Journal of Hydrology最新文献

{"title":"A comprehensive investigation of event-based rainfall analysis in arid and semi-arid climates: An integration of innovative storm volume-duration-frequency (SVDF) schemes and Event-Based dimensionless hyetographs (EDH)","authors":"Mohamed Elkollaly ,&nbsp;Ahmed Sefelnasr ,&nbsp;Mohsen Sherif","doi":"10.1016/j.jhydrol.2025.132959","DOIUrl":"10.1016/j.jhydrol.2025.132959","url":null,"abstract":"<div><div>Recent global shifts in climate have intensified variability in the hydrological cycle and heightened occurrences of extreme weather events. In arid regions, sporadic and intense rainfall often leads to extreme flash floods, posing serious risks to infrastructure, ecosystems, and public safety. This study investigates the frequency dynamics of rainstorm characteristics in arid and semi-arid climates, utilizing the Minimum Inter-Event Time (MIET) approach. The employed hourly precipitation datasets comprise all available pixels at a 0.1-degree resolution across the United Arab Emirates (UAE) over a 21-years. The research underscores the diversity of climatic profiles within the UAE. The appropriate MIET values, ranging from 6 to 9 h, were assigned to nine clustered climatic regions to discern storm attributes, i.e. volume, duration, intensity, and dry periods. The comprehensive frequency analysis, incorporating ten probability distributions and five statistical indices, showcases the robust performance of two distributions, Generalized Extreme Value (GEV) and the two-parameter lognormal, in capturing extreme storm features. Subsequently, the optimal models were utilized in the sensitivity analysis of the novel Storm Volume-Duration-Frequency (SVDF) scheme, revealing that longer storms do not necessarily produce the largest rainfall volumes, and extreme intensities are not restricted to the shortest storms. The innovative approach offers a more realistic interpretation of events-based rainfall patterns, challenging conventional frequency analyses. In region 5, a 7-hour storm resulted in 111 mm of rain, while the 8-hour storm yielded just 59 mm at a 100-year return period. Another critical observation was the shift in extreme storm behavior, i.e. the 5-hour storm produced the peak volume up to a 10-year return period in region 9, after which the 7-hour storm became dominant, reaching 104 mm at a 100-year return period. Overall, coastal regions are highly vulnerable to extreme events and flash flood hazards. An empirical formula was developed to describe the relationship between storm volume (V, mm), duration (D, hr), and return period (Tr, years) within the framework of SVDF curves. The derived SVDF curves were then integrated into Event-Based Dimensionless Hyetographs (EDH) to enhance rainfall intensity predictions. The EDH is delineated employing events-based historical temporal analysis. This study attempts to thoroughly describe the behavior of rainstorm patterns, deduce design storms, and thereby enhance hydrological modeling. The innovative methodology could change some hydrological concepts and contribute to more effective planning and hazard mitigation strategies.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"655 ","pages":"Article 132959"},"PeriodicalIF":5.9,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Large glaciers sustaining the Upper Indus Basin glacier runoff in the future","authors":"Muhammad Mannan Afzal ,&nbsp;Xiaolei Wang ,&nbsp;Yi Luo","doi":"10.1016/j.jhydrol.2025.132952","DOIUrl":"10.1016/j.jhydrol.2025.132952","url":null,"abstract":"<div><div>Hydrology and water resources are global concerns in basins where glacial melt contributes to water availability and are vulnerable to changes in climate and glacier dynamics. Investigating how glaciers of different dimensions respond to climate change and affect hydrological processes is crucial. This study addresses these issues in the Upper Indus Basin (UIB), which has extensive coverage of glaciers with diverse dimensions. We used a physically calibrated and evaluated Open Global Glacier Model (OGGM) model in eight sub-basins within the UIB to simulate glacier dynamics under CMIP6 climate change scenarios and investigate their dimensional effects. The average annual mass balance (MB) of the UIB was −0.16 ± 0.15 m w.e. a⁻¹, with substantial changes observed in the Zanskar sub-basin (−0.55 ± 0.11 m w.e. a⁻¹) over the last six decades. Our findings indicate that large glaciers are becoming narrower and thinner, while small glaciers are disappearing, driven