Microplastic pollution is an emerging environmental concern, and has been found in remote regions, including the high Himalaya mountains. However, the abundance and sources of microplastics in the region are not well documented. This research investigated the abundance, types, and potential sources of microplastics in the Sagarmatha National Park (SNP), a rural and sparsely populated region of Nepal on the southern side of the Himalaya mountains. Water samples were collected from streams and tributaries in SNP in May of 2022. The average microplastic concentration among all samples was 2.0 ± 1.7 pieces/L, similar to that of water samples collected in other high mountain areas and is in the lower range of that found in water samples across the globe. Microplastic abundance is higher in water samples collected near settlements than in streams far from human settlements, indicating the impact of human activities. The presence of microplastics in all samples, including headwaters immediately beneath glaciers, illustrates the widespread distribution of microplastics and suggests the potential for airborne sources. While the concentration of microplastics does not change dramatically from upstream tributaries to downstream rivers, the total load of microplastics increases due to higher discharge downstream. This research demonstrates the anthropogenic and air-borne influences on microplastics contamination on the southern side of the Himalayan range and contributes to filling the data gaps towards a better understanding of the global fate and transport of microplastics.
{"title":"Human Activities Increased Microplastics Contamination in the Himalaya Mountains","authors":"Bangshuai Han, Moayad Yacoub, Aihua Li, Kirsten Nicholson, Joshua Gruver, Klaus Neumann, Subodh Sharma","doi":"10.3390/hydrology11010004","DOIUrl":"https://doi.org/10.3390/hydrology11010004","url":null,"abstract":"Microplastic pollution is an emerging environmental concern, and has been found in remote regions, including the high Himalaya mountains. However, the abundance and sources of microplastics in the region are not well documented. This research investigated the abundance, types, and potential sources of microplastics in the Sagarmatha National Park (SNP), a rural and sparsely populated region of Nepal on the southern side of the Himalaya mountains. Water samples were collected from streams and tributaries in SNP in May of 2022. The average microplastic concentration among all samples was 2.0 ± 1.7 pieces/L, similar to that of water samples collected in other high mountain areas and is in the lower range of that found in water samples across the globe. Microplastic abundance is higher in water samples collected near settlements than in streams far from human settlements, indicating the impact of human activities. The presence of microplastics in all samples, including headwaters immediately beneath glaciers, illustrates the widespread distribution of microplastics and suggests the potential for airborne sources. While the concentration of microplastics does not change dramatically from upstream tributaries to downstream rivers, the total load of microplastics increases due to higher discharge downstream. This research demonstrates the anthropogenic and air-borne influences on microplastics contamination on the southern side of the Himalayan range and contributes to filling the data gaps towards a better understanding of the global fate and transport of microplastics.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139142387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-26DOI: 10.3390/hydrology11010003
Andri Gunnarsson, S. Gardarsson
Efficient water resource management in glacier- and snow-dominated basins requires accurate estimates of the snow water equivalent (SWE) in late winter and spring and melt onset timing and intensity. To understand the high spatio-temporal variability of snow and glacier ablation, a spatially distributed energy balance model combining satellite-based retrievals of albedo and snow cover was applied. Incoming short-wave energy, contributing to daily estimates of melt energy, was constrained by remotely sensed surface albedo for snow-covered surfaces. Fractional snow cover was used for non-glaciated areas, as it provides estimates of snow cover for each pixel to better constrain snow melt. Thus, available daily estimates of melt energy in a given area were the product of the possible melt energy and the fractional snow cover of the area or pixel for non-glaciated areas. This provided daily estimates of melt water to determine seasonal snow and glacier ablation in Iceland for the period 2000–2019. Observations from snow pits on land and glacier summer mass balance were used for evaluation, and observations from land and glacier-based automatic weather stations were used to evaluate model inputs for the energy balance model. The results show that the interannual SWE variability was generally high both for seasonal snow and glaciers. For seasonal snow, the largest SWE (>1000 mm) was found in mountainous and alpine areas close to the coast, notably in the East- and Westfjords, Tröllaskaga, and in the vicinity of glacier margins. Lower SWE values were observed in the central highlands, flatter inland areas, and at lower elevations. For glaciers, more SWE (glacier ablation) was associated with lower glacier elevations while less melt was observed at higher elevations. For the impurity-rich bare-ice areas that are exposed annually, observed SWE was more than 3000 mm.
