Hydrological Processes最新文献

{"title":"Modelling the Soil Evaporation Loss in Secondary Forests of the Subtropical Monsoon Region, Central South China","authors":"Yong Zhang,&nbsp;Xinping Zhang,&nbsp;Xiong Xiao,&nbsp;Junjie Dai,&nbsp;Wanjing Jiang,&nbsp;Zhen Du,&nbsp;Xuhong Zhan,&nbsp;Lu Liu","doi":"10.1002/hyp.70056","DOIUrl":"https://doi.org/10.1002/hyp.70056","url":null,"abstract":"<div>\u0000 \u0000 <p>Under more frequent, extreme global drought events, the use of stable isotopes to quantify soil evaporation losses (SEL) is of great significance for understanding the water supply capacity from soil to plants. During March 2017–September 2019, we continuously monitored meteorological factors, soil temperature (ST) and humidity, and collected precipitation and soil water stable isotope data. The Craig-Gordon (C-G) and line-conditioned excess (lc-excess) coupled with the Rayleigh fractionation (RL) models were used to quantify SEL in subtropical secondary forests. The results showed: (1) the theoretical evaporation line (EL) slope negatively correlated with air temperature (AT). Water source isotopic values are more positive in autumn and more negative in spring. The aridity index (AI) and soil evaporation loss ratio (<i>f</i>) from both models indicated drier conditions during March–September 2018 compared to 2017 and 2019; (2) comparative analysis showed the C-G model agreed more closely with measured evapotranspiration (ET₀) and water surface evaporation (<i>E</i>) than the RL model, indicating better suitability of the C-G model in the study region; (3) because the “inverse temperature effect” of the precipitation isotopes, the linear fitting method was not suitable for determining the water source in spring, summer, autumn, and on the annual scale, while the linear fitting method was consistent with the basic principle of soil evaporation in winter. Thus, the theoretical method was more suitable for determining the EL slope in such regions; (4) because of the different fundamentals, the C-G model positively correlated with AT and negatively correlated with relative humidity (<i>h</i>), while the RL model showed the opposite trends, indicating different applicability. The SEL is influenced by soil thickness, atmospheric evaporation and soil water supply capacity. These findings support stable isotope application techniques for quantifying SEL and are crucial for analysis of soil water resources in subtropical secondary forests.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143116626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stemflow Measurement on Large Leaning Quercus serrata Trees: Examination of Stem Lean Effect on Stemflow","authors":"Takanori Sato,&nbsp;Khotaro Ohosawa,&nbsp;Kazunari Ebata,&nbsp;Yoshitaka Matsumoto","doi":"10.1002/hyp.70046","DOIUrl":"https://doi.org/10.1002/hyp.70046","url":null,"abstract":"<div>\u0000 \u0000 <p>Stemflow measurements were performed on seven <i>Quercus serrata</i> and canopy structure metrics were obtained to identify factors that affect stemflow. Among the seven stems, two exhibited a large stem lean (&gt; 20°). Although a linear relationship between rainfall and stemflow was shown in all trees, stemflow volume on the highly leaning stems (Nos. 6 and 7) was clearly smaller than those on the others. To extract canopy structure metrics effective on stemflow, GLM analysis was conducted. The objective variable was the slope of the regression line <i>a</i> between rainfall and stemflow. Canopy structure metrics as explanatory variables were the diameter at breast height DBH, tree height <i>H</i>, canopy projection area CPA, stem lean parameters <i>L</i> and <i>L</i>_<i>d</i>, and stem length (SL). <i>L</i> is stem lean from the base to the top and <i>L</i>_<i>d</i> is stem lean at breast height. GLMs were constructed using all combinations of explanatory variables. GLMs that included at least one explanatory variable for which a statistically significant had been shown were selected. First, GLMs constructed using DBH, <i>L</i>, and <i>L</i>_<i>d</i> were selected. The relationship between DBH and <i>a</i> was positive, but the <i>R</i>² value using all data (<i>R</i>² = 0.39) was smaller than upon excluding stem Nos. 6 and 7 (<i>R</i>² = 0.85). This indicated the need to consider DBH and stem lean simultaneously. Second, a GLM constructed only using <i>H</i> was selected. <i>R</i>² values of DBH with <i>H</i> and <i>SL</i> were 0.57 and 0.72, respectively. According to the definition of <i>H</i>, the more the stem leans, the lower <i>H</i> is measured, at the same value of <i>SL</i>. Thus, <i>H</i> was a parameter that includes the effect of stem lean. Our results indicated that it is necessary to consider stem lean when evaluating the process of canopy interception in deciduous broadleaf forests.