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Environmental Effects of Natural Processes and Human Activities on the Water Environment in Watershed

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Water and Climate Change".

Deadline for manuscript submissions: closed (20 August 2024) | Viewed by 26660

Special Issue Editors


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Guest Editor
Institute of Earth Sciences, China University of Geosciences (Beijing), Beijing 100083, China
Interests: hydrology; hydro-geochemistry; water chemistry; water quality; aquatic geochemistry; isotopic geochemistry
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Guest Editor
Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China
Interests: water chemistry; environmental geochemistry; isotopic geochemistry; hydrogeochemistry

Special Issue Information

Dear Colleagues,

As an essential contributor to global biodiversity and ecological productivity, watershed aquatic ecosystems provide a broad range of services for all life on Earth, including water for drinking, irrigation, power generation and industry, biological habitat, and food and recreation places. However, the water environment and hydrology of the watershed have been increasingly threatened or changed, both directly and indirectly, by human activities and natural processes.

Globally, the environmental problems resulting from water and hydrology changes in watershed have been a cause for concern for over a century. In addition to water-quality deterioration, water environment changes such as eutrophication, pollutants exposure and migration, nutrients biogeochemical cycling, and greenhouse gas emissions in watershed are ongoing research hotspots, since they are essential to current water protection and management policymakers.

A watershed is the most important water-resource unit in the surface system, supporting social and economic development in most parts of the world. Despite the extensive time and financial resources dedicated to the identification of nonpoint sources of nutrients and pollutants in watersheds, many watersheds have not seen substantial improvement in water quality. Specific assessment of the fate and transformation of nutrients and other pollutants in different watershed scales and the influence of anthropogenic and natural processes remains critical. Considering hydrological changes in different-scale watershed, targeted studies of the cycling and transformation of the nutrients and pollutants under the influence of human activities and natural processes, and their environmental effects would provide useful implications for future watershed water environment and hydrology assessment and water management. Hydrologically, dam construction and changing the land use in the watershed, river impoundments for hydroelectric power generation and irrigation supply purposes alters or intercepts the nutrients and pollutants.

This Special Issue aims to present studies on water environment and hydrology changes in watershed under the influence of human activities and natural processes, and clarify the biogeochemical processes and influencing factors of the nutrients and pollutions in different watershed. This Special Issue intends to share innovative ideas from various perspectives within the field, and the topic could be addressed from several different viewpoints:

  • Watershed-scale transformation and migration mechanisms of nutrients and other pollutants influenced by human activities and natural progress.
  • Mechanisms of different kinds of water pollution and deterioration in watershed, including eutrophication, hypoxia, and greenhouse gas emissions.
  • Quantitative and qualitative identification of the contribution of potential sources of nutrients and pollutants.
  • Assessment of the environmental effects of human activities coupled with natural processes on biogeochemical cycling and transformations of nutrients and pollutants in watershed.

Prof. Dr. Guilin Han
Dr. Xiaolong Liu
Guest Editors

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Keywords

  • watershed water environment
  • nutrient pollution
  • element cycle
  • source identification
  • agriculture
  • urban sewage
  • river impoundment
  • weathering
  • water-air interface
  • greenhouse gas emission

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Published Papers (11 papers)

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Editorial

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6 pages, 187 KiB  
Editorial
Environmental Effects of Natural Processes and Human Activities on the Water Environment in Watershed
by Guilin Han and Xiaolong Liu
Water 2024, 16(20), 2929; https://doi.org/10.3390/w16202929 - 15 Oct 2024
Viewed by 877
Abstract
The Special Issue focused on the water environment changes within watersheds due to its critical role in sustaining ecosystems, supporting biodiversity, and providing essential resources for human life [...] Full article

