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In small mountain basins, hydrologic forecasting is particularly difficult, where spatial heterogeneity of rainfall is difficult to monitor by limited rainfall data. In response to this challenge, hydrologists have done a great deal of work on hydrologic forecasting, including statistical calculations, hydrologic mechanisms, and data-driven methods. As the most popular method in data-driven method, deep learning algorithm has considerable application prospects in hydrologic forecasting. LSTM's deep learning method with long-term memory ability has a natural advantage in hydrological forecasting, and the multiple eigenvalue setting makes the model calculation not completely dependent on the single indicator of rainfall, so that LSTM is more suitable for small mountain basins. Taking the Guanshan River Basin as an example, this paper constructs a traditional hydrologic model and a long short-term memory (LSTM) model to simulate the runoff of the Guanshan River and compare the simulation effects of the two schemes. The Nash-Sutcliffe efficiency coefficient of the traditional hydrologic model is 55%, and the corresponding Nash-Sutcliffe efficiency coefficient of the LSTM is 70%, under the same inspection period. The results show that the long-term and short-term memory (LSTM) model can better simulate the runoff in the Guanshan River Basin compared with the traditional hydrologic model. [ABSTRACT FROM AUTHOR]

Due to the usage of forecasting information, the reservoir flood control forecast operationmethod makes the reservoir more effective in regulating floods than the conventional method.However, it is necessary to conduct risk analysis on the forecast operation methodconsidering the uncertainty of the forecasting information. It is difficult for the traditional riskanalysis method to balance complexity, accuracy and application range. Inspired by the riskanalysis method based on the law of total probability (MLTP), we propose an analyticalmethod based on integral thought (AMIT) for risk analysis of reservoir flood control forecastoperation. AMIT introduces the concept of hazard domain, and the risk analysisresults can be obtained easily by computing the integral of the risk factor’s jointprobability density function (pdf) over the hazard domain. Dahuofang Reservoir, which islocated in the Hunhe River Basin, northeastern of China, is used as a case study.Though the risk analysis results of the two methods mentioned above are almostequal, the result obtained from AMIT is more concise than that from MLTP. Themethod developed in this paper can be used to analyze the risk of combined events,providing richer information and more decision-making support for reservoir managers.Furthermore, AMIT is also applicable to the risk analysis of other similar areas. [ABSTRACT FROM AUTHOR]

The objective of this paper was to use an unmanned aerial vehicle (UAV), to perform planialtimetric mapping of an erosive feature located in Rio Claro Municipality, Rio de Janeiro State. The study area is located within Piraí drainage basin, a tributary of Paraíba do Sul river. Paraíba do Sul valley presents a history of use and occupation strongly linked to the economic cycles of Brazil, where the native forest of the Atlantic Forest biome was cleared, in order to use the soil in a profitable way, making the exploration of sugar cane, coffee growing and opening of areas for pasture. The use of VANTs in geomorphological research effectively enabled a complete assessment of the erosion feature, where it was possible to make cross sections and longitudinal profiles, calculation of length, width and total area. In addition to being an equipment that facilitates the understanding and monitoring of areas of interest, the use of VANT's allow the capture of images of high resolution and precision, which are subsequently processed, giving rise to new ways of assessing the feature. To complement the research work, soil samples were collected from the soil surface layer for determining their chemical and physical properties. The results of the analyzes indicate that the soil presents favourable conditions for its erodibility, presenting high silt and fine sand content, high bulk density and low organic matter content and aggregate stability. Such properties, together with land use and inadequate management, generate highly impacted areas. [ABSTRACT FROM AUTHOR]