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143116091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Hillside Grass Distribution Patterns on Soil Erosion and the Particle Size Distribution of Sediments Under Different Rainfall Intensities","authors":"Tianyao Zhang,&nbsp;Youdong Cen,&nbsp;Kaixi Zhou,&nbsp;Lu Zhong,&nbsp;Yerong Zhou,&nbsp;Guangwen Ma","doi":"10.1002/hyp.70057","DOIUrl":"https://doi.org/10.1002/hyp.70057","url":null,"abstract":"<div>\u0000 \u0000 <p>The distribution patterns of grass cover on arid and semi-arid slopes significantly influence runoff and erosion processes. However, the mechanisms by which these patterns affect hydrological and erosion processes, and the subsequent selective transport of sediment particles, remain poorly understood. To address this knowledge gap, this study conducted rainfall experiments of varying intensities (60, 90 and 120 mm h⁻¹) across different grass distribution patterns—random (RP), checkerboard (CP), vertical strips (VP), step strips (SP), banded (BP) and bare slope (BS)—to investigate their effects on runoff, erosion and sediment particle size distribution (PSD). The results show that the BP pattern was most effective in reducing runoff and erosion rates, with reductions of 47.6%–76.5% and 75.4%–84.9%, respectively, compared to BS; SP follows, whereas VP demonstrates the least effectiveness. No significant differences were observed in runoff and erosion rates between the RP and CP treatments. Regarding sediment PSD, the sediments from BS, RP, CP and VP plots predominantly consist of clay and fine silt, accounting for 53.1%–62.8%, whereas sediments from the SP and BP plots are primarily composed of coarse silt (66.9%) and sand (79.2%), respectively. The enrichment of sediment particle size was influenced by the grass distribution patterns. At 60 mm h⁻¹ rainfall, clay and fine silt from BS plots are preferentially enriched as aggregates, while sandy particles are enriched in VP, SP and BP plots; the sediment distributions in RP and CP plots closely resemble that of the original soil. These findings elucidate the impacts of different grass distribution patterns on sediment PSD and provide insights for the development of grass-planting strategies.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143116094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing Water Requirements of Groundwater Dependent Ecosystems Using a Water Balance Approach and Streamflow Separation","authors":"Lisa B. Gurieff,&nbsp;Lucy P. Reading,&nbsp;Les Dawes","doi":"10.1002/hyp.70052","DOIUrl":"https://doi.org/10.1002/hyp.70052","url":null,"abstract":"<div>\u0000 \u0000 <p>Groundwater supports approximately one -third of global water consumption. With increasing pressures on this resource from both anthropogenic users and climatic influences, sustainable management of groundwater has become crucial. This article identifies groundwater requirements by Groundwater Dependent Ecosystems (GDEs) as groundwater evapotranspiration and groundwater discharge to surface water features (baseflow). These requirements are investigated using a soil moisture model combined with a water balance approach, baseflow separation techniques and groundwater level monitoring. The results are compared to groundwater evapotranspiration estimates based on diurnal water level fluctuations. For the period 2000 to 2019, the combined GDE requirements, including groundwater evapotranspiration and environmental baseflow requirements, ranged from 130 to 420 mm/year for the highest ecological indicator level within the study area of approximately 20 km². These estimates provide valuable information on the short-term (daily to monthly) to long-term (yearly to multi yearly) responses to climate variations and can be integrated into water stress assessments. These findings can be used to enhance our understanding of the role of GDEs water requirements and contribute to managing GDEs as part of sustainable management of groundwater resources.