-sectoral and hydrological effects of changes in water use as a response to various water-pricing policy scenarios. The main economic variables include water use, gross regional product, return flows in the river basin, and employment at sectoral and basin levels. The response of the different sectors to water pricing and of the sectoral productivity is derived from official data. The background of the model is based on previous research for the implementation of the UN System of Environmental-Economic Accounts and on the application of this framework to the Guadalquivir basin. Results based on the elicited curves illustrate that the structure of the demand function for irrigated agriculture passes from inelastic to elastic sections, while the function corresponding to the remaining economic sectors shows a continuous decreasing function with minor change in the elasticity structure of the curve. Results show that the impact of extreme measures of water pricing reduces water abstraction by up to 42% vs. the baseline scenario, with an economic reduction in regional Gross Domestic Product (GDP) of 1%.

In a riverbank area, a sustainable rural development is closely related to the success of a water user association (WUAs), which largely depends on the satisfaction of its members. Therefore, it is necessary to determine the satisfaction level of the members towards the service quality provided by a WUAs. This study was conducted at WUAs Subur Makmur, Indonesia. This WUAs was awarded the best WUAs at national level in 2012, and it has managed to maintain high income. This study aims at determining the satisfaction level of WUAs members in relation to its service quality. The data were collected from 88 respondents who live in five dusun (hamlets). They were selected purposively by considering the demographic characteristics, acquired land areas, and farmer types. The Spearman correlation analysis was used to analyze the relation between the WUAs services and the customer satisfaction. From the seven satisfaction indicators, the Product indicator has the highest correlation coefficient (0.585). Meanwhile, among the five service quality indicators, the Assurance indicator has the highest correlation coefficient (0.495) with the level of satisfaction of WUAs members. The results of this study will be beneficial as a reference for other WUAs in order to support sustainable rural development.

The occurrence of hydrological extremes in the Amazon region and the associated sediment loss during rainfall events are key features in the global climate system. Climate extremes alter the sediment and carbon balance but the ecological consequences of such changes are poorly understood in this region. With the aim of examining the interactions between precipitation and landscape-scale controls of sediment export from the Amazon basin, we developed a parsimonious hydro-climatological model on a multi-year series (1997&ndash, 2014) of sediment discharge data taken at the outlet of &Oacute, bidos (Brazil) watershed (the narrowest and swiftest part of the Amazon River). The calibrated model (correlation coefficient equal to 0.84) captured the sediment load variability of an independent dataset from a different watershed (the Magdalena River basin), and performed better than three alternative approaches. Our model captured the interdecadal variability and the long-term patterns of sediment export. In our reconstruction of yearly sediment discharge over 1859&ndash, 2014, we observed that landscape erosion changes are mostly induced by single storm events, and result from coupled effects of droughts and storms over long time scales. By quantifying temporal variations in the sediment produced by weathering, this analysis enables a new understanding of the linkage between climate forcing and river response, which drives sediment dynamics in the Amazon basin.

International audience; The hydrosocial cycle is a central analytical framework in political ecological approaches to water. It helps foreground multiple and subtle interactions between water and society, culture and politics. However, to date it has dealt little with matters other than water flows. In river contexts, biotic and abiotic components play critical roles in the way people engage with and make a living out of rivers, beyond water. This article aims to advance the hydrosocial framework with a deeper consideration of the materiality of rivers. To initiate this approach, the focus is here on sediments. Lives and livelihoods connected to river sediments remain both officially and academically under-explored. This certainly applies to the context of the Lower Ganges basin whose active channels transport huge loads of sediments mainly originating from the Himalayan slopes. Building upon an environmental history perspective and drawing on three spatially nested cases in West Bengal, India, the paper analyses instances of water-sediment-society interactions. The general case study presents colonial state interventions in the Lower Ganges basin waterscapes. The second case study zooms the focus on the 2 km long Farakka Barrage. These explorations reveal how an ‘imported’ conceptual land-water divide infused those interventions, leading to unforeseen effects on riverine lives and livelihoods. Focusing on Hamidpur char, situated few kilometres upstream of the barrage, the third case study recounts the contemporary efforts of local communities to obtain revision of administrative decisions unable to deal with ‘muddyscapes’. Finally, the paper engages with recent debates on the concept of hybridity in land-water nexus to reflect on the specific meaning and role of sediments.