Research

Jump to: Editorial

14 pages, 4940 KiB  
Article
The Impact of the Three Gorges Reservoir Operations on Hydraulic Characteristics in the Backwater Region: A Comprehensive 2D Modeling Study
by Yaqian Xu, Shengde Yu, Defu Liu, Jun Ma and Mingying Chuo
Water 2024, 16(14), 2045; https://doi.org/10.3390/w16142045 - 19 Jul 2024
Cited by 1 | Viewed by 858
Abstract
The Three Gorges Reservoir (TGR), a landmark of human engineering, has significantly altered the hydrodynamics and ecology of its surrounding environment. Our research explores the hydrodynamic and ecological changes in the TGR, focusing on their implications for reservoir-induced water quality and water resource [...] Read more.
The Three Gorges Reservoir (TGR), a landmark of human engineering, has significantly altered the hydrodynamics and ecology of its surrounding environment. Our research explores the hydrodynamic and ecological changes in the TGR, focusing on their implications for reservoir-induced water quality and water resource issues. We designed a 2D hydrodynamic and water quality model and implemented 15 operational scenarios with an advanced dynamic storage capacity method for the TGR during flood season, drawdown and impoundment periods. Our simulations well reproduced and predicted water levels, discharge rates, and thermal conditions of the TGR, providing critical insights. The dynamic storage capacity method significantly improved the precision of water level simulations. This approach achieved modeling errors below 0.2 m when compared to real measurements from seven stations. We performed a detailed analysis of the sensitive, sub-sensitive, and insensitive areas during three reservoir operation periods. The drawdown period showed the most extensive impact range (468 km river channel), while the impoundment period had the least impact range (76 km river channel). Furthermore, we quantified the delay of temperature waves during these periods, observing a maximum delay of approximately 120 km and a minimum delay of less than 10 km, which underscores the variability in hydrodynamic responses under different operational scenarios. Our findings reveal the complex sensitivities of the TGR to varied operational modes, aiding in the development of eutrophication and water resources control strategies. Our modeling application provides different operational scenarios and insights for ecological management strategies in large dam systems globally, informing future water resource management and policy-making, ensuring sustainable and effective management of large reservoir systems. Full article
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27 pages, 10717 KiB  
Article
Sustaining the Pearl River: A Critical Review of Changes in Fluvial Geomorphological Processes and the Driving Forces in the Pearl River Basin
by Haidong Ou, Shirong Cai, Wei Fan, Junliang Qiu, Xiaolin Mu, Tao Zhou, Xiankun Yang and Lorenzo Picco
Water 2024, 16(7), 1001; https://doi.org/10.3390/w16071001 - 29 Mar 2024
Cited by 1 | Viewed by 1898
Abstract
The Pearl River is one of China’s large rivers, the second-largest river and the fourth-longest river in China. Its unique geography, landform, and climate conditions create unique fluvial geomorphological processes. Affected by human activities and climate change, the fluvial geomorphological processes in the [...] Read more.
The Pearl River is one of China’s large rivers, the second-largest river and the fourth-longest river in China. Its unique geography, landform, and climate conditions create unique fluvial geomorphological processes. Affected by human activities and climate change, the fluvial geomorphological processes in the Pearl River Basin have undergone significant changes in recent decades, seriously affecting the river’s sustainable development. This paper critically reviews changes in fluvial geomorphological processes and analyzes influencing factors in the Pearl River Basin with a focus on possibilities for policy overhaul and strategic adjustments. Full article
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13 pages, 5760 KiB  
Article
Evolution Characteristics of Water Quality in Plain Reservoirs and Its Relationship with the Economic Development Response: A Case Study of Daheiting Reservoir in Northern China
by Budong Li, Kaiqi Chen, Xiaobo Liu, Chang Liu and Shiyan Wang
Water 2023, 15(18), 3229; https://doi.org/10.3390/w15183229 - 11 Sep 2023
Viewed by 1310
Abstract
In order to explore the evolution characteristics of TP and NH3-N in Daheiting reservoir since its construction, and their response to economic development, the monitoring data of water quality from 1992 to 2018 and statistical data of socio-economic development in Qianxi [...] Read more.