by changes in their length, area, and volume. By 2100, the ice volume is projected to decrease to 60.53 % and the area to 63.26 % in the UIB. Tipping points (peak runoffs) for glacial runoff are anticipated to occur early this century for small glaciers, in the mid-century for medium-sized glaciers, and in the late century for large glaciers. Glacial runoff will increase by 132.2 % in UIB, and this increase is mediated by Karakoram sub-basins glacier runoff. Specifically, UIB small, medium, and large glaciers are expected to contribute 18.33 %, 18.84 %, and 62.82 % of the total glacier runoff, respectively. Further investigation revealed that the in Karakoram sub-basins (Hunza, Shigar, and Shyok) large glaciers contribute 52.63 % to the UIB’s total glacier runoff, while the contributions from large glaciers in the Himalayas and Hindukush are only 5.82 % and 4.37 %, respectively, in the 2090s.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"657 ","pages":"Article 132952"},"PeriodicalIF":5.9,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143654644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment method for the hydraulic efficiency of urban drainage system components","authors":"Kamil Pochwat","doi":"10.1016/j.jhydrol.2025.132975","DOIUrl":"10.1016/j.jhydrol.2025.132975","url":null,"abstract":"<div><div>This study evaluates the performance of different retention solutions in stormwater drainage systems. The outcome of this study proposes a method to determine the hydraulic efficiency of different stormwater drainage retention components, in which instead of assessing retention capacities, the resistance time is used. The study was conducted in a laboratory setting, involving four different hydraulic units designed to increase channel retention in the drainage system. These units operate under diverse hydraulic conditions, including varying channel gradients, different inflow rates, and differential outflow reductions. The analysed units included a linear system (<em>U1</em>), a linear system with increased retention (<em>U2</em> and <em>U4</em>), and a ring system (<em>U3</em>). The experiments conducted laid the groundwork for a method to determine the hydraulic efficiency of drainage components in situations where estimating efficiency based on the analysis of required capacities is impossible or very time-consuming. The research results were utilised to assess the hydraulic efficiency of the studied hydraulic units <em>U1</em>-<em>U4</em>. The results of this study indicated a significantly higher efficiency of ring systems (<em>U3</em>) under all input scenarios at the highest tested flows (12L/s). In specific cases, its application allowed for over a 5-fold extension of the system’s correct operation time, and the determined hydraulic efficiency coefficient α values ranged between 4.5 and 11.4. For lower flows (10 L/s), the most effective system varied depending on the hydraulic conditions, with the channel gradient identified as the parameter that most significantly influenced the efficiency of individual solutions.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"655 ","pages":"Article 132975"},"PeriodicalIF":5.9,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A spatiotemporal hydro-economic optimization modeling framework for integrating the conjunctive surface water and groundwater management with the crop pattern in an arid endorheic river basin","authors":"Jian Song ,&nbsp;Jianfeng Wu ,&nbsp;Jinguo Wang ,&nbsp;Ziyue Yin ,&nbsp;Yun Yang ,&nbsp;Jin Lin ,&nbsp;Jichun Wu","doi":"10.1016/j.jhydrol.2025.132972","DOIUrl":"10.1016/j.jhydrol.2025.132972","url":null,"abstract":"<div><div>The spatial heterogeneity and temporal dynamics under hydrological and hydrogeological conditions for the large endorheic river basins urgently need to implement spatiotemporal hydro-economic optimization for agricultural and environmental water demand. However, the current optimization lacks a comprehensive modeling framework that fully integrates the crop pattern with conjunctive use of surface water (SW) and groundwater (GW) and the consequent hydrological responses of river–lake-groundwater system. To address this challenge, a novel hydro-economic simulation–optimization framework was developed to alleviate the conflicts between agricultural and environmental sectors. The simulation model integrated a machine learning model namely kernel extreme learning machine with physically-based MODFLOW-NWT to significantly lower the huge computational