Evaluation And Analysis Of Water And Soil Environmental Vulnerability In Karst Mountain Regions

Ecological vulnerability is one of the significant themes in environmental research,the issue of Karst Rocky Desertification is the current hotspot of international environment research focus.The special Karst landform in China accounted for a higher proportion of the land area,the research and evaluation of vulnerability are great importance for reducing contradiction between human and land,achieving sustainable development.At present,the domestic and international researches on the evaluation of the Eco-environment vulnerability of Karst areas are the mostly empirical researches,analysis and consideration of studying results.Besides,the research objects mainly focus on ecological fragility and groundwater vulnerability.The research objects mainly focus on two aspects: ecological vulnerability and groundwater vulnerability.At the current stage,there is no detailed standard and description of environmental vulnerability assessment in China.Each research scholar has its own system and his own independent index system,evaluation model and method.Most researchers are exploring and trying to be more suitable for their own research.The evaluation model and method of the region need to put forward a standard system for the evaluation of environmental vulnerability in karst mountainous areas.In this study,the Yanshan County in southeastern Yunnan province,which is the representative karst mountainous landform as the study area,and the administrative village as the evaluation unit,conducting ecological vulnerability assessments of the karst mountainous regions from both the land environment and the water resources environment.The assessment of land environmental vulnerability is based on two factors: natural and human driving factors.Fourteen factors were selected as evaluation indicators.The vulnerability of water resources was selected from the perspectives of surface water vulnerability and groundwater vulnerability.A total of 13 factors were selected as an evaluation index,the weights of each influencing factor in the two evaluation models are calculated by the analytic hierarchy process,and the vulnerability is evaluated respectively.Finally,the two evaluation results are combined to obtain the comprehensive vulnerability level and according to the evaluation results to analyze the spatial distribution and driving force.This paper combines GIS and RS technology,integrates remote sensing data,geographic information data,hydrogeological data,and human economic data to extract various impact factors in the evaluation model and apply comprehensive assessment methods and analytic hierarchy process to the study area.In the evaluation of regional water and soil environmental vulnerability in mountainous regions,the final vulnerability assessment results are obtained.The results show that the overall vulnerability of the study area is high.Among the 100 evaluation units,there are 3 village committees that are potential vulnerable areas,which are located in Jiayi Town,Jiangna Town and Weimo Town,accounting for 3.28% of the total area of the study area;There are 16 village committees in the general vulnerable area,which are mainly distributed in the central and eastern part of the study area,accounting for 14.65% of the total area of the study area;17 village committees are moderately fragile areas,mainly distributed in the west and east In the north,it accounted for 16.27% of the total area in the study area;33 village committees were highly vulnerable and distributed in all parts of the study area,accounting for 32.84% of the total area;31 village committees were extremely strong.The vulnerable areas are mainly distributed in the southwest and eastern regions,accounting for 32.96% of the total area of the study area.The natural conditions and human activities in the study area have obvious regional differences and spatial interfaces,but the assessment results of the two vulnerability assessment models of land environment and water resources environment have certain similarities in spatial distribution,from land and water resources.In terms of two aspects,the overall karst area of Yanshan County is widely distributed and the level of vulnerability is obviously high.The plan for local environmental protection and ecological protection needs to be urgently proposed.This paper proposes corresponding ecological restoration measures for different levels of vulnerability.Provide reference for future regional planning and decision-making in the study area.The applicability analysis of the constructed karst mountain area environmental vulnerability assessment model was conducted,and the results of environmental vulnerability of water and soil were compared with the vulnerability assessment results of the mountainous system.It was found that there were some differences in the assessment results of the vulnerability grade distribution,but the evaluation.The results are consistent with the distribution of the natural conditions in the study area,which suggests that the evaluation model proposed in this study has certain applicability to the karst mountain area in southeastern Yunnan.