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The aim of this research was to simulate the future water balance of the Silwani watershed, Jharkhand, India, under the combined effect of land use and climate change based on the Soil and Water Assessment Tool (SWAT) and Cellular Automata (CA)-Markov Chain model. The future climate prediction was done based on daily bias-corrected datasets of the INMCM5 climate model with Shared Socioeconomic Pathway 585 (SSP585), which represent the fossil fuel development of the world. After a successful model run, water balance components like surface runoff, groundwater contribution to stream flow, and ET were simulated. The anticipated change in land use/land cover (LULC) between 2020 and 2030 reflects a slight increase (3.9 mm) in groundwater contribution to stream flow while slight decrease in surface runoff (4.8 mm). The result of this research work helps the planners to plan any similar watershed for future conservation. [ABSTRACT FROM AUTHOR]

Common milkweed (Asclepias syriaca L.) is a widespread invasive alien forb in dry sandy habitats of Central Europe. It adversely affects native plant and animal communities, but its ecosystem-level effects, particularly on hydrology, are little known. Since milkweed has an extensive, deep root system and large, broad leaves, we assumed a negative effect on the soil moisture content of the hosting ecosystem. Following the before-after control-impact protocol, we first compared the soil moisture content of the top 120 cm of the soil under seven milkweed stands to that of non-invaded reference sites. We then treated half of the stands by mechanically removing all aboveground milkweed biomass and repeated the comparative soil moisture measurements. We found that milkweed stands had significantly drier soils than reference grasslands during the growing season, but the soil under milkweed stands recharged to the level of the references in autumn and winter. However, the amount of moisture needed for this recharge was lost from deeper percolation to groundwater. Milkweed treatment prevented the depletion of moisture during the growing season, saving 21.6 l m−2 of water on average. Treatment did not affect non-milkweed plant biomass, thus, moisture patterns could fully be attributed to the milkweed stands. Our results reinforce the importance of milkweed suppression in invaded grasslands, as, besides enabling the recovery of the native grassland ecosystem, it promotes groundwater recharge, which is particularly important in the dry regions of Central Europe, currently facing severe aridification due to climate change and unfavourable land use trends. [ABSTRACT FROM AUTHOR]

In the Southern Central Highlands of Vietnam, droughts occur more frequently, causing significant damage and impacting the region's socio-economic development. During the dry season, rivers, streams, and reservoirs often face limited water availability, exacerbated in recent years by increasing drought severity. Recognizing the escalating severity of droughts, the study offers a novel contribution by conducting a comprehensive analysis of surface water resource distribution in Lam Dong province, focusing on assessing water demand for agricultural production, a crucial factor in ensuring sustainable crop growth. Two scenarios, Current-2020 (SC1) and Climate Change-2025 (SC2), are simulated, with SC2 based on climate change and sea level rise scenarios provided by the Ministry of Natural Resources and Environment (MONRE). These scenarios are integrated into the MIKE-NAM and MIKE-HYDRO basin models, allowing for a thorough assessment of the water balance of Lam Dong province. Furthermore, the study utilizes the Keetch–Byram Drought Index (KBDI) to measure drought severity, revealing prevalent dry and moderately droughty conditions in highland districts with rainfall frequency ranging from 50 to 85%. Severe drought conditions occur with a rainfall frequency of 95%, indicating an increased frequency and geographic scope of severe droughts. Additionally, the study highlights that under abnormally dry conditions, water demand for the winter-spring crop is consistently met at 100%, decreasing to 85%, 80%, and less than 75% for moderate, severe, and extreme droughts, respectively. These findings offer insights into future drought conditions in the Lam Dong province and their potential impact on irrigation capacity, crucial for adaptation strategies. [ABSTRACT FROM AUTHOR]

The effective cathode flow field design can realize the internal water balance and higher current density output of proton exchange membrane fuel cells (PEMFC). Therefore, a segmented water management flow field is proposed in this study, i.e. a half separated-half coupled cathode (HSHC) flow field which has two inlets but just one outlet. A 3D numerical PEMFC model is applied to study the effect of the HSHC flow field on PEMFC performance and its operating strategy in terms of operating conditions. The study results are shown as follows: Compared with the two conventional cathode flow fields, the HSHC flow field improves the water balance along the channel and increases the current density by 17.1% at a cathode stoichiometry of 3.25. It is because the HSHC flow field can overcome the water loss at channels upstream and the water accumulation at channels downstream. The draw water phenomenon (DWP) in the HSHC flow field is observed, which is mainly affected by the water vapor pressure of channel. Based on the DWP, cooling channel inlet flow rates can be used to adjust water balance, but severe water loss should be avoided. In addition, the inlet temperature control in HSHC flow field should be that cell temperature>cathode channel inlet temperature>cooling channel inlet temperature> ambient temperatures for better water balance. [ABSTRACT FROM AUTHOR]

WetSpass-M model and multi-technique baseflow separation (MTBS) were applied to estimate spatio-temporal groundwater recharge (GWR) to be used to comprehend and enhance sustainable water resource development in the data-scarce region. Identification of unit Hydrographs And Component flows from Rainfall, Evaporation, and Streamflow (IHACRES) techniques outperform the existing 13 MTBS techniques to separate baseflow depending on the correlation matrix; mean baseflow was 5.128 m3/s. The WetSpass-M model performance evaluated by Nash-Sutcliff Efficiency (NSE) was 0.95 and 0.89; R2 was 0.90 and 0.85 in comparison to observed and simulated mean monthly baseflow and runoff (m3/s), respectively. The estimated mean annual water balance was 608.2 mm for actual evapotranspiration, 221.42 mm for the surface runoff, 87.42 mm for interception rate, and 177.66 mm for GWR, with an error of − 3.29 mm/year. The highest annual actual evapotranspiration was depicted in areas covered by vegetation, whereas lower in the settlement. The peak annual interception rates have been noticed in areas covered with forests and shrublands, whereas the lowest in settlement and bare land. The maximum annual runoff was depicted in settlement and bare land, while the lowest was in forest-covered areas. The annual recharge rates were low in bare land due to high runoff and maximum in forest-covered areas due to low surface runoff. The watershed's downstream areas receive scanty annual rainfall, which causes low recharge and drought. The findings point the way ahead in terms of selecting the best approach across multi-technique baseflow separations. [ABSTRACT FROM AUTHOR]

Anthropogenic revegetation is an effective way to control soil erosion and restore degraded ecosystems in China's northwest drylands (NWD). However, excessive vegetation cover expansion has long been known to increase evapotranspiration, leading to reduced local water availability, which can in turn threaten the health and services of restored ecosystems. Determining the optimal vegetation coverage (OVC) is critical for balancing the trade-off between plant growth and water consumption in water-stressed areas, yet quantitative assessments over the entire NWD are still lacking. In this study, a modified Biome BioGeochemical Cycles (Biome-BGC) model was used to simulate the long-term (1961–2020) dynamics of actual evapotranspiration (ETa), net primary productivity (NPP), and leaf area index (LAI) for the dominant non-native tree (R. pseudoacacia and P. sylvestris) and shrub (C. korshinkii and H. rhamnoides) species at 246 meteorological sites over NWD. The modified model incorporated the Richards equation to simulate transient unsaturated water flow in a multilayer soil module, and both soil and eco-physiological parameters required by the model were validated using field-observed ETa data for each species. Spatial distributions of OVC (given by the mean maximum LAI, LAImax) for the dominant species were determined within three hydrogeomorphic sub-areas (i.e., the loess hilly-gully sub-area, the windy and sandy sub-area, and the desert sub-area). The modified Biome-BGC model performed well in terms of simulating ETa dynamics for the four plant species. Spatial distributions of mean ETa, NPP, and LAImax generally exhibited patterns similar to mean annual precipitation (MAP). In the loess hilly-gully sub-area (MAP: 210 to 710 mm), the OVC respectively ranged from 1.7 to 2.9 and 0.8 to 2.9 for R. pseudoacacia and H. rhamnoides. In the windy and sandy sub-area (MAP: 135 to 500 mm), the OVC ranged from 0.3 to 3.3, 0.5 to 2.6 and 0.6 to 2.1 for P. sylvestris, C. korshinkii and H. rhamnoides, respectively. In the desert sub-area (MAP: 90 to 500 mm), the OVC ranged from 0.4 to 1.7 for H. rhamnoides. Positive differences between observed and simulated plant coverage were found over 51% of the forest- and shrub-covered area, especially in the loess hilly-gully sub-area, suggesting possible widespread overplanting in those areas. This study provides critical revegetation thresholds for dominant tree and shrub species to guide future revegetation activities. Further revegetation in areas with overplanting should be undertaken with caution, and restored ecosystems that exceed the OVC should be managed (e.g., thinning) to maintain a sustainable ecohydrological environment in the drylands. [ABSTRACT FROM AUTHOR]