We presented three new methods for assessment of the environmental risk of deterioration of a surface water state. We defined the ecological risk of deterioration of surface water at the state level as an addition of the integrated parameter of the state of surface waters and the integral index of anthropogenic loading. We used the official information of the National Report on the state of the environment of Ukraine to calculate the mentioned indicators. We developed classifications of anthropogenic loading on aquatic ecosystems and ecological risk of deterioration of water ecosystems. The assessment of the ecological risk of deterioration of surface water state in Ukraine showed that there are watercourses of the Siversky Donets river basin in the most dangerous state. A base of the methodology for assessment of the risk of water ecosystem well-being disruption is the determination of all parameters of the state of quality of surface waters that exceed the ecological standards using the probit-regression model. The process of determining ecological risk for watercourses of the Siversky Donets river basin in Kharkiv region showed a high level of danger to the well-being of the water ecosystem of the Udi river. We obtained the forecast of climatic changes by parameters of temperature and volumes of precipitation in Kharkiv region. We investigated the dynamics of wastewater discharge to the Udi river for the period from 1992 to 2016. The study on an influence of natural and anthropogenic factors on the ecological state of the Udi river revealed that the impact of wastewater discharge with a correlation coefficient of 0.747 is a significant factor. The application of a new methodology for assessment of the risk of degradation processes made it possible to determine a list of small rivers in Kharkiv region, which require implementation of measures based on the analysis of water use efficiency, taking into consideration landscape and ecological features of a catchment area. We proposed an algorithm for the improvement of water protection strategy based on determining the ecological risk of deterioration of the condition of surface water at the state, regional and local levels. The improvement of water preservation strategy aims at introduction of an integrated interactive surface water quality management. Проведено аналіз основних принципів і методів утилізації токсичних промислових відходів, що містять важкі кольорові метали. Наведено результати експериментів по обробці донних опадів хвостосховищ в сірчанокислому середовищі. Запропоновано схеми їх переробки, що дозволяє досягти максимальних показників вилучення основних цінних компонентів. Запропоновані технологічні рішення дозволять підвищити ефективність переробки зазначених видів техногенних відходів.

The semi-distributed physically based ECOMAG-HM model was applied to simulate the cycling of the heavy metals (HM) Cu, Zn, and Mn, and to identify spatial and temporal patterns of heavy metal pollution in water bodies of a large river catchment of the Nizhnekamskoe reservoir (NKR) in Russia. The main river of the catchment is the Belaya River, one of the most polluted rivers in the Southern Urals. The model was tested against long-term data on hydrological and hydrochemical monitoring of water bodies. It is shown that the pollution of rivers is formed mainly due to diffuse wash-off of metals into rivers from the soil-ground layer. Numerical experiments to assess the impact of water economic activities on river pollution were carried out by modeling scenarios of changes in the amount of metal discharged with wastewater, a disaster with a salvo discharge of pollutants, and the exclusion of anthropogenic impact on the catchment to assess self-purification of the basin. Modeling of chemical runoff in accordance with the delta-change climatic scenario showed that significant changes in water quality characteristics should not be expected in the near future up to 2050.

Vegetation response to flooding across large dryland areas such as Australia's Murray Darling Basin (MDB) is not understood synoptically and with locally relevant detail. We filled this knowledge gap by quantifying vegetation dynamics, defined here as greening and browning due to changing chlorophyll content and leaf area index, in response to flooding and rainfall across the floodplains of the entire MDB. We quantified vegetation and flooding dynamics using the same data source, namely 26 years of high resolution, wall-to-wall satellite data, in a top down statistical modeling approach, where we controlled for rainfall. Our time series (1986–2011) covered a period of extreme hydroclimatic variability, including the South East Australian Millennium Drought, thus providing a research opportunity to investigate how the relationship between vegetation and flooding changed during wet and dry periods. Our results showed that besides rainfall, flooding plays a key role in driving floodplain vegetation dynamics, yet the role of flooding varied across the MDB floodplains. We quantified a change in the relationship of how vegetation responds to rainfall and flooding with an unprecedented level of spatial detail. The change in the relationships coincided primarily with the onset of the Millennium Drought, yet local and regional differences in the timing of the change did occur, suggesting that the beginning of the Millennium Drought did not impact all floodplain areas at the same time. Our synoptic while locally relevant quantification of the changing response of vegetation to rainfall and flooding is a first step to help underpin Australia's investment into environmental water allocations.