Deciphering the origin of alluvia is an ongoing research question at the boundary of several geosciences. The most important fine sediment sources are slope erosion, river processes (channel scour and bank erosion) and gravitational processes (landslides). Nevertheless, the complex relationships between sediment-generating processes and sediment transfer rates towards the riverbeds have not yet been completely elucidated. The purpose of this paper is to analyze geomorphic processes functioning as fine sediment sources in a fluvial system with high sediment dynamics and characterized by human interventionsThe study focuses on the Jiu river basin (the largest tributary of Danube river in south-western Romania), well-known for its coal-bearing deposits (lignite and bituminous coal), the exploitation of which greatly affected water turbidity and fine sediment quality. Across its 10,070 sq.km, the study area overlaps a region with high rate of suspended sediment load (exceeding 10 t/ha/yr), considered to be the second in Romania in terms of the amount of fine sediment transited (the multiannual suspended sediment load of the Jiu River reaches 165 kg/s).To address the issue of fine sediment sources, a detailed mapping of geomorphic processes was conducted within a buffer of 1 km on each bank along the main rivers. To gain more insight into hillslopes' capacity to mobilize and supply rivers with sediments, a multi-temporal approach (2005–2012) was adopted, using remotely sensed images. Landslides, rill and gully erosion were taken into account as sediment generating geomorphic processes, their further evaluation including mechanism classification, estimating dimensions, deriving movement rates and recurrence intervals. The relation between daily liquid discharge (Q) and suspended sediment loads (R) from the analyzed period served to establish a discharge threshold able to discriminate between hillslope and in-channel sediment sources. Additionally, the relation between sediment sources and delivery was validated by means of geochemical fingerprinting of coal content in fine sediments.The geomorphic processes inventory led to identifying potential sediment sources in terms of slope deposits, including man-made ones. Hillslope-channel contact zones are described using nominal classification systems as well as simple quantitative measures (length of the affected channel, number and area of the slope processes affecting riverbeds). In this sense, priority was given to mapping and evaluating the degree of slope – riverbed coupling in the area of coal spoil heaps, which are very unstable and behave as a supplier of fine sediments for the rivers during storm events. The relative contribution of hillslope sources to suspended sediment transport was estimated to be above 80% during summer high waters and flood periods, while during low water intervals in winter, it can drop even below 20%. Established R-Q relation allowed for the prediction of the relative contribution of the hillslope domain in the suspended sediment yield for river sections where sediment measurements were not available. Uncertainties are discussed in terms of frequency-magnitude relations affecting sediment detachment and transport processes.The findings on slope-processes providing fine sediment inputs represent a preliminary research in understanding sediment connectivity, especially in the context a drainage basin strongly affected by coal mining. [ABSTRACT FROM AUTHOR]

The stable isotopes of hydrogen and oxygen are commonly used as tracers in catchment hydrology research. Most studies collect isotope samples from precipitation, streamflow, groundwater, and soil water at different times during the study period, but at only a few locations, and assume that these samples are representative for the catchment. To test whether this assumption is correct, we reviewed 149 peer-reviewed papers published in international journals between 1970 and 2017 that used at least one of the stable isotopes of hydrogen and oxygen to investigate hydrological processes at the small catchment scale (up to 10 km2). The objective was i) to determine the typical observed spatial variability in the isotopic composition of different hydrological compartments in small catchments around the world, and ii) to assess how this spatial variability might affect isotope-based hydrograph separation results. The majority of published studies were conducted in temperate and cold regions of the world. Only a few studies sampled a hydrological compartment at five or more locations throughout the catchment. Most studies that sampled a compartment at more than five locations reported a large spatial variability in the isotopic composition for that compartment. The reported spatial variability in the isotopic composition was largest for snowmelt and soil water (median range in δ18O up to 6‰ and maximum range up to 44‰), followed by throughfall and shallow groundwater. To test whether the observed spatial variability was significant, we adjusted the isotopic composition of throughfall, soil water and groundwater in a small catchment in Italy by the average observed spatial variability. We then re-ran the three component hydrograph separation for two rainfall-runoff events (using electrical conductivity as the second tracer). The calculated maximum contributions of the three components to streamflow differed by up to 26% from the reference scenario. This suggests that if the variability in the isotopic composition of throughfall, soil water and groundwater in this catchment was similar to the average observed variability, we could have obtained significantly different results if we had sampled throughfall, soil water and groundwater at different locations. These results thus suggest that we need to interpret isotope hydrograph separation results with care if they are based on only one or a few sampling sites, and that even in small catchments it is important to take samples at multiple locations.Keywords: stable isotopes in water; small catchments; spatial variability; hydrological compartments. [ABSTRACT FROM AUTHOR]

The new monitoring system based on Internet of things technology can provide advanced and complete capacity for wide range and sustainable field monitoring data acquisition and sharing. This paper introduces the application of the ecological monitoring IoT network of Heihe River Basin. By adopting a series of new monitoring equipment based on the technology of Internet of things, the monitoring of the key parameters of water, soil and air in the area of Heihe River Basin is realized. At the same time, combined with the technology of Data Automatic Assembling, through the unified remote data receiving module, data preprocessing module, automatic warehouse module, relational database system, and the online visual monitoring data management application platform, the efficient remote monitoring network and monitoring data application system can be formed, which can effectively improve the monitoring capability and the real-time and availability of monitoring data.As a application example, an application system was developed for the ecological monitoring IoT network of Heihe River Basin. The observation data gotten from the remote data collector would be collected, preprocessed, evaluated, and shared full automatically.The uploaded data first passed through the data interface. The function of the data interface is to normalize the raw data, which would come from different kinds of instruments, in a normalized way automatically. Then the raw data and the format-normalized data are putted into a specially designed relational observation database. All acquired data was saved in a relational database. Users can access the data via a mobile terminal or computer remotely. [ABSTRACT FROM AUTHOR]