The article discusses methodological approaches to the generation of long-term time series of water balance elements to assess and forecast river waters in the outlet section of a river catchment area. The study relies on the example of the Volga River basin. New approaches are proposed to determine difficult-to-measure water balance elements, such as evapotranspiration and changes in the basin soil moisture storage. [ABSTRACT FROM AUTHOR]

Knowing climate characteristics enables the detection of particular climate characteristics and their boundaries. This situation is essential in terms of providing sustainable use of areal resources and directing land use plans. For this reason, in this study, climate boundary maps of the Safranbolu district were created based on the need to form a basis for planning. For this purpose, measurement data of all meteorological stations in the district for the last 30 years were obtained; data were associated with the location, and the water balance of each station was calculated using the Thornthwaite climate classification method. In addition, the climate type was determined using different climate classification methods, and the results were compared. All applied methods have shown that Safranbolu has a humid climate; however, the humidity value in the north of Safranbolu is slightly higher than that in the central and southern parts. In addition, water shortage in the north of Safranbolu is observed in July–August, while water shortage in the central and southern parts is observed in July–August–September. Considering the long-term precipitation average of the Safranbolu district, the highest annual precipitation is observed in March and the lowest in August. Etp and Etr throughout the district are highest in July and lowest in January. Surplus water and surface flow occur in the months between December and May, with the highest amount of surface flow occurring in March. There is no month without rain in Safranbolu. Safranbolu, which is on the UNESCO World Heritage List, is a visiting area for local and foreign tourists because of its cultural, architectural, and historical features and geotourism potential. In addition to its current agricultural activities, the cultivation of the “Saffron” plant, which gives its name to the district, and its forest assets cause an increase in both the tourism capacity and population of the district. Considering all of these, studies on climate change risk management and water resources management in Safranbolu have been conducted. [ABSTRACT FROM AUTHOR]

This study analyzed the meteorological and hydrological droughts in a typical basin of the Brazilian semiarid region from 1994 to 2016. In recent decades, this region has faced prolonged and severe droughts, leading to marked reductions in agricultural productivity and significant challenges to food security and water availability. The datasets employed included a digital elevation model, land use and cover data, soil characteristics, climatic data (temperature, wind speed, solar radiation, humidity, and precipitation), runoff data, images from the MODIS/TERRA and AQUA sensors (MOD09A1 and MODY09A1 products), and soil water content. A variety of methods and products were used to study these droughts: the meteorological drought was analyzed using the Standardized Precipitation Index (SPI) derived from observed precipitation data, while the hydrological drought was assessed using the Standardized Soil Index (SSI), the Nonparametric Multivariate Standardized Drought Index (NMSDI), and the Parametric Multivariate Standardized Drought Index (PMSDI). These indices were determined using water balance components, including streamflow and soil water content, from the Soil Water Assessment Tool (SWAT) model, and evapotranspiration data from the Surface Energy Balance Algorithm for Land (SEBAL). The findings indicate that the methodology effectively identified variations in water dynamics and drought periods in a headwater basin within Brazil's semiarid region, suggesting potential applicability in other semiarid areas. This study provides essential insights for water resource management and resilience building in the face of adverse climatic events, offering a valuable guide for decision-making processes. [ABSTRACT FROM AUTHOR]

The research was employed to simulate the watershed's hydrologic behavior and to predict stream flow in the Mahan River catchment area alongside the effect of six underground (UG) and opencast (OC) mines for the past decades. Following the SWAT model run, the mining area sub-watersheds possess (SW20, SW26, SW28, SW31 and SW38) a comparatively lesser sediment yield of 61.41 Metric Ton/ha than that of non-mining area sub-watersheds 159.40 Metric Ton/ha. Amongst all hydrological components, evapotranspiration with 531.2 mm consumed 39% of the total annual precipitation (1365.3 mm). The total discharge was estimated to be 775.57 mm, which comprises Surface Runoff of about 351.89 mm, Return Flow (402.21 mm) and Lateral flow (21.47 mm), while percolation into the unconfined and confined aquifers as soil and groundwater storage also accounted for 58.86 mm. The statistical indicators and graphs indicate that the model performs satisfactorily for the daily streamflow (R2 = 0.875, p = 0.71, r = 0.76 and NSE = 0.87 during the validation (R2 = 0.817) as that during the calibration period. The model performed satisfactorily during the simulation and the results showed that the mines play a critical role in changing the hydrological regime of the watershed with low recharge and moderate evapotranspiration characteristics. Taken together, the SWAT model appears to be a reliable tool for forecasting stream discharge over long periods of time, in parallel with the likely impacts of mining activity on HRUs. [ABSTRACT FROM AUTHOR]

Irrigation is one of the major consumers of fresh water but crops consume only a small part of supplied water and huge quantities emerge downstream as rejuvenated flow and recharge groundwater. The assessment of these flows is cumbersome due to dependence on multiple factors; hence a fixed percentage is assumed by government agencies for designing downstream projects. Three different modeling and measurement techniques, i.e., water balance, isotopic analyses, and hydrological modeling were used to compute surface and sub-surface components of irrigation return flow in an irrigation project (Sanjay Sagar Project with the capacity of 82 MCM and 9863 ha command area) situated in the hard rock region of Central India. The water balance analysis confirmed that a major portion ranging from 12.3 to 35.9%, with an average of 22.9% of supplied water to the command reached the Bah River as regenerated flow, while 1.9–16% with an average of 10.2% of supplied water reached the groundwater body as recharge. The isotopic analysis yielded qualitative insights into the proportional influence of irrigation water on open wells and bore wells in the range of 81% and 9%, respectively. The outcomes of the SWAT model demonstrated that within Sanjay Sagar's command, irrigation led to approximately 27.8% of regenerated flow and 8.9% of recharge from applied irrigation. [ABSTRACT FROM AUTHOR]

Due to the rapid growth of human population and increasing living standards, there is a continuous increase in the gap between food productivity and demand. At the same time there is a global reduction in freshwater availability for agriculture. Several options have been proposed along the way to increase water use efficiency in the field. One promising possibility is the adoption of fertilization with silicon (Si) combined with biofertilizers (microorganisms). Si is estimated to impact on the root volume and distribution, while microorganisms added to the soil in the rhizosphere also impact directly on root growth. In this work we have tested the influence of Si fertilization (magnesium silicate + diatomaceous earth) combined with biofertilizers and 20% reduction in NPK fertilization in the growth of maize and the soil water balance on a field trial located in Companhia das Lezírias (Portugal). Data on soil water content was collected regularly and root analysis was performed at harvest. The water balance was calculated through the model HYDRUS, using root growth model calibrated for maize in the present conditions. Results showed that using an alternative source of fertilization (Si+microbes) while reducing NPK fertilization impacted on root growth development, with roots growing more horizontally, while conventional NPK fertilization resulted in deeper roots. As a consequence,, root water uptake increased and evaporation losses were lower in the treatment supplemented compared to the conventional, without compromising the yield obtained. Using biofertilizers combined with Si sources resulted in higher water use efficiency (2.64 kg m−3) than the NPK fertilization, normally applied for maize growth (2.56 kg m−3). The results imply that the supplementation+biofertilization allows a potential saving of 206 m3 ha−1 water and 157 kg NPK ha−1 fertilization in a growing season assuring the same yield as obtained with the conventional NPK fertilization (18.64 ton ha−1). Implications are important for Portuguese agriculture, where maize is one of the most important cereals cultivated, especially in Centre and Southern part of the country where water is a scarce resource. [ABSTRACT FROM AUTHOR]