Current life cycle impact assessment (LCIA) methods lack a consistent and globally applicable characterization model relating nitrogen (N, as dissolved inorganic nitrogen, DIN) enrichment of coastal waters to the marine eutrophication impacts at the endpoint level. This paper introduces a method to calculate spatially explicit characterization factors (CFs) at endpoint and damage to ecosystems levels, for waterborne nitrogen emissions, reflecting their hypoxia-related marine eutrophication impacts, modelled for 5772 river basins of the world. The proposed method combines environmental fate factors (FFs) integrating (i) DIN removal processes in soils and rivers, based on the NEWS 2-DIN model, and in coastal waters, based on water residence time; (ii) coastal ecosystem exposure (XF) to N enrichment, based on biological cycling processes; and (ii) effect factors (EFs) based on species sensitivity to hypoxia. Three emission routes are discriminated as N from soil and N in emissions to river and to coastal waters. Damage factors (DFs) are also estimated, based on endpoint metric conversion from potentially affected to potentially disappeared fractions of species (i.e. potentially affected fraction (PAF) to PDF m3 year kg N−1) and harmonization across coastal ecosystems based on spatially explicit density of demersal species, to further express CFs as species year per kilogram N−1. Endpoint CFs show 6 orders of magnitude (o.m.) spatial differentiation amongst the river basins for the soil emission route, 4 for the river and 2 for emissions to coastal waters. Damage CFs vary 7, 5 and 3 o.m. for the same routes. After aggregation at the level of continents, maximum CFs and DFs are consistently found in Europe, but the aggregation reduces spatial differentiation to 1 o.m. for each route in both factors. The FFNsoil and species density terms are responsible for most of the spatial differentiation of the damage model. Uncertainty is higher for the residence time term used in the FF model, due to scarcity and inconsistency of data sources, the assumptions of representativeness of DIN persistence and removal rates. Major contributions to the current state-of-the-art of marine eutrophication characterization modelling are (i) full pathway coverage, thus reaching damage level; (ii) significant increase in geographic coverage; (iii) mechanistic modelling of exposure and effect factors; and (iv) application of spatially explicit damage to ecosystems factors based on species densities. Application of the developed CFs in life cycle impact assessment is recommended at a river basin scale, provided that emission location is known.

Water Quality Index is an important water assessment that sustain and conserve the aquatic ecosystem. In Malaysia, the current classi ication practice on Department of Environmental Water Quality Index (DOE WQI) shows rigid value in term of assessing the input of parameters that close to a class boundary. Hence, this study proposed a technique to assess the parameters in a holistic manner by using the Fuzzy Inference System (FIS). The approach as an assessment tool represents the classes of various ranges and aggregating the parameters using membership function and Centroid Function respectively. A numerical example based on actual data from one of the sampling station from Inanam Likas River Basin was adapted in this study. It was adapted to demonstrate the proposed approach. Findings shown using the proposed methods indicate that the river has Poor water status. Overall, FIS is able to assess the parameters and execute into a single index that represent the condition from poor to excellent scales of the water quality.

Water resources have been increasingly impacted due to the growth of water demand associated with environmental degradation. In this context, the mapping of groundwater recharge potential has become attractive to water managers as it can be used to direct public policies and conserve this natural asset. The present study modi?es (improves) a spatially explicit model to determine groundwater recharge potential at the catchment scale, testing it in the Pandeiros River basin located in the state of Minas Gerais, Brazil. The model is generally based on the water balance approach and the input variables were compiled from institutional sources and processed in a Geographic Information System. The novelty brought by the aforementioned modi?cation relates to the coupling of physical variables (conventional way) and land management practices (introduced here) in the estimation of a percolation factor. The role of land management practices for percolation was assessed by the so-called Conservative Use Potential (PUC) method, which classi?es the areas of a river basin in terms of their potential for sustainable use. The results were validated by an independentmethod,namelytherecessioncurvemethodbasedontheinterpretationofhydrographs. In general, the groundwater recharge potential is favored in ?at to gently undulating areas and forested regions, as well as where the landscape is characterized by well-structured soils, good drainage conditions and large hydraulic conductivity. The map of groundwater recharge potential producedinthisstudycanbeusedbyplannersanddecisionmakersinthePandeirosRiverbasinasa tool to achieve sustainable use of groundwater resources and the protection of recharge areas. Made available in DSpace on 2020-04-02T00:36:46Z (GMT). No. of bitstreams: 1 Improvedmodel.pdf: 7547680 bytes, checksum: 4f23fd525910f0cea1b817bcaf0da53a (MD5) Previous issue date: 2020