在以冰川和积雪为主的流域进行有效的水资源管理，需要对冬末春初的雪水当量以及融雪开始的时间和强度进行精确估算。为了解积雪和冰川消融的高时空变异性，应用了一种空间分布式能量平衡模型，该模型结合了基于卫星的反照率和积雪覆盖率检索。流入的短波能量有助于对每日融化能量的估算，该能量受雪覆盖表面的遥感表面反照率制约。非冰川地区采用分数积雪覆盖率，因为它可以估算出每个像素的积雪覆盖率，从而更好地限制融雪量。因此，对于非冰川地区而言，特定区域每日可用的融化能量估算值是该区域或像素点可能的融化能量与部分积雪覆盖率的乘积。这就提供了融水的每日估计值，以确定 2000-2019 年期间冰岛的季节性积雪和冰川消融情况。陆地雪坑和冰川夏季质量平衡观测数据用于评估，陆地和冰川自动气象站的观测数据用于评估能量平衡模型的模型输入。结果表明，季节性积雪和冰川的 SWE 年际变化率普遍较高。就季节性积雪而言，最大的 SWE 值（大于 1000 毫米）出现在靠近海岸的山区和高山地区，特别是在东峡湾和西峡湾、特罗尔斯卡加以及冰川边缘附近。在中部高地、地势较平坦的内陆地区和海拔较低的地方，观测到的西南环流值较低。就冰川而言，较多的 SWE（冰川消融）与冰川海拔较低有关，而在海拔较高的地方则观察到较少的融化。在每年裸露的富含杂质的裸冰地区，观测到的西南降水量超过 3000 毫米。
{"title":"Spatial Estimation of Snow Water Equivalent for Glaciers and Seasonal Snow in Iceland Using Remote Sensing Snow Cover and Albedo","authors":"Andri Gunnarsson, S. Gardarsson","doi":"10.3390/hydrology11010003","DOIUrl":"https://doi.org/10.3390/hydrology11010003","url":null,"abstract":"Efficient water resource management in glacier- and snow-dominated basins requires accurate estimates of the snow water equivalent (SWE) in late winter and spring and melt onset timing and intensity. To understand the high spatio-temporal variability of snow and glacier ablation, a spatially distributed energy balance model combining satellite-based retrievals of albedo and snow cover was applied. Incoming short-wave energy, contributing to daily estimates of melt energy, was constrained by remotely sensed surface albedo for snow-covered surfaces. Fractional snow cover was used for non-glaciated areas, as it provides estimates of snow cover for each pixel to better constrain snow melt. Thus, available daily estimates of melt energy in a given area were the product of the possible melt energy and the fractional snow cover of the area or pixel for non-glaciated areas. This provided daily estimates of melt water to determine seasonal snow and glacier ablation in Iceland for the period 2000–2019. Observations from snow pits on land and glacier summer mass balance were used for evaluation, and observations from land and glacier-based automatic weather stations were used to evaluate model inputs for the energy balance model. The results show that the interannual SWE variability was generally high both for seasonal snow and glaciers. For seasonal snow, the largest SWE (>1000 mm) was found in mountainous and alpine areas close to the coast, notably in the East- and Westfjords, Tröllaskaga, and in the vicinity of glacier margins. Lower SWE values were observed in the central highlands, flatter inland areas, and at lower elevations. For glaciers, more SWE (glacier ablation) was associated with lower glacier elevations while less melt was observed at higher elevations. For the impurity-rich bare-ice areas that are exposed annually, observed SWE was more than 3000 mm.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139157207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-25DOI: 10.3390/hydrology11010002
M. Goodarzi, Mahnaz Heydaripour, Vahid Jamali, Maryam Sabaghzadeh, M. Niazkar
Climate change affects hydroclimatic variables, and assessing the uncertainty in future predictions is crucial. This study aims to explore variations in temperature and precipitation in the Kerman Plain under climate change impacts between 2023 and 2054. For this purpose, two climate models, MRI-ESM-2 and BCC-CSM2-MR, were used to simulate precipitation and temperature under two different scenarios. The Mann–Kendall test was employed to analyze the annual time series in the future period. The results indicated an increase in the average temperature of about 1.5 degrees Celsius based on both scenarios in the coming years. Furthermore, an average annual increase of 6.37 mm of precipitation was predicted under the SSP585 scenario. Meanwhile, under the SSP585 scenario, an increase was estimated using the MRI-ESM-2 model, and a decrease was predicted with the BCC-CSM2-MR model. The Mann–Kendall test revealed a downward trend in the BCC-CSM2-MR model under both scenarios and an upward trend in the MRI-ESM-2 model under both scenarios. The bootstrap method and the R-factor index were exploited in this study with a 95% confidence interval to estimate the uncertainty of the predicted data. The results demonstrated that the predicted precipitation is more uncertain than the temperature. Finally, it is postulated that the obtained results provide necessary information for water resource management under a changing climate in the study area.