Estimates of the water balance components (precipitation, evaporation, zonal and meridional advection of moisture) on the territory of Belarus for the cold (October–March) and warm (April–September) seasons have been obtained on the basis of the balance calculations of precipitation recycling and the ERA5 reanalysis data. It has been shown that the precipitation on the territory of Belarus results from westerlies in 77–84% of cases, from southerlies in 14–20% of cases, and from local evaporation in 2–4% of cases. Annual total precipitation exceeds annual evaporation by 18–30% (the maximum excess is observed in the north, and the minimum is registered in the southeast). During the warm seasons, there is a negative water balance in entire Belarus: evaporation exceeds precipitation by 8–23%. Over the period of global warming, the annual difference between precipitation and evaporation has decreased by 12–15%. The water balance for the warm season has decreased to negative values at the beginning of the current century due to the activation of summer warming. An increase in the amplitude of the water balance fluctuations has been revealed for the cold season, which indicates strengthening climate extremity. [ABSTRACT FROM AUTHOR]

Preserving longevity in snapdragon (Antirrhinum majus L.) flowers, an important cut flower with a short vase life is an economic issue that can be improved with some postharvest treatments. The Nanosilver application in preservative solutions and recut is effective techniques that can potentially prolong the vase life of cut snapdragon flowers. Hence, in this study, the effects of Nanosilver and recut on some postharvest characteristics were investigated. The results indicated that cut flowers treated with Nanosilver + recut extended the vase life of the flower up to 18.71 days. The recut flowers kept in the solution containing Nanosilver revealed higher RWC, carbohydrate content, and pH. Soluble protein content also increased significantly on day 15 compared to other treatments. This treatment, by reducing the content of H2O2 and MDA, caused a decrease in the electrolyte leakage and maintained the function of the membrane. Examining the TEM micrographs of Nanosilver + recut treatment showed the activity of plasmodesmata on the 15th day. The results of the present study indicate that the presence of Nanosilver in preservative solutions, especially when the stem end is recut, can be a promising method for delaying the signs of senescence and maintaining the postharvest quality of cut flowers. [ABSTRACT FROM AUTHOR]

The efficiency of runoff simulation, the values of parameters, and the dynamics of the estimated runoff components were analyzed for two conceptual hydrological models GR4J and HBV for 17 watersheds in the Upper Ussuri River (Primorsky Krai, Russia) with areas from 138 to 24 400 km2. Both models demonstrate an increase in the simulation efficiency (based on NSE criterion) with an increase in the catchment area up to 1–2 thousand km2, after which they stabilize within the interval of 0.75–0.85 for the calibration period and 0.70–0.80 for the verification period. The estimates obtained for the HBV model were 5–10% higher than those for the GR4J model. Analysis of the measured and calculated annual runoff maximums over the warm season suggests the conclusion that GR4J model is on the average 5–6% more efficient than the HBV model in calculating the maximal values of rain flood discharges. At the same time, the obtained values of the relative error BIAS demonstrate a more accurate reproduction of the annual average runoff by the HBV model. The main distinctions determining the efficiency of simulation in the study region are as follows: the method of considering the precipitation height increments within altitude belts, the specific features of the calculation of model evapotranspiration, the method for calculating the outflow from conceptual runoff-forming storages in the GR4J and HBV models. [ABSTRACT FROM AUTHOR]

Aim of the water balance study is to evaluate the distribution of hydrological responses towards water balance components for a watershed. The present study highlights the water balance study for a watershed of Mahanadi river basin of India. Impact estimation of Landuse Land Cover (LULC) on runoff using Soil and Water Assessment Tool (SWAT) model under varying levels of hydrological response unit (HRU) has also been determined. For the purpose, LULC maps are prepared and utilized in decadal intervals for the years 1994, 2004 and 2014. The sensitivity analysis was performed using local and global methods, where eight most sensitive parameters have been utilized for calibration and validation. The model showed good agreement between observed and estimated time scale and showed satisfactory results during calibration and validation. As per impact estimation of LULC during 1994 to 2014, it was noticed that significant percentage of runoff has been increased from 27.6 to 30.95%, respectively. It was also noticed that the annual average ground water contribution decreased with LULC, from 20.1% (1994) to 15.24% (2014). Sub-watershed (SWS-6) and SWS-2 have been identified as high priority for implementation of conservation measures and better water management. Because these sub-watersheds yielded maximum runoff. The HRU role in hydrological modelling revealed that a greater number of HRUs simulate runoff more precisely and more accurately useful for water management studies. [ABSTRACT FROM AUTHOR]

Assessment of accurate water balance components depends on a comprehensive performance evaluation of the hydrological model. In this study, the variable infiltration capacity (VIC) model was evaluated (calibration: 1992–1996; validation: 1997–1999) using ground-based observed and remote sensing-derived datasets, and the evaluated model was used for long-term simulations (1990–2016) to assess the spatial–temporal distributions of water balance components for the Tons river basin (drainage area of 17,440 km2) in India. A good agreement was found between simulated and observed discharge on a daily scale (coefficient of determination, R2 estimated as 0.74 and 0.75 during calibration and validation, respectively) and on a monthly scale (R2 estimated as 0.90 and 0.91 during calibration and validation, respectively). To substantiate the model prediction reliability, the simulated evapotranspiration (ET) and soil moisture were validated with the Moderate Resolution Imaging Spectroradiometer (MODIS-MOD16A2) and Advanced SCATterometer (ASCAT) datasets, respectively. A good match was found between VIC-simulated ET and MODIS-derived ET (R2 = 0.78), and VIC-simulated soil moisture and ASCAT-derived soil moisture (R2 = 0.60). The long-term simulations were run to estimate the average annual water balance components (rainfall, ET, runoff, and baseflow) and their monthly spatial variations. ET was found to be predominant in the basin, accounting for about 59% of annual precipitation (average annual ET was found to be 579.62 mm). Overall, quantifications of hydrological water balance components and their spatial–temporal variations could help decision-makers to effectively plan and manage the river basin. [ABSTRACT FROM AUTHOR]

Nowadays, large-scale and remotely sensed products have been widely used, and this study aims to investigate the effect of precipitation and evapotranspiration (ET) products on the performance of hydrological models, especially the water balance in Gheshlagh and Baghmalek basins in Iran with two different climates and model structures. For this purpose, five large-scale precipitation products, including CHIRPS, ERA, IMERG, TRMM, Terra and ET named GLEAM, SSEbop, MODIS, Terra, and Era, were implemented in five designed scenarios. These scenarios depend on how this information is applied and used in the model calibration process. Moreover, to evaluate the parametric behavior of these models, the uncertainties of their parameters were evaluated by the GLUE method. The parameters of the developed scenarios model with uncertain behavior were also measured in the main model. The results showed that in the absence of ground observations of precipitation or ET, the use of large-scale products in the mountainous and highland watersheds, where such measurements are not possible, is a suitable alternative for wrapping up the water balance equation. Using these products as the model input maintains model performance at the reference model level. The results also indicate that in the simultaneous calibration of ET and streamflow, the use of ET products improves the simulation of ET but reduces the accuracy of the simulated streamflow. No precipitation or ET product shows its best behavior in all conditions and all regions. This issue implies various products' functional values in different regions. [ABSTRACT FROM AUTHOR]