burden. The optimization model based on the <em>ɛ</em>-MOMA algorithm was used to maximize net agricultural economic profit, GW and lake water storage by optimizing crop pattern, SW/GW irrigation and ecological water diversion. The framework was validated in the Yanqi Basin, an arid endorheic river basin with intensive agricultural expansion. The optimization results demonstrate that the net economic profit conflicts with the GW and lake water storage subject to water scarcity in the arid basin. The representative Pareto schemes including the extreme and compromising solutions are compared with the historical scheme to uncover the management implications. First, the net profit, the lowest lake level can be elevated by up to 14.7 % and 1.60 m, respectively, and the largest GW drawdown can be reduced by up to 3.83 m compared to the pre-optimized scheme. Second, the cash crop acreage dominates net profit and can be increased in the first two management periods to maximize agricultural economic objective. However, the schemes maximizing GW and lake water storage objective need to lower cash crop acreage and reduce irrigation water demand throughout the management period. Then, SW irrigation is largely elevated by collaboratively optimizing the ecological water diversion to significantly reduce GW irrigation in the last two management periods compared to the pre-optimized scheme. Therefore, it is of great importance for achieving the optimal trade-offs between agricultural and environmental water demand to implement conjunctive SW and GW management. Finally, the location-dependent crop pattern and water policy can be optimized to identify spatial adjustment with the preferred objectives in the different irrigation districts. Overall, these results advance our understanding of conjunctive water management and crop pattern regulation in the arid endorheic river basin, and testify the flexibility and usefulness of the hydro-economic optimization framework.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"655 ","pages":"Article 132972"},"PeriodicalIF":5.9,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating machine learning with process-based glacio-hydrological model for improving the performance of runoff simulation in cold regions","authors":"Babak Mohammadi ,&nbsp;Hongkai Gao ,&nbsp;Petter Pilesjö ,&nbsp;Ye Tuo ,&nbsp;Renkui Guo ,&nbsp;Zheng Duan","doi":"10.1016/j.jhydrol.2025.132963","DOIUrl":"10.1016/j.jhydrol.2025.132963","url":null,"abstract":"<div><div>Hydrological modelling is essential for effective water resources management, as it represents complex physical processes through mathematical equations to improve our understanding of the water cycle. FLEX^G is a glacio-hydrological model that has been successfully applied and found to perform well in glacierized regions. This study seeks to improve the capability of classical FLEX^G model for glacio-hydrological simulations in northern Sweden using three different hybrid approaches. The first approach integrates the Random Forest (RF) algorithm with the FLEX^G model to simulate catchment runoff dynamics using the physical principles of catchments. This process-guided approach incorporates the concepts of glacier and non-glacier runoffs into RF training. The second hybrid approach refines runoff predictions by integrating residuals with meteorological and glacio-hydrological variables, demonstrating improved accuracy in simulated daily runoff. The third hybrid approach couples meteorological and glacio-hydrological variables via a sequential approach into RF model. The FLEX^G simulated daily runoff with Kling-Gupta Efficiency (KGE) of 0.68 and Nash-Sutcliffe Efficiency (NSE) of 0.58 during the validation period, while the best hybrid model (the second hybrid approach) achieved KGE of 0.90 and NSE of 0.86 in the same period. In addition, the best hybrid approach improved capability of the process-based hydrological model for detection of the top 10 % peak flow events, achieving False Alarm Ratio (FAR) of 0.11 and Probability of Detection (POD) of 0.90. The results showed that the proposed hybrid approaches are capable of improving the performance of the FLEX^G model. However, it is important to recognize that increasing the number of variables also adds complexity to the model’s structure. This research demonstrates the potential of hybrid modelling approaches to enhance glacio-hydrological predictions in cold regions, which can be useful for water resource management in rapidly changing glaciated environments.