Aim The formation history of Africa's current river basins remains largely unknown. In order to date changes in landscape and climate, we studied the biogeography of the African freshwater fish with the largest natural distribution. We also validated biogeographical units.Location Continental Africa.Taxon Clarias gariepinus sl.Methods We investigated mitochondrial cytb sequences of 443 individuals from 97 localities, using a haplotype network and a genetic landscape analysis. We inferred a dated phylogeny using maximum likelihood and Bayesian inference approaches and reconstructed ancestral areas with S-DEC and S-DIVA models. Microsatellite genotyping complemented the mitochondrial approach in the Congo basin, where the latter revealed complex patterns.Results Limited differentiation is found in northern and south-western Africa, and sharp genetic differentiation in the continent's east and centre. Populations with affinities to neighbouring basins occur at the edges of the Congo province. High diversity exists in the south of the Congo basin. The Zambezi province is partitioned into eastern, central and western sectors. In the east, specimens were related to those from the Congo. In the west, they were similar to Southern representatives. Phylogenetic inference placed the origin of C. gariepinus in the East Coast, with intraspecific diversification starting around the Great Lakes. These events occurred ca. 4.8-1.65 and 2.3-0.8 MYA respectively.Main conclusions Clades of C. gariepinus sl. show a clear geographical signature. The origin of C. gariepinus in the East Coast and diversification around the Great Lakes coincided with the periods of increased aridity. Low genetic differentiation in northern and southern Africa may result from connectivity during recent periods of higher rainfall. In contrast to other widespread African freshwater fish, colonization rather than extinction seemed to mediate distribution patterns. This can be explained by a high ecological tolerance. We highlight the species' suitability to study landscape and climate evolution at various scales. A.A. received a postdoctoral research fellowship from the KU Leuven and the Research Foundation - Flanders (FWO). M.V.S. and M.P.M.V. received PhD fellowships from FWO. MVS received travel grants of the FWO and the Leopold III funds for Nature Exploration and Conservation. A.C.M. received support from the Belgian Development Agency and the BTCCTB project PRODEPAAK. We sincerely thank the following colleagues for sample collection: J.-F. Agnèse, B. Benade, R. Bills, L. and G. Chapman, P. de Villiers, the late L. De Vos, J. Engelbrecht, P. Fouche, P. Galbusera, K. Goudswaard, D. Impson, R. Karssing, J. Munyandorero, A. Piers, C. Maguswi, J. Southey, the late G. Teugels, K. Van Lerberghe and the Department of Fisheries and Agriculture of Zambia. We benefited from insights from J.-F. Agnèse, T. Huyse, J. Maley, P. Skelton, J. Snoeks, K. Van Doninck and C. Sturmbauer. This study was performed on historical collections and on samples collected by researchers from certified institutes of the countries where collections were made. All material was collected prior to the implementation of the Nagoya protocol for access and benefit sharing.

The impact of the Atlantic Multidecadal Oscillation (AMO) on the variations in the streamflow in the Atrato River Basin (ARB) during the 1965&ndash, 2016 period was analyzed here by considering the cold (1965&ndash, 1994) and warm (1995&ndash, 2015) phases of this oscillation. The mean streamflow increased after 1994 (AMO phase change). This increase is related to the strengthening of the zonal gradients of the sea surface temperature (SST) and sea level pressure (SLP) between the tropical central Pacific and the tropical Atlantic after 1994 (warm AMO phase). These gradients contributed to strengthen the Walker cell related upward movement over northern and northwestern South America, in particular during November-December (ND). Consistently, the frequency (R20 mm) and intensity (SDII) of extreme daily rainfall events increased during the 1995&ndash, 2015 period. Our results show a connection between the AMO and the increase in the streamflow in the ARB during the last five decades. These results contribute to the studies of resilience and climate adaptation in the region.

River basin delineation can be inappropriate to determine surface water availability in a country, even if it is established by its water authority. This is because the effect of agricultural and urban infrastructure in runoff direction is ignored, and the anthropogenic changes in hydrography and topography features distort the runoff. This situation is really important because water rights are granted based on volumes that are not physically accessible. The existence of this problem is demonstrated through a case of study: the Culiacan River Basin in Mexico. To overcome such a situation, this study poses criteria to revise official river basin configurations and to delineate new river basins based on digital elevation models, vector files of agricultural infrastructure, and extensive field verification. Significant differences were noticed in surface water availability calculated under distinct river basin delineations.