The extensive exploitation of water resources in Chaharmahal va Bakhtiari province has led to a destructive impact on the water balance and quality of the region. In order to evaluate water quality of the study area, water quality parameters from 132 wells were analyzed to prepare spatial distribution maps of the IRWQI index. To analyze spatial and temporal rainfall anomalies, the SPI index was spatially interpolated using the ordinary Kriging method. Principal component analysis was used to investigate the relationship between water quality parameters. The suitability of data for PCA was evaluated by the Kaiser–Meyer–Olkin and Bartlett tests. Additionally, water balance components of the study area, including surface runoff and ground water, were simulated using the WetSpass-M model. According to the results of the IRWQI index, 54 wells, mostly located in built-up and agricultural lands, had poor quality․ Investigation of the average groundwater quality during the years 2007 to 2017 shows that the trend of groundwater quality decreased. Comparison of drought and water quality maps showed similar patterns so that in areas with extreme drought, water quality was bad. The highest and lowest recorded concentrations for nitrates were related to built-up and rangeland lands with concentrations of 35 and 21 mg/l, respectively. Comparison among land use classes showed that in the rangelands, groundwater quality was better and nitrate level was lower compared to agricultural and built-up areas. Overall, the results of this study show that water quality can be affected by land use types and water balance components. [ABSTRACT FROM AUTHOR]

The correct management of groundwater depends on information regarding the evolutionary processes of groundwater and the characterization of spatial variability of recharge mechanisms. GIS-based index models have become a reliable alternative for mapping and interpreting recharge models due to their adaptability and reliability in estimating recharge. Furthermore, stable isotopes of hydrogen and oxygen in water (δ2H and δ18O) help determine the origin and monitoring of water in the hydrological cycle. This paper aims to contribute to the knowledge of groundwater recharge by developing a conceptual recharge model using stable isotopes and estimating the recharge amount using a spatially distributed water balance model based on GIS for the Zamora River Basin (ZRB) in Ecuadorian Amazon. Due to the basin's size and geography, it was necessary to divide it into six precipitation blocks. The high precipitation rates resulted in high (18.22%) and moderate (30.93%) recharge zones across the basin. The analysis of stable isotopes in water indicates that precipitation water comes from the east, from the Amazon plain. In the valleys, precipitation enriched in δ18O suggests that it has undergone a recycling process in the basin; groundwater recharge comes from these precipitations. This analysis provides a simplified representation of reality that can assist in predicting the impacts of human activities on the basin. [ABSTRACT FROM AUTHOR]

Heavy Precipitation Events (HPE) are the result of enormous quantities of water vapor being transported to a limited area. HPE rainfall rates and volumes cannot be fully stored on and below the land surface, often leading to floods with short forecast lead times that may cause damage to humans, properties, and infrastructure. Toward an improved scientific understanding of the entire process chain from HPE formation to flooding at the catchment scale, we propose an elaborated event-triggered observation concept. It combines flexible mobile observing systems out of the fields of meteorology, hydrology and geophysics with stationary networks to capture atmospheric transport processes, heterogeneous precipitation patterns, land surface and subsurface storage processes, and runoff dynamics. As part of the Helmholtz Research Infrastructure MOSES (Modular Observation Solutions for Earth Systems), the effectiveness of our observation strategy is illustrated by its initial implementation in the Mueglitz river basin (210 km2), a headwater catchment of the Elbe in the Eastern Ore Mountains with historical and recent extreme flood events. Punctual radiosonde observations combined with continuous microwave radiometer measurements and back trajectory calculations deliver information about the moisture sources, and initiation and development of HPE. X-band radar observations calibrated by ground-based disdrometers and rain gauges deliver precipitation information with high spatial resolution. Runoff measurements in small sub-catchments complement the discharge time series of the operational network of gauging stations. Closing the catchment water balance at the HPE scale, however, is still challenging. While evapotranspiration is of less importance when studying short-term convective HPE, information on the spatial distribution and on temporal variations of soil moisture and total water storage by stationary and roving cosmic ray measurements and by hybrid terrestrial gravimetry offer prospects for improved quantification of the storage term of the water balance equation. Overall, the cross-disciplinary observation strategy presented here opens up new ways toward an integrative and scale-bridging understanding of event dynamics. [ABSTRACT FROM AUTHOR]

Animals can sense their changing internal needs and then generate specific physiological and behavioural responses in order to restore homeostasis. Water-saline homeostasis derives from balances of water and sodium intake and output (drinking and diuresis, salt appetite and natriuresis), maintaining an appropriate composition and volume of extracellular fluid. Thirst is the sensation which drives to seek and consume water, regulated in the central nervous system by both neural and chemical signals. Water and electrolyte homeostasis depends on finely tuned physiological mechanisms, mainly susceptible to plasma Na+ concentration and osmotic pressure, but also to blood volume and arterial pressure. Increases of osmotic pressure as slight as 1–2% are enough to induce thirst ("homeostatic" or cellular), by activation of specialized osmoreceptors in the circumventricular organs, outside the blood-brain barrier. Presystemic anticipatory signals (by oropharyngeal or gastrointestinal receptors) inhibit thirst when fluids are ingested, or stimulate thirst associated with food intake. Hypovolemia, arterial hypotension, Angiotensin II stimulate thirst ("hypovolemic thirst", "extracellular dehydration"). Hypervolemia, hypertension, Atrial Natriuretic Peptide inhibit thirst. Circadian rhythms of thirst are also detectable, driven by suprachiasmatic nucleus in the hypothalamus. Such homeostasis and other fundamental physiological functions (cardiocircolatory, thermoregulation, food intake) are highly interdependent. [ABSTRACT FROM AUTHOR]

The results of long-term field studies on small catchments in the upper reaches of the Ussuri River (Primorskii krai, Pacific Russia) are presented. By virtue of modern means of observation, a unique dataset was obtained to record effectively the complicated runoff formation process in small low-mountain river basins. Geochemical and hydrological modeling were used jointly to describe the catchment dynamics, and genetic components of the river flow were assessed to study more thoroughly the runoff processes and to evaluate the runoff modeling accuracy factors. [ABSTRACT FROM AUTHOR]

The SAFER (Simple Algorithm for Evapotranspiration Retrieving) algorithm and the radiation use efficiency (RUE) model were coupled to test large-scale remote sensing environmental indicators in Brazilian biomes. MODIS MOD13Q1 reflectance product and gridded weather data for the year 2016 were used to demonstrate the suitability of the algorithm to monitor the dynamics of environmental remote sensing indicators along a year in the Brazilian biomes, Amazon, Caatinga, Cerrado, Pantanal, Atlantic Forest, and Pampa. Significant spatial and temporal variations in precipitation (P), actual evapotranspiration (ET), and biomass production (BIO) yielded differences on water balance (WB = P−ET) and water productivity (WP = ET/BIO). The highest WB and WP differences were detected in the wettest biomes, Amazon, Atlantic Forest, and Pampa, when compared with the driest biome, Caatinga. Rainfall distribution along the year affected the magnitude of the evaporative fraction (ETf), i.e., the ET to reference evapotranspiration (ET0) ratio. However, there was a gap between ETf and WB, which may be related to the time needed for recovering good soil moisture conditions after rainfalls. For some biomes, BIO related most to the levels of absorbed photosynthetically active radiation (Amazon and Atlantic Forest), while for others, BIO followed most the soil moisture levels, depicted by ETf (Caatinga, Cerrado, Pantanal, and Pampa). The large-scale modeling showed suitability for monitoring the water and vegetation conditions, making way to detect anomalies for specific periods along the year by using historical images and weather data, with strong potential to support public policies for management and conservation of natural resources and with possibilities for replication of the methods in other countries. [ABSTRACT FROM AUTHOR]

