Journal of Hydrology最新文献

{"title":"Effects of vanishing power-law tails of river flows caused by damming on downstream hydrological connectivity","authors":"Li Dang ,&nbsp;Chao Ma ,&nbsp;Haixia Wang","doi":"10.1016/j.jhydrol.2024.132317","DOIUrl":"10.1016/j.jhydrol.2024.132317","url":null,"abstract":"<div><div>High-intensity dam operations have severely disturbed the power-law behaviors of natural river flows, which have important implications for the entire ecosystem’s integrity, diversity, and sustainability. This study investigated the effects of vanishing power-law tails of river flows caused by damming on downstream hydrological connectivity in the Wanquan river–floodplain (China) and determined the consequent ecological responses. A two-dimensional hydrodynamic model was established to estimate inundation regimes under different hydrological scenarios, and a statistics-based method was used to generate vanishing power-law tails. Connectivity assessments quantified the duration, magnitude, accumulation, and efficiency of connection events in the river–floodplain system for historical hydrological processes, current dam operating schemes, and simulated flow series with compressed power-law tails. The results showed significant reductions in downstream connection duration, magnitude, accumulation, and efficiency with compression of the natural power-law tail, especially for small (<em>P</em> &lt; 20 %) and large (<em>P</em> &gt; 90 %) connection events. Under a fully modified scenario, the cumulative large connection events were reduced by as much as 50 %. Damming also diminished the seasonal fluctuations of lateral exchanges and weakened the synergetic relationships among inflows, inundation extents and connectivity in the river–floodplain system. Furthermore, increasing damming led to an exponential and accelerated loss of downstream connectivity, with noticeable inflection points. Reduced or insulated hydrological exchanges would weaken material cycling, energy flow, and information transmission in the river–floodplain system, ultimately impacting the entire aquatic ecosystem. Our study emphasizes the importance of the power-law tail in the estimation of natural flows, which, although accounting for only a small part of the whole flow series (approximately 6 % in this case), is of great significance for maintaining the downstream connectivity necessary for healthy aquatic ecosystems.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"646 ","pages":"Article 132317"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701111","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":"Disaggregation of rainfall from daily to 1-hour scale through integrated MMRC-copula modelling","authors":"Payel Biswas,&nbsp;Ujjwal Saha","doi":"10.1016/j.jhydrol.2024.132338","DOIUrl":"10.1016/j.jhydrol.2024.132338","url":null,"abstract":"<div><div>Rainfall intensity is one of the most crucial meteorological parameters which is extensively used by water resource planners, hydrologists, irrigation experts, flood and draught regulatory authorities. Particularly, sub-daily temporal rainfall time series is quite essential for detailed planning of urban drainage design, storm water management. However, due to non-availability of reliable fine resolution rainfall data, under current scenario temporal disaggregation of existing rainfall record using various stochastic techniques is emerging as one of the most sought after option. In the present study, the Microcanonical Multiplicative Random Cascade (MMRC) model has been adopted for disaggregation of daily rainfall values to 1 h scale. Though MMRC is capable of generating statistically reliable rainfall time series, it is not competent enough to preserve the extreme rainfall characteristics.</div><div>In this paper, a new model has been presented where copula theory has been integrated with MMRC model to capture the dependence structure between coarse time step rainfall and its corresponding finer time steps. The procedure of disaggregation of coarse resolution rainfall series has been accomplished by this new Integrated MMRC-copula model with higher accuracy as it accounts for the random splitting procedure of cascade generator more precisely compared to MMRC model which generally leads to overestimation of extreme rainfall. An overall improved performance of the Integrated MMRC-Copula model in contrast to MMRC supports the model’s pertinence in the field of temporal disaggregation of rainfall.