Regional analysis is an essential step to improve water management plans and transpose flow characteristics on ungauged catchments. The Mediterranean region limited by the topographical boundary is a highly fragmented area with 1270 catchments ranging between 100 and 3000 km2 and draining towards the Mediterranean Sea. Qualified as one of the most sensitive and challenging regions to climatic and anthropogenic variations and lacking flow measurements, mostly in its southern side, this region stands as a good candidate for regional analysis.Despite all the research at the regional scale, a specific Mediterranean hydrology is long to be defined yet and require additional research related to the relation between hydrological processes and their climate and physiographic descriptors. This paper seeks to define these relations relying on multivariate analysis approach. The proposed methodology consists of (1) defining the most contributing climatic and physiographic indices, (2) classifying the catchments using k-means clustering and (3) regionalising flow characteristics based on the physio-climatic similarity issued from a canonical correlation analysis. The main characteristics were uniformly collected across the Mediterranean and a representative data set of catchments covering 15 countries was considered for the regionalisation.The canonical correlation analysis highlighted homogeneous sub-regions, similar catchments and resulted with a new cartography for Mediterranean catchments hydrological characteristics.Key words: Canonical Correlation Analysis, Regionalisation, Mediterranean hydrology, physio-climatic similarity [ABSTRACT FROM AUTHOR]

It is crucial to study ancient irrigation when developing understanding of the co-evolution of social and water systems. Given the low precipitation in south Mesopotamia, the available water in its rivers for cultivation was limited. This prompted the establishment of irrigated agriculture in south Mesopotamia, and lead to its sophisticated irrigation systems. The interactions between social activities and irrigation management, and the influence of physical process of rivers on irrigation system, are the main topics that researchers have been exploring for a long time. The study of natural channels and man-made canals in a long-term perspective may help to understand the evolution of irrigation systems under the joint influence of nature and human beings. The aim of this paper is to discuss the development of an agent-based model of the evolutionary process of these irrigation systems, including the physical attributes of channels and canals, water management strategies, and the changes of river courses, building on relationships between humans and their environment. Studying ancient irrigation systems also can allow us to develop a deeper insight into present irrigation management, thus providing strategies for better development. The irrigation landscape of south Mesopotamia will be reconstructed, by using archaeological records, remote sensing data, and hydraulic models. In order to investigate the behaviour of human, river regime, and irrigation organization, several scenarios will be considered, such as the changes of river layouts or inflows, irrigation regimes, and the development of settlements. The results will provide insights into how the configurations of irrigation changed according to the interactions between humans and nature. [ABSTRACT FROM AUTHOR]

A range of palaeoclimatic and palaeoenvironmental evidence suggests the Asian sub-continent experienced phases of arid-humid alterations on centennial and millennial scales during the Holocene, which were set against a backdrop of insolation-driven weakening of the Asian Monsoon system. These oscillations would have affected fluvial regimes on the plains of northwest India, which were occupied by the Bronze Age Indus Civilisation during the mid-Holocene. It has been suggested that a decline in regional river systems contributed to the decline of the Indus at ~4 ka (e.g. Giosan et al., 2012 (PNAS 109, E1688), Singh A. et al., 2017 (Nature Communications 8, 1617). In a recent study Orengo and Petrie (2017, Remote Sensing 9, 735) identify a complex channel network on the Sutlej/Yamuna interfluves, and Durcan et al. (in press, Quaternary International, doi.org/10.1016/j.quaint.2017.10.012) have highlighted complexity in the response of regional geomorphic systems to climatic/environmental change. Therefore, further work is required to understand the spatial and temporal dynamics of regional hydrological systems in order to assess the importance of changing climatic and environmental conditions in the establishment and decline of the Indus CivilisationThis paper presents luminescence dates from palaeochannel sediments and associated dune deposits on the Ghaggar-Hakra floodplain in northwest India, with particular focus on the area around the Indus site of Rakhigarhi. Rakhigarhi is the largest and potentially most important site in northwest India (Singh R.N. et al., 2010, Man and Environment, 35, 37-53), although its relationship to local and regional fluvial systems is unclear. Reconstructing fluvial activity and palaeoenvironmental variability allows a comparison between the documented archaeological record of the Indus Civilisation and an absolute chronology of regional landscape dynamism. Luminescence dating shows that the fluvial network around Rakhigarhi pre-dates the establishment of the site, and that regionally, there is no simple relationship between documented climatic deterioration and changing fluvial activity. This study presents a new reconstruction of palaeoenvironmental change on the Ghaggar-Hakra floodplain, and provides new insights into the fluvial landscapes occupied by the Indus Civilisation during the Holocene. [ABSTRACT FROM AUTHOR]