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"656 ","pages":"Article 132963"},"PeriodicalIF":5.9,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143563185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Introducing the novel method of equation-oriented modeling for pollutant transport in different types of river networks","authors":"Shayan Farhadi,&nbsp;Mehdi Mazaheri","doi":"10.1016/j.jhydrol.2025.132913","DOIUrl":"10.1016/j.jhydrol.2025.132913","url":null,"abstract":"<div><div>Rivers are vital for ecosystems, water resources, and sustaining life on Earth. Modeling pollutant transport in river networks is essential for reducing environmental contamination but classical numerical methods struggle with the complexities of these networks. This research introduces a novel Equation Oriented Modeling approach using open-source mathematical software to enhance flexibility, transparency, ease of modification and integration of multiple physics in complex river networks. The EOM approach formulates the problem as a coupled system of partial differential equations. In this approach, the boundary conditions at internal nodes are defined to ensure mass conservation and concentration continuity, while also accounting for the effect of dispersion in the transport of pollution to other branches which often overlooked in classical methods. Once the boundary and initial conditions for the network are established, the system is solved using method of lines. unlike classical method, EOM using the power of mathematical software to discretize the equations to reduce coding, especially in loop networks, provides the option to define equation terms to apply more complexity to modeling and integrate multiphysics in modeling, and consider the effect of dispersion in mixing and rejection of pollution at the nodes and also facilitates coupling with other tools for post-processing. To verify this method, two networks of tree-type and loop-tree type were utilized. According to the results, the error parameters such as RMSE and MAE are close to zero and the R² parameter was between 98 and 100. However, considering the results of the error parameters and graphs, especially in the case 2 test at times 0.33, 0.5, 0.58 and 0.67, it can be stated that whenever the dispersion mechanism becomes more pronounced due to the increase in the dispersion coefficient and in addition to the time difference in the pollution reaching the node, the difference between the results of the classical method and EOM becomes apparent, so that at time 0.58 the values of R2, RMSE, MAE reached 0.87, 0.0542 and 0.0296, respectively. In addition, the results of the EOM model had appropriate stability due to the severe changes in the flow parameters in the case 2 test and convergence was achieved.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"655 ","pages":"Article 132913"},"PeriodicalIF":5.9,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143508854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel insights into the DOM-driven processes affecting nitrogen cycling in shallow aquifers of the West Liao River Plain: Evidence from FT-ICR MS and isotope analyses","authors":"Jiaqi Jiang ,&nbsp;Chunli Su ,&nbsp;Han Geng ,&nbsp;Yanxin Wang ,&nbsp;Weili Ge ,&nbsp;Hongjie Pan ,&nbsp;Xianjun Xie ,&nbsp;Guojie Feng","doi":"10.1016/j.jhydrol.2025.132969","DOIUrl":"10.1016/j.jhydrol.2025.132969","url":null,"abstract":"<div><div>The significant influence of hydro(bio)geochemical processes induced by organic matter (OM) on groundwater nitrogen contamination has been widely reported. However, the mechanisms controlling the heterogeneous distribution of this contamination as well as the impact of the biodegradability of OM on nitrogen species in sedimentary aquifers are not yet well understood. In the West Liao River Plain (WLRP), northeastern China, shallow groundwater is severely affected by ammonia nitrogen (NH₄⁺-N), accompanied by high Fe²⁺ concentrations. This study used high-resolution organic matter spectroscopy (FT-ICR MS) and stable isotope techniques to investigate the contrasting sources of DOM and their effect on nitrogen cycling in two adjacent reaches with different hydrogeological settings. The disparities in controlling nitrogen occurrence and transformation by coupled processes involving OM and Fe oxides in the two reaches were identified. High levels of NH₄⁺-N (average 1.94 mg/L) in groundwater were observed in the reaches of XKR, where groundwater flow is sluggish and