Journal of Hydrology-Regional Studies最新文献

{"title":"Adaptive meta-modeling of evapotranspiration in arid agricultural regions of Saudi Arabia using climatic factors, drought indices and MODIS data","authors":"Osama Elsherbiny ,&nbsp;Salah Elsayed ,&nbsp;Obaid Aldosari ,&nbsp;Muhammad Sohail Memon ,&nbsp;Ahmed Elbeltagi","doi":"10.1016/j.ejrh.2025.102279","DOIUrl":"10.1016/j.ejrh.2025.102279","url":null,"abstract":"<div><div><strong>Study Region:</strong> The research was conducted in three arid agricultural regions of Saudi Arabia: Wadi Ad-Dawasir, Ranya, and Abha.</div><div><strong>Study Focus:</strong> The objective is to develop an intelligent approach that utilizes ET-AI (Release 1, developed by Osama Elsherbiny), an accessible and user-friendly software, to compute actual evapotranspiration (AET) with both speed and accuracy. This can enhance irrigation efficiency and optimize water resource management. The data collected from 2000 to 2023 encompass four environmental factors (EF), two drought indices (DI), and six MODIS spectral indices (SI). Machine learning models, including the backpropagation neural network (BPNN) and XGBoost Regressor (XGB), enhanced with an adaptive meta-model (AMM) strategy, were evaluated for predicting monthly AET. The best-performing model was designated based on statistical metrics, with a focus on minimizing discrepancies between predicted and actual AET values.</div><div><strong>New Hydrological Insights for the Region:</strong> The results revealed robust correlations between AET and the combination of climatic water deficit (Def) with minimum (Tmin) or maximum temperature (Tmax), with R² values ranging from 0.70–0.67 in Wadi Ad-Dawasir, 0.59–0.57 in Ranya, 0.80–0.77 in Abha, and 0.64–0.55 for combined data. These findings highlight the regional sensitivity of AET to temperature and water deficit variations, offering valuable insights for water management strategies. Furthermore, the study reveals distinct spatial patterns of evapotranspiration dynamics across the region, which are crucial for improving irrigation practices under varying climate conditions. The BPNN-AMM model, deploying eleven EF-DI-SI features, delivered superior performance (R²=0.914, RMSE=6.115) compared to the standalone BPNN model (R²=0.850, RMSE=7.289). It also outperformed the XGB-AMM model with seven hybrid traits (R²=0.869, RMSE=9.285), in contrast to the separate XGB model (R²=0.684, RMSE=10.584). By refining the precision of AET predictions, the model clarifies water balance processes in arid regions. These insights have the potential to guide regional water resource management and enable real-time AET monitoring. The developed software is available for access at (<span><span>https://drive.google.com/file/d/1dPMiDzngtzDIY65xIyo8MAIVbJMudeBc</span><svg><path></path></svg></span>).</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102279"},"PeriodicalIF":4.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond streamflow: Plausible hydrological modelling for the Upper Blue Nile Basin, Ethiopia","authors":"Aseel Mohamed ,&nbsp;Micha Werner ,&nbsp;Pieter van der Zaag","doi":"10.1016/j.ejrh.2025.102290","DOIUrl":"10.1016/j.ejrh.2025.102290","url":null,"abstract":"<div><div><em>Study region:</em> Upper Blue Nile Basin (UBNB), Ethiopia.</div><div><em>Study focus:</em> We explored the potential of using the globally available actual evapotranspiration (ETa) dataset in the model calibration processes to enhance hydrological model plausibility for the large UBNB. We compared three calibration strategies: conventional single-point calibration based on streamflow data, spatially explicit ETa-based calibration, and a multi-variable approach incorporating both streamflow and ETa data.</div><div><em>New hydrological insights for the region:</em> Our results underscore the limitations of single-variable calibration in capturing the heterogeneity of the UBNB, particularly in the estimation of ETa. By integrating ETa into the calibration process, multi-variable calibration offers improved performance across both streamflow and ETa simulations, providing valuable insights into basin dynamics and internal processes. This approach, leveraging ETa as a signature of basin heterogeneity in the calibration, demonstrates significant promise for enhancing the plausibility of hydrological models in the complex, and large UBNB while maintaining computational simplicity. We used SWAT+, which is the most recent version of the most used hydrological model in the UBNB, SWAT. Thus, this study provides a benchmark for the employment and calibration of the SWAT+ model.