In order to explore the evolution characteristics of TP and NH3-N in Daheiting reservoir since its construction, and their response to economic development, the monitoring data of water quality from 1992 to 2018 and statistical data of socio-economic development in Qianxi County were analyzed to examine the interannual evolution of TP and NH3-N and their correlation with upstream water quality, various economic indicators, and the scale of cage fish culture. The results show that, influenced by economic development, the evolution process of TP and NH3-N in Daheiting reservoir can be divided into three stages. In Stage I, the economic development of Qianxi County was slow, and the water quality of upstream water and the reservoir was good, with TP and NH3-N concentrations remaining relatively stable. In Stage II, Qianxi County entered a period of rapid economic development, and the TP and NH3-N in upstream water and Daheiting reservoir both increased significantly, with TP exceeding the standard limit. In Stage III, the intensity of external pollution control increased, and all cages were removed from the reservoir. Both TP and NH3-N showed a downward trend, but TP still exceeded the standard limit. Pearson correlation analysis and RDA analysis revealed that the levels of TP and NH3-N in Daheiting reservoir were mainly affected by the water quality of upstream water and the development of primary industry (including cage fish culture). Full article
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14 pages, 7257 KiB  
Article
Hydrochemical Characteristics, Water Quality, and Evolution of Groundwater in Northeast China
by Tao Zhang, Pei Wang, Jin He, Dandan Liu, Min Wang, Mingguo Wang and Shibin Xia
Water 2023, 15(14), 2669; https://doi.org/10.3390/w15142669 - 24 Jul 2023
Cited by 9 | Viewed by 3061
Abstract
Groundwater is vital to local human life and agricultural irrigation, and the quality of the water is critical to human health. As a result, it is critical to investigate the hydrochemical evolution and water quality of groundwater in the Sanjiang Plain. There were [...] Read more.
Groundwater is vital to local human life and agricultural irrigation, and the quality of the water is critical to human health. As a result, it is critical to investigate the hydrochemical evolution and water quality of groundwater in the Sanjiang Plain. There were 259 samples obtained. Furthermore, hydrogeochemical simulation was performed to highlight groundwater’s hydrochemical features, evolution process, and water quality. The analytical results show that the groundwater in the study area is somewhat alkaline with a mean TDS of 285.94 mgL−1 and the primary contributing ions being Ca2+ and HCO3. The closer the concentration of TDS and NO3 is to the city, the higher the concentration, indicating that the chemical composition of the water body has been affected by certain human activities. The Piper diagram, Gibbs diagram, and correlation analysis results demonstrate that the chemical type of groundwater is mostly HCO3-Ca and the hydrochemistry is primarily regulated by weathering and carbonate and silicate dissolution. According to the entropy-weighted water quality index, the groundwater quality in this location is pretty acceptable. This study could help strengthen groundwater quality monitoring based on local conditions, identify the source of nitrate, provide data support for the safe use of local water resources, and serve as a reference for global water chemical evolution and water quality evaluation in cold regions. Full article
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15 pages, 9790 KiB  
Article
Distribution Characteristics and Genesis of Iron and Manganese Ions in Groundwater of Eastern Sanjiang Plain, China
by Mingguo Wang, Min Wang, Li Yang, Tao Yang, Jingjie Li and Yuanming Chen
Water 2023, 15(11), 2068; https://doi.org/10.3390/w15112068 - 30 May 2023
Cited by 7 | Viewed by 2367
Abstract
Groundwater resources are an essential component of global water resources. Long-term consumption of groundwater exceeding the standard levels for iron and manganese can lead to chronic diseases, posing a threat to human health. The Sanjiang Plain is the largest swamp wetland area in [...] Read more.