This paper aimed to measure the fractal dimension values of the spatial distribution of landslides in different geomorphic units, stratigraphic and basin zones based on the fractal theory and geological investigation, taking the landslides in Nanxi county, Yibin city, Sichuan province as a case study. The results demonstrate that the fractal dimension value of spatial distribution of landslide in Nanxi county is 1.1858. After classification and partition, the fractal dimension value of each small region is all less than the whole region. The fractal dimension values of different geomorphic types are sorted as platform deep hilly area, middle hilly area, low mountain area, shallow hilly area and valley flat area. The larger the fractal dimension value, the greater the contribution of the geomorphic unit to the development of landslide disasters will be. In the fractal dimension values of the stratigraphic types, they are Jurassic, Triassic, cretaceous and quaternary in order. In Jurassic strata, the bedding and oblique slopes of sand-mudstone interbeds with strata dip angle for more than 15° develop landslides the most. Fractal dimension values of stratigraphic types reveal the influence degree of stratum lithology and tectonic action on landslide development. Besides, The fractal dimension values of basins are sorted as Huangsha River, Longtan River, Meixi River, Bailichong River, Macaoxi River, Luqu River and Changxing River. With a maximum fractal dimension value, the Huangsha River basin has the widest distribution area and the largest river discharge in the study area. The riverbank slope is prone to landslide disaster because of the stronger flow erosion. This indicates the control of river hydrogeology on the landslides.Therefore, based on the calculation of fractal dimension values and the geological investigation of landslides in the study area, the results indicate that the fractal dimension value of spatial distribution of landslides is the comprehensive reflection of topography, stratigraphy, lithology, structure and hydrogeology, and it is the quantitative expression of regional landslides development complexity and susceptibility. Moreover, the fractal characteristics of the spatial distribution of landslides can be an important significance to division for the landslides-prone area. The calculation of fractal dimension could be an effective method to predict the susceptibility of geohazards in a regional scale. [ABSTRACT FROM AUTHOR]

Wetlands have many functions and are very important to human life and ecosystems. To quantitatively preserve and manage wetlands, it is necessary to analyze the hydro-ecological changes and evaluate its function and sustainability. In this paper, we predicted the plant habitat according to the change of wetland hydrology and have proposed measures to effectively manage wetlands by evaluating future wetland functions and sustainability. In this study, we selected Binae wetland which is the riverine wetland in Namhan river basin. And then, we defined the Inundated Exceedance Probability(IEP) which is the probability of inundation of riverine wetland and analyzed in three aspects. (1) Based on the IEP, we analyzed the water level, inundation area, inundated depth, and inundation period considering climate change and predicted future plant habitat environment. (2) To evaluate the wetland functions, we proposed Modified Hydrogeomorphic method(Modified HGM). And we evaluated future wetland functions considering the change of hydro-ecological environment due to climate change. (3) To evaluated sustainability of Binae wetland, we proposed Wetland Sustainability Index(WSI) considering water environment change, weather and climate, plant and animal environment factors. As the study results, emergent and submerged plants are expected to maintain or increase their status because future(2040~2099) inundation period and areas are similar to or better than in the past(2000~2017). But in the near future(2018~2039), the average water level, inundated depth, inundation area decreased conpared to the past. It can be seen that the inundation period also decreases. Especially, it is considered that the area where the inundation period and area decreased can be changed from emegent or submerged plants to shrubs & woody plants. And, because wetland function and sustainability are both high, so they will continue to be maintained. However, Binae wetland has a poor future environment in hydrological function and sustainability of fish. So it is necessary to manage in its aspects. It is expected that methodology presented in this study will be a basic data to predict the plant habitat environment and evaluate its function and sustainability.Acknowledgment: This work is supported by the Korea Environmental Industry & Technology Institute(KEITI) grant funded by the Ministry of Environment(Grant 18AWMP-B083066-05). [ABSTRACT FROM AUTHOR]

Affected by global warming and environmental changes, meteorological and hydrologicalfactors in the Dagu River Basin have also undergone a series of response changes, resulting inchanges of time and space in the quantity of water resources, and the natural ecologicalenvironment and the economic development of human society have been seriously affected.In this paper, hydrometeorological factors such as temperature, rainfall and runoff areselected as the research objects. Mann-Kendall order correlation test, sliding t test,YAMAMOTO test signal to noise ratio (SNR) and other mutation point test methods are usedto analyze the mutation law of meteorological and hydrological elements in the Dagu RiverBasin in the past 50 years. The results show that in the last 50 years, the trend of climatewarming in Dagu River basin is basically consistent with the general trend of climate changein China, and the annual mean temperature mutation is mainly after 1985, and theabrupt point of annual precipitation in the basin occurred during 1975-1985. Theannual evaporation in the basin fluctuates with time, and the decreasing trend issignificant. By means of sliding t and SNR test, it is found that the abrupt point of annualrunoff occurred between 1965-1968 and 1975-1983 in the studied area, and theprecipitation mutation is the main cause of the abrupt change of annual runoff. [ABSTRACT FROM AUTHOR]

