Water Budget Research Articles (Page 1)

ABSTRACT The commencement of the Industrial Revolution has resulted in an unprecedented increase in the concentration of atmospheric CO2 (pCO2). It is, therefore, important to understand how plant communities respond to increased levels of CO2 levels in the environment. To this end, we examined the effects of spatial variation in pCO2 on plant physiology using carbon isotope ratios (δ13C values) and stomatal index (SI) in C3 plant leaves along a transect from the central Ganga Plain to the foothills of the Himalayas with industrial and non-industrial zones. Our study shows that the plants adjacent to the industrial areas have much lower δ13C values (avg. −31.8 ‰) and absorbed more fossil fuel-derived carbon (ca. 18 %) than those growing in non-industrial areas (−28.3 ‰). We also observed ca. 25 % lower SI values from the industrial area, suggesting that the increase in CO2 concentration (for a given water budget) led to high photosynthetic rates with low stomatal conductivity. Therefore, a long-term increase in pCO2 would lead to higher water-use efficiency in C3 plants, which would allow them to function better in low moisture conditions. We also suggest that the δ13C and SI values can be used for mapping carbon sequestration by plants growing in industrialized regions.

Amphibians balance their thermal and water budgets depending on their physiological state and the physical environment, with both factors capable of constraining activity. Most mechanistic assessments emphasize thermal over water constraints, potentially missing important aspects of amphibian ecophysiological patterns. Here, we evaluate the potential role of thermal and hydric constraints on the activity time of three Neotropical frogs ( Leptodactylus fuscus , L. mystacinus , and L. macrosternum ) across their geographic distribution. We inferred environmental suitability based on heat and mass transfer principles through a mechanistic modeling procedure anchored to empirically obtained laboratory and field data. We integrated species‐specific thermal, hydric, and performance attributes with their immediate physical environment (ground‐level microclimate) under nocturnal conditions, while allowing for the interactive response of retreating into shelter when facing physiological heat or water stress. Our results demonstrate the desiccation‐prone role of smaller body sizes in increasing hydric restrictions and inhibiting activity, even under thermally adequate conditions, as well as the role of shelters as thermal and hydric refugia. More strikingly, thermal‐induced restrictions in activity were linked to low temperatures rather than warmer conditions, indicating that their engagement in activity is mostly driven by the lower thermal bounds of their functional organismal performance. These findings provide a broader picture of climatic constraints on anuran activity and distribution, as well as insights into how species may respond to changing climatic conditions.

The sustainable management of groundwater resources in Côte d'Ivoire requires a reliable estimate of groundwater recharge. This study proposes a methodology for assessing the recharge of the Davo watershed (South-West Côte d'Ivoire) through distributed hydrological modelling with the HYDROTEL software. Physiographic (DEM, soils, land cover) and hydrometeorological (rainfall, discharge, evapotranspiration) data were integrated into the model via PHYSITEL. The three-layer vertical water budget (BV3C) was used to estimate vertical flows and potential aquifer recharge. The results indicate an average annual recharge of 221 mm, with spatial variability between –27 and 644 mm/year depending on the hydrological units. The performance of the model is considered satisfactory (Nash-Sutcliffe = 0.62), volume deviation = -1.11%). The sensitivity analysis shows the major role of evapotranspiration and land use on recharge, confirming the impact of deforestation and enthronization on the reduction of infiltration. This integrated approach provides a robust scientific basis for the quantitative assessment of groundwater resources and can be replicated in other similar contexts when all the required conditions are met.

