Guan'gai paishui xuebao (Oct 2023)
Evaluation of Water Environmental Security in the Haihe River Basin and Analysis of Dynamic Coupling Coordination
Abstract
【Objective】 The Haihe River plays a pivotal role in supporting various industrial and agricultural sectors in northern China. This paper presents a comprehensive evaluation of its environmental security and coordinated development to identify factors that influence environmental security most. 【Method】 The analysis was based on the pressure-state-response model, from which we proposed an improved comprehensive and systematic indicator system, including indicators that have been neglected, such as biodiversity and non-conventional water sources. A fuzzy comprehensive evaluation method was used to assess the water environmental security, and the entropy weight method and principal component analysis method were used to calculate the weights. A dynamic ternary-coupled coordination degree model was used to analyze the dynamic coupling and quantitatively calculate the coordination of the subsystem of pressure, state, and response. The key factors affecting water environmental security were identified through comprehensive consideration of the contribution rate and elasticity of the indicators. 【Result】 ①From 2009 to 2020, water environmental security in the basin had gradually improved, experiencing a transition from primary-coupling to advanced coupling. During this period, the coordinated development level decreased first followed by an increase. The deviation from the coordination had increased from 22.8° to 24.0°, except in 2020 in which it fell to 17.3°. ②The security of primary indicators had increased in all levels, among which the state indicator improved most significantly, despite still in relatively dangerous status. ③The secondary indicators had different influences on water environment security, among which the increase in population and urbanization had the most detrimental effect. Ammonia nitrogen and total phosphorus in the basin had been greatly reduced, but water quality in some parts of the basin were still category I-III, with potential to grow further. Increasing the use of non-conventional water sources can improve water environmental security. 【Conclusion】 In medium and long term, water environmental security in the basin can be improved by reducing the discharge of pollutants such as COD, BOD-5, and permanganate. Increasing use of desalinated seawater and rainwater collection, as well as storage capacity of green landscape can also improve water environmental security. It is crucial to maintaining and enhancing biodiversity and vegetation coverage to reduce water and nutrient losses to improve water security in the basin.
Keywords