International audience; Peninsular India is an amalgam of transient landscapes evolved from the interactions between tectonic and climatic forcings. In order to appraise the tectono‐geomorphic evolution of South India, it is essential to understand the relationships between intrinsic and extrinsic processes and their geomorphic expressions at a river basin scale.Seven geomorphometric parameters, namely, longitudinal profile (Lp), asymmetry factor (Af), hypsometric curve and hypsometric integral (HI), mountain front sinuosity (Smf), river sinuosity (R), stream length gradient (Sl), and shape factor (Shp) were calculated for selected drainage basins of South India. Spatial analyses of these parameters in the light of systematic field mapping were attempted in this study. The results show the occurrences of southern sub‐basins with convex hypsometric curves indicating a youth stage and significant tectonic influence. The low and moderate Smf values within the basins are indicative of mountain fronts witnessing a high level of tectonic activity. The net effects of tectonic and geomorphometric processes are inferred to have been the responses of anti‐clockwise rotation of the Indian Plate and ridge uplift‐push from west. Directional change in Thamirabarani River Basin and drainage channel reorganizations in the Cauvery and Vaigai River basins stand testimony to these, among others. Amidst these, occurrences of tectonically quiescent regions and multiple incisions by river channels and flow of modern river channels in inherited palaeovalleys but on tangent directions of ancient flows are also observed. Five stages of landscape development are envisaged: First, inheritance of river basins from palaeodrainage systems; second, reversal of river flow directions during early part of Cenozoic and inception of evolution of modern river systems; third, during Miocene–Pliocene; fourth, during Pleistocene–Early Holocene; and fifth, during the Holocene–Anthropocene. The recent resurgence of tectonics is not only reflected in the shifting of axial rivers, but is also evidenced by seismicity and landslides/faulting. Together, transient nature of the Southern Indian Plate, first‐order control of tectonics, followed by climate and lithology over landscape evolution, inheritance of river valleys, synonymy of river basin responses to intrinsic and extrinsic geomorphic processes, however with unique signatures and basin‐scale responses, are inferred. Detailed morphometric studies and supplementation with precise age data may fine‐tune the proposed model. According to the model, inheritance of Mesozoic valley/structures during Late Jurassic–Early Cretaceous, drainagereversal and initiation of Cenozoic–Recent river basin evolution, intense peneplanation during Miocene–Pliocene, intense incision during Pleistocene, periodic climatic extremes during Early Cenozoic, Palaeocene–Eocene, Oligocene and corresponding pedogenesis, and terrace formation and sedimentation have been recognized. Based on the numerical ages and documentation of basin‐scale distribution of specific types of lithologies/weathering profiles/palaeosols, provisionally we recognize the laterite/ferricrete–bauxite–calcrete 53–50 and 37–23 Ma to be the oldest weathering profiles, palaeosols (I generation palaeosols) of alluvial fans with texturally immature parent rock clasts to be of 23–9 Ma, palaeosols with intensive calcitized rootlets that are found to occur in fluvial terraces of palaeo‐floodplain/natural levee (II generation palaeosols) to be of 3.5–2.5 Ma, and relict alluvium that are documented in inland river terraces and older deltaic plains and calcareous sandstones that are documented in coastal terraces to be of ~1 Ma old and attribute them to be the results of significant climatic events and Early Cenozoic uplift of Western Ghatthat proceeded from south–north and its intensive tilt toward east since 25 Ma until today at a rate of 0.1 mm/year to be tectonic events that have significantly contributed toward landscape development on basin‐regional scales and concur with the evolutionary stages proposed in our model.

Due to global warming, a reduction in available water will occur in many watersheds and conflicts concerning water use will take place. This situation is already typical in semi-arid areas, where many reservoirs have been constructed for water storage. Increased energy demands and climate change have led to severe and increasing pressure on aquatic systems. Today, the environmental policies of many countries, such as Brazil, give priority to constructing new reservoirs for hydropower use, and an adopted reservoir and river basin management plan must minimize environmental impacts. Moreover, the production of energy plants will promote more requirements for new dam projects. The Itaparica reservoir is 30 years old, located in the S&atilde, o Francisco river in Northeast Brazil, and is the focus of an environmental study. The article focus of investigations is on the environmental and social impacts after the construction of Itaparica reservoir, governance difficulties, and adopted actions to minimize those impacts. Significant environmental impacts are recognizable, such as increased sedimentation in the inflow area, damage to the lakeshore zone by operational water level variation, water losses by evaporation and infiltration, and degradation of inundated vegetation. Furthermore, a trophic upsurge has been registered with severe eutrophication processes, such as the occurrence of cyanobacteria, oxygen deficit in the hypolimnion, and mass development of macrophytes (Egeria densa). With the creation of the dam there was compulsory displacement of the population of the municipalities around Itaparica reservoir with consequent difficulties of adaptation in the new spaces. Furthermore, there was de-structuring of social relation networks, loss of arable land and improvements, and small and insufficient indemnities for land. In this context, concepts for an advanced reservoir management under consideration of water scarcity are presented and discussed. This study aims to contribute to sustainable reservoir management