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"647 ","pages":"Article 132338"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700465","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":"Rapid urban inundation prediction method based on numerical simulation and AI algorithm","authors":"Xinxin Pan ,&nbsp;Jingming Hou ,&nbsp;Guangzhao Chen ,&nbsp;Donglai Li ,&nbsp;Nie Zhou ,&nbsp;Muhammad Imran ,&nbsp;Xinyi Li ,&nbsp;Juan Qiao ,&nbsp;Xujun Gao","doi":"10.1016/j.jhydrol.2024.132334","DOIUrl":"10.1016/j.jhydrol.2024.132334","url":null,"abstract":"<div><div>Urban inundation caused by extreme torrential rains has become one of the most prominent natural disasters globally, and rapid and precise forecasting of such events is now a primary measure in flood emergency management. However, AI-based rapid inundation forecasting requires sufficient historical inundation data, and existing forecasts only predict urban inundation without addressing elements such as the load on urban drainage systems. Therefore, this paper combines physical process models and AI technology to develop a rapid forecasting model for urban inundation, designed to quickly predict surface water accumulation, link capacity, and water depth at control nodes in storage pools due to extreme rainfall. To address the issue of insufficient historical rainfall and inundation monitoring data, the model integrates one-dimensional link network models and two-dimensional hydrodynamic models to address the shortage of flood data. The model simulates flood data for various rainfall intensities and patterns in the study area, forming a rainfall-inundation outcome matrix. This matrix is then trained using a BP neural network algorithm, ultimately producing a rapid forecasting model for urban inundation applicable to the study area. The results show: (1) In terms of computational accuracy, the predicted values for surface water accumulation, link capacity, and water depth at storage pool control nodes have <em>R²</em> values of no less than 0.826, 0.951, and 0.765, respectively, demonstrating the model’s reliable prediction accuracy; (2) In terms of computational efficiency, the rapid forecasting model averages 27.44 s to forecast a single flood event, achieving a speed increase of approximately 322 times compared to traditional two-dimensional hydrodynamic models, indicating a fast computation speed. Thus, this forecasting model can provide more time for urban emergency decision-making, thereby reducing the economic losses and casualties caused by urban inundation.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"647 ","pages":"Article 132334"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700952","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":"Flood inundation mapping in SAR images based on nonlocal polarization combination features","authors":"Huifu Zhuang ,&nbsp;Peng Wang ,&nbsp;Ming Hao ,&nbsp;Hongdong Fan ,&nbsp;Zhixiang Tan","doi":"10.1016/j.jhydrol.2024.132326","DOIUrl":"10.1016/j.jhydrol.2024.132326","url":null,"abstract":"<div><div>Accurately and promptly monitoring of flood inundation is crucial for disaster relief and loss assessment. Although some advancements have been achieved in flood mapping based on synthetic aperture radar (SAR) data, the current research usually extracts flood information at a level such as a single temporal image, single polarization or local neighborhood features. In addition, these methods often rely on learning samples, geographic features, or priori hypotheses (e.g. the histogram of the image has bimodal characteristics), which limits their practicality in large-scale rapid automated mapping. Therefore, we propose an automated flood inundation mapping method for multi-temporal SAR images by using a nonlocal polarization combination feature (NPCF). In this study, we first construct multiple polarization combination features of Sentinel-1 data, and then select the optimal combination feature suitable for flood mapping. On this basis, the different information, before and after the flood disaster, is extracted based on NPCF. Finally, the flood inundation area is obtained through an optimal automated threshold method. Experimental results show that: 1) <span><math><mrow><msup><mrow><mtext>(VV + VH)</mtext></mrow><mn>2</mn></msup></mrow></math></span> performs better than the other dual-polarization combination features and the single polarization (VV or VH) feature in flood inundation mapping; 2) NPCF performs better than 10 other advanced flood inundation mapping methods. Additionally, NPCF was further used for rapid mapping of two flood events, and the results showed that Kappa was greater than 0.85. Overall, NPCF achieves automated mapping of flood inundation areas, and can provide timely and reliable disaster information for disaster relief in flood events with high timeliness requirements.