Search

Water scarcity and soil erosion are the main constraints small holder farmers are facing in Tigray, the northern most part of Ethiopia. Both very high and very low precipitation can cause a damage to agriculture which is the case in semi-arid regions like Tigray. While too little rainfall cannot support the growth of crops resulting in crop failure, the short but intense rainfall also causes a runoff thereby washing away essential soil nutrients. Installation of different micro/macro-catchment rainwater harvesting can address both water scarcity and soil erosion if they are properly designed prior to construction. This research was intended to develop a methodology for identifying suitable rainwater harvesting (rwh) sites by using weighted overlay analysis. It also utilizes Ahp (analytical hierarchy process) as effective multi-criterion decision-making tool in eastern Tigray at Kilte Awlaelo district on an area of 1001 km2. This method was chosen because it is simple to use, cost effective, flexible and widely adopted. Physical, hydrological, climate and socio-economic aspects were taken into account during criteria selection. The result indicated four suitability classes with 8.74% highly suitable areas (85.25 km2), 56% suitable areas (550.75 km2), 30.8% moderately suitable areas (303.2 km2) and 4.46% less suitable areas (43.87 km2). The produced rwh suitability map was also validated by both ground truth on google earth pro and a field trip to the study site. In situ and ex situ rwh including bench terraces, wells, and exclosure areas were identified during the field visit that verified the suitability model. Finally, depending on weight and scale of criteria and sub-criteria that matched to each identified suitable areas, different micro-catchment and macro-catchment techniques of water harvesting are recommended. This methodology can be utilized as decision-making tool for rwh practitioners, local and foreign organizations working on soil water conservation programmes and policy-makers during their early planning stages.

Water conservation is critical because it is one of the most significant factors for all species' survival. According to the Central Ground Water Board's estimates, underground water will be scarce in 15 Indian states by 2025 [1]. However, as per the report from Ministry of Environment and Forest, only 10 to 20% rainwater is harvested. In urban areas, it is seen that nowadays concrete structures are constructed everywhere, so it is not possible to recharge the water table by natural process of raining. All the rainwater which is one of the sources for fresh water goes to drain. This causes the depletion of groundwater level which may be fatal in the future. Therefore, a rainwater harvesting system is required in Indian household to conserve water. On the other hand, the urban cities are having high pollutant levels which in turn affecting the quality of water. The government has defined certain parameters for quality checking of water. With the aid of the suitable sensors and IoT boards, quality checking, monitoring and water segregation can be easily achieved. In this work, an efficient and cost effective technique of rainwater harvesting has been presented. Some real case studies have been done at Indian houses in order to validate the effectiveness of system in terms of its implementation and cost analysis. As a result, the proposed system becomes one of the smart solutions to address the modern problem of rainwater harvesting with water quality management in low cost.

This work is a 7-year study of monsoonal rainwater chemistry (n = 302), over mid-Brahmaputra plain during 2012 to 2018. The samples were analyzed for major chemical parameters viz. pH, electrical conductivity (EC), and ions (SO42−, NO3−, Br−, Cl−, F−, Mg2+, Ca2+, K+, NH4+, Na+, and Li+) to assess the chemistry. The mean pH of rainwater varied among the years, which was maximum in 2018 (6.18 ± 0.72) and minimum in the year 2014 (5.39 ± 0.54), and the variations were significant at p

Rainwater harvesting and treatment systems (RHTS) are used in many places around the world as a part of sustainable water management. They decrease the risk of overloading the sewage network and environmental pollution. The efficiency and reasonableness of using such solutions in specific erosive conditions are not sufficiently understood. The aim of the study was to evaluate the operation of RHTS, receiving effluents from the wholesale market and fuel station (twenty years of observations). The studied system is located in an area endangered by water erosion. In the study period, due to the accumulation of erosive phenomena, it was necessary to optimise the system (including the installation of new devices and increasing the capacity of reservoirs). The analyses referred to the stability and work safety of the most important equipment and water treatment efficiency. The quality of water in the reservoirs was measured before and after the modernisation of the system. Selected physical, oxygen, biogenic and salinity indicators were determined in the water. During the study, RHTS had a positive effect on the quality of rainwater runoff – the values of many contaminants were reduced (RHTS 1: suspended solids, nitrogen, iron, potassium; RHTS 2: conductivity, suspended solids, nitrogen). Design and operational errors were noticed that in the long run may contribute to deteriorating the operational efficiency and even lead to a building collapse (intense erosive phenomena). This study clearly demonstrates that building a rainwater management system is a highly site-specific issue.

Sponge City, as a new concept on urban stormwater management, implies well-adapted and resilient of a city on possible stormwater and the derived disaster consequently. It is similar to Low Impact Development (LID) in United States and Sustainable Drainage Systems (SuDS) in the United Kingdom, Sponge City emphasizes that the stormwater should be managed from source and origin. It has significance meaning to cities in the semi-arid loess region due to highly uneven precipitation distribution and serious water resources shortage. In order to explore the rational utilization mode of rainwater resources in loess region, the available amount of rainwater resources is evaluated taking the main urban area of Xi'an for example. Moreover, on the basis of the current land use situation of Xi'an derived from remote sensing image data, 7 green infrastructures renovation scenarios were set for simulating the possible effects of Sponge City construction in the city based on SWMM (Storm Water Management Model). The results show that, the potential available amount of rainwater resources in the main urban area of Xi’an is 1.42 × 108m3 approximately, close to the annual public water consumption, this implies good economic and social benefits for a semiarid city in northwest China like Xi’an. The effects of different green infrastructure modes present quite differences on runoff control under conditions of the different rainstorm intensities and the combination four (green roof and rain garden and permeable pavement) is the best. For the decision maker, a practicable Sponge City renovation scheme should be determined based on the overall planning, all such factors as investments, negative influences in construction periods, and future developments should be all considered in advance.

The mangrove-agriculture system is a distinct ecosystem that evolved in the Sundarbans, India in the last century due to anthropogenic activities and climate change consequences. Degraded-mangrove and agriculture (rice-based systems and aquaculture) exist side by side, each having their specific challenges and opportunities. In this review, we analyzed challenges faced by this unique ecosystem along with opportunities derived from technological advancement and site-specific climate change adaptation strategies. Both the mangrove and lowland rice ecosystem could act as carbon (C) sink to the tune of 27 and 0.93 t ha−1 per annum, respectively. Apart from C sequestration, mangrove-rice systems provide many ecosystem services. However, 40% of tropical and 10.5% of Sundarban mangroves (between 1930 and 2013), have been lost due to climate change induced sea-level rise, extreme weather events and human interferences. The specific challenges in this system are freshwater scarcity, high salinity, insufficient real-time seed supply, poor fertilizer-management, lack of irrigation network, and unprecedented occurrence of extreme events which seriously hamper the productivity of mangrove, rice, and aquaculture. There also exist some unique opportunities in terms of cheap labour availability, mangrove-conservation acts, cheap river-communication, and scope of ecotourism which fortunately get the attention of national and international funding agencies. In the last section of this review, we recommended ten climate change adaptation strategies that may be considered at the policy and farmer levels. The strategies broadly include the development of small-scale rainwater harvesting structures in series, the introduction of salt tolerant cultivars with water management, land shaping, establishment of multipurpose cyclone shelter at each block and empowerment of women through self-help groups.