The zoning of groundwater recharge potential would be attractive for water managers, but is lacking in many regions around the planet, including in the Jequitiba River basin, Minas Gerais, Brazil. In this study, a physically based spatially distributed method to evaluate groundwater recharge potential at catchment scale was developed and tested in the aforementioned Jequitiba River basin. The data for the test was compiled from institutional sources and implemented in a Geographic Information System. It comprised meteorological, hydrometric, relief, land use, and soil data. The average results resembled the annual recharge calculated by a hydrograph method, which worked as validation method. The spatial variation of recharge highlighted the predominant contribution of flat areas, porous aquifers, and forested regions to groundwater recharge. They also exposed the negative effect of urbanization. In combination, these factors elected the following sectors of the Jequitiba River basin as regions of high recharge potential: the south-southeast part of the headwaters in Prudente de Morais, Sete Lagoas towards the central part of the basin, and the region between Funil&acirc, ndia and Jequitiba, near the Jequitiba river mouth. Some management practices were suggested to improve groundwater recharge. The map of groundwater recharge potential produced in this study is valuable and is therefore proposed as tool for planners in the sustainable use of groundwater and protection of recharge areas.

Soil erosion is a severe environmental problem worldwide as it washes away the fertile topsoil and reduces agricultural production. Nepal, being a hilly country, has significant erosion disputes as well. It is important to cognise the soil erosion processes occurring in a river basin to manage the erosion severity and plan for better soil conservation programs. This paper seeks to calculate the sediment yield and maximum outflow from the Sarada river basin located in the western hills of Nepal using the computer-graphic Intensity of Erosion and Outflow (IntErO) model. Asymmetry coefficient of 0.63 was calculated, which suggests a possibility of large floods to come in the river basin in the future whereas the maximum outflow from the river basin was 1918 m&sup3, s&minus, 1. An erosion coefficient value of 0.40 was obtained, which indicates surface erosion of medium strength prevails in the river basin. Similarly, the gross soil loss rate of 10.74 Mg ha&minus, 1 year&minus, 1 was obtained with the IntErO modeling which compares well with the soil loss from the erosion plot measurements. The IntErO model was used for the very first time to calculate soil erosion rates in the Nepalese hills and has a very good opportunity to be applied in similar river basins.

In order to characterize the occurrence and intensity of droughts in the Doce River Basin, as well as to develop a system for its classification, four different drought indexes were evaluated: Percent of Normal Precipitation (PNP), Deciles Method (DM), Rainfall Anomaly Index (RAI) and Standardized Precipitation Index (SPI). The indices were calculated annually, based on precipitation data from 89 rainfall stations of the Brazilian National Water Agency (ANA). Nine analysis units (AUs) were determined in the basin and the Thiessen Polygons method was used to obtain the average precipitation in the respective drainage areas. The indices were calculated for each AU and then related to the drought intensity classes. An overall classification of the indices was proposed for the drought classification system for a 30-year base period, from 1985 to 2015. The most critical hydrological years of the Doce River Basin in relation to the drought were 1994/1995, 2000/2001 and 2014/2015, the latter being the most critical of the last 30 years. The results show that the annual drought classification system proved to be efficient in the identification of events, allowing to verify that the Doce River Basin presents a severe climatic drought condition, on average, every seven years.

This study is a part of the Conservation Effects Assessment Project (CEAP) aimed to quantify the environmental and economic benefits of conservation practices implemented in the cultivated cropland throughout the United States. The Soil and Water Assessment Tool (SWAT) model under the Hydrologic United Modeling of the United States (HUMUS) framework was used in the study. An automated flow calibration procedure was developed and used to calibrate runoff for each 8-digit watershed (within 20% of calibration target) and the partitioning of runoff into surface and sub-surface flow components (within 10% of calibration target). Streamflow was validated at selected gauging stations along major rivers within the river basin with a target R2 of &gt, 0.6 and Nash and Sutcliffe Efficiency of &gt, 0.5. The study area covered the entire Mississippi and Atchafalaya River Basin (MARB). Based on the results obtained, our analysis pointed out multiple challenges to calibration such as: (1) availability of good quality data, (2) accounting for multiple reservoirs within a sub-watershed, (3) inadequate accounting of elevation and slopes in mountainous regions, (4) poor representation of carrying capacity of channels, (5) inadequate capturing of the irrigation return flows, (6) inadequate representation of vegetative cover, and (7) poor representation of water abstractions (both surface and groundwater). Additional outstanding challenges to large-scale hydrologic model calibration were the coarse spatial scale of soils, land cover, and topography.