Climate change has already caused major effects in agricultural production and derived earnings on farming income worldwide. The farming areas in southeast Mediterranean are expected to incur production losses due to temperature increase, less precipitation volume and frequent drought occurrences. Such an example may be traced in Lake Karla watershed, in Central Greece, where intensified agricultural production is highly dependent on surface and (mainly) groundwater irrigation. The particular feature of Lake Karla watershed is the current refiling of a large part of the former lake aiming at environmental restoration and sustainable irrigation patterns. In this paper, we attempt to assess the climate change effects in farming produce of various crops cultivated in Lake Karla watershed by adopting mild, middle and severe climate projections on the period 2006-2100. The climate change projections are conducted through the downscaling of the IPCC's Representative Concentration Pathways (RCPs) based on monthly meteorological data from 1960-2005. We also adopt different scenarios of agricultural water demand depending on separate and conjunctive surface and groundwater use as well as cropping pattern variations. The Water Evaluation and Planning System (WEAP) tool is employed to assess water balance within the selected scenarios while the CROPWAT software is introduced to account for the relevant productivity effects. A linear economic modeling is also employed to measure the profit alterations occurring due to climate change in the farmlands. The findings suggest that the reinforcement of surface water supply coupled with new cropping patterns may considerably offset climate change impacts and economic losses of agricultural income in Lake Karla watershed. Notwithstanding the major impacts of climate change in agriculture, it is however noticed that different interventions in irrigation volume (regarding technical measures increasing the efficiency in water use) and techniques may mitigate the impacts. More detailed information on the current irrigation demand and sources per farming area is anticipated to better clarify the relations between climate change and irrigation interventions in the study area. Finally, useful outcomes occur about modeling uncertainties carried by climate change hypotheses. [ABSTRACT FROM AUTHOR]

On a global scale the main wastewater treatment options for rural and suburban communities which lack access to centralised wastewater treatment are split between septic tanks, latrines and other improved on-site wastewater treatment systems (DWTSs) – estimated to be used by at least 2.8 billion people. In Ireland, more than one third of the population (approximately 500,000 dwellings) use DWTSs, of which more than 87% are septic tanks. Previous studies have found that the effectiveness of DWTSs in treating domestic wastewater varies widely, depending on local soil attenuation capabilities, system design, installation and maintenance. Consequently, the potential impacts of such on-site effluent, especially in cases of inadequate DWTS performance, are microbial and chemical pollution of groundwater and / or surface water.Karst aquifer systems are exceptionally vulnerable to pollution from such potential contamination sources as a result of predominantly rapid recharge of water from the surface and strong aquifer heterogeneity in these regions. These karst network characteristics and multiple pollution sources make it complex to trace the origins of pollution using conventional methods whereby targeted pollutants in groundwater can be linked to their specific sources and quantified at the same time. This is particularly important in karst aquifer systems where numerical modelling of the fate and transport of pollutants from prevailing contamination origins is extremely challenging and yet increasingly necessary for the implementation of appropriate management strategies at a catchment scale.To overcome these challenges, this paper presents the results of research being conducted using a wide range of novel, non-conventional and traditional methodologies capable of detecting low concentrations of contaminants in order to determine and quantify human faecal pollution impacts on karst springs. A variety of microbial and chemical source apportionment methodologies are being tested across several Irish rural catchment areas with high densities of DWTSs. The catchments have been selected to compare contrasting groundwater vulnerabilities, different sizes and types of karst systems. A thorough analysis of the results obtained so far using a multiple-tracer approach has been conducted and methods have been evaluated in terms of applicability, sensitivity and accuracy.The results show that detection and quantification of source specific chemicals such as fluorescent whitening compounds (FWCs), fluorescence-based investigations of organic matter using the excitation-emission matrix (EEM) and PARAFAC analysis, specific anion ratio signatures, faecal sterol and stanol profiles and ratios, and several microbial fingerprinting methodologies in parallel can provide sufficient information for decision making processes and adaptive management strategies. Notably, whilst some of the techniques tested are not capable of being able to link pollutants directly with any particular pollution source, they can still quantify specific pollutants, in some cases to a very high accuracy, thereby determining the overall impacts of contaminants on groundwater quality at karst springs. Furthermore, it has been found that techniques for advanced investigation of microbial populations may be exceptionally advantageous for numerical modelling of the fate and transport of contaminants of DWTSs effluent origin through karst aquifer systems. [ABSTRACT FROM AUTHOR]