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143116088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Spatiotemporal Variability of Soil Water δ18O and δ2H Reveals Hydrological Processes in Two Floodplain Soils","authors":"Amanda Ceming-Barbato,&nbsp;Richard F. Keim","doi":"10.1002/hyp.70060","DOIUrl":"https://doi.org/10.1002/hyp.70060","url":null,"abstract":"<div>\u0000 \u0000 <p>Soil water budgets in floodplains are distinct from uplands because there are more potential sources of water yet remain poorly understood and poorly represented in the empirical literature. Stable isotopes of hydrogen (²H) and oxygen (¹⁸O) in water are useful as tracers of water movement and have improved conceptual understanding of soil hydrological processes. We sampled two adjacent microsites at a ridge-swale sequence in a forested floodplain Louisiana, USA to determine temporal and spatial soil water isotopic variability in soils of similar climate and ecosystem but contrasting textures and hydrological processes. Repeated soil borings indicated that soil water isotopic variability was greater than any source water sampled (range of δ¹⁸O (‰): −11.9 to −0.9, range of δ²H (‰): −44 to 0; <i>n</i> = 783) including throughfall (range of δ¹⁸O (‰): −7.6 to +4.7, range of δ²H (‰): −40 to +11; <i>n</i> = 162), groundwater (range of δ¹⁸O (‰): −6.2 to 0, range of δ²H (‰): −31 to −7; <i>n</i> = 39), ponded water within the swale (range of δ¹⁸O (‰): −6.3 to +0.2, range of δ²H (‰): −33 to −4; <i>n</i> = 16), and free water from boreholes (range of δ¹⁸O (‰): −21 to +5, range of δ²H (‰): −4.5 to +5.8; <i>n</i> = 64). Soil water isotopic variability among samples of the same depth and date was not related to soil texture, organic content, or water content, but was instead likely related to seasonal wet up. Soil water isotopic mixing models indicated soil water recharge regimes varied by microsite: Swale soils were dominated by replacement of event water and ridge soils were dominated by conservative mixing at the profile scale. The isotopic composition of bound water was less variable spatially within structured clay soil than it was in coarser textured soil (average difference in <i>s</i>² 0.241 for δ¹⁸O and 2.6 for δ²H) apparently because the microtopography of the site allowed for greater inundation and more persistent source waters among swale soils.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143116093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Empirical Evidence of Dynamic Hydrogeomorphic Feature Inundation in a Lowland Floodplain","authors":"Molly R. Cain,&nbsp;Jase L. Hixson,&nbsp;C. Nathan Jones,&nbsp;Bruce L. Rhoads,&nbsp;Adam S. Ward","doi":"10.1002/hyp.70043","DOIUrl":"https://doi.org/10.1002/hyp.70043","url":null,"abstract":"<div>\u0000 \u0000 <p>Floodplains along low-gradient, meandering river systems contain diverse hydrogeomorphic features, ranging from isolated depressions to hydrologically-connected channels. These ephemerally-flooded features inundate prior to river water overtopping all banks, enhancing river-floodplain connectivity during moderately high flow stages. Predicting when and where ecological functions occur in floodplains requires understanding the dynamic hydrologic processes of hydrogeomorphic features, including inundation and exchange. In this study, we examined storm event-scale inundation and exchange dynamics along a lowland, meandering river system in central Illinois (USA). We monitored surface water presence/absence, surface water level, and groundwater level across floodplain hydrogeomorphic feature types (i.e., isolated depression, backwater channel, and flow-through channel). Using these data, we evaluated inundation onset and recession characteristics, drivers of groundwater-surface water interactions, and direction of hydrologic exchange with the river channel. Surface water presence/absence patterns suggested inundation onset timescales were primarily controlled by microtopography and recession timescales were correlated with floodplain elevation. Employing a novel hysteresis approach for characterising groundwater-surface water interactions, we observed distinct patterns indicating differences in water sources across hydrogeomorphic units and event characteristics. Finally, differences in hydraulic head along floodplain channels revealed that channels with multiple inlets/outlets (i.e., flow-through channels) conveyed down-valley flow and channels with single inlets primarily functioned as sinks of river-derived water to the floodplain with short source periods. These results highlight the heterogeneity of hydrologic processes that occur along lowland, meandering river-floodplains, and more specifically, point to the important role hydrogeomorphic features play in controlling dynamic connectivity within the river corridor.