Organically modified silica gels that show melting gel behavior were coated on sand-blasted steel substrates. The gel surfaces were patterned using silicone rubber molds and nickel mesh. Grooved and hexagonally imprinted surfaces were compared to an unpatterned substrate for their ability to condense water from water vapor in humid air. The patterns of vertical lines were best able to condense the vapor in a way that lead to more liquid water collection per area. The motivation for studying patterned surfaces is to find ways to extend water harvesting capabilities in regions of low humidity.

Quantifying seasonal variation of plant root water uptake depth is critical for optimizing irrigation scheduling and improving utilization efficiency of irrigation water in arid region. The stable isotopes (δD and δ18O) in rainfall, stem water, irrigation water and soil water in the jujube (Zizyphus Jujube Mill.) orchard under basin and drip irrigation were investigated to determine the seasonal water uptake patterns of jujube. The jujube mainly acquired water from the upper 40 cm soil layer. The contribution of soil water from the 0–10 cm layer in the basin-irrigated jujube (29.06%) was similar to that of the drip-irrigated jujube (30.15%). However, there were significant differences in the percentage of absorbing soil water from the 10–20 cm, 20–40 cm and 40–100 cm layers between the drip-irrigated jujube (16.61%, 18.35% and 35.74% respectively) and the basin-irrigated jujube (13.79%, 13.69% and 43.26% respectively). Approximately 19.6% and 9.9% of irrigation water and rainwater infiltrated into soil layer below 100 cm for the basin and drip irrigation, respectively. These results suggested that reducing irrigation rate with efficient irrigation method should be recommended to improve irrigation water use efficiency in arid regions.

Green roof is known to minimize urban waterlogging owing to its water retention capacity due to the presence of substrate soil layer. Biochar, which is a carbon-negative material, appears to be an essential soil amendment in green roof due to its water-holding capacity and stability. Recently, incentives are provided in developed countries to enhance commercial production of biochar for usage in green infrastructure, with an aim to meet carbon reduction goals of 2030. Further, biochar has a longer half-life (over 100 years), compared to other materials that are easier to degrade. In this study, the influence of different biochar contents on hydrological performance of green roof is evaluated using a combination of experiment and numerical simulation. Four soil columns with different biochar contents (0, 5, 10 and 15%) were subjected to artificial rainfall. Hydraulic parameters were obtained using inverse solution from the collected rainfall data. Numerical simulations were used to explore the impact of different biochar contents on green roof rainwater management performance during real rainfall process. Biochar is found to enhance saturated water content and, however, tends to reduce saturated hydraulic conductivity. The green roof with 10% BAS (10% biochar content) has better ability of comprehensive rainwater management, with the highest peak outflow reduction and the longest rainwater outflow delay. Green roof with 5% BAS has highest runoff reduction and longest peak outflow delay. These results provide a suitable selection of biochar content for urban areas with different rainwater management requirements.

The increasing demands of humankind contribute to the scarcity of natural resources and foster climate changes. For this reason, sustainable development has become a fundamental agenda in the twenty-first century. The intense urbanization induces significant changes in the natural water cycle, and this feature, coupled with neglecting the natural water dynamics in the urban planning process, increases the population’s vulnerability to urban floods. In this context, sustainable urban drainage techniques have been proposed to match the urban and natural demands, while preserving or recovering the environmental functions, as much as possible. However, such techniques are often not adopted, even in developed cities, and this fact seems to be related to the improper awareness of the whole set of benefits involved in their use. This article aims to evaluate the economic viability of sustainable urban drainage systems, in a simple and easily acceptable way, considering the ecosystem services provided by green roofs and rainwater harvesting barrels, and including their action in delivering urban revitalization and valorization. The proposed method can be easily used and understood by decision-makers, facilitating its diffusion and use in urban policy-making process. The results showed a best-performing scenario for the rainwater harvesting system with a payback of approximately three years, a benefit-cost ratio of four, and an internal return rate of 45%. The ecosystem service benefits represent 36.3% to 50.8% of total benefits.

Pluvial floods have become common in recent times due to climate change leading to heavy rainfall, and high rate of urbanization, preventing the natural infiltration of water into the ground. Within this work, measures are selected, designed and implemented, which consider all the relevant stakeholders and other environmental limitations, with the aim of mitigating pluvial floods caused by heavy rainfall in urban areas. Lohbrugge, an urban region situated in Hamburg, Germany, is used as the study area in which the flood investigation is carried out and adequate measures to curb pluvial flooding are implemented and assessed using the ArcGIS software. The measures selected and implemented include Green Roofs, Roof Catchment Rain Water Harvesting Systems, Sewer Grate Inlet, Retention Basins, Swales and the Dredging Measure, through the use of the delineation tools in the ArcGIS software. Results obtained show that the Dredging Measure had the most significant impact on the mitigation of the potential pluvial flooding, with a 100-year rainfall event data corresponding to a heavy rainfall used for analysis. Other measures implemented showed limited capacity to curb pluvial flooding under heavy rainfall conditions. It was concluded that urban areas should have adequate flood mitigation measures incorporated in their design and planning, to help curb flooding in anticipation of heavy rainfall, while more research need to be carried out to develop state-of-the-art technologies to further combat pluvial flooding in urban areas.

Urban development and climate change have led to severe waterlogging in cities. To study the degree of mitigation of urban waterlogging using the design of sponge city roads, this study employed No. 9 Road in the Sino-German Eco-park. By establishing the scaled physical model, the pavement structure of the sponge city road was optimized. Furthermore, water migration (seepage, impoundment, and drainage) rule was obtained under different rainfall intensities using the optimal pavement scheme. The following conclusions were drawn from the studies. Good permeability of the sidewalk surface structure is conducive for rainwater collection. The sponge urban road rainwater collection and utilization system could absorb up to 88% of rainwater under the rainfall intensity of 173 mm (extra heavy rain), and could absorb up to 100% of rainwater under heavy rain conditions. The seepage volume increased exponentially with the rise in rainfall intensity, and the amount of water storage increased linearly with the rainfall intensity. These results can provide guidance for safety early warning of urban waterlogging on No. 9 Road in the Sino-German Eco-park and deeper insights in the design of sponge city roads.

Mediterranean countries are still characterized by a great variety of historical cultural landscapes, as a result of the millenary human presence that has shaped the territory through agro-silvo-pastoral practices. In the arid regions of south eastern Tunisia, the land use is predominantly olive trees cropping and, because of the difficulties related to water scarcity, local population have developed a peculiar water harvesting technique ensuring the cultivation activities and minimising the risk from droughts. Jessour consist of small dams built across gullies and wadi thalwegs, creating a succession of terraces that partially retain the surface water and sediments required for crop growth. These structures are commonly built inside the watercourses to intercept runoff and sediments or at the foot of slopes. Considering that the biodiversity associated to traditional agricultural practices is important, especially in difficult environments, for ensuring food and nutrition to local communities, it results fundamental to preserve these peculiar practices. Moreover, taking into account that the presence of these water harvesting techniques allows the existence of a wide variety of flora and fauna species it result to be even more important to identify and maintain them from an ecological point of view. The research focused on the jessour identification and mapping in order to define their distribution nearby Douiret, in south of Tunisia, and describe the wide variety of species cultivated thanks to this traditional water harvesting solution. Moreover, using QGis software it was possible to analyse both jessour structure and peculiarities as well as their distribution according to the local morphological structure.