sedimentary aquifers are rich in OM derived from terrestrial humic components. The strong humification and degradation of DOM as well as the preferential utilization of terrestrial humic-like components with high NOSC values mediate the reductive dissolution of Fe oxides to produce a large amount of Fe²⁺, which provides sufficient electron donors for DNRA and promotes the presence of high ammonia groundwater. In contrast, in groundwater from the WLR reaches, DOM is mainly biogenic and less degraded. The degradation of DOM and N-containing DOM is dominated by aliphatic and highly unsaturated compounds, respectively, resulting in the mineralization of N-containing molecules and relatively high NH₄⁺-N concentrations (average 0.73 mg/L). Significant accumulation of heteroatom(S)-containing DOM is evident in WLR groundwater, highlighting the importance of sulfate reduction in shaping the composition of DOM, dissolution of Fe oxides, and DNF process. These findings provide new evidence and perspectives for understanding the hydro(bio)geochemical processes controlling nitrogen cycling in alluvial aquifer systems.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"655 ","pages":"Article 132969"},"PeriodicalIF":5.9,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing extreme rainfall using Max-Stable Processes under changing climate in India","authors":"Degavath Vinod,&nbsp;Amai Mahesha","doi":"10.1016/j.jhydrol.2025.132922","DOIUrl":"10.1016/j.jhydrol.2025.132922","url":null,"abstract":"<div><div>Climate change has markedly intensified the frequency and intensity of extreme rainfall events globally over recent decades. The present investigation introduces a novel approach to modeling Intensity-Duration-Frequency (IDF) curves for major river basins in India using max-stable processes (MSPs). In contrast to earlier studies that mainly dealt with univariate extreme value theory and point-based IDF curves, this work uses a variety of MSP characterizations, such as Brown-Resnick, Schlather, Geometric Gaussian, and Extremal-t, to capture the spatial dependencies and non-stationary characteristics of extreme rainfall. This comprehensive two-stage modeling approach incorporates geographical covariates to capture spatial variation in extreme rainfall, followed by additional climate-informed covariates. One hundred fifty-six surface response models are analyzed across nine hourly extreme rainfall durations over 11 river basins.</div><div>The Brown-Resnick process effectively captured spatiotemporal dependencies across all durations in the annual timeframe, while the Geometric Gaussian process also demonstrated strong performance. During the Indian Monsoon season, distinct covariates such as the Southern Oscillation Index (SOI) and Global Temperature Anomaly (GTA) significantly influenced extreme rainfall patterns. The analysis reveals that the Brahmaputra basin consistently exhibits the highest short-duration extreme rainfall, while the Indus basin shows the lowest. Long-term projections indicate alarming trends, with potential short-duration extreme rainfall reaching 338.9 mm for a 100-year return period in the Godavari basin. The findings highlight the importance of updating IDF relationships in climate variability, providing insights that could lead to disaster preparedness and resilience planning for vulnerable communities across India.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"655 ","pages":"Article 132922"},"PeriodicalIF":5.9,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toward a better understanding of curve number and initial abstraction ratio values from a large sample of watersheds perspective","authors":"Abderraman R. Amorim Brandão ,&nbsp;Dimaghi Schwamback ,&nbsp;André Simões Ballarin ,&nbsp;John J. Ramirez-Avila ,&nbsp;José Goes Vasconcelos Neto ,&nbsp;Paulo Tarso S. Oliveira","doi":"10.1016/j.jhydrol.2025.132941","DOIUrl":"10.1016/j.jhydrol.2025.132941","url":null,"abstract":"<div><div>The Natural Resources Conservation Service Curve Number method (NRCS-CN) is the most widely used approach to estimate runoff from rainfall events. However, some uncertainties in the method remain linked to the value of the standard initial abstraction ratio (λ) and discrepancies between computed and standard tabulated Curve Number (CN) values. Here, we compute CN values and investigate the effects of λ on runoff estimation performance using a large sample of 3,578 watersheds distributed across the globe. We evaluate the impact of the default λ value of 