Hydrological processes are considered non-stationary under the influences of climate changeand human activities. This non-stationarity highlights the need to adopt time-varyingparameters in hydrological models. Most existing literature quantifies time-varyingparameters by incorporating real observations of only one basin into a hydrological model,which are limited in their information on catchment characteristics and climatic factors, toconstrain time-varying parameters, and thus models are difficult to apply for hydrologicalpredictions outside the calibration periods. This paper formulated the time-varyingparameters for a lumped hydrological model as explicit functions of physically-basedcovariates that captured the catchment characteristics and used a hierarchical Bayesianframework to incorporate the similarity of adjacent basins to reduce the uncertaintyof the assumed functions of time-varying parameters. Four modeling scenarioswere developed to explore the spatial coherence between different characteristics ofadjacent basins. Five criteria were adopted to evaluate the performance of assumedfunctional forms. Four spatially adjacent catchments in central United States wereselected as case studies to examine the validity of the proposed method. Resultsshowed that (1) the proposed method succeeded in reducing the uncertainty oftime-varying parameters, and (2) the seasonality of the catchment storage was morecoherent between adjacent basins, indicated by the largest increase in model predictionperformance (i.e., 9%). This study improved our understanding of the spatial coherence oftime-varying parameters, which will help improve hydrological predictions in the future. [ABSTRACT FROM AUTHOR]

Check dams serve multiple purposes, such as reducing sediment erosion, favoring floodmitigation, avoiding soil fertility losses and recharging aquifers. Moreover, check dams havebeen proved to be a useful tool for controlling soil erosion and runoff on a catchment scale. Inthis context, the effectiveness of check dams depends on multiple characteristics, includingwatershed area, the physical properties of the soil, types of vegetation, the farming system,and land uses. Hence, check dams are a topic of interest in many different countries.Conducting a review of the check dams in several countries where erosion control hasexperienced a pioneering period is interesting, because it can help explain culturalsimilarities, and explore the different approaches taken to manage soil and waterconservation. This study presents the extant research conducted on the usefulness anddevelopment of check dams globally. Check dam development and utilization has a longhistory in China. Indeed, the Loess Plateau occupies 3200 km2 of check-dam farmland, andanother 3512 km2 of check-dam farmland is located in the black soil, windy, sandy, hilly andmountainous regions. In Spain, numerous studies have been conducted on checkdams, as the interest in researching them has increased considerably over the last 30years. After check dams were installed in northern Italy, significant differences weredetermined in sediment, vegetation development and channel formation. Severalstudies have also been undertaken to determine the varying effects of check damsin Iran. Moreover, more than 150 years of research has reported that check damsare landmark civil engineering structures used in the French Soil ConservationProgram. This paper will be helpful for policy makers to extend check-dam projects inerosion-prone, arid and semi-arid areas. It is suggested that more research is needed onthis subject to formulate strategies and implement plans for sustainable river basinmanagement. * The first three authors Naseer Ahmed Abbasi, Xiangzhou Xu and Manuel EstebanLucas-Borja, contributed equally to this work. [ABSTRACT FROM AUTHOR]

Urban water pollution control is a major city problem challenged the new round of urbanization and sustainability in developing countries. For example, Shenzhen city, China invests 100 billion Chinese yuan per year for urban water environment remediation projects. How to make effective operation and maintenance on catchment water quality control is challenging local governments and operating company and it is an important task to make sure sustainability of governance effectiveness. As the increasing trends of the fusion between emerging information technology and environmental science, it is necessary to integrate enabling technologies to build novel intelligent supervising system based on environmental models and monitoring infrastructures.This paper designed a novel system including hardware, software and the monitoring network to detect water quality anomaly and identify the potential pollutant release sources on drainage system and receiving water. The core component of the system is an in-situ intelligent equipment integrating a high-frequency water quality sensor module, a data communication and transmission module, spectroscopic detector module, a card type master computer with fixed environmental models, and a power management module, etc.The sensor module tends to establish a linear or gray-box model of surrogate relationship between normal water quality parameters and specific chemical from the pollutant sources. Rapid forecasting of historical water quality baseline employed data-driven models like ARIMA, Facebook Prophet, and wavelet-ANN within a fixed time window. The anomaly, transient water quality events, was detected by forecasting baseline error distributions and thresholds of the calibrated model. Spectroscopic detecting employed 3D fluorescence, Raman scatter and ultra-violet technology. PARAFAC and self-organizing map (SOM) were used to analyze the real-time results of spectroscopic response. Computer vision and other figure matching algorithms were developed to identify most probable pollution sources from the spectroscopic database, which is previous established. A three level monitoring network was designed to capture the potential confidential release on the drainage system. This pilot system is currently installed in a 5 km river section of Maozhou River, Shenzhen, China. As shown by numerical experiments and artificial field tracer experiments, the response time and accuracy of the water quality anomaly detection, and source identification is acceptable. More practical issues on the application are going to be discussed. This smart system automatically supervise the pattern and drivers of water quality changes in urban rivers and drainage system. It provides a promising framework and tools for river operating companies and administrators achieving the critical water quality standards. [ABSTRACT FROM AUTHOR]