This study focuses on the Alentejo and Algarve regions of southern Portugal, which is characterized by a typical Mediteranean climate. In the Mediterranean region, evaporation plays a significant role in reservoir water budgets. Therefore, estimating water surface evaporation is essential for efficient reservoir water management. This study aims to (i) assess the reservoir evaporation pattern in southern Portugal from meteorological offshore measures, (ii) benchmark various indirect methods for evaluating reservoir evaporation at a monthly scale, and (iii) provide recommendations on the most suitable indirect method to apply in operational practices. This study presents meteorological data collected from floating weather stations on instrumented platforms across nine reservoirs in Alentejo and Algarve. This is the first time that so many offshore local measurements have been made available in a Mediterranean climate region. The reservoir evaporation was estimated by the Energy Budget (Bowen Ratio) method, having concluded that monthly evaporation rates across the nine reservoirs ranged from 0.8 mm d­−1 in winter to 4.6 mm d­−1 in summer, with an annual average of 2.7 mm d­−1. Annual evaporation values ranged from 750 to 1230 mm, showing a positive gradient from the northern Alentejo region to the southwest Algarve region. To evaluate the performance of five empirical and semi-empirical evaporation indirect methods, a benchmarking analysis was conducted. The indirect methods studied are Mass Transfer (MT), Penman (PEN), Priestley and Taylor (PT), Thornthwaite (THOR), and Pan Evaporation (PE). Regarding the MT method, an N function of a reservoir superficial area is presented for the Mediterranean climate regions. In the Pan Evaporation method, the pan coefficient was considered equal to one. The benchmarking analysis revealed that all studied methods produced estimates that had good correlation with the Energy Budget method’s results across all reservoirs. All the methods showed small biases at the monthly scale, particularly in the dry semester. The estimates’ evaporation variability depended on the reservoir. Overall, the evaluation of evaporation methods concluded that (i) the stakeholders should considerer having an evaporation pan offshore; (ii) to manage the water balance of the studied reservoirs, the manager must apply the method with the best performance, depending on the data available; (iii) to manage other reservoirs located in the Mediterranean climate region, the manager must compare reservoir characteristics and the data available in order to choose the most suitable method to apply.

Abstract: This review evaluates the economic impact of Farmer Producer Companies (FPCs) under the Atal Bhujal Yojana (ABY) on per capita economic value in Solapur district's Gram Panchayats, a drought-prone region in Maharashtra, India. It explores the intersection of sustainable groundwater management and economic empowerment through collective farming models, addressing challenges in water-scarce agricultural systems. A systematic literature synthesis was conducted, integrating peer-reviewed articles, government reports, and case studies from 2015–2025, alongside analysis of Solapur's agricultural and economic trends. Findings indicate that FPCs, supported by ABY's water budgeting and monitoring tools (e.g., piezometers, water flow meters), enhance per capita income by 10–15% through improved agricultural productivity, with jowar yields increasing from 1.2 to 1.5 tons/ha, and cost savings of ₹5,000–7,000 per hectare via collective procurement. Water-use efficiency improved by 20%, driven by community-led water management, while market access through value-added products like organic jowar flour boosted incomes. ABY's community-driven approach fosters groundwater conservation and inclusive FPC governance, particularly for women. The study highlights policy implications for scaling FPCs, including expanded training, streamlined funding, and integration with schemes like MGNREGA. These findings contribute to sustainable agriculture and rural economic development, offering scalable solutions for drought-prone regions. Future research should explore longitudinal impacts and comparative analyses across Maharashtra's water-stressed districts.

ATMOS-BUD: A Comprehensive Python Tool for Analyzing Heat, Vorticity and Water Budgets on the Atmosphere

Foliar water uptake (FWU) and its role in hydraulic redistribution are critical yet understudied mechanisms, particularly in temperate tree species of Europe. This study investigates FWU in beech (Fagus sylvatica L.), with a focus on its contribution to the tree's water balance beyond leaf level. By using a combination of different imaging techniques such as silver nitrate tracing, positron emission tomography (PET), and autoradiography, we identified foliar water uptake from the point of entry to its subsequent transport. The ionic tracer, silver nitrate (AgNO3), precipitated mainly at trichome bases and extended into subepidermal tissues, enabling the identification of water entry points. However, its inability to reach deeper vascular structures limited the ability to draw conclusions about further water transport and redistribution. Therefore, PET imaging and autoradiography were used and successfully visualised reverse sap flow of radiotracer-labelled water from treated leaves to connected branches, driven by a significant water potential gradient of 1.4 ± 0.9 MPa. Compartmental modelling quantified a net exchange rate eX-P of 0.15 ± 0.07 min⁻¹ between xylem and surrounding parenchyma and a front velocity vFWU of 3.31 ± 0.56 mm min⁻¹ under the imposed Δψ. These findings demonstrate that FWU may actively contribute to replenishing branch water pools, emphasising its role as a critical hydraulic mechanism. This research underscores the utility of integrating PET imaging with complementary methods to better understand FWU dynamics and its implications for plant water budgets under changing climatic conditions.