As small-bodied terrestrial organisms, insects face severe desiccation risks in arid environments, and these risks are increasing under climate change. Here, we investigate the physiological, chemical, and behavioral mechanisms by which harvester ants, one of the most abundant arid-adapted insect groups, cope with desiccating environmental conditions. We aimed to understand how body size, cuticular hydrocarbon profiles, and queen number impact worker desiccation resistance in the facultatively polygynous harvester ant, Pogonomyrmex californicus. We measured survival at 0% humidity of field-collected worker ants sourced from three closely situated populations within a semi-arid region of southern California. These populations vary in queen number, with one population dominated by multi-queen colonies (primary polygyny), one population dominated by single-queen colonies, and one containing an even mix of single- and multi-queen colonies. We found no effect of population on worker survival in desiccation assays, suggesting that queen number does not influence colony desiccation resistance. Across populations, however, body mass and cuticular hydrocarbon profiles significantly predicted desiccation resistance. Larger-bodied workers survived longer in desiccation assays, emphasizing the importance of reduced surface area-to-volume ratios in maintaining water balance. Additionally, we observed a positive relationship between desiccation resistance and the abundance of n-alkanes, supporting previous work that has linked these high-melting point compounds to improved body water conservation. Together, these results contribute to an emerging model explaining the physiological mechanisms of desiccation resistance in insects. [ABSTRACT FROM AUTHOR]

Scots pine, as one of the dominant European tree species in the temperate zone, is experiencing intensified water deficits, especially in north-western and central Poland, where it suffers from frequent droughts and generally low precipitation. This work investigates drought impact on forest functioning, by analysing ecosystem transpiration under normal as well as dry conditions. Therefore, eddy covariance (EC) and sap flow measurements (using the thermal heat balance, THB, method) were combined to estimate transpiration (T) in two different-aged Scots pine (Pinus sylvestris) stands in north-western Poland: Mezyk (ME; 26 years old) and Tuczno (TU; 67 years old). Transpiration (T) estimates regarding EC measurements were derived from gross primary productivity (GPP) fluxes and vapour pressure deficit (VPD) dependence, considering their common relationship with stomatal activity. In 2019, the year following severe drought in Poland and Europe in general, total annual transpiration estimated based on sap flow measurements (TSF) was significantly lower than EC-derived transpiration (TEC) at both sites. The total ratio of TSF/TEC for the growing season (March–August) was 0.64 and 0.41 at ME and TU, respectively. We thus speculate that the understory, which was more abundant in TU than in ME, and which could only be observed by the EC system, may be responsible for the observed discrepancies. Bigger differences between TSF and TEC occurred under dry and wet conditions, while both were fairly similar under moderate conditions. The analysis of the relationships between TSF and soil water content (SWC) at depth of 10 cm revealed that there is a thresholds (SWC ~ 3.5%) at which TSF starts to decrease sharply, presumably due to stomatal closure. However, the decrease in GPP fluxes at the same time was less pronounced, indicating the impact of additional non-stomatal factor on water conductivity. We generally conclude that care should be taken if the conclusion of the occurrence of drought stress of some plants is derived from a bulk evapotranspiration flux, as it is commonly done with EC measurements averaging over the whole ecosystem. Our results also support the notion that non-stomatal water losses are an important element during extreme dry conditions, and that these may appear not only when stomata are already closed. [ABSTRACT FROM AUTHOR]

Water balance was measured for five field experimental cells with an oxygen-barrier type of reclamation cover combined with elevated water table including a control cell with functional layer of desulfurized tailings over a reactive tailings layer, and four other cells with additional layers and different vegetation. Hydrogeological (moisture content and suction in layers, water table positions in cells), and precipitation data collected throughout three successive growing seasons after revegetation were compared to investigate the effects of different material layering and vegetation scenarios on the water balance. Above- and below-ground vegetation developments were also monitored. Results showed that for all tested scenarios the main water balance component remained the evapotranspiration (79–98% of the total precipitated water). Herbaceous vegetation was found to provide much safer support for the cover performance than woody vegetation, keeping the reactive tailings more saturated during the whole study period (mean Sr > 90.77%). In presence of woody plants, however, the Sr in the reactive tailings could reach a value as low as ~ 32%. Increasing the thickness of the additional layer over 30 cm above the functional layer with fine-grained HDS sludge could also pose a threat against its functionality by stimulating willow growth, lowering the water table position as well as the Sr in the reactive tailings. Finally, adding a coarse-grained capillary break layer impeded the willow root colonization of the functional layer in the short term but increased percolation and should be coupled to water conservation strategies in the overall system to maintain the elevated water table. [ABSTRACT FROM AUTHOR]

Thailand has set the 20-year National Strategy (2018–2037) towards sustainable development and building adaptability to climate change. The strategy promotes forestation and higher bioethanol energy demand. This study aims to investigate the effects of the climate and land-use changes on water balance in 2037, the end of the National Strategy, for the Mun River Basin, NE Thailand. The simulated climate dataset used in this study was ensemble means from IPCC AR5 Global Circulation Models for representative concentration pathway (RCP) 4.5 and 8.5 climate scenarios. The land-use change was simulated using the Dyna-CLUE (Conversion of Land Use and its Effects) model. The Soil and Water Assessment Tool (SWAT) was used to assess the water balance (considering evapotranspiration—ET, percolation—PERC, surface runoff—SURQ, and groundwater lateral flow—LATQ). The combined effects could increase monthly ET, whereas the climate change effect could outrun the land-use changes, resulting in increasing PERC. The sustainable development under the National Strategy (2018–2037) could be insignificantly affecting the water balance, whereas the "Bioethanol-Oriented" land-use scenario could increase SURQ and decline LATQ, which could intensify flooding. Soil-water conservation measures are recommended to mitigate the adverse effects of bioenergy. [ABSTRACT FROM AUTHOR]

Long-term variations of water balance components are compared for the deltas of the Pechora and Koluma rivers, flowing in the occurrence area of discontinuous and continuous permafrost rocks. Trends in the variations in the major components of water balance equation (river water flow, precipitation, and losses or increment of runoff in the delta) are considered for the conditions of climate warming (the late XX–early XXI centuries). A distinct increase, most pronounced in 2008–2018, was recorded in the major components of water balance. [ABSTRACT FROM AUTHOR]

Considering the sensitivity and importance of water resources in the Himalayan uplands, this study intended to assess the hydrological responses to climate change in the Jhelum basin. Representative concentration pathway (RCP)–based projections from six dynamically downscaled global circulation models (GCMs) were bias-corrected for developing the climatic projections over the twenty-first century. The uncertainty associated with GCM outputs was addressed by using multi-model ensemble projections developed through Bayesian model averaging (BMA) technique. The assessment reveals that compared to the baseline (1980–2010) values, the annual mean maximum temperature in the basin will rise by 0.41–2.31 °C and 0.63–4.82 °C, and the mean minimum temperature will increase by 1.39–2.37 °C and 2.14–4.34 °C under RCP4.5 and RCP8.5, respectively. While precipitation is expected to decrease by 7.2–4.57% and 4.75–2.47% under RCP4.5 and RCP8.5, correspondingly. BMA ensemble projections were coupled with the Soil and Water Assessment Tool (SWAT) to simulate the future hydrological scenarios of the drainage basin. With the changing climate, the discharge of rivers in the Jhelum basin is expected to witness reductions by about 23–37% for RCP4.5 and 19–46% for RCP8.5. Moreover, the water yield of the basin may also exhibit decreases of 17–25% for RCP4.5 and 18–42% for RCP8.5. The projected scenarios are likely to cause water stress, affect the availability of water for diverse uses, and trigger transboundary water-sharing-related conflicts. The impact of climate change on discharge demands early attention for the formulation of mitigation and adaptive measures at the regional level and beyond. [ABSTRACT FROM AUTHOR]