{"title":"Investigating Uncertainty of Future Predictions of Temperature and Precipitation in The Kerman Plain under Climate Change Impacts","authors":"M. Goodarzi, Mahnaz Heydaripour, Vahid Jamali, Maryam Sabaghzadeh, M. Niazkar","doi":"10.3390/hydrology11010002","DOIUrl":"https://doi.org/10.3390/hydrology11010002","url":null,"abstract":"Climate change affects hydroclimatic variables, and assessing the uncertainty in future predictions is crucial. This study aims to explore variations in temperature and precipitation in the Kerman Plain under climate change impacts between 2023 and 2054. For this purpose, two climate models, MRI-ESM-2 and BCC-CSM2-MR, were used to simulate precipitation and temperature under two different scenarios. The Mann–Kendall test was employed to analyze the annual time series in the future period. The results indicated an increase in the average temperature of about 1.5 degrees Celsius based on both scenarios in the coming years. Furthermore, an average annual increase of 6.37 mm of precipitation was predicted under the SSP585 scenario. Meanwhile, under the SSP585 scenario, an increase was estimated using the MRI-ESM-2 model, and a decrease was predicted with the BCC-CSM2-MR model. The Mann–Kendall test revealed a downward trend in the BCC-CSM2-MR model under both scenarios and an upward trend in the MRI-ESM-2 model under both scenarios. The bootstrap method and the R-factor index were exploited in this study with a 95% confidence interval to estimate the uncertainty of the predicted data. The results demonstrated that the predicted precipitation is more uncertain than the temperature. Finally, it is postulated that the obtained results provide necessary information for water resource management under a changing climate in the study area.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139157968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-23DOI: 10.3390/hydrology11010001
Antoine Picard, Florent Barbecot, Gérard Bardoux, Pierre Agrinier, Marina Gillon, J. C. Corcho Alvarado, Vincent Schneider, J. Hélie, Frédérick de Oliveira
Accurate discharge measurement is mandatory for any hydrological study. While the “velocity” measurement method is adapted to laminar flows, the “dilution” method is more appropriate for turbulent streams. As most low-gradient streams worldwide are neither laminar nor turbulent, a methodological gap appears. In this study, we demonstrate that the application of the “dilution” method to a low-gradient small stream gives very satisfactory results in addition to revealing surface/subsurface processes. A variety of chemical and isotopic tracers were injected into the stream (anions, fluorescent dyes, and chloride and hydrogen isotopes). We report the first use of 37Cl for stream discharge measurement and show that 37Cl and 2H can be reliably used as quantitative tracers. Discharge uncertainty calculations show that deuterium is the most accurate tracer method used. We also compare the differences in the tailing part of the restitution curves of tracers and investigate the role of transient surface and hyporheic zones in solute transport in light of a simple transport modelling approach. We conclude that isotopic tracers can be used as “environmentally friendly” tracers for discrete stream discharge measurements and that the application of multi-tracers tests in rivers opens the path to a better understanding of surface–subsurface interaction processes.