Sustainable Development Goal 13 emphasized the demand for climate action, which is crucial for understanding climatic variability and its consequences on agricultural planning as well as water resource management. The present study analyzed the trend, frequency, and magnitude of rainfall, temperature, and their extreme climate events using daily time series data for 42 years (1982–2023) with a special focus on coastal climate change in the West Bengal coast. The Mann–Kendall and descriptive statistics, Sequential Mann–Kendall, Innovative Trend, and 21 extreme climate indices have been measured. The results reveal a statistically significant decreasing trend of maximum temperature at the stations Contai and Diamond Harbour, whereas, an increasing trend at Digha and Sagar Island. The minimum temperatures with rising trends have been detected for all the stations. A statistically significant upward trend in rainfall has been observed in this area. The seasonal analysis indicates a notable increase in rainfall trends across all seasons within the region. Surprisingly, post-monsoonal rainfall increases with greater magnitude at all stations and exceeds the magnitude of monsoon rainfall, leading to a shifting of the rainfall pattern. Alterations in rainfall patterns negatively impact both the environment and the economy, leading to an increased likelihood of flooding during the post-monsoon season. This situation can adversely affect agricultural output and may give rise to concerns regarding food security. The Sequential Mann–Kendall test measured significant multiple change points of annual rainfall. The number of Consecutive Wet Days (CWD) in this area has been increasing, potentially affecting the hydrology of groundwater recharge. A prolonged series of wet days allows for greater rainwater absorption into the soil, thereby improving the replenishment of groundwater resources. The area may have experienced storm surge and extreme coastal flood due to increasing RX1 days and RX5 days. These results will enhance the understanding of the seasonal and annual water budget, which is essential for agricultural planning and the overall well-being of the region.

Water budget, fire, and Land Use in the Brazilian Ramsar Sites: Wetlands Drying Out

Abstract Dissolved manganese (dMn) is an essential bioactive element required for marine organisms. Redox condition determines its solubility and its solid phase removal from seawater. It displays a typical scavenging type profile in the Indian Ocean with an elevated concentration in the Oxygen Minimum Zone (OMZ) of the Bay of Bengal (BoB). The surface dMn decreases southward in the BoB, and its concentration gradient correlates well with salinity because of the enormous riverine influx. Reductive dissolution of Iron‐manganese (Fe‐Mn) oxyhydroxides‐rich sediments brought by the Ganga‐Brahmaputra rivers enriches dMn in the bottom waters of the shelf regions (∼25 nM), which gets advected to the open ocean through cross‐shelf transport. The atmospheric input is the prominent source of dMn in the BoB. Transport of the Indonesian Through Flow waters supplies high dMn in the surface waters of the Central Indian Ocean Basin. Internal cycling seems to control the dMn distribution in the water column in addition to its external sources. Water column denitrification increases dMn in the OMZ waters of the BoB through the reductive dissolution of sinking Mn oxide particles under the prevailing suboxic conditions. The presence of two sub‐surface peaks of dMn associated with nitrite maxima suggests active denitrification in the OMZ waters of the BoB, similar to the Arabian Sea. The interaction of circulating fluid with subducting Fe‐Mn‐rich crusts enriches the deep water dMn in the Java Sumatra region. Further, the hydrothermal activity over the Southeast and Central Indian Ridges contributes significantly to the dMn budget of the deeper waters.