Groundwater resources are an essential component of global water resources. Long-term consumption of groundwater exceeding the standard levels for iron and manganese can lead to chronic diseases, posing a threat to human health. The Sanjiang Plain is the largest swamp wetland area in China and has high levels of iron and manganese in the groundwater, but the cause still needs to be clarified. Based on the results of water quality tests of 41 groundwater samples in the Eastern Sanjiang Plain, this paper analyzes the distribution characteristics and causes of iron and manganese from the perspectives of the original strata environment, redox conditions, pH conditions, and hydrochemical indicator factors in the research area, using statistical methods and GIS technology. The results show that high iron and manganese content in groundwater is prevalent in the Eastern Sanjiang Plain, and the exceedance rate of manganese is higher than that of iron (87.80% and 82.90%, respectively). The primary sources of iron and manganese in groundwater are iron and manganese minerals in the original strata environment. Influenced by factors such as acidic conditions, reducing environment, and rich organic matter, insoluble high-valent iron and manganese oxides are reduced to low-valent and soluble divalent iron and manganese. At the same time, groundwater’s high mineralization and evaporation concentration are conducive to increased iron and manganese content, while the influence of human activities is small. Full article
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15 pages, 4235 KiB  
Article
Hydrochemical Characteristics and Risk Assessment of Tongzi River, Guizhou Province, Southwest China
by Jiemei Lü and Yanling An
Water 2023, 15(4), 802; https://doi.org/10.3390/w15040802 - 18 Feb 2023
Cited by 4 | Viewed by 2208
Abstract
This study collected 31 water samples from the Tongzi River, Guizhou Province, Southwest China to conduct a risk assessment to understand the hydrochemical characteristics and major ion sources of irrigation and drinking water quality and their effects on human health. The results showed [...] Read more.
This study collected 31 water samples from the Tongzi River, Guizhou Province, Southwest China to conduct a risk assessment to understand the hydrochemical characteristics and major ion sources of irrigation and drinking water quality and their effects on human health. The results showed that ion abundance in the Tongzi River is Ca2+ (66%) > Mg2+ (24%) > K++Na+ (10%) for cations and HCO3 (75%) > SO42−(21%) > Cl (4%) for anions. Additionally, the hydrochemical type of the water is Ca-Mg-HCO3, controlled by carbonate weathering. Methods including ion ratios, principal component analysis (PCA), and correlation analysis (CA) were used to analyze the source of main ions in the river water. PC1, with the most significant variance (54.9%), decides the hydrochemical characteristics and is affected by the positive loadings of SO42− (0.92), pH (0.85), Ca2+ (0.80), Cl (0.72), Na+(0.66), NO3 (0.65), and K+ (0.57). PC2 explains 19.2% of the total variance, with strong positive loadings of Na+ (0.75), K+ (0.63) and Cl (0.59). Mg2+ (0.84) and HCO3 (0.85) exhibits high loadings in PC3, explaining 9.3% of the variance. The results showed that intensive agricultural activities in the basin were the main source of nitrate NO3, whereas SO42− was mainly derived from mining activities. The lower concentrations of Na+, K+, and Cl were from coal combustion, domestic wastewater discharge, and agricultural fertilizer applications. The study area was mainly affected by carbonate rock weathering; natural processes (mainly the weathering of carbonate rocks) were still the main origin of Ca2+, Mg2+, and HCO3. Moreover, the United States Salinity Laboratory (USSL) diagram and the Wilcox diagram showed that 100% of the samples fell in the C2S1 zones, and the water quality had good suitability for irrigation. The health risk assessment (HRA) results showed that HQNO3 was much larger than HQNH4+ and indicated that nitrate pollution dominated non-health hazards. About 6.5% of the samples in the tributaries represented an unacceptable risk for infants and children, and the HQ value for infants and children was always higher than that for adults. Additionally, the non-carcinogenic health risk of riverine ions for infants and children in the Tongzi River was very noteworthy, especially in the tributaries. Full article
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16 pages, 18525 KiB  
Article
Spatial Distribution and Sources of Rare Earth Elements in Urban River Water: The Indicators of Anthropogenic Inputs
by Xi Gao, Guilin Han, Jinke Liu and Shitong Zhang
Water 2023, 15(4), 654; https://doi.org/10.3390/w15040654 - 8 Feb 2023
Cited by 12 | Viewed by 3169
Abstract
Rare earth element (REE) concentrations in river water reflect both local geological background and the intensity of anthropogenic activities. The increasing demand for high-tech applications is accompanied by an increase in REEs in water environments, especially in urban regions. Therefore, the dissolved REEs [...] Read more.