Projections indicate that the Mediterranean region is an area where drastic changes in climate will occur, which will significantly affect water resources. In a context of increasing pressure on water resources as a result of the reduction in water availability, it is essential and urgent to structure water management in a way that allows for adaptation to the challenges that the changing climate will bring to an already water scarce region. It is necessary to generate experiences and methodologies that are based on real case studies that will lay the foundations for the generalisation of practices of climate change adaptation in water management. In this study, we have developed a ready to use analytical framework to evaluate the coherence of water management plans and programs with climate change adaptation principles. We have tested the applicability of the framework that was developed on the Tordera River Basin Adaptation Plan (TRBAP). The analytical framework has proven to be easy to apply and to allow for identifying the inclusion or exclusion of key climate change adaptation features appropriately. We have structured this analytical framework as a starting point contributing to further assessments of how climate change adaptation is incorporated in water management.

With the rapid socio-economic development, human disturbances are believed to have resulted in the degradation of the watershed ecosystem. The ecological damage to and environmental pollution of river basins have caused great losses. It is widely agreed upon that the protection and restoration of river ecosystems should be on the agenda. Ecological compensation, an important tool to prevent the deterioration of water environments and achieve sustainable watershed development, has attracted increasing interest as a research subject. In this study, the upper reach of Hun River basin was selected as a typical study area. The primary purpose was to determine the allocation costs of ecological compensation in different regions for the river basin. The amount of willingness-to-pay (WTP) for the eco-compensation was estimated at 3.2 million dollars by the Contingent Valuation Method (CVM). Based on linear programming techniques, a Data Envelopment Analysis (DEA) created a primary value of the allocation costs. Considering the different weights of each region, a modified coefficient was introduced to correct the primary result on the basis of a questionnaire survey of river ecological protection and construction.

Assessing climate change impact on hydrology and biomass yield of a tropical river basin is necessary for formulating a suitable coping strategy. A hydrological modelling framework was established for Subarnarekha river basin through calibration and validation of SWAT model with the observed river discharge at four gauging locations. The global sensitivity analysis was performed to establish the robustness and stability of the model to reproduce outputs resultant to various extremes of precipitation and other weather events. The 5-GCMs, namely HadGEM2-ES, MIROC-ESM, NCAR-CCSM4, CSIRO-MK3.6, and CESM1-CAM5 were analyzed and HadGEM2-ES was selected based on its performance with respect to ensemble of remaining 4 GCMs (p ≤ 0.05). The AR5-HadGEM2-ES monthly database (1 km2 resolutions) was used to generate bias factor for preparing daily climatic variables in the future projection which was employed as a forcing to simulate river discharge and other hydrological fluxes for the future climate scenario. Increase in precipitation from 14 to 36%, the runoff increased from 39.7 to 104.1%. When compared to the present period, an increase in monsoon runoff is expected 100 and 200% during 2030 and 2080, respectively. Higher degree of uncertainty in expected runoff volumes was expected in mid- and far future time period. Intra-RCP scenarios analyses indicated a significant surge in monsoon season runoff volume during 2070 and 2080 and insignificant surge during 2030 and 2050. As the basin constitute a rice ecosystem, the simulation approach involved a detailed accounting of the operational activities of a rice to realistically capture its manifestation in the annual accrual of actual evapotranspiration in the simulated hydrological fluxes. During monsoon season, potential evapotranspiration (PET) and actual evapotranspiration (AET) increased by 2.2–12.7% and 1.0–9.0%, respectively. Following simulation output, it was found that the basin was expected to suffer a crop biomass loss of 2 to 3% due to climate change. Simple yield response technique to estimate biomass yield losses was found to be promising alternatives to complex crop modeling studies.

Contemporary trends in cultivated land and their influence on soil/gully erosion and river suspended sediment load were analyzed by various landscape zones within the most populated and agriculturally developed part of European Russia, covering 2,222,390 km2. Based on official statistics from the Russian Federation and the former Soviet Union, this study showed that after the collapse of the Soviet Union in 1991, there was a steady downward trend in cultivated land throughout the study region. From 1970–1987 to 2005–2017, the region lost about 39% of its croplands. Moreover, the most significant relative reduction in cultivated land was noted in the forest zone (south taiga, mixed and broadleaf forests) and the dry steppes and the semi-desert of the Caspian Lowland—about 53% and 65%, respectively. These territories are with climatically risky agriculture and less fertile soils. There was also a widespread reduction in agricultural machinery on croplands and livestock on pastures of the region. A decrease in soil/gully erosion rates over the past decades was also revealed based on state hydrological monitoring data on river suspended sediment load as one of the indicators of the temporal variability of erosion intensity in river basins and the published results of some field research in various parts of the studied landscape zones. The most significant reduction in the intensity of erosion and the load of river suspended sediment was found in European Russia’s forest-steppe zone. This was presumably due to a favorable combination of the above changes in land cover/use and climate change.