WATcycle: A software for terrestrial water cycle and budget analysis with case studies on the Amazon and Mississippi Basins

Remote monitoring of plant drought stress with the apparent heat capacity.

Toward optimal rainfall for flood prediction in headwater basins – improving soil moisture initialization to close the water budget within observational uncertainty

Abstract Land surface water and energy balances are important for understanding the coupling between land and atmosphere in Earth’s climate system. This study employs principal component analysis (PCA) and a variation on Granger causality to investigate land–atmosphere (LA) interactions among soil water content (SWC), surface latent heat flux (LE), sensible heat flux (H), and net radiation (RAD) at flux observation sites across seasons. The time scales of variability for each surface variable are key: For daily data, H is a crucial variable in LA interactions across all seasons, while LE becomes important for LA interactions mainly during warm seasons. SWC, despite its direct link to the surface water budget, appears less influential than energy at daily time scales, as its variability is mainly at longer time scales. Effects of RAD vary seasonally, being more significant in energy-limited regimes during spring and summer. The familiar SWC:LE correlation metric is expanded into a two-dimensional LA coupling matrix by including SWC:H relationships. This matrix facilitates fine classification of LA feedback providing a clearer understanding of water- and energy-limited regimes. Spatial analysis of observation sites shows significant LA interactions mainly in midlatitudes, influenced by solar radiation. The global distribution of LA feedback regimes underlines the complexity of defining such regimes, which vary according to geographic location, local climate, and land/vegetation types. Meanwhile, climate models and reanalyses fail to capture many observed aspects of LA interactions. Such insights are vital for enhancing the predictability of climate models and comprehending the intricate interplay between different surface conditions in LA interactions.

ABSTRACTAlthough many studies have investigated the effects of forest cover reduction, typically resulting from logging, on evapotranspiration or runoff in forested catchments, few have addressed the impact of landslides. In this study, we evaluated the effect of forest cover reduction caused by dense landslides on evapotranspiration in a hilly catchment that was originally entirely forested. The landslides, triggered by the 2018 Hokkaido Eastern Iburi Earthquake, led to the loss of 37% of the forest cover. Evapotranspiration, calculated using the short‐term water budget method approximately 3 and 4 years after the earthquake, was 27% (15%–38% considering uncertainty) and 19% (5%–32%) lower than the evapotranspiration without the impact of landslides, as estimated using a forest evapotranspiration model based on the heat balance calculation developed in Japan. These reductions are comparable to those reported from logging activities. Furthermore, a comparison with a nearby site affected by windthrow suggested that landslides may exert a more severe impact on evapotranspiration, likely due to the reduction of both the forest canopy and the understory. Land managers should be aware that a reduction in evapotranspiration leads to increased runoff, which has the potential to heighten the risk of flooding and increase streamwater turbidity downstream.

Impact of parthenium weed on water budget, evapotranspiration, photosynthetic traits, and osmolytes in vegetables: a method development approach

Abstract The lacustrine Gördes Supradetachment Basin developed along the Simav Detachment Fault during the Early–Middle Miocene postorogenic extension in the north of the Menderes Massif in western Anatolia. The basin‐fill consists of alluvial fan, Gilbert‐type delta, shoal‐water delta, foreshore, shoreface, offshore‐transition and peat‐forming mire deposits. The alluvial fans and fan deltas deposited along all the margins serve as sensitive recorders of tectonic, climatic, and base‐level variations. Process‐based facies analyses of the alluvial fan and fan‐delta deposits provide an excellent opportunity to reconstruct the palaeogeographical evolution. The alluvial fans consist of braided channel‐fill, hyperconcentrated flow and debris flow facies, indicating high‐energy sediment transport mechanisms. Progradational wedges of Gilbert‐type fan deltas formed atop the alluvial fans reflect a rapid rise in lake level. This rise resulted from asymmetrical subsidence of the basin floor, which shifted the water mass laterally, causing rapid regression on one coast and coeval transgression on the other. Changes in basin floor configuration in the Gördes Basin were driven by movement of the Simav Detachment Fault on the southern margin, while the hanging wall was segmented by an antithetic normal fault on the northwestern margin. Consequently, faulting on both sides increased the depth of the accommodation through a sudden lake level rise. Climate controlled both the lake water budget and the catchment sediment yield. The subsidence rate subsequently decelerated, sediment yield decreased and shallow lake conditions prevailed on the NW margin, as evidenced by the shoal‐water deltas. This occurred due to tectonic activity insufficient to produce the large‐scale deepening required for Gilbert‐type delta development. Finally, the clastic components of the offshore transition facies diminished as the carbonate content increased towards the basin's interior and in the upper parts of the succession during the maximum lake expansion.