The prevalence of ancient abandoned fluvial landforms in the northern Chilean Atacama Desert is a testament to both the long-term hyperaridity of this setting and its sensitivity to change. Ascertaining what has driven drainage adaptations has the potential to reveal past environmental changes and whether they were localized or regional in extent. However, it is typically unclear whether processes related to climate, tectonics, or both, are the cause of drainage reorganization. Alternatively, an often overlooked driver of topographic change is the breaching of geomorphic thresholds, whereby abrupt erosional or depositional episodes occur without the need for external causes. Instances of geomorphic thresholds include periods of degradation and aggradation experienced by ephemeral streams, or stream piracy events. In this paper we will discuss the incision history of the Tiliviche River (Quebrada Tiliviche) in northern Chile and unravel the contributions made by climate, tectonics and geomorphic thresholds to the evolution of this drainage.Like most of the rivers in northern Chile that reach the Pacific Ocean, the Tiliviche River has its source in the Andes Mountains (Precordillera) and takes a westward route through the hyperarid Central Depression and Coastal Cordillera. Using a cosmogenic nuclide derived chronology for the formation of a flight of river terraces located in the Central Depression we infer a dramatic increase of the incision rate of the Tiliviche River at around 350 ka ago. The fluvial terraces lie downstream of a subtle, fault-related, upward warping of the surrounding pediment surface for tens of km north and south of our sample site. Explanations for a more rapid rate of river incision over the last ca. 350 ka include: an increase in the amount of water available for discharge, possibly related to more precipitation in the Andean headwaters of the basin, or brought about by a stream capture event increasing the upstream catchment area; base-level drop in response to local fault driven uplift; or a base-level fall resulting from the draining of a paleolake downstream or connection of the Tiliviche River to the sea. The likelihood of each of these explanations is considered in greater detail with reference to characteristics of the local faults, the timing of abandonment of adjacent paleochannels and mapping of other Tiliviche River terraces, the dating of which is currently underway. [ABSTRACT FROM AUTHOR]

The Lancang River Basin, a window for China’s external cooperation is facing the disruptionof the nutrient balance of aquatic ecosystem. Phosphorus is a crucial limiting factor of theaquatic ecosystem in the Lancang River. This study proposed a framework for estimating thetotal phosphorus (TP) load and spatial distribution in the Lancang River Basin in the absenceof measured data. Because the difference of the sources of TP load, both integrated empiricalmodel based on social-economic data and distributed mechanism model (ie. ULSE) are usedin the accounting process. The uncertainties of some key parameters in this frameworkand some input data were also analyzed. Moreover, the TP load in Lancang RiverBasin was compared with those of some large-scale basins, i.e., the Yangtze River,the Yellow River, the Pearl River, the Huai River, the Hai River, and the SonghuaRiver. Results showed that the annual average TP load is in the range of 1.6×104t to3.9×104t, increasing from the upper reaches to the lower reaches, and the lower reachesaccounted for about 60% of that in the whole basin. Among them, natural soil erosion isthe dominant source of TP load with large uncertainty, accounting for about 69%of the whole basin. Compared with other large-scale basins, the TP load in theLancang River Basin is at a very low level, mainly because the land use types inthe basin are natural forest and grassland, and the farmland area is less than 10%,which is less affected by human activities. The data set of TP load in Lancang RiverBasin is given in this paper, which can be used to guide the integrated watershedmanagement, as well as provide a more scientific basis for the relationship between upperreaches and lower reaches, and also offer some data support and reference for futureresearch. Keywords: Lancang River Basin, total phosphorus load, spatial distribution, uncertaintyanalysis. [ABSTRACT FROM AUTHOR]

Glacial-dammed lakes play a prominent role in the natural landscape shaping processes of the Karakoram. In the upper Shimshal and Shishper valleys, the surging glaciers continually pose a threat to the downstream settlements due to formation and failure of ice dams. About 22 glacial floods have been identified and attributed to these glaciers in the central Karakorum from the last century including the outburst of 2017 in the Shimshal valley. The current of the Shishper lake is also expected to present devastating consequences. The erosion potential is obviously noticeable from the high loss of settlement areas in the Shimshal, Pasu villages and KKH (Karakorum high way). Previously, the lake formations were mainly attributed to the surging activities of these glaciers. Surge movements were recently recorded on November 2016 in Khurdopin glacier and 22 November 2018 in Shishper glacier, which caused the creation of new glacial dams which consequently evolved into GLOF hazards on 21 July 2017. This outburst event resulted to the damage of buildings and hanging bridges, and eroded agricultural lands the Shimshal valley. In this paper, we present a methodological approach for the glacier dynamics and GLOF draining processes via Pipe flow calculations of the subglacial tunnel drainage and downstream impact evaluation. The methodology was applied to the Hunza river basin. The Khordopin glacier has been shown to advance at an average surge of around 18 m per day from April 2017 to May 2017 which reduced to 10 m/day from May to June 2017 as computed from the satellite imagery obtained by Landsat 8 and Sentinel 2. The surge was observed to have advanced to a total distance of 18 kilometers from the terminus of the glacier. Different locations on the glacier, exhibited distinctive surge behaviors. The movement of the Shishper glacier is still being observed up to the present moment. Calculations of the increasing lake level (Shishper lake) and draining processes through subglacial tunnel and 1D hydraulic models of the river flood give consistent results and further verify the simulation findings. Through a field survey conducted to assess the potential damage caused by GLOF, it was found that a peak outburst flood could be in the order of 1672.34 m3/s. The analysis demonstrates that a large area of agriculture land, livestock, bridges and a huge amount of infrastructure are exposed to the GLOF. It is concluded that regular monitoring and the establishment of early warning systems are necessary for the prediction of glacial surging activities and glacial lake formations in the Shimshal and Shishper valleys. [ABSTRACT FROM AUTHOR]