Land use exerts a considerable impact on runoff in the semiarid basin of the Yellow River. Assessing the effects of land-use changes on runoff characteristics is a vital task for water resource managers. The goal of this study is to evaluate the impact of a change in land use on water resources by using the Soil and Water Assessment Tool (SWAT) model. This is needed for the rational organization of the water economy of the country. Considerable land-use changes have been noticed in the study area. The conversion of lands of various types into urban land results in uncertain parameters in the SWAT model. The data indicate that the SWAT model may be successfully used to assess the impacts of land-use variability on water resources of the study basin. The results of this research may become an important reference for the rational use of water resources and soil conservation and may be used in ecohydrology of the river basin. [ABSTRACT FROM AUTHOR]

Possible consequences of the construction of the Uldza River reservoir in Mongolia related to a change in the hydrological regime of the Torey Lakes and of the transboundary basin are analyzed. Climatic and hydrological characteristics of the Uldza River and the Torey Lakes are analyzed based on data of hydrological surveys of 1965–2020. It is revealed that the main factor of variability of their hydrological regimes is represented by cyclic climate changes accompanied by large temperature amplitudes, the extremely uneven distribution of precipitation over seasons and particular years, high water filtration and evaporation losses (often exceeding the local runoff), and the periodic drying up of rivers and lakes. The configuration and filling and drawdown modes under different water conditions of the designed reservoir are simulated using available material of the tender documentation for the Mongolian Onon-Ulz project, open raster data of satellite sounding of the Earth, various GIS sources, and other global data. Based on the simulation results, quantitative estimates of possible mean monthly deviations of the regulated runoff, levels, and area of the water surface of Lake Barun-Torey from the natural ones are obtained. Calculations of the operating conditions of the designed reservoir show that it can only be filled at a probability of the flow rate of 50% or lower. Thus, it will remain unfilled for a long time, which casts some doubt on the economic expediency of its creation. Despite the low absolute discharge, its relative deviations from the natural conditions vary widely (from 3 to 192%). The effect of the reservoir on the deviation of the discharge and the levels and area of the lakes as compared to natural conditions is the most significant in dry periods. Thus, the creation of the reservoir may result in a significant change in the natural hydrological conditions of the Uldza River and the Torey Lakes and in negative consequences for the ecosystem. [ABSTRACT FROM AUTHOR]

The water balance components are essential to determine the area's hydrological process and groundwater resource management. This study aims to characterize the water balance components over the Ataye watershed using the WetSpass model. The WetSpass model can simulate water balance components' spatial and temporal variation, mainly evapotranspiration, surface runoff, and groundwater recharge. The input data for the WetSpass model are land use/land cover, elevation, slope, soil texture, temperature, potential evapotranspiration, wind speed, and groundwater depth. Those spatial datasets were prepared in the raster format and transformed into ASCII file format using GIS spatial analysis techniques. As a result, the findings of this study confirmed that the mean evapotranspiration values of the Ataye watershed in the winter, summer, autumn, spring, and annual seasons were 33.6 mm, 117.35 mm, 100.98 mm, 158.96 mm, and 410.88 mm, respectively. Besides, the computed surface runoff values of the Ataye watershed in the winter, summer, autumn, spring, and annual seasons were 15.30 mm, 376.24 mm, 43.74 mm, 59.89 mm, and 495.16 mm, respectively. Similarly, the mean groundwater recharge values of the Ataye watershed in the summer, autumn, winter, spring, and annual seasons were 148.47 mm, 29.83 mm, 5.62 mm, 13.73 mm, and 197.65 mm, respectively. This study's findings can be a reference for water resource specialists and policymakers to develop and manage various water resource-related projects in the present study area. [ABSTRACT FROM AUTHOR]

Failure in Environmental flow in quantity, timing, and quality leads to failure to support ecosystems, human livelihoods, and well-being. Irrigation water use is one of the main actors in impacting the water flow of rivers in quantity and time but was not well investigated in many ungauged catchments under smallholder irrigation systems. This study examined the impact of irrigation water use on environmental flow in Arata's small ungauged catchment. The study estimated the flow in sub-catchment using the area ratio method, the crop irrigation water requirement using F.A.O. cropwat 8.0, and the water balance in the Water Evaluation and Planning System tool and the environmental flow in Tennants, Q95, asnd local area thumb rule. The result showed that the minimum environmental flow of the Arata catchment is 290, 310, and 60 li/sec in the Tennant, Q95, and the local thumb rule. Irrigation consumes only 9% of the water resources of the catchment while 91% is contributed to downstream lake Ziway via Ketar river. January and February have unmet water demand and zero environmental flow. In December Tennant's 10% and Q95 recommended environmental flow had 19% and 24% deficit while the thumb rule environmental flow is 291% more than the minimum requirement. The rest of the months are by far more than the minimum environmental flow requirement. Given the result, meeting the environmental flow of the system throughout the year needs the installation of a water storage facility from upstream to downstream, the introduction of different water-saving irrigation technologies, farmers' capacity building in irrigation water management, and a standardized environmental flow estimation mechanism. [ABSTRACT FROM AUTHOR]

Copyright of Österreichische Wasser- und Abfallwirtschaft is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The idea of water balance calculations within the landfill is to determine the distribution of water input and output, and finally the volume of leachate generated. The scope of this data is essential for rational planning of water and wastewater management, and designing leachate drainage network and leachate treatment systems. The aim of this study was to assess the possible amounts of leachate generation regarding ten different scenarios of landfill sealing systems. The calculations were performed using the Hydrologic Evaluation of Landfill Performance (HELP) model. It was revealed that the greatest share among the components of water balance in the landfill has precipitation (on average 509 mm in the 5-year period of simulation), together with evapotranspiration (on average 391 mm in the 5-year period of simulation). The study shows that the minimum amount of leachate (797–803 m3/year) occurs when the best placement quality (=5) is regarded for the geomembrane installed in the bottom of the landfill. The maximum leachate generation (830 m3/year) was found for those scenarios in which only three layers of bottom sealing systems were adopted, with the worst placement quality (=1) assigned to geomembranes. The results of this study confirm that the application of multilayer sealing systems has visible impact on the reduction of leachate generation of around 33 m3/year. [ABSTRACT FROM AUTHOR]

Modeling framework for simulation at a finer scale is important for long-term water resources planning for management. It has always been a challenge to select the appropriate model to simulate the hydrology of a watershed/river basin at a finer spatial resolution. Comparative evaluation of models based on field observations could help researchers to select the suitable model for their purpose. However, a single hydrologic model generally leads to simulation uncertainties due to poor input data, model structure, and model output uncertainty in large-scale exercises. The ensemble model approach could be a better decision-making tool to overcome uncertainty in modeling hydrological processes. In the present study, a widely used macroscale hydrologic model, the three-layer Variable Infiltration Capacity (VIC-3L), was employed to simulate runoff and evapotranspiration (ET) at 3′ × 3′ grids (~ 5.5 km) resolution over an agriculture-based Marol watershed (5092 km2) of India. The VIC-simulated results were compared and assessed with the results obtained from the Hydrologic Response Unit (HRU)-based Soil and Water Assessment Tool (SWAT) hydrologic model. Further, the ensemble of VIC and SWAT outputs (EnSwaVi; averages of individual model-simulated datasets with equal weights) was also assessed. Simulated runoff and ET were evaluated using observed discharge data at the outlet of the watershed and the actual ET product (MOD16A2) of Moderate Resolution Imaging Spectroradiometer (MODIS), respectively. The simulated discharge values generated by the two models were closely matched with the observed flow. Conversely, ET simulated by VIC was found to be more precise as compared to SWAT. A minimal difference between two model results can be due to the difference in the model structure and runoff simulation method. In general, the ensembles of VIC and SWAT outputs (EnSwaVi) were found better than the individual model outputs. The ensemble modeling approach could provide more reliable assessments of hydrological processes for the planning and management of water resources. [ABSTRACT FROM AUTHOR]