Abstract Lakes are experiencing ice declines and fundamental changes in winter conditions. For Earth's largest lakes that experience seasonal ice cover, the relationship between ice conditions and evaporation is critical to water balance estimates and global freshwater storage. Here, we analyze robust data sets of net basin supplies, satellite‐derived products, and model estimates of surface turbulent heat flux for the Laurentian Great Lakes during the period 1973–2022. We show that ice cover does not have a strong relationship with lake evaporation in winter months and that often the magnitude of the ice effect on moisture flux reduction is within the range of natural variability and the uncertainty of water budget estimates. This suggests that differences in lake evaporation between cold and warm winters is driven by seasonal overlake atmospheric conditions, more broadly, and that ice cover reduces but does not determine the resultant evaporation.

ABSTRACT This study assesses the impacts of climate change on water budget components in the semi-arid Faria catchment, Palestine. Using climate projections from SimClim AR6 under the SSP2-4.5 and SSP5-8.5 scenarios and hydrological modeling via the Soil and Water Assessment Tool, the research evaluates changes in precipitation, temperature, humidity, wind speed, and solar radiation for the years 2060 and 2100. Calibration and validation show good model performance (R2 = 0.67, NSE = 0.64). Results reveal declining precipitation and relative humidity, with groundwater recharge expected to drop by up to 27.43% and surface runoff by up to 43.31% by 2100. Simultaneously, rising temperatures lead to higher evapotranspiration, reaching a 9.64% increase under the SSP5-8.5 scenario. These shifts result in a significant decrease in overall water yield, posing a threat to water security in the region. The study highlights the urgent need for adaptive water management strategies and promotes the use of integrated climate-hydrological modeling for sustainability planning in similar semi-arid catchments.

Abstract. Achieving water budget closure improves the consistency of water budget component datasets, including precipitation (P), evapotranspiration (ET), streamflow (Q) and terrestrial water storage change (TWSC), thereby advancing our understanding of basin-scale water cycle dynamics. Existing water budget closure correction (BCC) methods typically aim to eliminate the entire water imbalance error (ΔRes) by fully redistributing it across budget components. However, this often overlooks the trade-off between achieving perfect closure and the errors introduced into the corrected components through this redistribution. Moreover, inaccurate estimation of redistribution weights can lead to contradictory outcomes, such as negative values in P, ET, or Q. In this study, we quantify the uncertainties introduced by four existing BCC methods (CKF, MCL, MSD, and PR) at the monthly scale across 84 basins spanning diverse climate zones. We then propose a novel method, IWE-Res, which identifies an optimal redistributing strategy by minimizing the combined error from both the errors introduced to individual budget components and the remaining ΔRes error. This method also reduces the occurrence of negative values in the corrected datasets. Our results show: (1) Existing BCC methods can result in negative values in 0 %–10 % of the time series for each corrected budget component (typically <5 %); (2) The proposed IWE-Res method improves the accuracy of corrected components compared to existing methods, reducing RMSE by 29.5 % for P, 24.7 % for ET, 69.0 % for Q, and 6.8 % for TWSC; and (3) For most basins, excluding those in cold regions, the optimal redistribution is achieved when 40 %–90 % of ΔRes is redistributed. By offering a more balanced approach to water budget closure, this study improves the accuracy and reliability of corrected budget component datasets.