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102290"},"PeriodicalIF":4.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling groundwater futures under climatic uncertainty for local policy and planning: A case of quantification of groundwater resources at sub-regional level in the Ganges basin","authors":"Syed Adil Mizan ,&nbsp;Alok Sikka ,&nbsp;Shreya Chakraborty ,&nbsp;Alison Laing ,&nbsp;Anton Urfels ,&nbsp;Timothy J. Krupnik","doi":"10.1016/j.ejrh.2025.102315","DOIUrl":"10.1016/j.ejrh.2025.102315","url":null,"abstract":"<div><h3>Study region</h3><div>Nalanda district, Bihar, India, a sub-tropical region, and part of middle Ganga River basin.</div></div><div><h3>Study focus</h3><div>Assessing the impacts of climate change on aquifers' seasonal replenishment is thus crucial for planning for future local food and water security. This study looks at how future groundwater levels will be affected by climate change in relation to important functioning thresholds that are typical for aquifers that replenish periodically.</div></div><div><h3>New hydrological insights for the region</h3><div>The result shows the projected groundwater levels from 2018 to 2060 using the CMIP6 global climate model, using rainfall data from three GCMs selected based on their different projected scenarios of levels of high intensity rainfall. Given the key role of low intensity rainfall in groundwater recharge, we find that incorporating rainfall intensity in groundwater models can be crucial for more robust projections. Our findings also show that higher total rainfall does not necessarily equate to higher groundwater recharge or lesser groundwater declines. Instead, the least groundwater declines were found in projections, where relatively higher total rainfall was also associated with lower high intensity rainfall periods, highlighting the need for combining and comparing varied SSPs and climate models for accurate future trends. At the sub-regional level, we find that climate change could lead to maximum groundwater loss of ∼ 0.8 km3 in 42 years in Nalanda district. Current trend analysis (2000–2018) already shows a negative annual groundwater balance. Even assuming no changes to current groundwater extraction rates, climate change will result in decreased groundwater levels and storage. The projection trends also reveal distinct short-term, medium-term, and long-term shifts which offer different policy windows for managing and governing the groundwater resources.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102315"},"PeriodicalIF":4.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the spatiotemporal evolution pattern of the synergistic relationship among high temperature, drought, and CHTDs in climate transition zones","authors":"Hui Su ,&nbsp;Chunxiao Wu ,&nbsp;Shuai Zhou ,&nbsp;Xiangxu Song ,&nbsp;Jiaqi Tian ,&nbsp;Xiaoqing Han ,&nbsp;Xiao Zhang ,&nbsp;Ting Zhang","doi":"10.1016/j.ejrh.2025.102312","DOIUrl":"10.1016/j.ejrh.2025.102312","url":null,"abstract":"<div><h3>Study region</h3><div>The Yellow River Basin (YRB)</div></div><div><h3>Study focus</h3><div>Based on the dry and wet characteristics of the basin, various climate zones are delineated. Subsequently, predictions from the coupled four climate models (CanESM5, CNRM-CM6–1, CNRM-ESM2–1, and IPSL-CM6A-LR) and the statistical downscaling model are used to construct standardized precipitation evapotranspiration indices and standardized temperature indices, which reveal the spatiotemporal evolution characteristics of drought and high temperatures in the watershed under different future scenarios (SSP126, SSP245, SSP585). Finally, the spatiotemporal dynamic evolution characteristics of high temperatures, droughts, and CHTDs (compound high temperature and drought events), where high temperature and drought events occur simultaneously, are analyzed.