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143116092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding the Hysteretic Behaviour of Hydraulic Variables in Lowland Rivers Using Multivariate Monitoring Approaches","authors":"Marian Muste,&nbsp;Kyeongdong Kim,&nbsp;Dongsu Kim,&nbsp;Gábor Fleit","doi":"10.1002/hyp.70008","DOIUrl":"https://doi.org/10.1002/hyp.70008","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper demonstrates that the multivariate monitoring methods are capable to underpin the systematic investigation of the hysteretic behaviour occurring during gradually-varied flows. For this purpose, we present simultaneous measurements of stage, index velocity and free-surface slope acquired continuously with high-frequency sampling instruments deployed at several river gaging sites exposed to different storm magnitudes. The experimental evidence reveals intrinsic features of unsteady open-channel flow mechanics that are hinted by pertinent governing equations but rarely substantiated with in situ measurements. The illustrations are intentionally made for fluvial waves propagating in lowland rivers where the relationships among flow variables are most likely displaying hysteretic phasing in the progression of the hydraulic variables and loops in their relationships. The presented measurements highlight that: (a) the hysteretic behaviour is apparent in both time-independent and time-dependent graphical representations of any two of the hydraulic variables; (b) the severity of the hysteresis is commensurate with the geomorphic, hydraulic and hydrological characteristics of the measurement site; and (c) there are flow monitoring paradigms that can more accurately track changes of the flow variables during gradually-varied flows than those currently used in practice. Also discussed are research needs for advancing the understanding of the mechanisms underlying the movement and storage of water in the lowland river environments as well as for increasing the accuracy of streamflow monitoring, modelling and forecasting.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143115199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"The Influence of Sanitary Infrastructure on Event Nutrient Dynamics in a Headwater Catchment","authors":"Caroline Spill,&nbsp;Lukas Ditzel,&nbsp;Matthias Gassmann","doi":"10.1002/hyp.70036","DOIUrl":"https://doi.org/10.1002/hyp.70036","url":null,"abstract":"<div>\u0000 \u0000 <p>Many low-order streams are recipients of effluents from wastewater treatment plants (WWTPs) and combined sewer overflows (CSOs). Not only do these facilities have to meet fewer requirements compared to their bigger counterparts in more densely populated areas, but they also discharge into smaller, more vulnerable streams, with low dilution potential. Although these local point sources can dictate the local water quality and quantity dynamics, they are barely monitored and often not included in catchment-wide analyses. In this case study we measured stream water quantity and quality in a first-order, point source-influenced stream. We have specifically addressed point sources in our monitoring programme, which included the installation of a low-budget probe at the CSO outlet to monitor overflow timing. By clustering hysteresis loops and using Principal Component Analysis, we were able to identify hydro-meteorological drivers and reveal seasonal patterns of discharge and nutrient export dynamics. Mobilisation of nitrate from agricultural sources clearly dominated event dynamics during periods with high soil moisture, while point source dynamics overlaid catchment responses during the rest of the time. Thus, the dilution potential of the stream was found to be a controlling factor for water quality dynamics. Groundwater infiltration into the sewer system probably increased the risk of CSO discharges, especially in winter and spring. In summer, CSO spillages occurred as a result of high-intensity rainfall. These events were related to an increase of turbidity and a mobilisation of particulate phosphorus. With our novel approach, including urban point sources in our monitoring setup, we were able to show the close relationship between sanitary infrastructure in rural areas and stream nutrient dynamics. Including point sources more closely into monitoring and analysis is essential to improve the process understanding.