{"title":"The Potential of Isotopic Tracers for Precise and Environmentally Clean Stream Discharge Measurements","authors":"Antoine Picard, Florent Barbecot, Gérard Bardoux, Pierre Agrinier, Marina Gillon, J. C. Corcho Alvarado, Vincent Schneider, J. Hélie, Frédérick de Oliveira","doi":"10.3390/hydrology11010001","DOIUrl":"https://doi.org/10.3390/hydrology11010001","url":null,"abstract":"Accurate discharge measurement is mandatory for any hydrological study. While the “velocity” measurement method is adapted to laminar flows, the “dilution” method is more appropriate for turbulent streams. As most low-gradient streams worldwide are neither laminar nor turbulent, a methodological gap appears. In this study, we demonstrate that the application of the “dilution” method to a low-gradient small stream gives very satisfactory results in addition to revealing surface/subsurface processes. A variety of chemical and isotopic tracers were injected into the stream (anions, fluorescent dyes, and chloride and hydrogen isotopes). We report the first use of 37Cl for stream discharge measurement and show that 37Cl and 2H can be reliably used as quantitative tracers. Discharge uncertainty calculations show that deuterium is the most accurate tracer method used. We also compare the differences in the tailing part of the restitution curves of tracers and investigate the role of transient surface and hyporheic zones in solute transport in light of a simple transport modelling approach. We conclude that isotopic tracers can be used as “environmentally friendly” tracers for discrete stream discharge measurements and that the application of multi-tracers tests in rivers opens the path to a better understanding of surface–subsurface interaction processes.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139163058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-13DOI: 10.3390/hydrology10120238
Felipe Duque, Greg O’Donnell, Yanli Liu, Mingming Song, E. O'Connell
Polders are low-lying areas located in deltas, surrounded by embankments to prevent flooding (river or tidal floods). They rely on pumping systems to remove water from the inner rivers (artificial rivers inside the polder area) to the outer rivers, especially during storms. Urbanized polders are especially vulnerable to pluvial flooding if the drainage, storage, and pumping capacity of the polder is inadequate. In this paper, a Monte Carlo (MC) framework is proposed to evaluate the benefits of rainfall threshold-based flood warnings when mitigating pluvial flooding in an urban flood-prone polder area based on 24 h forecasts. The framework computes metrics that give the potential waterlogging duration, maximum inundated area, and pump operation costs by considering the full range of potential storms. The benefits of flood warnings are evaluated by comparing the values of these metrics across different scenarios: the no-warning, perfect, deterministic, and probabilistic forecast scenarios. Probabilistic forecasts are represented using the concept of “predictive uncertainty” (PU). A polder area located in Nanjing was chosen for the case study. The results show a trade-off between the metrics that represent the waterlogging and the pumping costs, and that probabilistic forecasts of rainfall can considerably enhance these metrics. The results can be used to design a rainfall threshold-based flood early warning system (FEWS) for a polder area and/or evaluate its benefits.
