Influence of watershed topographic and socio-economic attributes on the climate sensitivity of global river water quality

Abstract

Surface waters exhibit regionalization due to various climatic conditions and anthropogenic activities.Here we assess the impact of topographic and socio-economic factors on the climate sensitivity of surface water quality, estimated using an elasticity approach (climate elasticity of water quality (CEWQ)), and identify potential risks of instability in different regions and climatic conditions. Large global datasets were used for 12 main water quality parameters from 43 water quality monitoring stations located at large major rivers. The results demonstrated that precipitation elasticity shows higher sensitivity to topographic and socio-economic determinants as compared to temperature elasticity. In tropical climate class (A), gross domestic product (GDP) played an important role in stabilizing the CEWQ. In temperate climate class (C), GDP played the same role in stability, while the runoff coefficient, slope, and population density fuelled the risk of instability. The results implied that watersheds with lower runoff coefficient, thick population density, over fertilization and manure application face a higher risk of instability. We discuss the socio-economic and topographic factors that cause instability of CEWQ parameters and conclude with some suggestions for watershed managers to bring sustainability in freshwater bodies.

How Do Terrestrial Determinants Impact the Response of Water Quality to Climate Drivers?—An Elasticity Perspective on the Water–Land–Climate Nexus

“…Those interesting equations potentially were useful to make climate change adaptions on a watershed scale like scenario analysis. quality [29]. Precipitation had stronger links to water quality compared to temperature.…”

“…It was evident from high values of R 2 that precipitation elasticity had stronger models compared to temperature elasticity for both terrestrial determinants like anthropogenic biomes and surficial geology. Precipitation elasticity of water quality developed many linear empirical equations with determinants compared to temperature elasticity of water quality [29]. Precipitation had stronger links to water quality compared to temperature.…”

“…The same study looked at impacts of determinants i.e., soil (soil nutrient retention capacity and soil nutrient availability) and land use (cultivated and managed area, bare area, herbaceous cover or shrub cover, and tree cover) which was captured partly using the nonparametric Kruskal-Wallis test. Recently, the sensitivity of CEWQ was assessed on a global scale where precipitation elasticity was found to be highly sensitive to socio-economic and topographic determinants compared to temperature elasticity [29]. The main contributions of this manuscript are to develop linear models using soil texture (sand, silt, clay and gravel) and anthropogenic biomes (dense settlements, villages, croplands, rangelands, forested and wildlands) at three typical watersheds: The Yukon, Mekong and Murray watersheds.…”

Complex Linkage between Watershed Attributes and Surface Water Quality: Gaining Insight via Path Analysis

“…Mean population has positive linkage with croplands because Indus is the largest basin in Pakistan where people live and grow crops. Riverine flow regime has negative linkage with EC which might be due to dilution effects [24]. Moreover, 2/3 climate models demonstrated that annual average runoff would increase in future [17].…”

“…Rangelands play key role in controlling nonpoint source pollution. Dissolved organic carbon and NOX-F are negatively associated with rangeland biomes [24]. Rangeland's biomes have lower human interference as well as good nutrients retention capacity which help in water environment protection [25][26][27].…”