This paper addresses the nexus of climate change and variability, soil moisture and surface runoff over the Lake Baikal catchment. Water level and distribution of dissolved and suspended matter over Lake Baikal are strongly affected by river inflow during rain-driven floods. In this study, we evaluate river flow changes at 44 streamflow gauges as well as related precipitation, evaporation, potential evaporation and soil moisture obtained from the ERA5-Land dataset. Based on Sen's slope trend estimator, Mann–Kendall non-parametric test, and using dominance analysis, we estimated the influence of meteorological parameters on river flow during 1979–2019. We found a significant correlation between the precipitation elasticity of river flow and catchment characteristics. Half of the gauges in the eastern part of the Selenga River basin showed a significant decreasing trend of average and maximum river flow (up to −2.9%/year). No changes in the central volume date of flood flow have been found. The reduction in rainfall amount explains more than 60% of runoff decrease. A decrease in evaporation is observed in areas where precipitation decrease is higher than 0.8%/year. Catchments, where the precipitation trends are not as substantial, are associated with increasing evaporation as a result of the increasing potential evaporation. Negative precipitation trends are accompanied by negative trends of soil moisture. Finally, the study reveals the sensitivity of catchments with steep slopes located in humid areas to precipitation change. [ABSTRACT FROM AUTHOR]

Relationships between the amount and chemistry of atmospheric water, river water, and groundwater are analyzed in the catchments of six small tributaries of the Tom River near Tomsk City (Russian Federation, West Siberia, Ob R. basin) using data of long-term hydrogeological and hydrological observations (from the 1970s to 2019). A decrease in the rate of water exchange was shown to cause an increase in the interaction time in the water–rock system and, accordingly, in the total concentration of dissolved salts in groundwater. For the first time for the lower reaches of the Tom R., it was shown that the intensity of interaction between river water, subsoil water, and artesian water can be evaluated with the use of the coefficient of variation Cv(Ym) of the monthly runoff depth values of small rivers—the greater the value of Cv(Ym), the greater the closeness of deep aquifers and groundwater TDS. The processes of rock leaching and dissolution were found to dominate in areas with considerable replenishment of water reserves in the warm season of the year (on the right side of the Tom R. catchment), while the input of substances from outside, e.g., with precipitation, dominates in the area were groundwater resources are mostly replenished during snow melting. [ABSTRACT FROM AUTHOR]

The hydrology of Himalayan region is influenced by temperature lapse rate (TLAPS) and precipitation lapse rate (PLAPS). Therefore, hydrological modeling considering TLAPS and PLAPS is crucial to manage the water resources in these terrains. In this research, Himalayan Gandak River basin is considered as the study area where TLAPS and PLAPS vary significantly due to high altitude of Himalayas. To assess the impact of TLAPS and PLAPS on water balance components, Soil Water Assessment Tool (SWAT) model was calibrated (2000–2007) and validated (2008–2014) on daily time step for three projects i.e., Reference Project (RP), Snowmelt Project (SP) and distributed elevation band snowmelt project (SWAT-ETISM). The analysis discloses that SWAT-ETISM model (which has TLAPS and PLAPS parameters) outperforms the RP and the SP models in predicting streamflow with improved statistical indicators R2 =0.88, NSE =0.84 and PBIAS = 11.9. Furthermore, it was observed that SWAT-ETISM model comprehensively improved the streamflow statistics by improving the snow water equivalent and water balance components through the consideration of TLAPS and PLAPS values for the region. Hence, the proposed SWAT-ETISM model can be used for estimation of the water budget at the high-altitude and data scarce alpine Himalayan regions and worldwide, where PLAPS and TLAPS are substantial due to altitudinal variation. [ABSTRACT FROM AUTHOR]

This paper discusses the formation of level regimes in lakes located in arid parts of Central Asia. Water resource formation specifics in the studied region include the presence of runoff formation and dispersal zones in river basins. When rivers leave mountainous areas, the dispersal of runoff occurs due to seepage losses from river channels and the remaining waters fill drainless depressions, thus forming enclosed or terminal lakes. Water levels in such lakes depend entirely on water content fluctuations in rivers, and their sizes fluctuate in a wide range, up to completely drying up. Factors determining the hydrological regimes of terminal lakes whose catchment basins are located in the Russian Federation, Mongolia, and the People's Republic of China are examined. Approaches to the stochastic modeling of water balance components in lakes and probabilistic forecasts of their long-term water level fluctuations are presented. Using the examples of the Torey Lakes (the Russian Federation) and lakes located in the Heihe River basin (the People's Republic of China), the level regime formation and its probabilistic forecasting are described, including situations involving severe anthropogenic impacts. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agricultural water use has long accounted for more than 70% of water consumption in Northeast China. Estimating farmland irrigation water requirements and water balance is essential to ensure safe agricultural water and promote rational development and utilization of regional water resources. In this study, based on the modified Penman–Monteith equation recommended by the Food and Agriculture Organization (FAO) and Geographic Information System (GIS) technology, the net crop irrigation water requirements for four main crops in Northeast China were calculated, and the spatiotemporal distribution characteristics were also analyzed. Additionally, regional farmland irrigation water requirements were estimated, water balance in a typical year was determined, and the dominant factors affecting farmland irrigation water requirements in different regions were analyzed. From 1986 to 2020, the net irrigation water requirements for four main crops all showed the temporal trend of no significant increase and the spatial distribution characteristic of being high in the west and low in the east. The farmland irrigation water requirement decreased, and the monthly average farmland irrigation water requirement peaked in July during 2010–2019. Compared with 2010, in 2019, the irrigation water requirement per cultivated land grid cell in 20 cities increased and that in 16 cities decreased. Most cities were facing varying degrees of water shortage. Precipitation had the greatest direct effect on the farmland irrigation water requirement in different regions. These results quantify the farmland irrigation water requirement and water balance in Northeast China, and provide a reference for water resources and related environmental governance. [ABSTRACT FROM AUTHOR]

The current values of the components of the water balance of the Parana delta, one of the largest deltas of South America, as well as the results of calculations of the actual distribution and redistribution of water runoff and sediment yield in the delta branches are presented. Response of the components of the Parana delta water balance on climate variations is revealed. Long-term changes in the water and sediment flow distributions in the delta branches are considered. Analysis of dynamics of estuarine delta coastline shows stable increase of the river delta area, which could cause dangerous hydrological phenomena at the Parana delta. [ABSTRACT FROM AUTHOR]

Environmental changes of the last decades are taking their toll on Lake Sfanta Ana, a crater lake situated in the Eastern Carpathians. The once crystal-clear water of the lake became greenish and turbid in the past decade due to flourishing algae populations, the surface area, depth and the volume of the water body marked a significant decrease during the past century. These changes are considered to be a consequence of sediment transport from the inner slopes of the crater, eutrophication attributed to nutrients of anthropogenic origin and decrease of water level. Having no permanent surface inflow and outflow sources, the water level of the lake depends on other water-budget components like precipitation, overland inflows during high intensity precipitations or snow-melting, evaporation, subsurface inflow and outflow. The research is aimed to identify the main components of the water budget, based on establishing relations between in situ measured meteorological data and the changes of water level. The results indicate a powerful relationship between water level, precipitation, and evaporation, the latter two are the main factors responsible for the variations of the lake's water level. [ABSTRACT FROM AUTHOR]