Enabling ecosystems is central to achieving sustainable development goals (SDGs), for which understanding, assessing and modeling ecosystems’ interactions remained proactive research agenda and difficult tasks, especially the agroecosystems of semi-dry environments. This study evaluated and modeled the ecological interactions of Panicum maximum in semi-dry environments enhanced with in situ rainwater harvesting systems (RWH). The field experiment (10 m × 10 m per plot) included two treatments (ridges and terraces RWH) with three replicates in a randomized complete block design in the Gezira State, Sudan. Meteorological, phenological, and soil moisture (0–100 cm) datasets were routinely collected along the season (2020) and statistically analyzed (P = 0.05) using spreadsheets. The adopted in situ RWH systems have significantly ameliorated interactions of P. maximum with the semi-dry environment compared to the control, attested by its increased biomass production (558–635%), improved water use efficiency (85%), and better-quality soil hydrological properties (a reduction of 9–17% in the soil bulk density). Coupled with improved chemical components (crude protein, nitrogen and organic carbon) of P. maximum. The quadratic function provided the best-fitted model (R2 > 0.97) for the leaf area index (LAI) and the plant height (RMSE 0.19–4.1 m2 m−2), with cautions at establishment and peak crop stages. Also, the fresh biomass was significantly regressed on LAI, minimum and maximum air temperatures (RMSE = 1.1–1.6 t ha−1), among which the minimum temperature negatively interacted with the fresh biomass. Plants’ growth development modelers shall consider the essential differences between rainfed and irrigation conditions in modeling LAI.

Improving the rainwater retention capacity (RRC) of green roofs has been proposed as an important component of urban stormwater management. In this study, a two-layered soil green roof model was established to enhance RRC compared to each single soil column model. The hydrological process of layered soil green roofs was simulated using the HYDRUS-1D program, with simulation results verified by measured results. The results showed that the RRC of the layered soil was 5% and 1% higher than that of each single substrate under a long-term dry-wet cycle and increased by 15% and 11% per event compared with the single substrates. In addition, higher peak drainage reduction and longer peak drainage delay were observed in the layered soil green roof compared to each single soil. The layered soil slowed the movement of the soil wetting front and increased the maximum water content of the upper soil. The water loss of the layered soil was reduced after rainfall and mainly occurred in the lower layer of the layered soil. These results suggest that the structures of green roofs with an upper layer with higher permeability and a lower layer with lower permeability have better hydrological performance.

Challenges faced by water resource systems are multi-faceted. The problem can be even more pronounced in a dry continent like Australia where the water resources can often be afflicted by high salinity and turbidity. Therefore, modern water resource systems require to appropriately manage both water quality and quantity. This study aims to illustrate the trade-offs between water quantity and quality in a reservoir, based on decisions to harvest different inflow sources. Taylors Lake of the Grampians reservoir system in Western Victoria, Australia was chosen as the case study for this research as it is sufficiently complex and includes many of the contemporary water resources challenges seen around the world. Different operational scenarios were analysed which included increasingly stringent water quality criteria before the water was harvested or otherwise allowed to by-pass the storage. The study suggests that selective harvesting of water can be an option to improve the overall and long-term water quality within a reservoir, but stringent water quality measures can lead to an associated loss of overall water quantity. This research study provides useful insight to water planners and stakeholders in similar catchment settings around the world, to identify water harvesting regimes with competing water quality constraints.

Soil and water quality crisis owing to industrialization is massive at present due to the illegal discharge of wastewater to the environment. Textile is one such industry, discharges untreated wastewater into nearby environment and poses major threats worldwide. Similar situation was observed for the last three decades (1980–2013) along Noyyal river in Tiruppur, India. Since 2013, zero liquid discharge (ZLD) has been adopted by the textile industries in Tiruppur to reduce further deterioration of environment. The groundwater from open wells and soil from agricultural land was examined continuously for three years (2015, 2016 and 2017) in order to assess the existing environment status along Noyyal river basin in Tiruppur. The GIS study reveals that 71% of groundwater remains unsuitable for drinking and also 54% are unfit for irrigation use. The findings further reveal that 61% of surface and 20% of subsurface soils are not suitable for agriculture. The detailed investigations established that the open wells located in the downstream of textile industries and near to Orathupalayam reservoir are highly contaminated with organic and inorganic contaminants associated with textile processing activities. The temporal variation of groundwater in these open wells indicated that the dilution by rainwater is very slow. It is also identified that soils near to the contaminated open wells are extremely affected and soil of 15 cm depth is extremely contaminated. Thus, implementation of ZLD somewhat reduced discharge of wastewater into the basin; however the recovery of groundwater to potable quality and soils for agriculture production needs immediate remediation.

With many countries facing water scarcity and the demand for water ever-increasing, more people are turning to rainwater harvesting (RWH) as a feasible way of supplementing supply. However, the success of RWH systems depends on several factors, including rainfall, catchment characteristics and socio-economic factors. Hence it is essential to carry out location-specific studies to evaluate the potential of RWH in a particular area. This study sought to assess the influence of seasonal rainfall and climate change, and socio-economic constraints on RWH in the City of Johannesburg. A GIS-based MCDA was run to estimate RWH suitable sites as influenced by various socio-economic factors. The RWH suitability map shows that at least 50% of the city is suitable for RWH. These, together with climate data was embedded into a rainfall-runoff model developed in HEC-HMS to simulate runoff volumes up to the year 2050. The Deficit and Constant loss method was employed to calculate infiltration losses. After calibration, the model results were within acceptable limits (R2 = 0.68 and 0.79). The rainfall-runoff simulation results show that high runoff volumes are received during the wet season, which is more than double the non-potable water demand. These results indicate that, with ample storage, RWH systems are feasible despite the rainfall seasonality. Therefore, it is recommended to invest in diverse and multipurpose storage to improve RWH reliability.

In this study, the cooling effects of urban green roofs and water misting were explored for buildings in cold regions during the summer. We selected five different plant types and water-misted areas on the roof of a commercial building in Xi’an, and obtained temperature and humidity field measurements for the planted and water-misted areas, and concrete roofing as a control. Measurements and theoretical analysis confirmed that the direct cooling effect (effect on roof surface temperature) of the water-misted area was about 12 °C. The effect of privet was highest among the plants at about 22 °C and the other plants also had remarkable cooling effects. Moreover, the plants had significant effects on stabilizing temperature fluctuations. In terms of the indirect cooling effect (effect on air temperature and indirect effect on roof surface temperature), that of the water-misted area reached 4.14 °C and privet was highest with about 4.68 °C at a height of 300 mm. The mechanisms responsible for the indirect and direct cooling effects of plants and water misting were also analyzed. The results confirmed that different types of roof plants and water-misted areas at various heights could increase the environmental relative humidity to indirectly affect the air temperature. Finally, the direct and indirect cooling effects of roof plants and water-misted roofs in cold regions were compared with green roofs in other climate zones, as well as the other functions of water-misted roofs, such as landscape beautification, rainwater collection, and reuse.

Geoelectric imaging is carried out to assess aquifer conditions using Schlumberger soundings in Raipur city, Chhattisgarh, India. A total of 80 vertical electric soundings were conducted at different geological conditions for the entire study area. The layer parameters, resistivity, and thickness are obtained from the recorded field resistivity data through a 1-D sounding inversion software. Five geoelectric cross-sections along the east to the west, starting from north to south in the study area, are selected to overview sub-surface resistivity variation. Resistivity contour maps are prepared layer-wise for depth 10m, 30m, 50m, 70m, and 100m to understand sub-surface heterogeneity. The factor analysis technique was utilized to identify probable fracture zones. The obtained results may be useful to the researchers for pinpointing the drilling site for groundwater sustainable groundwater development and management by selecting artificial recharge sites, rainwater harvesting, and urban planning.

