Study on the accumulation characteristics and conduction trend of water environment risk from Taizihe River Basin,...

The accumulation and conduction of water environmental risks is of great significance to the ecological safety of river basins. To resist the outbreak of water environmental risk events, it is important to control the risk during its production and conduction phases and cut the chain of risk conduction. Currently, there are rarely reports on the research of water environment risk conduction in river basins. In order to reveal the risk accumulation characteristics and conduction trend of water environment from Taizihe River Basin, this study tried to calculate the risk level coefficient, the comprehensive risk index, the probability and intensity of the risk conduction based on the risk energy theory, and reveal the risk conduction trend in the region. The results showed that the risk sources in the study area mainly include mining, petrochemicals, metallurgical industries and equipment manufacturing industries, and habitats were waters, cultivated land, forest land, grasslands and urban land. There were one region (R4) in the slight risk area, one region (R6) in the low risk area, two regions (R3 and R5) in the medium risk area, one region (R7) in the high risk area, and two regions in the very high risk area (R1 and R2). The upper reaches of the Taizihe River was the main risk accumulation area, and the middle and lower reaches were the main risk conduction release areas. The most important contributors to the risk were TN and NH₃-N. The excess of nitrogen elements constituted the main risk source of node water quality. The highest risk during the wet and dry season occurred in the downstream section, and Tangmazhai, Xiaojiemiao, Sanchahe and Guchengzi all showed higher comprehensive risk values. This study breaks the previous idea of simple risk assessment, and observes the risk-shifting direction, which provides a theoretical and methodological support for watershed environmental risk research.