</div></div><div><h3>New hydrological insights for the regions</h3><div>By analyzing the evolution patterns of drought in historical and future periods, the results indicate that severe drought in arid regions will alleviate during the period of July to August in the future. Compared to historical periods, the arid region will experience extreme drought, and the southeastern part of the semi humid region will experience varying degrees of drought. Further analysis of the evolution of high temperature events indicates that by 2060, the timing of high temperature events in the basin is expected to gradually shift to late spring. The high temperature events from May to July will cover most of the central and eastern parts of the basin and continue to develop into heatwave events (defined as three consecutive days of high temperature). The spatial variation pattern of CHTDs is relatively similar in three scenarios. From May to July, the CHTDs is expected to become more severe in all climate regions except for arid region, especially in the southeastern semi-humid region, where the affected areas will significantly expand and affect some irrigation districts. In the SSP126 scenario of the future period, the maximum coverage of CHTDs is the largest (19.06 %), and the occurrence month is similar to history. However, in the SSP245 and SSP585 scenarios, the maximum coverage of CHTDs is also advanced to July, but the coverage rate (SSP245 is 17.82 %, SSP585 is 17.80 %) is smaller compared to the SSP126 scenario. From a temporal perspective, as the scenario worsens, the occurrence of CHTDs gradually increases, but mainly concentrated in the near term (2020–2040), and gradually decreases in the medium to long term, especially in the SSP585 scenario, where the occurrence of CHTDs in the long term (2071–2100) is 0. This study provides important reference value for the spatiotemporal evolution of composite events in climate transition zones under different scenarios.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102312"},"PeriodicalIF":4.7,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying the impact of nuisance flooding on urban coastal communities under present and future climatic conditions: Norfolk, Virginia as a case study","authors":"Jiwoo Jeong ,&nbsp;Sergio A. Barbosa ,&nbsp;Jonathan L. Goodall","doi":"10.1016/j.ejrh.2025.102304","DOIUrl":"10.1016/j.ejrh.2025.102304","url":null,"abstract":"<div><h3>Study region</h3><div>Norfolk, Virginia, United States</div></div><div><h3>Study focus</h3><div>Nuisance flooding, characterized by frequent but minor floods, has been on the rise and the trend is expected to continue due to climate change. Utilizing a two-dimensional surface flow / one-dimensional pipe hydrodynamic model, this study presents a methodology for simulating flooding from low return period tidal and rainfall events to quantify the impact of nuisance flooding on urban coastal communities under present and future climatic conditions. Applying the methodology, the results show the impact of nuisance flooding from tidal alone and compound (i.e., rainfall and tide) events.</div></div><div><h3>New hydrologic insights for the region</h3><div>Using 2020 as a base year, the model suggests tidal nuisance flooding (TNF) impacts approximately 4 % (1.87 km²) of the study area. With a projected 1-meter sea-level rise by 2100, the TNF extent is projected to increase to approximately 12 % (5.85 km²) — more than tripling the 2020 TNF extent. For the 2020 base year, when rainfall and high tide occur simultaneously, compound nuisance flooding (CNF) leads to 11 % (5.15 km²) of the study area being inundated. By 2100, the projected inundated area by CNF is estimated to be 20 % (9.41 km²). Overall, sea level rise drives the expansion of TNF along riverbanks and adjacent areas, while submerging many urban drainage system outlets. This prevents efficient rainfall drainage, which causes CNF on inland low-lying areas.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102304"},"PeriodicalIF":4.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating stream power distribution along river longitudinal profiles using Log S – log A plots","authors":"Jui-Tien Tsai ,&nbsp;Yen-Yu Chiu ,&nbsp;Su-Chin Chen","doi":"10.1016/j.ejrh.2025.102305","DOIUrl":"10.1016/j.ejrh.2025.102305","url":null,"abstract":"<div><h3>Study region</h3><div>Eighteen main rivers in Taiwan.</div></div><div><h3>Study focus</h3><div>This study focused on the analysis of total stream power (TSP) and specific stream power (SSP) along river longitudinal profiles, which are critical indicators of river dynamics. A new two-parameter regression model is proposed, addressing inaccuracies in traditional models and providing a more-precise representation of river profiles. By incorporating concavity, drainage area distribution, discharge, and river width relationships, the model identifies the locations of the TSP and SSP peaks. The study employs log (river slope, <em>S</em>) – log (drainage area, <em>A</em>) plots to evaluate the spatial variability of these metrics under diverse geomorphological and hydrological conditions.