Urban water management is a growing concern in India's rapidly urbanizing cities. Population growth and climatic variability are exuberating the impact on surface and underground water supply. Understanding the causes and the extent of water vulnerability is required for developing effective strategies for water insecurities. This study attempts to assess the water vulnerability across different wards of a touristic city of Himalaya-Nainital using IPCC approach considering the three dimensions: exposure, sensitivity, and adaptive capacity. Seven indicators, mostly spatial, i.e. edaphic (aspect, elevation) and climatic (land surface temperature) besides some water infrastructural (distance to water distribution) and population, were considered for development of vulnerability index using Analytical Hierarchy Process for assigning weights. These indicators were simple to extract and easy to obtain and mostly available from secondary sources and were capable to account the variability at micro-level. Moreover, the current adaptation mechanisms for water security were also derived through conducting surveys by randomly selecting households across the wards. Staff House and Harinagar wards were the most vulnerable. The survey results that the adaptation mechanism should be managed at individual and organization level. Policy measures such as optimum use of water, grey water recycling, spring rejuvenation, rain water harvesting, and leakage proof infrastructure with intervention of new technologies, may be adopted and implemented for reducing the water vulnerability in the city along with the public participation. The appropriate measures for water vulnerability would further provide support for improving the facilities to the tourists in the city thereby improved economic opportunities to the locals.

When Charles Darwin moved to Down House, England (UK), in 1842, he inherited a deep well, penetrating 325 ft (~100 m) into the Chalk. The groundwater from this well was used exclusively for the household, whereas his garden was watered from buried rainwater tanks. It was perceived that drinking the “chalky” groundwater provided him with health benefits, whereas its high lime content was considered detrimental to his plants. The seasonal variations in water level are presented from Darwin’s notes and allow the reduced level of the potentiometric surface to be calculated. Groundwater quality is also assessed. Historical records including the English Heritage Down House archives, Darwin’s correspondence and the recollections of his children, for the first time allow for a description of the design and operation of the well. The well has been abandoned and capped but the detail provided will allow the wellhead to be reconstructed at its original location.

A new methodology for the rotational stability analysis of a gravity retaining wall supporting inclined backfill under earthquake and heavy rainfall conditions has been presented. According to the movement mode of retaining wall and the characteristics of backfill sliding and rainwater infiltration, a sliding model of the infinite soil strip and rainwater infiltration model were established respectively. By calculating the internal energy dissipation rate and external loads power of the wall-soil system mechanism, a formula to calculate seismic yield acceleration coefficient under coupling conditions of earthquakes and rainfall was deduced. The results revealed a large effect size of infiltration depth of rainwater and the backfill inclination on the seismic yield acceleration coefficient. When the rainwater reaches 1/5 the height of the retaining wall and the backfill inclination exceeds 15°, the seismic yield acceleration coefficient will decrease rapidly. Moreover, the results obtained in this paper showed good consistency with those obtained by numerical simulation.

Ethiopia currently faces many critical climate-related challenges that affect the lives and livelihoods of smallholder farmers. It is important to understand how differently situated communities perceive climate variability. This study investigates farmers’ perception of historical changes in climate and associated effects on agriculture in Ambassel District, Northern Ethiopia. The study was based on multi-stage sampling techniques to select the study area and 147 sample household respondents. Both primary and secondary data were used for data analysis. Primary data were collected through a household survey, focus group discussion and key informant interviews. The collected data were analyzed using descriptive statistics. We used regression model to determine the relationship between historical climate data and yield for food crops. Chi-square tests were also employed to compare the difference among agro-ecological zones. The results revealed that majority of the farmer’s perceived changes in the level of local climate and experienced its effects over two decades. As a result, both crop and livestock production by smallholder farmers have already been adversely affected. The regression analysis revealed significant relationship between rainfall and crop yields, teff (Eragrostis tef) and sorghum, which was consistent with perceived impacts of climate variability on crop production. Significant relationship was also observed between maximum temperature and sorghum yield. Therefore, there is a need to introduce water-related interventions such as small-scale irrigation and water harvesting as a drought adaptation strategy.

In developing countries, the intensification of urban processes affects the correct management of the territories. Specific natural hazards such as landslides, floods or soil sealing are influencing several urban settlements worldwide. One example can be found in the oldest city of the world, i.e., Hamadan City, where floods are associated with human and economic losses and the destruction of several ancient sites. However, solutions to be implemented to reduce the risks in such a city are still scarce. Therefore, this research aims to evaluate roof rainwater harvesting (RRWH) in reducing the urban floods in Hamadan City. To achieve this goal, three different scenarios are tested, i.e., simulation of the rainfall-runoff process through the Hamadan City (1) without any RRWH, (2) considering that the harvested rainfall is used for household consumes, and (3) considering that the RRWH is used for garden irrigation. The results showed that scenario 2 (using harvested rainfall for household consumption) presented reductions of 30.4% and 28.52% in the inflow volume compared to scenario 1 respectively for 2-year and 100-year return periods, whereas these reductions were 38% and 31.9% for scenario 3. Besides, a remarkable difference was noted between scenarios 2 and 3. In scenario 3, we found that the current drainage network has more capability to transfer surface runoff through Hamadan City, which would help reduce the risk of floods in the city. Therefore, it is concluded that the policymakers and land managers should consider these possibilities, and awareness of the urban inhabitants must be enhanced to reduce the risks and promote sustainability.

Roof-harvested rainwater (RHRW) is considered relatively clean water, even though the possible presence of pathogens in the water may pose human health risks. In this study, we investigated the occurrence of enteric viruses in the first flush (10 mm) of RHRW from a densely populated and low-income urbanized region of Rio de Janeiro. One hundred samples (5 L) were collected from 10 rainfall events between April 2015 and March 2017. RNA and DNA viruses were concentrated using the skimmed milk flocculation method and analyzed using the TaqMan® quantitative RT-qPCR and qPCR. Human adenoviruses, noroviruses, rotaviruses A, and avian parvoviruses were detected in 54%, 31%, 12%, and 12% of the positive samples. JC polyomavirus, also targeted, was not detected. Virus concentrations ranged from 1.09 × 101 to 2.58 × 103 genome copies/Liter (GC/L). Partial nucleotide sequence confirmed the presence of HAdV type 41, norovirus genotype GII.4, and avian parvovirus 1. The results suggest that the first flush diversion devices may not adequately remove enteric virus from the rainwater. Additional treatment of RHRW is required to mitigate potential health risks from potable use of captured water.

Underground space is becoming increasingly vulnerable to inundation owing to the enhanced likelihood and consequences of urban flooding. However, previous studies on flooding of underground space have paid little attention to how rainwater flows inside an underground space, what the optimal escape route might be, how much time would be required to escape, and how dangerous one specific area might be in comparison with another. This study investigated a method for assessing the spatiotemporal risk of flooding of an underground space considering both the flood intensity and the escape route. Two-dimensional hydrodynamic flow analysis was implemented to evaluate the flood intensity. Then, the shortest escape route was determined by applying the Dijkstra algorithm to the nodes and elements used in the 2D flow analysis. In addition, the risk of flooding in the underground space for a case without a water shield was compared with that determined for a case with an installed water shield.