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"646 ","pages":"Article 132326"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701145","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":"Anthropogenic exacerbations of summer-autumn compound dry-hot severity in the middle and lower reaches of the Yangtze River","authors":"Shuyun Feng ,&nbsp;Xihui Gu ,&nbsp;Yansong Guan ,&nbsp;Quan J. Wang ,&nbsp;Lunche Wang ,&nbsp;Lingtong Du ,&nbsp;Jie He ,&nbsp;Xiang Zhang ,&nbsp;Dongdong Kong","doi":"10.1016/j.jhydrol.2024.132346","DOIUrl":"10.1016/j.jhydrol.2024.132346","url":null,"abstract":"<div><div>The middle and lower reaches of the Yangtze River (MLRYR), one of the most densely populated and economically developed regions in China, have suffered several severe compound dry-hot events (CDHEs) during the summer-autumn seasons in recent decades. However, it is unclear for spatiotemporal evolutions in this season’s CDHE severity and anthropogenic influence on them. Here, we calculated the Standardized Compound Event Indicator (SCEI) to quantify the CDHE severity during the summer-autumn season (August to November). During the past twelve decades, significant decreases in SCEI (–0.81 per century) in MLRYR have been found in observations, with the dependence of SCEI on low precipitation shifting to high temperatures. Temperatures change primarily contribute to the changes in SCEI with (82.3 %) or without (57.1 %) considering the effects of long-term warming. Quantitative detection and attribution results show that during 1901–2020, 86.7 % of the observed decrease in SCEI in MLRYR can be attributed to anthropogenic warming. In a warmer future, SCEI is projected to dramatically decrease before global warming reaches 3.5 °C above the preindustrial level. After exceeding 3.5℃, the CDHE severity in MLRYR is projected to stay at a new-normal serious level which exceeds the most severe CDHEs (such as in 2019 and 2022) during the past century. This new-normal serious level could be avoided if the global warming level is limited to around 2 °C. Early action to achieve the 1.5 °C or 2 °C temperature goal can therefore markedly reduce the likelihood that MLRYR would be exposed to record-shattering CDHEs and related impacts.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"646 ","pages":"Article 132346"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701143","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":"Groundwater flow and salinity dynamics in swash Zones: Combined effects of Evaporation, Waves, and geologic heterogeneity","authors":"Xiaolong Geng ,&nbsp;Holly A. Michael ,&nbsp;James W. Heiss ,&nbsp;Michel C. Boufadel ,&nbsp;Hailong Li ,&nbsp;Yan Zhang","doi":"10.1016/j.jhydrol.2024.132322","DOIUrl":"10.1016/j.jhydrol.2024.132322","url":null,"abstract":"<div><div>This study employs groundwater simulations to examine the combined effects of waves, evaporation, and geologic heterogeneity on the flow and salinity dynamics in a shallow beach environment. The modeling results reveal that wave motion generates a saline plume beneath the swash zone, with hypersalinity near the surface triggered by evaporation. Geologic heterogeneity critically controls the temporal and spatial patterns of evaporation, moisture content, and salinity in the swash zone. Heterogeneous capillarity creates localized moisture hotspots within the unsaturated zone, which support enhanced evaporation and therefore facilitate salt accumulation at the surface, even when the overall moisture conditions along the swash zone are not conducive to high rates of evaporation. The formation of capillary barriers allows these moisture hotspots to persist over tidal cycles, leading to the retention of saltwater pockets within heterogeneous unsaturated finer sediments. As the swash zone recedes and evaporation intensifies, salt begins to accumulate near the beach surface. The moisture hotspots create preferential pathways that facilitate the penetration of hypersaline water into deeper, saturated sediments. In contrast, within the saturated zone, groundwater flow and salt transport are predominantly driven by preferential flow within high-permeability coarse sediments where capillarity is relatively low. Such transport and capillary mechanisms are crucial for a better understanding of coastal groundwater flow, interstitial habitats, biogeochemical conditions, and consequent nutrient cycling and contaminant transport in coastal zones. This highlights the necessity of considering integrated coastal physical drivers when investigating flow and transport processes in coastal swash zones.