Dynamic Evaluation And Prediction Of Landscape Ecological Security In Rocky Desertification Area

Rocky desertification is the most serious ecological environment problems in Southwest China,which results the bare rock,thin soil,land degradation,soil erosion and so on.Rocky desertification is a concentrated expression of the contradiction between increasing population and limited natural resources,which has caused widespread concern in society.The Guanling-Zhenfeng Huajiang Integrated Management Demonstration Area was chosen.The landscape model method was used to evaluate and predict the ecological security of rocky desertification area in this paper.It has a certain theoretical and practical significance to enrich the theory of ecological restoration in rocky desertification area,to speed up the implementation of ecological restoration measures and to promote the sustainable development of social economy.Aiming at the main problems of the ecological environment in the rocky desertification area,the ecological security problem based on the landscape pattern was discussed by using “3S” technology,field investigation and verification,statistical analysis,evaluation of ecological security,prediction model and other technical means,Based on the analysis of landscape pattern change and driving factors,the Landscape Fragmentation Index,Separation Index,Dominance Index and Vulnerability Index were used to construct the ecological security evaluation model and which were revised by the actual situation of study area.The spatial distribution characteristics are analyzed quantitatively,the ecological security developmental trend are detected.The CA-Markov model is used to simulate landscape pattern in 2020,and the ecological security developmental trend and spatial difference are analyzed.This research will be rich Karst rocky desertification area of landscape ecology and ecological security,conduct the ecological environment protection and recovery in Huajiang and other rocky desertification area,and promote the sustainable development of regional social economy and ecological system.The main results are:(1)In 2000 – 2015,the Landscape Ecological Security Index(LESI)of the demonstration area decreased from 0.5231 in 2000 to 0.4867 in 2005,then increased to 0.5457 in 2010,continued increased to 0.6457 in 2015,showed the "V" type.This phenomenon corresponded with the actual situation.(2)The comprehensive analysis of the study area in the year of 2000,2005,2010 and 2015 found that: the forest conservancy areas in peak cluster valley and peak cluster depression where have better conditions areas were fine;the land,garden and artificial construction where in the platform of river cross were moderate;the bare rocks,quarries and other areas were worse.(3)Demonstration area in addition to the excellent did not exist,the area of the other grades were different.In 2000,the severe area accounted for 9.48% of the demonstration area,worse accounted for 17.93% of the total area,moderate accounted for 39.12%.Fine accounted for 35.18%.In 2015,severe and worse decreased significantly,and moderate and fine proportion increased.These changes showed that the ecological environment in the demonstration area was improved.In the future,we still need strengthen the comprehensive management of rocky desertification,while developing the quarry should also pay attention to protecting the ecological environment,and taking into account the unity of economic and ecological benefits.(4)The CA-Markov model was used to predict the landscape pattern of the study area in 2020,and then predicted the ecological security: the severe rose 0.45%,the worse fell 4.38%,the moderate increased 2.87% and the fine increased 1.41%.Overall the area of high ecological security index proportion will increased,so the degree of ecological security will improve.