Mixed-species plantations are generally thought to increase soil carbon stocks, but it is unclear whether they can enhance soil water-holding capacity. By quantifying the contribution of rainwater to soil water (CRSW) following three different scales of rainfall events in Pinus massoniana and Schima superba monoculture plantations and a mixed P. massoniana and S. superba plantation, we aimed to examine the variations in CRSW and influencing factors for different plantations. Stable hydrogen isotope compositions of rainwater, soil water and groundwater were analyzed to assess the CRSW of three plantations following three rainfall events in a subtropical monsoon region in China. We further used regression analysis to quantify the relative importance of canopy openness, litter characteristics, soil physical properties and root biomass to the CRSW. The CRSW in the P. massoniana monoculture plantation and mixed plantation was higher than that in the S. superba monoculture plantation following the three rainfall events. No significant difference in the CRSW was found between the P. massoniana plantation and the mixed plantation within nine days following the 8.7 mm rainfall event. Furthermore, the CRSW was significantly higher in the mixed plantation than in the two monoculture plantations within 11 days following the 15.3 mm and 36.9 mm rainfall events. The most important factors affecting the CRSW were canopy openness and root biomass after the 8.7 mm rainfall event, whereas root biomass and litter characteristics acted as the primary regulatory factors after the 15.3 mm rainfall event. Under the 36.9 mm rainfall event, dry weight and saturation moisture capacity within the semi-decomposed litter layer had the greatest influence on the CRSW. Mixed-species plantations in humid subtropical regions have a higher capacity to intercept and maintain heavy rainfall than their respective monoculture plantations, and thus can enhance their adaptation to extreme rainfall events, as well as after frequent droughts.

The implementation of a green roof is best suited for urban areas, as it provides an array of environmental benefits toward mitigating and adapting to climate change, including reduced flood risk, greenhouse gas emissions, urban heat island effects, and air pollution. However, green roof research and maintenance awareness in Malaysia are comparatively scarce, largely due to the absence of local tropical green roof guidelines. Therefore, this paper aims to explore current green roof maintenance practices and challenges for non-residential buildings in Malaysia through case studies and in-depth interviews. These results were then compared with three international green roof guidelines, namely those of the Royal Institution of Chartered Surveyor, Singapore’s National Parks Board, and the US Environmental Protection Agency. The findings show that current green roof maintenance elements implemented in the case studies are insufficient and inadequate for Malaysia’s tropical climate conditions. The paper recommends nine (9) green roof maintenance elements specific for non-residential buildings in Malaysia and the tropical climate: plant selection, rainwater harvesting system, pest control, monitoring performance, accessibility, irrigation cleaning, waterproofing membrane maintenance, plants and growing medium, and maintenance of outdoor furniture. As this paper has only included data from Kuala Lumpur, this limits the generalizability of the findings to other buildings in Malaysia and a tropical climate. The implications of this study may provide further direction for researchers to consider a larger sample size and other cities in a tropical climate. This study will allow policymakers and building stakeholders to develop suitable green roof maintenance guidelines.

In this study, the precipitation effects because of the weather variations and receiving water volumes collected by the sewage treatment plants were examined to obtain the knowledge required for improving the construction of the ideal sewage plants located in cool climates. The weather and water quantity data were acquired from the Meteorological Society of Japan and the Mombetsu Aqua Center, respectively. The results showed a positive correlation between the amount of water reaching the plant and the precipitation between May and November. The correlations of the data obtained from January to April were not considerable. Because the sewage system in the Mombestu Aqua Centre was combined, the release of rainwater to rivers or sea was considered necessary for protecting the city area from flooding, and maintaining the water treatment and storage facilities in response to a potential influx from rain during cool months was prioritized. Further, the relation trends were analyzed to obtain an improved picture of the long-term weather forecasts at the sewage treatment plant. Therefore, these results are important for maintaining sewage plants in cold regions, especially in places with a high degree of snowfall during winter.

Rethinking to revive traditional water sources is the need of the hour, considering the present context of water crisis at both the global as well as local level. Darjeeling city, located in the eastern Himalayan region is endowed with numerous natural springs, and people use these as their daily sources of water for long. However, these indigenous water practices are constantly being threatened by the so-called development process of city-making. Many of the natural springs have already dried up and many others are in shrinking phase of flow. Municipal water supply system, developed by the British in the early nineteenth century is not sufficient for the entire city at present, and not affordable for the people of all classes too. In this circumstance, private water supply and rainwater harvesting have emerged as the alternative sources of water, which again are not so viable for the poor. Majority of people, who are essentially poor face an acute water crisis throughout the year, except a few months of monsoon season. The city administration concentrates only on the insufficient centralised hydraulic infrastructure rather than managing and reviving the natural springs. Using both the quantitative and qualitative methods, this empirical study critically assesses the present waterscapes of the city considering its socio-physical nature. The article analyses the process of expanding private water market using common water resources with illegal and tacit support from the local administration. It argues for the intervention of city administration and effective community participation to revive the springs for making the city’s water future secure.

The carbonaceous content of rainwater was investigated in samples collected at an urban background site in northern India. Sampling was performed on an event basis during two seasons: pre-monsoon (PM) and monsoon (MN) season covering May-June and July-August, respectively, in 2016. The concentrations of different fractions of water-insoluble organic carbon (WIOC) and elemental carbon (EC) were precisely determined, and the sources of WIOC and EC were also analysed. The result revealed that the average WIOC and EC concentration in rainwater ranged from 0.4 to 52 mgC/L and from 0.1 to 15.3 mgC/L, respectively. The concentrations of WIOC and EC were found to be ~ 9 times and ~ 12 times higher, respectively, in the PM season than MN season. The WIOC/EC ratio indicated higher variation in PM season as compared to that of the MN season, suggesting divergent emission sources during the PM season. The formation of water-insoluble secondary organic carbon (WISOC) has also been identified as one of the causes for the extensive difference in the WIOC/EC ratio in different seasons. Results showed that the WIOC and its fractions were efficiently scavenged through rain. While EC and its fractions were less significantly scavenged, due to its hydrophobicity and fine size. The atmospheric scavenging coefficients of selected carbonaceous components were found significantly correlated with rain intensity (RI) during both the seasons. Higher rain intensity caused greater rates of carbonaceous component wash-out and decreasing concentrations of carbonaceous components in the rain.

People around the world are facing water scarcity, and the demand for freshwater is continuously increasing. The purification of water is the only way to satisfy the need for water. Purification can be done in many ways by purifying seawater or by storing rainwater and letting it to the ground. Different types of solar still are there, which are used to increase the output of water produced. Among others, inclined solar still (ISS) is an outstanding solution as it has a wide exterior area of water, having less depth of water to complement the regular potable water production, even the effectiveness of the inclined solar still. A lot of research had been done by increasing the surface area of water. The day to day collection of water from the ISS was found to be 1–8 kg m− 2. In this review, an analysis was made on the current status of different ISS designs to make advance modifications and research to improve the productivity of the ISS to satisfy the increasing demand for potable water. From this investigation, it is identified that active ISS and hybrid ISS are the most effective as compared to other ISS techniques.