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"646 ","pages":"Article 132322"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664266","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":"Minimizing nitrate output from soil organic nitrogen mineralization in citrus orchard catchments through green manure mulching","authors":"Yue Luo ,&nbsp;Xian Wu ,&nbsp;Xu Zhao ,&nbsp;Lingying Xu ,&nbsp;Xiaoqi Liu ,&nbsp;Hengbin Xiao ,&nbsp;Bin Liao ,&nbsp;Ronggui Hu","doi":"10.1016/j.jhydrol.2024.132369","DOIUrl":"10.1016/j.jhydrol.2024.132369","url":null,"abstract":"<div><div>In the catchments predominantly occupied by citrus orchards in central China, the discharge of nitrate (NO₃⁻) poses a significant threat to the downstream aquatic ecosystems, elevating the risk of eutrophication. It is imperative to comprehend the origins, factors influencing, and methods of regulating NO₃⁻ release in these catchments to effectively manage and mitigate NO₃⁻ pollution. This research utilized a continuous catchment-scale monitoring experiment in areas with varying percentages of citrus orchards (CW: citrus orchards catchment; RR: cropland catchment with few citrus orchards), along with a field experiment involving different treatments (CK: no fertilizer; CF: conventional fertilizer; OM: CF with organic manure; GM: CF with green manure) to investigate the sources and influencing factors of NO₃⁻ output as well as to evaluate control measures. The results indicated a noteworthy increase in NO₃⁻ output with an increase in the percentage of citrus orchards, with NO₃⁻ loss predominantly stemming from runoff and leaching as a result of soil organic nitrogen (SON) mineralization in citrus orchards. The implementation of green manure mulching emerged as an effective measure to reduce NO₃⁻ output caused by SON mineralization, leading to a substantial 33.2 % reduction in NO₃⁻ loss compared to conventional fertilizer and a 10.5 % reduction compared to organic manure. These findings offer valuable insights for the regulation of NO₃⁻ output and the enhancement of agricultural sustainability in agricultural catchments.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"646 ","pages":"Article 132369"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701113","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":"Green roof runoff reduction of 84 rain events: Comparing Sedum, life strategy-based vegetation, unvegetated and conventional roofs","authors":"Joel Lönnqvist,&nbsp;Ico Broekhuizen,&nbsp;Maria Viklander,&nbsp;Godecke Blecken","doi":"10.1016/j.jhydrol.2024.132325","DOIUrl":"10.1016/j.jhydrol.2024.132325","url":null,"abstract":"<div><div>Green roofs have emerged as effective stormwater management systems, but understanding the contribution of their various components to hydrological performance is crucial for optimizing their design and implementation. More empirically measured data on the hydrological function of green roof vegetation is needed, especially under realistic low-maintenance, non-irrigated scenarios. Further, targeted, evidence-based plant selection based on ecological theories may improve green roof hydrological performance. Previous research has suggested that, in contrast to monocultures, mixtures of species with complementary traits could optimize provisioning of various ecosystem services. Thus, species mixtures based on their adaptive life strategy using the CSR theory (Competitor, Stress tolerator, and Ruderal) were hypothesized to have better hydrological performance than a <em>Sedum</em> monoculture or bare substrate under natural conditions over multiple seasons. To test this hypothesis, the runoff from thirty 2 m² green roof modules was measured. The retention and detention performance of different green roof treatments were evaluated for 84 precipitation events of varying rain depth and intensity during snow-free periods. Differences in retention as well as detention between the vegetation treatments varied, but generally increased with increasing rain event volume and the Stress-tolerant treatment generally performed better than bare substrate. On a mean event basis, the mixture of stress-tolerator species demonstrated a 74 % retention rate, while the Bare substrate retained 72 % of the rainfalls. Overall, the green roofs, including bare substrate and vegetated treatments, effectively retained &gt;50 % of the cumulative precipitation depth. In line with previous studies, the <em>Sedum</em> monoculture generally showed worse hydrological performance than other non-succulent vegetation mixtures, despite its relatively high cover and survival. The vegetated treatment with the highest species richness and diversity in life strategies (Mix) did not provide the best vegetation cover, or hydrological performance. Instead, the Stress-tolerant treatment, characterized by the high survival rate of a single graminoid species, consistently demonstrated superior event-based stormwater retention and peak attenuation capabilities.