{"title":"Evaluating the Benefits of Flood Warnings in the Management of an Urban Flood-Prone Polder Area","authors":"Felipe Duque, Greg O’Donnell, Yanli Liu, Mingming Song, E. O'Connell","doi":"10.3390/hydrology10120238","DOIUrl":"https://doi.org/10.3390/hydrology10120238","url":null,"abstract":"Polders are low-lying areas located in deltas, surrounded by embankments to prevent flooding (river or tidal floods). They rely on pumping systems to remove water from the inner rivers (artificial rivers inside the polder area) to the outer rivers, especially during storms. Urbanized polders are especially vulnerable to pluvial flooding if the drainage, storage, and pumping capacity of the polder is inadequate. In this paper, a Monte Carlo (MC) framework is proposed to evaluate the benefits of rainfall threshold-based flood warnings when mitigating pluvial flooding in an urban flood-prone polder area based on 24 h forecasts. The framework computes metrics that give the potential waterlogging duration, maximum inundated area, and pump operation costs by considering the full range of potential storms. The benefits of flood warnings are evaluated by comparing the values of these metrics across different scenarios: the no-warning, perfect, deterministic, and probabilistic forecast scenarios. Probabilistic forecasts are represented using the concept of “predictive uncertainty” (PU). A polder area located in Nanjing was chosen for the case study. The results show a trade-off between the metrics that represent the waterlogging and the pumping costs, and that probabilistic forecasts of rainfall can considerably enhance these metrics. The results can be used to design a rainfall threshold-based flood early warning system (FEWS) for a polder area and/or evaluate its benefits.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139003316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-12DOI: 10.3390/hydrology10120237
Hanaa Megahed, A. Farrag, Amira A. Mohamed, Paola D’Antonio, A. Scopa, Mohamed A. E. AbdelRahman
In arid and hyper-arid areas, groundwater is a precious and rare resource. The need for water supply has grown over the past few decades as a result of population growth, urbanization, and agricultural endeavors. This research aims to locate groundwater recharge potential zones (GWPZs) using multi-criteria evaluation (MCE) in the Wadi Qena Basin, Eastern Desert of Egypt, which represents one of the most promising valleys on which the government depends for land reclamations and developments. These approaches have been used to integrate and delineate the locations of high groundwater recharge and the potential of the Quaternary aquifer in the Wadi Qena basin. After allocating weight factors to identify features in each case based on infiltration, land use/land cover, slope, geology, topology, soil, drainage density, lineament density, rainfall, flow accumulation, and flow direction, these thematic maps were combined. The results of the GIS modeling led to the division of the area’s groundwater recharge potential into five groups, ranging from very high (in the western part) to very low (in the eastern part of the basin). The zones with the best prospects for groundwater exploration turned out to be the alluvial and flood plains, with their thick strata of sand and gravel. The groundwater recharge potential map was validated using data from the field and earlier investigations. The promising recharging areas show high suitability for soil cultivation. The results overall reveal that RS and GIS methodologies offer insightful instruments for more precise assessment, planning, and monitoring of water resources in arid regions and anywhere with similar setups for groundwater prospecting and management.
{"title":"Groundwater Recharge Potentiality Mapping in Wadi Qena, Eastern Desert Basins of Egypt for Sustainable Agriculture Base Using Geomatics Approaches","authors":"Hanaa Megahed, A. Farrag, Amira A. Mohamed, Paola D’Antonio, A. Scopa, Mohamed A. E. AbdelRahman","doi":"10.3390/hydrology10120237","DOIUrl":"https://doi.org/10.3390/hydrology10120237","url":null,"abstract":"In arid and hyper-arid areas, groundwater is a precious and rare resource. The need for water supply has grown over the past few decades as a result of population growth, urbanization, and agricultural endeavors. This research aims to locate groundwater recharge potential zones (GWPZs) using multi-criteria evaluation (MCE) in the Wadi Qena Basin, Eastern Desert of Egypt, which represents one of the most promising valleys on which the government depends for land reclamations and developments. These approaches have been used to integrate and delineate the locations of high groundwater recharge and the potential of the Quaternary aquifer in the Wadi Qena basin. After allocating weight factors to identify features in each case based on infiltration, land use/land cover, slope, geology, topology, soil, drainage density, lineament density, rainfall, flow accumulation, and flow direction, these thematic maps were combined. The results of the GIS modeling led to the division of the area’s groundwater recharge potential into five groups, ranging from very high (in the western part) to very low (in the eastern part of the basin). The zones with the best prospects for groundwater exploration turned out to be the alluvial and flood plains, with their thick strata of sand and gravel. The groundwater recharge potential map was validated using data from the field and earlier investigations. The promising recharging areas show high suitability for soil cultivation. The results overall reveal that RS and GIS methodologies offer insightful instruments for more precise assessment, planning, and monitoring of water resources in arid regions and anywhere with similar setups for groundwater prospecting and management.