To evaluate the mercury sources and its transportation mechanism from a global hotspot region (the Ganga Alluvial Plain, northern India), two sets of time-series samples of shallow groundwater (n = 31) and river water (n = 31) were collected in alternate days, from the Behta River Basin, in July and August 2019. The estimation of total dissolved mercury was performed by using the Flow Injection Atomic Absorption Spectroscopy-Mercury Hydride System. The mercury concentrations ranged high (> 1400 ng/L), in the three orders of magnitude, emphasizing the importance of mercury transportation, through the unconfined alluvial aquifer system, linked with the monsoon precipitation. In July, the accumulative intensity of monsoon precipitation favored the increasing mercury concentrations in the river water, as well as, in the groundwater. The infiltration of mercury contaminated water is the prominent hydrological process accountable for the peaked mercury concentration (above the World Health Organization’s drinking water standard of 1000 ng/L) in the river basin. In August, about 67% of the collected samples reported base-level mercury concentrations. Temporal variations of mercury concentration in the groundwater and the river water showed significantly higher values in July, than in August. These results illustrate the importance of the interaction between the monsoon precipitation, and anthropogenic mercury, in the river basin, for the riverine and groundwater mercury transportation as the fundamental hydraulic control. The present study underscores the significance of monsoon precipitation on the groundwater transportation of global mercury cycling by the Ganga River.

A climatic water balance study, along with an analysis for stable isotopes (oxygen-18 and hydrogen-2), and hydrogeochemical signatures were together used to understand the groundwater recharge environment and hydrogeochemical processes in the semi-arid region of Gooty Mandal, District of Anantapur, India. The study revealed that the annual potential evapotranspiration was thrice the annual rainfall, indicating the influence of evaporation both during rainfall and after infiltration resulting in the enrichment of salts in the soil and the stable isotopes in shallow groundwater. Stable isotopic signatures suggest that the source of groundwater recharge is contributed by several components and not just direct precipitation. The argument is further supported by the relation between oxygen-18 and chloride. The most dominated water type in the dry season was found to be sodium-chloride followed by calcium-sodium-bicarbonate, while in the wet season calcium-sodium-bicarbonate was followed by sodium-chloride. Calcium-magnesium-chloride and sodium-chloride showed high temporal variability in stable isotopic concentrations, particularly in wells with shallow groundwater, suggesting that the rainwater might have undergone evaporation before recharge and/or recirculation due to agricultural activities. Hydrogeochemical signatures show that 61% of the samples sodium concentration decreased with the increase in chloride ions, revealing that the cation exchange reaction absorbs sodium in exchange for magnesium and calcium. Almost all samples from the calcium-sodium-bicarbonate, sodium-bicarbonate and magnesium-bicarbonate water types and a few samples of sodium-chloride and calcium-magnesium-chloride water types had a low chloride concentration (

With the explosive growth of the world’s population and the rapid increase in industrial water consumption, the world’s water supply has fallen into crisis. The shortage of fresh water resources has become a global problem, especially in arid regions. In nature, many organisms can collect water from foggy water under harsh conditions, which provides us with inspiration for the development of new functional fog harvesting materials. A large number of bionic special wettable synthetic surfaces are synthesized for water mist collection. In this review, we introduce some water collection phenomena in nature, outline the basic theories of biological water harvesting, and summarize six mechanisms of biological water collection: increased surface wettability, increased water transmission area, long-distance water delivery, water accumulation and storage, condensation promotion, and gravity-driven. Then, the water collection mechanisms of three typical organisms and their synthesis are discussed. And their function, water collection efficiency, new developments in their biomimetic materials are narrated, which are cactus, spider and desert beetles. The study of multiple bionics was inspired by the discovery of Nepenthes’ moist and smooth peristome. The excellent characteristics of a variety of biological water collection structures, combined with each other, are far superior to other single synthetic surfaces. Furthermore, the main problems in the preparation and application of biomimetic fog harvesting materials and the future development trend of materials fog harvesting are prospected.

Intensifying urban stormwater runoff and pollution caused by urbanization and climate change threatens property and lives in cities around the world. Low-impact development (LID) is an effective approach to improve urban flood resistance, but there is a lack of quantitative evaluation criteria to determine the best scenario in the newly built and built-up urban areas. In this study, based on the Fuzzy Comprehensive Evaluation method (FCE), a multi-index evaluation system is established to quantify the LID performance for the environment, technology, economy, and society. For overcoming subjective arbitrariness, the Criteria Importance Though Intercriteria Correlation (CRITIC) and Analytical Hierarchy Process (AHP) methods are used to evaluate the weight of each evaluation index. The proposed method is demonstrated for the Xi’an City, China. Results show that the integrated configuration of green roof, infiltration pavement and grass swale has the best comprehensive efficiency under the proposed method. More specifically, the allocation of different LID combinations in the newly built area can effectively manage the flooding in this area. However, the comprehensive efficiency of increasing the diameter of the storm sewer is optimal in the built-up area. The increased pipe diameter can discharge more rainwater through the urban storm sewer and mitigate overflow. A multi-index evaluation framework beyond the traditional subjective evaluation standard is established, which can quantitatively evaluate the effectiveness of LID facilities. The proposed quantification evaluation method can provide an efficient recommendation for sponge city construction and evaluation.

In order to get the law of rainwater infiltration and the law of progressive water damage, the slope of Tianshang bridge foundation in Yunnan Province is taken as the engineering basis. The site investigation of the damaged slope is carried out, The traditional Green-Ampt model is improved by considering the ponding effect of dynamic water flow on the slope surface. Based on the variation characteristics of wetting front obtained by the improved infiltration model, the progressive failure process of slope with continuous infiltration is simulated by FLAC3D software. The results show that: the water damage of Tianshang bridge slope is mainly caused by the slope absorbing a lot of rainwater in a short time, which has obvious time discontinuity characteristics in time, and shows obvious multi-layer progressive failure characteristics in failure space. The wetting front characteristics obtained by the improved Green-Ampt infiltration model are more consistent with the engineering practice, the water accumulation effect of surface water gradually weakens with the increase of the wet front depth. the slope failure develops gradually from the toe to the top and from shallow to deep, and the intermittent failure characteristics provide surplus time for the engineering treatment, the gravel soil slope should be treated after a small-scale water damage occurs.

The purpose of the current study is to investigate the potential of rooftop rainwater harvesting (R-RWH) and its physio- and socioeconomic effects on the peoples in two catchments (Salghara and Malach) of the Rawal watershed, Pakistan. A questionnaire-based analysis was used not only to gather the required design parameters (roof area, household size, water usage) but also to investigate the physio- and socioeconomic effects. Results revealed that the highest rainfall change is found from January to March and June to September but the lowest was observed in November–December near the Salghara region. In the Malach region, the positive rainfall is measured in February and June but the negative is found in May, July, and August. The survey analysis showed that 77 m3 minimum roof area is required and suitable material to implement the R-RWH for a 6-family size. 121 m3 and 76 m3 annual average water yield is recorded for Salghara and Malach catchments, respectively. A storage tank capacity of 13 m3 and 32.5 m3 is observed for Salghara and Malach, respectively. This difference in capacity is found due to the length of the dry periods. The low-cost rainwater harvesting system is proposed between 600 and 400 USD per household. Furthermore, it was noticed that people do believe rooftop RWH can positively impact both their economic and health conditions, particularly for women as they spend most of their time struggling to fetch water. It is concluded that rooftop RWH has great potential as an alternative household water source in the Rawal watershed catchment regions.