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"646 ","pages":"Article 132325"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701116","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":"Improving ensemble forecast quality for heavy-to-extreme precipitation for the Meteorological Ensemble Forecast Processor via conditional bias-penalized regression","authors":"Sunghee Kim ,&nbsp;Ali Jozaghi ,&nbsp;Dong-Jun Seo","doi":"10.1016/j.jhydrol.2024.132363","DOIUrl":"10.1016/j.jhydrol.2024.132363","url":null,"abstract":"<div><div>The River Forecast Centers (RFC) in the US use the Meteorological Ensemble Forecast Processor (MEFP) to generate bias-corrected ensemble precipitation forecasts for hydrologic forecasting. Operational experience and verification indicate that the MEFP tends to under-forecast heavy-to-extreme precipitation significantly. To address the above, a conditional bias-penalized regression (CBPR) method has been developed as an enhancement to the ordinary least squares regression method currently used in the MEFP in the bivariate normal space. The two methods are then comparatively evaluated for 277 locations in 13 RFCs for the wettest consecutive 2 months using the ensemble mean precipitation forecasts from the Global Ensemble Forecast System version 12 reforecast dataset as input. The results show that the proposed method improves probabilistic forecasts for heavy-to-extreme precipitation by widely-varying margins for all 13 RFCs. The margin of improvement as measured by the continuous ranked probability skill score ranges up to about 5 to 40 % for Day-1 and Day-2 precipitation exceeding 50.8 mm for 24-hr amounts for different RFCs, and is generally larger for heavier precipitation, shorter lead times, the western RFCs and 0–96 hr precipitation. This improvement in conditional performance, however, is achieved at the expense of slight deterioration in unconditional performance and moderate wet bias. With urbanization and climate change, addressing Type-II error and conditional bias is an increasingly important topic in hydrologic forecasting. For the above, CBPR is particularly appealing in that its positive impact is likely larger for larger events.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"647 ","pages":"Article 132363"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696333","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":"Identifying solute loss from karst conduit to fissures under concentrated recharge conditions","authors":"Mingming Luo,&nbsp;Zhihao Zhou,&nbsp;Jing Chen,&nbsp;Xiangyu Peng,&nbsp;Zehao Zhao,&nbsp;Wenhui Zhao","doi":"10.1016/j.jhydrol.2024.132370","DOIUrl":"10.1016/j.jhydrol.2024.132370","url":null,"abstract":"<div><div>The aquifer within karst areas exhibits significant heterogeneity, accompanied by intricate runoff processes and swift hydrological responses. The solute transport process within karst conduits is influenced by various factors, including karst development characteristics and variations in hydrodynamic conditions, thereby displaying a high level of complexity. This complexity plays a crucial role in governing the safe utilization of karst water resources and the prevention of groundwater pollution. In this paper, a typical karst conduit system in southern China is chosen to investigate the influence mechanism of hydrodynamic conditions on the solute transport process within the karst conduit. This investigation is conducted through multiple sets of field artificial tracer tests. An intriguing phenomenon was observed: When the mean flow velocity of the conduit flow is either low (&lt;200 m/h) or high (&gt;1000 m/h), the solute concentrations and recovery rates are low. Conversely, the solute concentration and recovery rate are highest at a medium flow velocity (560 m/h), with the recovery rates ranging from 0.13 % to 92.44 %. A theoretical formula has been derived to estimate the solute loss from conduit flow to fissure flow. When the conduit is filled with water, an increase in the mean flow velocity leads to an augmentation in the amount of water recharged from the conduit into the fissures, as well as an increase in the stored solute mass, which results in a decrease in the solute recovery rate. The condition that poses the highest risk of groundwater pollution occurs at a medium flow velocity, where the solute concentration and recovery rate are all at their maximum levels. When the recharge rate at the sinkhole is very small, both the cross-sectional area and the mean flow velocity of the karst conduit are reduced. The rough bottom of the karst conduit leads to an increase in dispersivity, resulting in low solute concentration and recovery rate. The results elucidate the reasons behind the significant variations in solute recovery rates under different hydrodynamic conditions. They provide novel evidence for comprehending the water and solute exchange processes between conduits and fissures under concentrated recharge conditions. Furthermore, these findings offer a valuable reference for assessing the risk of groundwater pollution in karst areas.</div></div>","PeriodicalId":362,"journal":{"name":"Journal of Hydrology","volume":"647 ","pages":"Article 132370"},"PeriodicalIF":5.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696464","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}