Can Tho city in the Mekong Delta is in the top ten areas affected by climate change. Therefore, assessing climate change impacts, social and economic activities require proposed solutions to respond to climate change. This study aims to (i) apply the MIKE 11 model (Hydrodynamic module and Advection–Dispersion module) to simulate the impacts of climate change scenarios on water resources in Can Tho city; (ii) calculate water balance in Can Tho city; and (iii) suggest climate change adaptation plan for sustainable social-economic activities of the city. The results show that when the rainfall changes due to climate change, the flow rate tends to decrease at high tide and increase at low tide. When the sea level rises due to climate change, the flow rate tends to increase at high tide and decrease at low tide. For 2030, the flow will decrease up to 15.6% and 14.3% at the low tide period for RCP 2.6 and RCP 8.5 compared to the present, respectively. The flow will increase up to 63.5% and 58.9% at the high tide period for RCP 2.6 and RCP 8.5 compared to the present, respectively. The water demand evaluation shows that the water resource reserve in Can Tho city meets water demands in current and future scenarios under climate change. While rainwater and groundwater can provide enough water in the rainy season, the city has to use surface water during the dry season due to a lack of rainwater. Of these, agriculture contributes the most water demands (85%). Eight adaptation measures to climate change for Can Tho city are developed from 2021 to 2050. [ABSTRACT FROM AUTHOR]

Saving body water by optimal reabsorption of water filtered by the kidney leading to excretion of urine with concentrations of solutes largely above that of plasma allowed vertebrate species to leave the aquatic environment to live on solid ground. Filtered water is reabsorbed for 70% and 20% by proximal tubules and thin descending limbs of Henle, respectively. These two nephron segments express the water channel aquaporin-1 located along both apical and basolateral membranes. In the proximal tubule, the paracellular pathway accounts for at least 30% of water reabsorption, and the tight-junction core protein claudin-2 plays a key role in this permeability. The ascending limb of Henle and the distal convoluted tubule are impermeant to water and are responsible for urine dilution. The water balance is adjusted along the collecting system, i.e. connecting tubule and the collecting duct, under the control of arginine-vasopressin (AVP). AVP is synthesized by the hypothalamus and released in response to an increase in extracellular osmolality or stimulation of baroreceptors by decreased blood pressure. In response to AVP, aquaporin-2 water channels stored in subapical intracellular vesicles are translocated to the apical plasma membrane and raise the water permeability of the collecting system. The basolateral step of water reabsorption is mediated by aquaporin-3 and -4, which are constitutively expressed. Drugs targeting water transport include classical diuretics, which primarily inhibit sodium transport; the new class of SGLT2 inhibitors, which promotes osmotic diuresis and the non-peptidic antagonists of the V2 receptor, which are pure aquaretic drugs. Disturbed water balance includes diabetes insipidus and hyponatremias. Diabetes insipidus is characterized by polyuria and polydipsia. It is either related to a deficit in AVP secretion called central diabetes insipidus that can be treated by AVP analogs or to a peripheral defect in AVP response called nephrogenic diabetes insipidus. Diabetes insipidus can be either of genetic origin or acquired. Hyponatremia is a common disorder most often related to free water excess relying on overstimulated or inappropriate AVP secretion. The assessment of blood volume is key for the diagnosis and treatment of hyponatremia, which can be classified as hypo-, eu-, or hypervolemic. [ABSTRACT FROM AUTHOR]

Water and land resources are limited and dwindling in quantity and quality due to pollution and the effects of climate change. The "world needs to produce over sixty percent more food to feed" its 9.9 billion population in 2050 using these dwindling resources. Increased food production is also necessary to achieve most of the "UN's SDGs such as SDG1 (No Poverty), SDG2 (Zero Hunger), SDG3 (Good Health and Well-Being), and SDG15 (Life on Land)", etc. The aforesaid "goal can be accomplished by optimizing the distribution of available water and land resources, which can be done through an optimization model". In this study, a water balance model was first developed "to assess the long-term groundwater recharge, which will help to understand the dynamics of the system". Then, after analyzing the results, an optimization model was formulated to maximize the net annual farm income in an irrigated region of India. The water balance model showed excellent results as indicated by "high R-squared (0.9728) and model efficiency (0.91)", and low RMSE (0.2516 m) and ME (-0.0526 m) values. The water balance analysis revealed "that the aquifer level has been rising at a steady rate" over the past two decades. The results of the water balance model were used to formulate various constraints of the optimization model. Under the optimal cropping system, the area of paddy decreases against an increase in the area of sorghum, pearl millet, and cotton during the monsoon. Whereas "during the winter, the area of wheat increases", and the area of mustard and barley decreases. Groundwater "abstraction has increased, eventually lowering the aquifer level and thus alleviating salinization and waterlogging problems in the region". Net yearly income in the region enhanced by more than twenty-two percent to ₹821.24 million from the present ₹671.33 million. The sensitivity analysis revealed that the crops' market price is the most sensitive factor in the optimization model. "It is recommended that government agencies and real-world agricultural farmers practice increased use of groundwater in conjunction with canal water to maximize farm income. The approach used is the first of its kind in the region under study, is easy to apply, and can be replicated in other regions of the world" dealing with comparative issues. [ABSTRACT FROM AUTHOR]

Balancing the systems of waters in mines or in selected parts of them is an important part of works carried out by geological services of the mines, including the works aiming, for instance, at recording the types of waters flowing into mine excavations, assessing the impact of mining operations on the environment and foreseeing water threats. The article presents research performed with the objective of balancing the selected water systems of the deep coal mine "Jankowice." The research was performed with the help of the software dedicated directly for balancing water systems, in particular water systems in mines. The computational methods of this software are based on the techniques of matrix calculations, in particular on the methods of results coordination. It allows to obtain fully compliant balances with minimal adjustments of the measured values describing both the types of the system incoming waters and collective waters which are a mixture of types of waters incoming to the system. The results of the conducted research showed the usefulness of the KYBL software for balancing the water systems of deep mines. It was also shown that this tool could also be used to balance any other water systems with a similar physical mixing model as in the case of deep mine water systems. [ABSTRACT FROM AUTHOR]

Fu's equation has been widely adopted to examine the regional (inter-catchment) variability of the water balance at the catchment scale due to the simplicity and effectiveness of the Budyko framework. Fu's equation has also been used to analyze the temporal (inter-annual) variability of the water balance, but ignoring inter-annual storage changes is a recognized weakness. The regional variability of the water balance was examined through application of Fu's equation to long-term (1951–2000) observations of climate and runoff in 194 Model Parameter Estimation Experiment catchments across the contiguous United States. A set of hydroclimatic metrics was used to simulate spatial variability in the partitioning of precipitation for the study catchments using the free parameter ω of Fu's equation. Through the use of a stepwise regression model, it was found that four widely available variables, namely, seasonality of precipitation and potential evapotranspiration, seasonal synchronicity between moisture and energy, and the soil moisture storage index, explained 59.2% of the variability in ω . Application of the empirical formula of ω to Fu's equation explained 96.5% of the spatial variability in long-term runoff for an independent set of catchments. To explore the inter-annual variability of the water balance, a modified Fu equation was developed by incorporating inter-annual water storage changes into the estimation of evaporation and total water supply. The time-varying functional forms of the parameter ω , in terms of one or more of the selected environmental factors for each of 194 catchments, were also established at the annual scale. The results indicated that the modified Fu equation with time-varying parameter (MFETP), which accounted for the impacts of inter-annual changes in water storages and the time-variation process of ω , greatly improved estimates of inter-annual variability in the water balance compared to the conventional model. The MFETP offers an improved model for assessment of the inter-annual responses of runoff to changes in climate and watershed properties at the catchment scale. [ABSTRACT FROM AUTHOR]