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139009501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-12DOI: 10.3390/hydrology10120236
Giovanni De Luca, Giorgia Rivieccio
Climate change is a significant environmental challenge that affects water resources, agriculture, health, and other aspects of human life. Bivariate modeling is a statistical method used to analyze the relationship between variables such as rainfall and temperature. The Pearson correlation coefficient, Kendall’s tau, or Spearman’s rank correlation are some measures used for bivariate modeling. However, copula functions can describe the dependence structure between two or more variables and can be effectively used to describe the relationship between rainfall and temperature. Despite the literature on bivariate modeling of rainfalls and temperature being extensive, finding flexible and sophisticated bivariate models is sometimes difficult. In this paper, we use rotated copula functions that can arrange any type of dependence that is empirically detected, especially negative dependence. The methodology is applied to an Italian municipality’s bivariate daily time series of rainfall and temperature. The estimated rotated copula is significant and, therefore, can be used for simulating the effects of extreme events.
{"title":"Modeling and Simulating Rainfall and Temperature Using Rotated Bivariate Copulas","authors":"Giovanni De Luca, Giorgia Rivieccio","doi":"10.3390/hydrology10120236","DOIUrl":"https://doi.org/10.3390/hydrology10120236","url":null,"abstract":"Climate change is a significant environmental challenge that affects water resources, agriculture, health, and other aspects of human life. Bivariate modeling is a statistical method used to analyze the relationship between variables such as rainfall and temperature. The Pearson correlation coefficient, Kendall’s tau, or Spearman’s rank correlation are some measures used for bivariate modeling. However, copula functions can describe the dependence structure between two or more variables and can be effectively used to describe the relationship between rainfall and temperature. Despite the literature on bivariate modeling of rainfalls and temperature being extensive, finding flexible and sophisticated bivariate models is sometimes difficult. In this paper, we use rotated copula functions that can arrange any type of dependence that is empirically detected, especially negative dependence. The methodology is applied to an Italian municipality’s bivariate daily time series of rainfall and temperature. The estimated rotated copula is significant and, therefore, can be used for simulating the effects of extreme events.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139007014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-09DOI: 10.3390/hydrology10120235
Amadou Keïta, M. Zorom, M. Faye, Djim Doumbe Damba, Yacouba Konaté, László G. Hayde, Bruno Lidon
Obtaining accurate values of saturated hydraulic conductivity (Ksat) is very important for managing all natural or artificial processes involving water flow into soils. Double-ring infiltration (DRI) is one of the easiest-to-work-with techniques commonly used for Ksat determination. Unfortunately, when improperly used, it leads to important variations and inaccurate results. This study was designed to investigate the necessary conditions to reach the true-value or real-world saturated hydraulic conductivity (Ksat-real-world) in the field. For this purpose, the effects of two factors—namely, the measured infiltration data type (cumulative, instant rate, and average rate) and the related non-linear regression equation type—were analyzed. Measurements with DRI were performed with samples from 106 locations in three West African countries, namely, Burkina Faso, Mali, and Cote d’Ivoire. The soils were composed of loam, sandy loam, and sandy clay loam. The results show that when infiltration rates are used rather than cumulative infiltration non-linear regression curves, the variability between the measured Ksat and the real-world saturated hydraulic conductivity (Ksat-real-world) could reach from 2.2% to 58.8%. This variability was caused by the approximate amplification—according to the procedure used—of time-increment measurement errors. Extending the test duration to more than 4 h, especially when clay soils were involved, and using the exponential one-phase decay non-linear regression of the cumulative infiltration data based on a clear measurement protocol provided the Ksat values that were closest to Ksat-real-world.
