Study On Regional Water Environment Carrying Capacity Based On DPSIRH And SD

The study and evaluation of the water environment carrying capacity(WECC)of Luoyang City in the Yiluo River Basin will help to understand the current status and potential problems of its water environment,explore its main influencing factors,provide technical support for the protection and improvement of water environment conditions in the later period,and also provide a theoretical basis for the formulation of water environment protection and management regulations.In addition,it is of great practical significance to alleviate the contradiction between local water environment protection and economic development and to build a healthy and sustainable development society.This paper is based on the theoretical connotation of WECC,combined with system theory and harmonization degree theory,takes WECC as the goal,takes water environment pressure,water environment state,water environment response as criteria layer,and uses Driving force,Pressure,State,Influence,Response and Harmonization as subsystem construct an evaluation index system for the WECC of the Luoyang section of the Yiluo River Basin,and frequency analysis and principal component analysis are used to screen the index system;The weight of each index is obtained by AHP-Entropy combination weighting method,and the WECC index is obtained based on the DPSIRH model.At the same time,the theory of system harmonization is introduced,and the index of water environment system harmonization index is obtained by using the evaluation model of minimum harmonization degree of deviation coefficient.Then through the coupling model constructed,a more objective and comprehensive evaluation index of WECC is obtained.In addition,based on the theory of System Dynamics,a dynamic model of water environment system is built by using Vensim software.The model is applied to make short-term simulation prediction of water environment system in Luoyang section of Yiluo River Basin,and the short-term development and change of WECC and health status in the region are obtained according to the simulation prediction results.The study found: Although the comprehensive evaluation index of the WECC of Luoyang City in the Yiluo River Basin from 2009 to 2018 is mostly at a poor level,there are signs of improvement.In 2017,its comprehensive evaluation index for WECC reached 0.4262,which entered the eligibility criteria and remained until 2018;The analysis of evolution characteristics shows that the main criterion layer affecting the evaluation index of WECC is the Pressure criterion layer,the main subsystem is the Driving force and Pressure subsystem,and the main evaluation indexes are the percentage of industrial output value in GDP,energy consumption per unit GDP and wastewater discharge per unit industrial production value;Using the System Dynamics(SD)model simulation,it is found that under different development scenarios,the water environment condition of Luoyang section of Yiluo River Basin will be improved in different degrees in the next 7 years(2019-2025),of which scenario 6 has the largest relative improvement,and its comprehensive evaluation index is 0.6277 in 2025,reaching a good level.Compared with scenario 1(current situation)in 2025,the comprehensive evaluation index of WECC is the number increased by 0.0801,up nearly 15%;According to the simulation prediction results and the analysis conclusion of evolution characteristics,the paper puts forward five measures to guarantee the water environment,which mainly include the efficient use of energy,water conservation and sewage interception and emission reduction,optimization of industrial structure,improvement of environmental protection investment and supervision of water environment protection and so on.