0.2 and the proposed value of 0.05 across three methods and examine two rainfall event thresholds for CN calibration. We further investigated the association between the parameters of the NRCS-CN method and the catchment and climatic characteristics of the watersheds using machine learning techniques. Our findings indicated that the Least-Squares (LS) method better calibrates CN values and performs more accurately using λ = 0.05 compared to the default λ = 0.2 and that the 25.4 mm precipitation threshold showed better performance for calibrating the methods. The CN spatial variability revealed that high values of CN are controlled by the spatial variation of slope, precipitation, and soil silt content, while lower CNs aligned with forest lands, and strongly correlated to regions of sandy soils, down to the aridity index. Land cover emerges as the most influential characteristic in determining the λ, with cropland percentage exhibiting the greater influence. Arid regions, increases cropland, urban areas, and soil sand content are associated with λ = 0.05, whereas higher pasture percentages correspond to λ = 0.2. We also provide equations for converting parameters from λ = 0.2 to λ = 0.05. Several watersheds worldwide are ungauged, and this study emphasizes the non-linear and complex nature of hydrological processes influencing the NRCS-CN method parameters. Our study provides a better understanding of the NRCS-CN method, bringing significant practical implications for various applications, including hydrological processes, stormwater management, flood forecasting, sediment management, hydrological modeling, and water resources engineering.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"655 ","pages":"Article 132941"},"PeriodicalIF":5.9,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143508838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Necessity of incorporating realistic land surface parameters for trend analyses of potential evapotranspiration and drought","authors":"Shanlei Sun ,&nbsp;Yifang Zhang ,&nbsp;Mengyuan Mu ,&nbsp;Zaoying Bi ,&nbsp;Yi Liu ,&nbsp;Jinjian Li ,&nbsp;Yang Zhou ,&nbsp;Xiaoyuan Li ,&nbsp;Haishan Chen","doi":"10.1016/j.jhydrol.2025.132938","DOIUrl":"10.1016/j.jhydrol.2025.132938","url":null,"abstract":"<div><div>Potential evapotranspiration (PET) is a necessary input for various offline drought indices and, therefore, crucial for accurately evaluating drought conditions. Since representing land surface characteristics is needed for estimating PET, studying the impacts of land surface parameters on PET and offline drought indices is significant. Therefore, this study used the Food and Agriculture Organization of the United Nations’ report 56 (FAO-56) Penman-Monteith equation with the default and realistic land surface parameters to conduct two simulations worldwide from 1983 to 2020, based on the Standardized Precipitation-Evapotranspiration Index (SPEI) and various inputs (e.g., land use/cover, canopy height, and meteorological dataset). Then, the effects of land surface parameters on changes in PET and drought conditions were quantified by comparing these two simulations. Results suggested that in comparison to the default parameters, the realistic parameters-based results showed a more substantial and significant increase in annual PET, decrease in annual 3-month SPEI (SPEI3; i.e., drying), increase in drought duration (DD) and drought area (DA), and intensification of drought intensity (DI) globally. Despite the spatial similarity of the changes in annual PET and drought conditions, there were evident regional variations between the two simulations. The default parameters-based simulation showed weaker, stronger, and opposite trends in annual PET over 74.1 %, 16.7 %, and 9.2 % of the world, respectively, compared to the realistic parametrizations-based simulation. The default parameters could lead to weaker (more robust) drying and wetting over 50.9 % (36 %) of the world and opposite trends of annual SPEI3 over 13 % of the world. Moreover, the default parameters-based DD (DI) trends showed more than 46 %, 36 %, and 14 % of the world, respectively, with weaker, stronger, and opposite signs. Overall, our analyses highlight the importance of realistically representing the land surface characteristics for accurately capturing changes in PET and drought conditions.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"655 ","pages":"Article 132938"},"PeriodicalIF":5.9,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}