{"title":"Achieving Real-World Saturated Hydraulic Conductivity: Practical and Theoretical Findings from Using an Exponential One-Phase Decay Model","authors":"Amadou Keïta, M. Zorom, M. Faye, Djim Doumbe Damba, Yacouba Konaté, László G. Hayde, Bruno Lidon","doi":"10.3390/hydrology10120235","DOIUrl":"https://doi.org/10.3390/hydrology10120235","url":null,"abstract":"Obtaining accurate values of saturated hydraulic conductivity (Ksat) is very important for managing all natural or artificial processes involving water flow into soils. Double-ring infiltration (DRI) is one of the easiest-to-work-with techniques commonly used for Ksat determination. Unfortunately, when improperly used, it leads to important variations and inaccurate results. This study was designed to investigate the necessary conditions to reach the true-value or real-world saturated hydraulic conductivity (Ksat-real-world) in the field. For this purpose, the effects of two factors—namely, the measured infiltration data type (cumulative, instant rate, and average rate) and the related non-linear regression equation type—were analyzed. Measurements with DRI were performed with samples from 106 locations in three West African countries, namely, Burkina Faso, Mali, and Cote d’Ivoire. The soils were composed of loam, sandy loam, and sandy clay loam. The results show that when infiltration rates are used rather than cumulative infiltration non-linear regression curves, the variability between the measured Ksat and the real-world saturated hydraulic conductivity (Ksat-real-world) could reach from 2.2% to 58.8%. This variability was caused by the approximate amplification—according to the procedure used—of time-increment measurement errors. Extending the test duration to more than 4 h, especially when clay soils were involved, and using the exponential one-phase decay non-linear regression of the cumulative infiltration data based on a clear measurement protocol provided the Ksat values that were closest to Ksat-real-world.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138983077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-07DOI: 10.3390/hydrology10120234
Elsa Dindi, Ardian Shehu
Vjosa is the main river of South Albania. Currently, the confined Quaternary gravelly aquifer in its lower course supplies drinking water for roughly 300,000 local residents. In the past years, extracted groundwater quantity has increased, whereas the groundwater quality has been affected by seawater intrusion. This paper aims to assess the groundwater quality and to discuss the dominant hydrochemical processes in the aquifer. To fulfil this goal, the study discusses the groundwater quality’s spatial and temporal variations on the basis of the hydrochemical parameters and ratios for 2010–2021 period, during which data are collected from three monitoring wells, located 6, 14 and 17 km, from the sea. While for 1961–2009 period, hydro-chemical water types and TDS maps are prepared using roughly 100 chemical analyses. The hydro-chemical parameters are discussed related to the factors controlling the groundwater’s chemical constituents and the groundwater extraction. Heavy metals and nitrates’ contents indicate that the aquifer is not affected by anthropogenic pollution. The main conclusion is that the groundwater quality is affected by seawater intrusion due to overexploitation. The study reveals its gaps, mentions its possible usefulness, and underlines the discrepancy between the policy makers and the hydrogeologists approaches concerning groundwater extraction.