Rare earth element (REE) concentrations in river water reflect both local geological background and the intensity of anthropogenic activities. The increasing demand for high-tech applications is accompanied by an increase in REEs in water environments, especially in urban regions. Therefore, the dissolved REEs in a typical urban river (Yongding River) were analyzed to reveal the influence of anthropogenic inputs. It was found that the sum of dissolved REE (ΣREE) concentrations in river water were 6.27~86.26 ng L−1 (mean 31.05 ng L−1). The spatial distribution of REEs is significantly affected by both natural processes and human activities. To eliminate the effect of upstream land use on downstream measurements, this study established a 500 m buffer zone alongside the river and identified the anthropogenic origin of REEs through correlations among land use proportions within the buffer zone, the population density, and REEs. The Post-Archean Australian Shale (PAAS)-normalized REEs revealed pronouncedly positive Gd anomalies in the range 0.30~20.16 in all river samples. Spearman correlation analysis indicated that the proportion of cultivated land was positively correlated with most of the REEs. A three-dimensional tracer system was established via Gdanth, NO3/Na+ and Cl/Na+ to characterize the impact of sewage treatment plants, hospitals and agricultural activities on river water. The results indicate that with the acceleration of urbanization, abnormal REEs can be considered as a sensitive indicator to assess the influence of anthropogenic activities on water ecosystems. Full article
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19 pages, 3510 KiB  
Article
Geochemistry and Sources Apportionment of Major Ions and Dissolved Heavy Metals in a Small Watershed on the Tibetan Plateau
by Wencong Xing, Lai Wei, Wenmin Ma, Jun Li, Xiaolong Liu, Jian Hu and Xiaoxia Wang
Water 2022, 14(23), 3856; https://doi.org/10.3390/w14233856 - 26 Nov 2022
Cited by 7 | Viewed by 2575
Abstract
Due to environmental sensibility and fragility, the water chemistry revolution and heavy metals accumulation influenced by natural and anthropogenic processes in the rivers on the Tibetan Plateau have recently become a global concern. However, targeted studies in small watersheds on the Tibetan Plateau [...] Read more.
Due to environmental sensibility and fragility, the water chemistry revolution and heavy metals accumulation influenced by natural and anthropogenic processes in the rivers on the Tibetan Plateau have recently become a global concern. However, targeted studies in small watersheds on the Tibetan Plateau are relatively limited. A study of surface waters in Duilong Qu (DLQ), a small watershed located on the Tibetan Plateau, have been conducted to assess the impact of natural and anthropogenic activities on the water environment of the DLQ by analyzing the major ions and heavy metals (Cd, Cr, Mn, Fe, Ni, Cu, Zn, Pb, and As) in the river waters. The results of the analysis of major ions showed that SO42 and HCO3 were the dominant anions and Ca2+ was the dominant cation, indicating that the water chemistry of the river waters was mainly of the HCO3-Ca type. The results of Piper diagram and Gibbs diagram analysis indicate that the water solute is mainly controlled by the weathering of carbonate rocks, followed by the influence of geothermal water confluence. Compared to the world river average, the concentrations of Cr, Pb, and As in the studied rivers were relatively high. The heavy metal concentrations satisfy the standards of WHO and GB (Chinese national standard) guidelines. The PCA-APCS-MLR model has been employed and evidenced as a reliable tool to identify the sources of the heavy metals in this study. The results revealed that the heavy metals in the DLQ are caused by natural sources, geothermal water, and mining operations. The primary sources of As (93.63%), Cr (93.07%), Mn (73.53%), Fe (59.54%), and Pb (58.28%) in the DLQ were geothermal water, while Zn (91.41%), Mn (20.67%), Fe (40.46%), and Pb (26.15%) originated mainly from natural sources. Additionally, Cu (91.41%) was primarily influenced by mining operations, and Ni originated from mining (53.61%) and geothermal water sources (46.39%), while Cd (97.88%) originated from unknown sources. In the high-flow season periods from 1992 to 2017, the As concentrations in the DLQ decreased significantly, which might result from increasing precipitation and runoff. Overall, the results of this study suggest that both natural and anthropogenic activities have jointly affected the solutes in small rivers on the Tibetan Plateau, and heavy metal pollution should be emphasized in the future. Full article
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22 pages, 5978 KiB  
Article
Pollutants Source Assessment and Load Calculation in Baiyangdian Lake Using Multi-Model Statistical Analysis
by Guangwei Wang, Cuicui Lv, Congke Gu, Yang Yu, Zhenglun Yang, Zhixiong Zhang and Changyuan Tang
Water 2022, 14(21), 3386; https://doi.org/10.3390/w14213386 - 26 Oct 2022
Cited by 4 | Viewed by 2620
Abstract