University campuses usually have more trees and can provide various ecosystem services. However, there are few reports on tree ecosystem services of Chinese university campuses, especially in northern China. This study investigated the trees in the campus of Shenyang Institute of Technology and analyzed its ecological benefits and monetary value through i-Tree Streets. The campus trees contained a total of 5193 trees of 66 species, of which Catalpa ovata G. Don, Acer mono Maxim., Rhus typhina Nutt, and Salix babylonica L. accounted for 59.7% of the total number. The age structure of the trees in the campus was not ideal, with 71.5% of young trees, 24.0% of maturing trees, 4.5% of mature trees, and only 0.04% of old trees. The trees in the campus provided more energy saving benefits ($60,850, $11.7/tree), carbon reduction benefits ($34,318, $6.6/tree) and aesthetic benefits ($30,150, $5.8/tree). The benefits resulted from air pollutant removal ($12,889, $2.5/tree) and rainwater runoff interception ($15,534, $3.0/tree) were smaller. In addition, tree species with more maturing trees and mature trees (i.e., with larger diameter at breast height) and large leaf area in the campus contributed significantly to ecosystem services. Our results can provide suggestions and certain insights for Chinese campus greening managers in tree species selection and tree management.

Pollutants emitted into the air not only have local effect but can also affect areas further from the source. The goal of this study was to assess a method for identifying the sources of element pollution in rainwater using enrichment factors supported by Weather Research and Forecasting (WRF) model. In this study, we collected nineteen rainwater samples at the two locations of Durham and Chimney Ridge in North Carolina, USA in July of 2014. The samples were analyzed for pH, conductivity and levels of major ions and a range of trace elements. These data showed that the pH of precipitation ranged between 3.91 and 6.65, with an average value of 4.98. The average electrical conductivity was 15.58 and 17.7 μS/cm for rainwater collected at Durham and Chimney Ridge, respectively. The lowest concentration of the elements analyzed was for thorium (Th) with an average concentration of 0.002 ppb, whereas the highest elemental concentration was for calcium (Ca) with an average concentration of 980.3 ppb. Enrichment factors for trace elements were assessed within three different groups as: (1) rarely enriched, (2) significantly enriched, and (3) highly enriched. Copper (Cu), zinc (Zn), arsenic (As), molybdenum (Mo), silver (Ag), cadmium (Cd), and lead (Pb) were highly enriched trace elements. The wind fields acquired by the WRF model indicated the probable contamination sources. Source identification indicated that the highest contribution of elements to precipitation was from industry. The results showed that the combined use of enrichment factors and the WRF model can be used to identify the sources of pollutants in precipitation samples.

The artificial recharge structures (ARS) project was taken up on Kakatiya University campus, Warangal urban district, Telangana state with the dual purpose of meeting the growing demand for water supply on campus and to demonstrate the benefits of artificial recharge to the students and society at large. Different types of site-specific recharge structures were developed in tune with the local hydrogeological conditions. 9 check dams, 2 mini-percolation tanks (MPT), 2 percolation tanks, 1 Gabion structure, 1 farm pond, and a series of continuous contour trenches, staggered contour trenches, and 69 rooftop rainwater harvesting structures at 19 different buildings were constructed. These structures together contributed 27.62 ham of water to the local aquifer in the year 2013; the estimate is substantiated by applying GEC methodology-1997. The mean water levels have risen by 8.41 m between 2012 and 2014 and a rising trend of 3.05 m is displayed on an average in hydrographs of the observed wells. Efficacy of ARS was visible in terms of feeble adverse effect in 2014 (the change in the head was −0.71 m) despite a deficit rainfall of 42%. Water chemistry displayed a mixed response to induced recharge; cation content was reduced in some samples whereas anions were added in about half of the tested samples. Hydrological properties, together with solute load and absorption-desorption capacity of percolating water, might have led to hydrochemical variability. The locations and appropriate designs enabled to harvest the rainwater in the most effective way leading to a net rise in depth of water levels by 3.24 m and 2.30 m between pre-monsoon of 2012–2013 and 2013–14 respectively. In the post-monsoon season, it was 1.68 m and −3.22 m for the same years (in the 2014 monsoon the area received 171 mm deficit rainfall). Despite poor rainfall in 2014, due to the completion of the ARS scheme, the bore wells yields stabilized at 4.07 lakh liters/day which was about 40% more than the pre-project year, May 2012.

This paper aims to forecast the Nyabugogo River flood risk and to propose mitigation measures that can reduce flood impacts using hydrological and hydraulic models. The annual Nyabugogo River floods that have led to human and economic losses are mainly due to the high topography, rainfall, soil texture and urbanization. It was found that the medium to high flood vulnerability is located in cropland, open grassland, open shrubland, settlement, sparse forest and wetlands. The results for 10-, 30- 50- and 100-year return periods show a slight increase in the flood inundation area and in water depth. The simulation shows that the 100-year return period gives a water depth of 3.24 m. Therefore, flood mitigation measures are needed, which can include the construction reservoirs upstream, relocation of infrastructures within the flood plain area, buffer zoning around the river, rainwater harvesting and raising public awareness. This paper provides basic support for decision-makers and can help in land use planning and flood management within the basin.

Connecting climate-induced yield anomalies to the key climatic variables (KCVs) and large-scale atmospheric circulation index (LACI) is crucial to developing a strategic policy for food security in developing countries including Bangladesh. However, the effects of the KCVs and LACI on rice yield are still less explored in Bangladesh. This study aims to investigate daily climatic datasets from 18 sites and five LACIs during 1980–2017 to explore climate-induced yield anomalies to the KCVs and LACIs in different sub-zones of Bangladesh using the decoupling model and ensemble empirical mode decomposition (EEMD). We demarcated four sub-zones (northern, southwestern, south-central, and western) with different climate-induced yield index (CIYI) of winter Boro rice oscillations by employing principal component analysis. The CIYI time series in the northern zone was dominated by a 2–4-year oscillation, whereas the CIYI in the western zone demonstrated a prominent 6.5-year oscillation. Among the four sub-zones, south-central and northern zones had the most notable CIYI-KCV and CIYI-LACI associations, while the potential evapotranspiration (PET) in March and multivariate ENSO indices (MEI) in January were identified as the best yield prediction indicator. Wavelet coherence analysis indicated significant in-phase and out-phase coherences between KCVs and CIYI fluctuations at different time-frequency bands in these sub-zones. The random forest model also confirmed the MEI as the key driver influencing the rice yield fluctuation in Bangladesh. The isotopic signature of rainwater also demonstrated that the temperature variation is the main driver for event-based precipitation change in the south-central rice-growing zone. These outcomes can provide a scientific basis to take adaptive measures to mitigate the reduction in rice yield in western and northern Bangladesh for associated decision-makers and practitioners.

The quality of the water consumed by a given community is related to its quality of life. In this sense, this study aimed to evaluate, from the perspective of health risk, the physical, chemical, and microbiological quality of drinking water, in a quilombola community, and the qualitative aspects intrinsic to its use and storage. For this, water samples, collected at the exits of the collective water supply system and from eight cisterns that store rainwater, used for human consumption, were analyzed. The samples were subjected to physical, chemical, and microbiological analysis, including adenovirus (HAdV) and enterovirus (EV). The probability of an individual acquiring infection through water consumption was determined by quantitative microbiological risk analysis using HAdV and Escherichia coli (EC) as reference pathogens. The results showed that the water in the deep tubular well had 270.8 mg/L of total hardness, leading to the rejection of its consumption by ingestion. Alternativity, the people in the community consume rainwater stored in cisterns. For this type of water, the presence of heterotrophic bacteria was found in 75%, total coliform was present in 100%, and Enterococci were detected in 25%. Furthermore, EC was present in 25%, EV in 50%, and HAdV in 100% of the samples. The probability of annual infection with HAdV and EC was, in the worst situation, 100% and 1.3%, respectively. Regarding the qualitative and quantitative aspects, there was a significant positive correlation between the absence of EC and the withdrawal of water from the cistern using a pump and the opposite when the withdrawal was carried out using a bucket or hose. Based on the results found, it is important to carry out actions aimed at improving water quality and, consequently, the quality of life of people living in the study community.

