Impact of Agricultural Non-Point Source Pollution on River Water Quality: Evidence From China

Abstract

Identifying the effect of agricultural non-point source pollutants on water quality is very important for water pollution management. This study used NH3N as an indicator to empirically study the influence of fertilizer application on river water quality based on panel data of 46 prefecture-level cities and 18 state-controlled water quality monitoring points through which the main streams of Yangtze River and Yellow River flow from 2004 to 2019. It is found that: (1) An increase in agricultural fertilizer application amount will exacerbate water pollution, and the worsening water quality in the upper watershed and the influence of precipitation will lead to transboundary water pollution in the lower watershed. (2) The amount of fertilizer application and fertilizer application intensity had a threshold effect on river water quality pollution. When the former exceeded the threshold value of 11.496 tons, and the latter exceeded the threshold value of 7.991 ton/km2, the positive effect of fertilizer application on pollutants in rivers was further enhanced. (3) The amount of fertilizer applied had a long-term effect on water quality through a lagged effect, and as the number of lags increased, the accumulative effect of the negative influence gradually rose. Based on the findings of the empirical study, it is proposed that the inter-basin and inter-regional synergy should be formed in the prevention and control of agricultural non-point source pollution, and the overall top-level design of agricultural subsidies and agricultural environmental policies in the areas along the basin should be considered.

Threats to aquatic biodiversity and possible management strategies in Lake Victoria

“…Over the last 50 years, both point and non‐point source water pollution have become important issues as a result of the negative impact of de‐oxygenation, which has fundamentally shifted the environmental state of Lake Victoria from mesotrophic to eutrophic conditions (LVBC, 2011; Xu, Tan, et al., 2022). Agricultural runoff (including pesticides and herbicides), untreated industrial waste, pharmaceuticals from nearby metropolitan areas like Kisumu, Kampala and Mwanza and household sewage from lakeshore settlements are the major sources of wastes in Lake Victoria (Nassali et al., 2020).…”

Assessing heavy metal and physiochemical pollution load of Danro River and its management using floating bed remediation

“…Field observations reveal that the accumulation of these materials results in sediment dunes, continuously altering morphological characteristics and causing bank erosion 23 , 24 . At the same time, the quality of the river water has declined to the extent of experiencing eutrophication, a condition linked to non-point source pollution originating from agricultural activities and the release of domestic and industrial sewage 25 – 28 . Belchampa Ghat, situated along the riverbanks, contends with widespread illegal sand mining, provoking severe environmental consequences.…”

Investigating Algal Sensor Utilization Methods for Three-Dimensional Algal Control Technology Evaluation

“…Moreover, temperature increases are causing changes in rainfall, including increased rainfall pattern variability [4][5][6]. Additionally, primary production or eutrophication is accelerating because of increased nutrient levels (e.g., nitrogen and phosphorus) in water bodies as a consequence of industrial development and the use of agricultural fertilizers [7]. This phenomenon is expected to occur more frequently [5,8,9].…”