Baiyangdian lake, the largest fresh lake on the Haihe Basin in North China, has attracted wide attention on account of the distinguished ecological water bodies in Xiong’an New Area. Although remarkable achievements have been made in pollution control in Baiyangdian lake, the problem [...] Read more.
Baiyangdian lake, the largest fresh lake on the Haihe Basin in North China, has attracted wide attention on account of the distinguished ecological water bodies in Xiong’an New Area. Although remarkable achievements have been made in pollution control in Baiyangdian lake, the problem facing the overall water environment remains serious. The complex pollutant sources, drastic pollutant flux changes, and the unclear impact of the role of pollutants pose great challenges to the water quality, water environment management, and long-term restoration of the ecological environment. Here, the potential pollution sources, their contribution ratio, and the influence of the pollution load of different sources on the water quality in the priority source areas of Baiyangdian lake are discussed in detail based on collected and existing monitoring data. It is proven that the primary pollution sources of for nitrogen, phosphorus, and organic pollutants are from agricultural and rural non-point source pollution; the load contribution rates exceed 50%, of which the contribution rate to the total phosphorus load reaches 73.37%. The total load contribution of runoff to the three pollutants was small, although the contribution of soil erosion to total nitrogen was 22.95%. The contribution of point source pollution to COD was high, with a rate of 22.33%. In order to ensure the environmental quality of Baiyangdian lake, it is obligatory to strengthen the control of agricultural and rural pollution discharge and to standardize the pollution discharge of livestock and poultry breeding. This study provides a helpful support for protecting the water ecology of the national Xiong’an New Area. Full article
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16 pages, 4358 KiB  
Article
Are UK Rivers Getting Saltier and More Alkaline?
by Shan Jiang, Xuan Wu, Sichan Du, Qin Wang and Dawei Han
Water 2022, 14(18), 2813; https://doi.org/10.3390/w14182813 - 9 Sep 2022
Cited by 6 | Viewed by 4104
Abstract
River salinisation and alkalinisation have become one of the major environmental problems threatening the safety of global freshwater resources. With the accelerated climate change and aggravating anthropogenic influences, it is important to identify the trends and causes of river salinisation and alkalinisation so [...] Read more.
River salinisation and alkalinisation have become one of the major environmental problems threatening the safety of global freshwater resources. With the accelerated climate change and aggravating anthropogenic influences, it is important to identify the trends and causes of river salinisation and alkalinisation so that better mitigation measures could be taken. This study has focused on the UK rivers because there has been insufficient investigation on this topic. To understand the salinisation and alkalinisation trends and causes of rivers in the UK over the past 20 years from a vertical (analysis of each river) and horizontal (comparison of all rivers) perspective, this study uses the Theil-Sen regression and Mann-Kendall test to deal with the trends of conductivity (proxy on salinisation) and pH (proxy on alkalinisation), obtains outliers of conductivity and pH by boxplot, and calculates the Pearson’s and the Kendall’s Tau correlation coefficients (α = 0.05) between the water quality data and the potential factors (potential road salting, normalized difference vegetation index (NDVI), river discharge, agricultural and urban lands). The results show that the UK rivers are becoming more alkaline with a median pH increase of 0.05 to 0.40, but less salty with a median conductivity decrease of 0.06 to 0.11 mS/cm. And the changes in conductivity and pH have seasonality and regionality, which shows that there are usually greater changes in trends and medians of them in winter or through reaches with more anthropogenic disturbance. Furthermore, from a vertical perspective, the conductivity of more than 50% of rivers in this study is negatively correlated with NDVI and river discharge, and positively correlated with potential road salting, and the pH of that is positively correlated with agricultural lands. While from a horizontal perspective, NDVI and agricultural lands are positively correlated with pH, and potential road salting and urban lands are positively correlated with conductivity. Therefore, road salting, urbanisation, agricultural lands, river discharge and vegetation cover can be considered to affect river salinisation and alkalinisation in the UK. Full article
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