{"title":"Spatial and Temporal Variations of the Hydrochemical Parameters in the Gravelly Aquifer of the Lower Course of Vjosa River, Albania","authors":"Elsa Dindi, Ardian Shehu","doi":"10.3390/hydrology10120234","DOIUrl":"https://doi.org/10.3390/hydrology10120234","url":null,"abstract":"Vjosa is the main river of South Albania. Currently, the confined Quaternary gravelly aquifer in its lower course supplies drinking water for roughly 300,000 local residents. In the past years, extracted groundwater quantity has increased, whereas the groundwater quality has been affected by seawater intrusion. This paper aims to assess the groundwater quality and to discuss the dominant hydrochemical processes in the aquifer. To fulfil this goal, the study discusses the groundwater quality’s spatial and temporal variations on the basis of the hydrochemical parameters and ratios for 2010–2021 period, during which data are collected from three monitoring wells, located 6, 14 and 17 km, from the sea. While for 1961–2009 period, hydro-chemical water types and TDS maps are prepared using roughly 100 chemical analyses. The hydro-chemical parameters are discussed related to the factors controlling the groundwater’s chemical constituents and the groundwater extraction. Heavy metals and nitrates’ contents indicate that the aquifer is not affected by anthropogenic pollution. The main conclusion is that the groundwater quality is affected by seawater intrusion due to overexploitation. The study reveals its gaps, mentions its possible usefulness, and underlines the discrepancy between the policy makers and the hydrogeologists approaches concerning groundwater extraction.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138592709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-06DOI: 10.3390/hydrology10120233
Marco Albert Öttl, Felix Simon, Jens Bender, Christoph Mudersbach, Jürgen Stamm
The design of a river-basin-specific flood hydrograph generator based on gauge records enables the generation of synthetic flood hydrographs for the dimensioning of hydraulic structures. Based on selected flow time series, flood waves can be described using four parameters based on flood characteristic simulations, as described by Leichtfuss and Lohr (1999). After successfully adapting suitable distribution functions, dependencies in the load structure are quantified in the next step using copula functions. This newly developed approach builds on the procedure proposed by Bender and Jensen (2012), which assumes hydrological independence. Using copula functions results in increased accuracy in the extended flood characteristic simulation. Moreover, considerable enhancements are achieved through the utilization of genetic algorithms, wherein the descending branch of the flood hydrograph is adjusted by employing an additional variable factor. Subsequently, any number of synthetic flood hydrographs can be generated by combining these parameters. In keeping with the principle of Monte Carlo simulation, a sufficiently high number of synthetic events results in extreme conditions with a low probability of occurrence being reliably represented. Hence, this endeavor has the potential to enhance result reproducibility and prediction quality. As a result, this expanded approach can be employed to provide dependable assessments regarding inflows aimed at optimizing reservoir capacity, for instance.
{"title":"An Extended Flood Characteristic Simulation Considering Natural Dependency Structures","authors":"Marco Albert Öttl, Felix Simon, Jens Bender, Christoph Mudersbach, Jürgen Stamm","doi":"10.3390/hydrology10120233","DOIUrl":"https://doi.org/10.3390/hydrology10120233","url":null,"abstract":"The design of a river-basin-specific flood hydrograph generator based on gauge records enables the generation of synthetic flood hydrographs for the dimensioning of hydraulic structures. Based on selected flow time series, flood waves can be described using four parameters based on flood characteristic simulations, as described by Leichtfuss and Lohr (1999). After successfully adapting suitable distribution functions, dependencies in the load structure are quantified in the next step using copula functions. This newly developed approach builds on the procedure proposed by Bender and Jensen (2012), which assumes hydrological independence. Using copula functions results in increased accuracy in the extended flood characteristic simulation. Moreover, considerable enhancements are achieved through the utilization of genetic algorithms, wherein the descending branch of the flood hydrograph is adjusted by employing an additional variable factor. Subsequently, any number of synthetic flood hydrographs can be generated by combining these parameters. In keeping with the principle of Monte Carlo simulation, a sufficiently high number of synthetic events results in extreme conditions with a low probability of occurrence being reliably represented. Hence, this endeavor has the potential to enhance result reproducibility and prediction quality. As a result, this expanded approach can be employed to provide dependable assessments regarding inflows aimed at optimizing reservoir capacity, for instance.","PeriodicalId":37372,"journal":{"name":"Hydrology","volume":null,"pages":null},"PeriodicalIF":3.2,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138597690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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