Rainwater harvesting is an effective alternative practice, particularly within urban regions, during periods of water scarcity and dry weather. The collected water is mostly utilized for non-potable household purposes and irrigation. However, due to the increase in atmospheric pollutants, the quality of rainwater has gradually decreased. This atmospheric pollution can damage the climate, natural resources, biodiversity, and human health. In this study, the characteristics and physicochemical properties of rainfall were assessed using a qualitative approach. The three-year (2017-2019) data on rainfall in Peninsular Malaysia were analysed via multivariate techniques. The physicochemical properties of the rainfall yielded six significant factors, which encompassed 61.39% of the total variance as a result of industrialization, agriculture, transportation, and marine factors. The purity of rainfall index (PRI) was developed based on subjective factor scores of the six factors within three categories: good, moderate, and bad. Of the 23 variables measured, 17 were found to be the most significant, based on the classification matrix of 98.04%. Overall, three different groups of similarities that reflected the physicochemical characteristics were discovered among the rain gauge stations: cluster 1 (good PRI), cluster 2 (moderate PRI), and cluster 3 (bad PRI). These findings indicate that rainwater in Peninsular Malaysia was suitable for non-potable purposes.

Enhanced weathering is a negative emissions technology based on the accelerated weathering of alkaline minerals. Such materials can be reduced to a fine powder and applied to land sinks to maximize the area exposed for reaction with rainwater and dissolved CO2. The carbon is captured in the form of bicarbonate ions in the runoff, which ultimately carries it to the ocean for virtually permanent sequestration. Enhanced weathering has been demonstrated in proof-of-concept laboratory and field tests, but scale-up to a level that delivers significant CO2 removal is still an engineering challenge that requires a system-level perspective. Future enhanced weathering networks should be planned like industrial supply chains, taking into account constraints in the supply of alkaline minerals and the availability of land sinks. Optimization of such networks should also take into account techno-economic uncertainties that are inherent in any emerging technology. To fill this research gap, this work develops a fuzzy mixed-integer linear programming model for optimal planning of enhanced weathering networks. The model is capable of handling multiple conflicting objectives and accounting for system uncertainties. The use of the model is illustrated with two case studies. First, a pedagogical example is solved; then, the model is demonstrated for a realistic scenario which shows that 0.69% of Taiwan’s CO2 emissions can be offset by the use of blast furnace slag for enhanced weathering.

Raindrops brim with pollen even when there is no ambient local pollen. How does this nonlocal pollen get inside rain? The likely answer is long-range transport beneath or inside clouds. To test this hypothesis, we captured rain-delivered pollen on Ocracoke Island, NC, USA over a 12-day interval before local pine pollen release then reconstructed its trajectory and its atmospheric exposure conditions. Findings were as follows: four rain episodes yielded a total of 632 pollen grains of which 6.7% germinated. To find pollen sources, we first identified pollen-releasing forested areas using a predictive heat sum equation for each rain episode. Next, we constructed the backward trajectory for air parcels carrying rain-delivered pollen from those forests using the MLDP atmospheric transport and dispersion model. Nonlocal sources were located at distances up to 300 km from Ocracoke Island and distances lessened with each successive episode. Below-cloud transport time was 8 and 17 h for Episodes A and B, respectively. Pollen grains were exposed to harsh atmospheric conditions during below-cloud transport, yet some grains still germinated. Atmospheric turbulence patterns changed for each episode, so distance from pollen source was poorly correlated with pollen transport time. Pollen germination was not closely correlated with either distances or transport time. In-cloud transport was more likely for pollen sampled during Episodes C and D. Pine pollen, although rarely allergenic, brings fresh insights into how atmospheric events can trigger human respiratory distress.

The present study is a part of hard rock aquifer of Telangana, South India, where the groundwater is withdrawn heavily for drinking, irrigation, and small-scale industrial purposes. Geochemical characteristics explain the chemical processes, which control the groundwater chemistry and consequently the groundwater quality, while the chemical quality of groundwater is adversely affected by anthropogenic activities, which damage the water environment. The focus of the present study was, thus, to know the origin of geochemical characteristics and also to evaluate the quality of groundwater for various purposes for taking the suitable remedial measures to provide safe water to the local community. Geochemical relations (GR) and hierarchical cluster analysis (HCA) were used to assess the geochemical characteristics. Entropy weighted groundwater quality index (EWGQI), United States Soil Salinity Laboratory Staff (USSLS)’s diagram, and groundwater quality criteria for water supply pipes (GQCW) were used to evaluate the groundwater quality for drinking, irrigation, and industrial purposes, respectively. The study found that the water-rock interactions associated with ion exchange and evaporation were the prime geochemical factors controlling the geochemical characteristics and the anthropogenic activities as the secondary factor. These observations were further supported by HCA. According to the EWGQI, 34.97% of the spatial area was found to have the poor and very poor groundwater quality zones for drinking purpose, because of the dominance of TDS, Na+, Cl−, $$ {\mathrm{SO}}_4^{2-} $$ , $$ {\mathrm{NO}}_3^{-} $$ , and F− contents in the groundwater system. Based on the USSLS’s diagram, 79.55% of the present study area was observed to be poor and very poor water quality type for irrigation utilization due to salinity hazard. The GQCW demonstrated that the 7.91% and 8.82% of the areas were not suitable for industrial purpose due to influence of incrustation based on $$ {\mathrm{HCO}}_3^{-} $$ and $$ {\mathrm{SO}}_4^{2-} $$ , respectively, and 1.85%, 12.32%, and 1.25 of the areas are unfit due to influence of corrosion based on pH, TDS, and Cl−, respectively. Therefore, boiling, activated carbon filter, rainwater harvesting, suitable coatings on metal surfaces of water supply pipes, etc. are the important suggested effective strategic measures to provide safe water for drinking, irrigation, and industrial purposes.

Water harvesting (WH) and aquifer recharge (AR) have been promoted in recent decades as solutions to the overexploitation of groundwater resources in many countries around the world. Remote sensing (RS) and geographic information system (GIS) technologies with multi-criteria decision analysis (MCDA) enable the analysis of many parameters to identify potential WH and AR sites and suitable zones for site-specific and cost-effective recharge structures. Iraq is located within an arid and semiarid region and thus suffers from water scarcity and absent surface water resources. The use of RS and GIS technology for detection of appropriate sites for WH and AR could potentially increase water availability. The criteria selected for determining appropriate WH and AR areas were runoff, drainage, geology, groundwater depth, slope, soil texture, and land use/land cover. The selection of these criteria was found to be more important and more frequent in a literature review for WH and AR, and the weightage of each criterion should be based on the opinion of experts. The obtained results indicated only five optimum sites for check dam construction for WH, due to their locations in suitable land class, slope (