The purpose of this research consists in the elucidation of spatial and economic aspects of the water use in the Răut river basin. The main topics presented in this paper are: 1) the dynamics of volume of wastewater discharged into the river Raut basin and its sections; 2) wastewater discharge by the degree of treatment; 3) spatial and branch profile of wastewater discharged: 4) existing problems in evaluation and monitoring of waste water. To achieve these objectives were used traditional methods of geographical and economic research.

Summary The increasing population and large scale growth with the development of modern science and technology has indicated very high stress on water sector in Rajasthan in India. Availability of water and uniformity of rainfall distribution is changing day by day due to shifting of monsoon in Rajasthan. The spatial and temporal variations in the rainfall in different river basins in Rajasthan are drastic due to which flood situation arises in the tributaries of Chambal river basin every year. Simultaneously on the other hand drought situation arises in the other different places in the most of the river basins which are also under dark zone. In totality natural water resources are also limited in Rajasthan so there is an urgent need for its proper planning, development and management of the available water duly taking care of environmental, ecological, socio-economic aspects and their inter-relationships. Annual surplus water of about 1437 MCM in the river Chambal is going waste and ultimately reaches to sea after creating flood situations in various places in India including Rajasthan, while on the other hand 1077 MCM water is a requirement in the four other basins in Rajasthan i.e. Banas, Banganga, Gambhir and Parbati at 75% dependability. Interlinking and water transfer from Chambal to these four river basins is the prime solution for which 372 km link channel including 9 km tunnel of design capacity of 300 cumec with 64 m lift is required.

This study utilized Spatial Information Technology (SIT) such as Remote Sensing (RS), a Geographical Information System (GIS), the Global Positioning System (GPS) and a high-resolution Digital Elevation Model (DEM) for a morphometrical analysis of five sub-basins within the Lower Niger River Basin, Nigeria. Morpho-metrical parameters, such as the total relief, relative relief, relief ratio, ruggedness number, texture ratio, elongation ratio, circularity ratio, form factor ratio, drainage density, stream frequency, sinuosity factor and bifurcation ratio, have been computed and analyzed. The study revealed that the contribution of the morphometric parameters to flooding suggest catchment No. 1 has the least concentration time and the highest runoff depth. Catchment No. 4 has the highest circularity ratio (0.35) as the most hazardous site where floods could reach a great volume over a small area.

The Soil and Water Assessment Tool (SWAT) is often used to evaluate the impacts of different land use scenarios on streamflow and sediment yield, but there is a need for some clear recommendations on how to select the parameter set that defines a given land use scenario and on what is the most appropriate methodology to change the selected parameters when describing possible future conditions. This paper reviews the SWAT formulation to identify the parameters that depend on the land use, performs a sensitivity analysis to determine the ones with larger impacts on the model results and discusses ways to consider future land use conditions. The case study is the Atibaia river basin, with 2838 km2 (S&atilde, o Paulo, Brazil). The parameters identified by sensitivity analysis with the largest impacts on streamflow and sediment yield were the initial curve number for moisture condition II (CN), maximum canopy storage for each land use (CANMX) and the cover and management factor (USLE_C). The identification and appropriate parameter change can provide real estimates of the magnitudes in the land use changes, which were verified in this study. Such information can be used as an instrument for proposing improvements in the basin&rsquo, s environmental quality and management.

In the low Mediterranean basin, late spring and autumn rainfall events have the potential to increase discharge and transport substantial amounts of sediment soil (that is, the net soil erosion from a watershed). For the Alento River Basin (ARB), located in the low Tyrrhenian coast of Italy, we estimated changes of net erosion as dependent on the seasonality of antecedent soil moisture and its control on rainfall-runoff and erosivity. Based on rainfall and runoff erosivity sub-models, we developed a simplified model to evaluate basin-wide sediment yields on a monthly basis by upscaling point rainfall input. For the period 1951&ndash, 2018, the reconstruction of a time series of monthly net erosion data indicated a decreasing trend of the sediment yield after 1991. Revegetation and land abandonment that occurred in the last decades can explain such a decrease of net erosion, which occurred even when rainfall erosivity increased. This response, obtained at the basic scale, does not exclude that rapidly developing mesoscale convective systems, typically responsible for the heaviest and most destructive rainfall events in the ARB, can affect small catchments, which are the most vulnerable systems to storm-driven flash floods and soil erosion hazards during soil tilling in spring and at beginning of autumn.