</div></div><div><h3>New hydrological insights for the region</h3><div>The model was used to categorize 18 rivers in Taiwan into three groups based on river source elevation and drainage area–flow length exponents. Key findings indicate that lower source elevations correspond to increased upstream drainage-area distribution and greater concavity. This highlights the interplay between intrinsic watershed characteristics and external hydrological forces in shaping TSP and SSP distributions. These insights provide a basis for improved river management, sediment transport predictions, and conservation efforts.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102305"},"PeriodicalIF":4.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the economic impact of droughts in Europe in a changing climate: A multi-sectoral analysis at regional scale","authors":"Corrado Motta ,&nbsp;Gustavo Naumann ,&nbsp;Diego Gomez ,&nbsp;Giuseppe Formetta ,&nbsp;Luc Feyen","doi":"10.1016/j.ejrh.2025.102296","DOIUrl":"10.1016/j.ejrh.2025.102296","url":null,"abstract":"<div><h3>Study region</h3><div>The EU member states plus UK, Norway, and Switzerland.</div></div><div><h3>Study Focus</h3><div>In the recent past, Europe has faced several extreme drought events that have generated high economic losses across socioeconomic sectors. Climate change is expected to alter the frequency and intensity of these events. In order to increase drought resilience through adaptation it is essential to discern regional and sectoral drought risk patterns that account for the specific characteristics of local territories. In this study, we integrate drought hazard modelling with regional exposure mapping and vulnerability assessment to quantify drought impacts in drought-sensitive sectors across 1366 administrative territorial units of Europe, considering present climate conditions and a range of global warming levels.</div></div><div><h3>New hydrological insights for the region</h3><div>Our results show a strong regional disparity in future drought impacts, with an overall increase in drought losses in southern, south-eastern, and western regions of Europe and a decrease in northern regions. Regional differences are amplified with increasing global warming and depend on the intensity of the drought, modulated by the exposure and vulnerability of drought-sensitive socioeconomic sectors. In some of the most impacted regions, economic losses could become substantial, with expected annual losses corresponding to 1–2 % of regional gross domestic product, while the agriculture sector could lose 15 % of its gross value added with high levels of global warming.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102296"},"PeriodicalIF":4.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An integrated hydrological model to simulate terrestrial water storage in a large river basin: Evaluation using GRACE data","authors":"Sai Srinivas Gorugantula,&nbsp;BVN P Kambhammettu","doi":"10.1016/j.ejrh.2025.102309","DOIUrl":"10.1016/j.ejrh.2025.102309","url":null,"abstract":"<div><h3>Study region</h3><div>Krishna River Basin, India</div></div><div><h3>Study focus</h3><div>Integrated hydrological models that simulate surface and subsurface processes, and their interactions in a single framework are essential for effective management of large-scale river basins. This research is aimed at developing an integrated hydrological model for the Krishna River Basin (KRB), India by tightly coupling a semi-distributed hydrological model (SWAT) with a fully distributed groundwater model (MODFLOW).</div></div><div><h3>New hydrological insights for the region</h3><div>For the first time, the coupled SWAT-MODFLOW model was applied to a large (&gt;250,000 km²), conjunctively managed, complexly interacted river basin. SWAT simulated streamflows and evapotranspiration (ET) for the seven sub-basins agree with gauge flows (R: 0.45–0.85; NSE: 0.2–0.69) and MODIS-derived ET fluxes (R: 0.18–0.81; NSE: −3.18–0.66). However, MODFLOW simulated heads are in less agreement with observed groundwater levels (R: −0.6–0.6) due to spatial averaging. The coupled SWAT-MODFLOW is used to estimate terrestrial water storage anomalies (TWSA) at sub-basin level and validated with downscaled GRACE data at 0.25^° resolution. Model performance is good for the lower reaches (NSE &gt;0.3; R &gt;0.65) with high flow exchanges and is low for the upper reaches due to underestimation of individual fluxes (NSE &lt;0.3; R &lt;0.65). We observed a basin-wide decline in TWSA during the simulation at a rate of 1.45 mm/month. Our findings can help in developing contextual plans for effective management of water resources.