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/hyp.70036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143113719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Compartmentalisation and Hydrogeological Parameters of the Karst Aquifer System in Central Region of Minas Gerais State, Brazil","authors":"Matheus Alonso Castelo Pena,&nbsp;Rodrigo Sérgio de Paula,&nbsp;Leila Nunes Menegasse Velasquez,&nbsp;Débora Maria Diniz Barbosa","doi":"10.1002/hyp.70051","DOIUrl":"https://doi.org/10.1002/hyp.70051","url":null,"abstract":"<div>\u0000 \u0000 <p>The Environmental Protection Area of Lagoa Santa Karst (EPA) is a critical karst region in Brazil, renowned for its rich biodiversity and archaeological significance, including discoveries by researchers such as Peter W. Lund and the oldest human skeleton in the Americas, Luzia. However, the region faces threats from rapid socioeconomic and industrial development, stressing its vulnerable aquifer systems. This study updates the hydrogeological conceptual model for the EPA using well log data, map algebra and hydrodynamic parameters obtained through the Agarwal (1980) recovery method . It builds on models by De Paula (<i>Conceptual Model in Pelitic-Carbonate Aquifers in the Lagoa Santa Karst APA Region, MG</i>, 2019) and refined by Dantas et al. (<i>Journal of South American Earth Sciences</i>, 2023, 123, 104219), reassessing the boundaries of various aquifer units. Horizontal compartmentalisation in the karst-fissured aquifer was achieved by combining transmissivity and porosity data, while vertical separation was determined based on water entry density and productivity, identifying four zones of increased karstification. In the fissured aquifer, vertical limits align with those established by Dantas et al. (<i>Journal of South American Earth Sciences</i>, 2023, 123, 104219), confirming the anisotropy and heterogeneity of the karst-fissured and fissured aquifers, and the isotropy and productivity of the alluvial aquifers. These findings provide crucial insights for managing aquifer reserves and mitigating water conflicts in the EPA region.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143113517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sediment Load Variation in Typical Watersheds of the North–South Transitional Zone, China","authors":"Ren Geng,&nbsp;Peixuan Zhang,&nbsp;Peng Tian,&nbsp;Guangju Zhao,&nbsp;Yu Shi,&nbsp;Xingmin Mu,&nbsp;Meixiang Xie,&nbsp;Bo Bi","doi":"10.1002/hyp.70049","DOIUrl":"https://doi.org/10.1002/hyp.70049","url":null,"abstract":"<div>\u0000 \u0000 <p>The north–south transitional zone (NSTZ) is a key geographic and ecological transition zone in China. The runoff and sediment load (SL) of rivers in this zone have changed significantly, directly influencing the ecological restoration and exploitation of water resources in water basins. The previous studies have focused on one water basin; however, few studies have systematically investigated the spatiotemporal variation characteristics of SL and their driving factors in the rivers of the entire zone. Thus, this study attempted to probe the spatiotemporal variation of SL and its contributing factors in the Han River basin (HRB), Jialing River basin (JRB) and the mainstream of the Wei River basin (WRB) in the transitional zone, using observed data from 56 representative hydrological stations in this region from 1961 to 2019. The results indicated that the annual SL decreased significantly during 1961–2019 at each hydrological station (<i>p</i> &lt; 0.01). The SL of Xianyang, Huangzhuang and Beibei stations during 2010–2019 had decreased more than 83%, compared to that of the 1960s. The annual SL exhibited different abrupt change points, mainly occurred in the late 1960s and around the 1990s. The specific sediment yield (SSY) of the study area was lower in the east and higher in the west. Meanwhile, the SSY displayed a generally declining trend with time. Human activity was the leading contributing factor, accounting for greater than 94% of the total SL reduction. In summary, the SL reduction in the WRB was primarily affected by soil and water conservation practices, whereas it was related to ecological restoration projects and cascade reservoirs in the HRB and JRB. The results of this study are valuable for soil erosion control and comprehensive reclamation of river basins in different regions under complicated conditions worldwide.</p>\u0000 </div>","PeriodicalId":13189,"journal":{"name":"Hydrological Processes","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143113518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}