Study On Environmental Status Of Wushaoling Area In Qilian Mountains Based On PSR Model

The environment problem of Qilian Mountains has always been a hot topic.For this reason,based on the field investigation and indoor analysis of the environment in the Wushaoling area of Qilian Mountains,the paper is based on the pressure-state-response conceptual framework model（ie PSR model）.Based on the results of field investigation and indoor analysis,the environment evaluation system of Wushaoling area was constructed.The entropy weight method and comprehensive index method were used to calculate the comprehensive evaluation value of ecological environment status in Wushaoling area of Qilian Mountains from 2007 to 2018.The main research contents are as follows:1.Through the evaluation and analysis of the monitoring section data of Zhuanglang River,it is found that in addition to the reference evaluation index total nitrogen and fecal coliform bacteria exceeding the standard in the surface water environment of the study area,the other 20 required evaluation indicators can reach the Class II water quality standard;Analysis of 11 sampling monitoring points along the river found that the dissolved oxygen concentration decreased with increasing altitude and temperature,and increased with increasing pH.2.Through the analysis of water content,pH,SOC,TN and heavy metals in 49 soil samples in Wushaoling area,it is found that the soil moisture content in this area is higher,and the drought degree is 77.55%of the suitable and partial wetness level,suitable for vegetation.Growth;soil pH is between 7.00 and 9.40,the mean is about 8.28,which is generally weakly alkaline;SOC and TN are high,and its spatial distribution is closely related to vegetation coverage.3.On-site monitoring of the atmospheric environment found that the total suspended particulate matter（TSP）concentration,ozone（O₃）concentration,sulfur dioxide（SO₂）concentration,and nitrogen oxide（NO_x）concentration in the ambient air of the Wushaoling area were in compliance with the Ambient Air Quality Standard.The primary standard concentration limit in（GB3095-2012）,but both PM₁₀0 and PM_2.5 exceed the standard limit,that is,the main pollution factors affecting the ambient air quality in the Wushaoling area are PM₁₀ and PM_2.5.4.Based on the PSR conceptual framework model and the analytic hierarchy process,combined with the field survey results,the environment assessment system of the Wushaoling area of Qilian Mountains was constructed.The system consists of three subsystems:pressure layer,state layer and response layer.Among them:8 indicators in the pressure layer,7 indicators in the status layer,and 3 indicators in the response layer,a total of 18 indicators.The calculation results of entropy weight method show that there are some differences between the weights of the three subsystems,which are 0.3097,0.3749 and0.3154,respectively,which indicates that there is a significant primary-secondary relationship between the interactions of pressure P,state S and response R.That is,a certain degree of pressure change will cause a greater degree of change in the entire system.It is a more sensitive subsystem that needs to be focused.5.Using the entropy weight method and the comprehensive index method,the comprehensive index of environment conditions in Wushaoling area between 2007 and2018 was calculated to be between 0.3889 and 0.5599,with a variation range of 0.1710.This indicates that the environmental status index level of Wushaoling area in Qilian Mountains is basically at a general level,and the overall trend is a tortuosity.