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102309"},"PeriodicalIF":4.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data-driven assessment of climate change and vegetative cover dynamics in traditional oases","authors":"Elisa Baioni,&nbsp;Giulia Fiantanese,&nbsp;Giovanni Michele Porta","doi":"10.1016/j.ejrh.2025.102266","DOIUrl":"10.1016/j.ejrh.2025.102266","url":null,"abstract":"<div><h3>Study region:</h3><div>Abiod Valley, Aurès region, Algeria.</div></div><div><h3>Study focus:</h3><div>This work focuses on the relation between climatic forcing and vegetation cover dynamics in traditional oases. This study pursues two main objectives: (1) estimate the vegetative surface cover of traditional oases from satellite images, (2) quantify the impact of climatic variables on vegetation dynamics and assess future scenarios. We propose a methodology that leverages satellite imagery and derived indices (NDVI, NDMI) to quantify vegetation cover and water stress events at the oasis spatial scale. We then assess the feedback between climate and vegetation cover at monthly and yearly scale through multivariate analyses based on vector autoregression (VAR) and vector error correction (VEC) models.</div></div><div><h3>New hydrological insights for the region:</h3><div>Our findings reveal an appreciable decrease in vegetation cover over the last decade across three considered traditional oases in the study region. The monthly scale analysis suggests a lagged effect of climatic variables, especially cumulative precipitation, on vegetation water stress. The long term VEC prediction of climatic variables aligns with GDDP-CMIP6 climate projections, forecasting an increase in average temperature and potential evapo-transpiration. A significant decline in vegetative surface cover is predicted by 2050 from the analysis of yearly data, highlighting the critical need for water management interventions to safeguard oasis ecosystem and prevent desertification.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"59 ","pages":"Article 102266"},"PeriodicalIF":4.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrologic pathways and nutrient loading in the headwaters of the Western Lake Erie Basin","authors":"Mark R. Williams ,&nbsp;Chad J. Penn ,&nbsp;Kevin W. King","doi":"10.1016/j.ejrh.2025.102275","DOIUrl":"10.1016/j.ejrh.2025.102275","url":null,"abstract":"<div><h3>Study region</h3><div>Western Lake Erie Basin (WLEB). The WLEB is a flat, artificially drained, and intensively managed agricultural region typical of the U.S. Midwest.</div></div><div><h3>Study focus</h3><div>The study objective was to quantify hydrologic pathways using tracer-based hydrograph separation in a headwater watershed (19 km²) of the WLEB and assess relationships between water sources and fluxes and nutrient delivery. High-frequency measurement of two tracers (oxygen-18, δ¹⁸O; electrical conductivity, EC) along with discharge and nutrient concentration (nitrogen, N; phosphorus, P) was conducted at the watershed outlet (2017–2020).</div></div><div><h3>New hydrological insights for the region</h3><div>Results provide new insights into hydrologic and nutrient transport processes in artificially drained agricultural watersheds. Findings showed that 76 % discharge occurred during the winter and spring due to a threshold relationship with precipitation and soil moisture deficit. Hydrograph separation using δ¹⁸O and EC provided similar estimates of event water (26 ± 13 % and 26 ± 11 %, respectively), but substantial differences (up to 21 %) were observed between tracers for individual storms. Annually, event water comprised 13–27 % of discharge. Nutrient loads during storm events were strongly correlated to discharge, as flow-weighted mean concentrations (FWMCs) were consistent among storms and seasons. Both dissolved reactive P and ammonium-N FWMC were correlated to water sources. Findings suggest that decreasing discharge, decreasing the nutrient supply, and enhancing nutrient removal within ditch networks are needed to decrease nutrient loading drained watersheds in the WLEB.</div></div>","PeriodicalId":48620,"journal":{"name":"Journal of Hydrology-Regional Studies","volume":"58 ","pages":"Article 102275"},"PeriodicalIF":4.7,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}