The landscape development in the Kosi River basin in the central Himalaya is strongly influenced by large tectonic and climatic gradients. Dynamic behaviour of the Kosi River in the alluvial part has been well-documented and is strongly linked to high sediment supply from the upstream hinterland area. Hence, reach scale erosion mapping in the hinterland area is a major issue, which can be tackled by highlighting sediment generating areas within the Kosi River basin. Sediments generated through hinterland erosion are routed downstream and spatially distributed in lower reaches of the Kosi River. The spatial distribution of energy available for sediment transport is governed by stream power (function of discharge and slope). This sediment transport competency approach has been applied in this paper to unravel erosion at basin/reach scale using spatial distribution pattern of specific stream power (SSP). A physically-based semi-distributed hydrological model, Soil and Water Assessment Tool (SWAT) has been used to simulate the reach scale stream power variability through estimation of channel slope and discharge. Stream power distribution pattern for different months was extracted at reach scale, through SWAT model by utilizing basic inputs such as precipitation, temperature, elevation, land use land cover and soil data. We observed that stream power is higher in channel reaches of the Sun Kosi and Arun. Downstream variation in SSP plot shows that mid-channel reaches in the Higher Himalaya have higher stream power in the Kosi River basin. The results also highlight a significant role of channel slope on stream power distribution pattern. Spatial distribution of slope data shows higher channel slope in western and main channel of the Kosi River that also results in higher stream power. This increased fluvial incision event is manifested in the spatial distribution of sediment yield. Further, since the estimation of SSP incorporates spatial variation in channel width, the peaks in specific stream power shift downstream in comparison to stream power distribution due to spatial variability in channel width. The reaches of high specific stream power and stream power therefore represent the major erosional zones, and therefore this approach can be used as a proxy for sediment erosion to understand sediment dynamics in the Kosi River basin. [ABSTRACT FROM AUTHOR]

Estimation of the Same Frequency Test and Recurrence Level of Rainstorm and Flood in the Design of Medium and Small Watersheds in South ChinaZHAO Lingling1,2*，LIU Changming2，CHEN Zishen3(1.Guangzhou Institute of Geography, Guangzhou 510002, China: 2.Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101；3. College of Water Sciences, Beijing Normal University, Beijing,100875，4. School of Geography and Planning, Sun Yat-Sen University, Guangzhou,510275)Abstract: The rationality of design flood has a direct impact on the safety of people's lives and property in flood protection zones.The design flood is deduced from the design storm based on the assumption that the rainstorm flood has the same frequency in the current flood design of small and medium-sized basins. Therefore, the assumption of the same frequency of rainstorm flood and the probability distribution of rainstorm flood encounter have become the key to verify the rationality of design flood in small and medium watersheds. Based on the hourly rainstorm and flood observation data from 1967 to 2013 in the typical heavy rainfall basin of Caojiang River in the upper reaches of Jianjiang River, this paper firstly analyzes the marginal distribution of the maximum surface rainfall and the maximum flood peak discharge of corresponding fields, then analyzes the encounter probability of the joint distribution of rainstorm and flood peak, and calculates the design recurrence level. The main conclusions are as follows: 1) the probability of the same frequency of rainstorm and flood is small in the basin; more rainstorm and flood appear in the same frequency in the corresponding period of rainstorm and flood field; 2) the condition that the peak discharge is greater than or equal to the design value of a certain frequency when the rainfall is greater than or equal to the design value of a certain frequency in the basin. The probability decreases with the decrease of the probability of excess value; 3) The probability of rainfall and flood peak discharge encountering conditions shows that there are many flood control design criteria; 4) Compared with the "or" joint recurrence period and the "and" recurrence period, the Kendall recurrence period more accurately reflects the risk rate of R-Q combination, and the maximum probability principle does not predict the risk. The Kendall recurrence period design value, which combines the probability of surfacerainfall and flood peak discharge encountering in the same basin, can provide more reference for the selection of flood control standards and risk management. Key words: design storm flood; hydrologic excerpt table; encounter probability; Kendall recurrence period; small and medium watershed [ABSTRACT FROM AUTHOR]