1995-2018年广西中越边境地区土地利用变化与生态风险研究

Study on Land Use Change and Ecological Risk in Guangxi Areas of Sino-Vietnam Border from 1995 to 2018

本文采用土地利用动态度、信息熵、土地转移矩阵、生态风险指数等方法分析了广西与越南接壤的8个县(市、区)的土地变化的生态风险异质性特征,研究了土地利用变化对该区域土地生态风险的影响。研究结果如下:(1)广西中越边境地区平均综合土地利用动态度指数为3.40%,土地利用变化较为剧烈。(2)土地利用结构信息熵从1995年的0.832 Nat增加至2018年的0.877 Nat,土地利用的空间结构特征变化较大。(3)研究区土地利用存在30种相互转化类型,各地类土地利用转移数量存在显著差异,转出地类以建设用地和草地为主。(4)研究区土地利用生态风险指数年均值从1995年的0.187上升至2018年的0.196,由较低风险上升至中度风险。(5)土地生态安全具有区域差异性,从1995—2018年各县(市、区)的平均土地利用生态风险指数来看,研究区从东南至西北方向呈现出近似W型的生态风险等级特征,其中,中部和南部区域生态风险程度更高。在国家兴边富民政策实施以来,广西中越边境地区社会经济快速发展和城市化进程的加快导致土地利用类型变化显著,但在追求经济发展的同时也应该注重生态安全,实现生态保护与经济高质量发展同步。

In this paper,methods of land use dynamics,information entropy,land transfer matrix,ecological risk index,etc.were used to analyze the ecological risk heterogeneity characteristics of land change and the impact of land use change on the land ecological risk in 8 Guangxi counties(cities and districts)of Sino-Vietnam border from 1995 to 2018.The following results are found.(1)The average comprehensive dynamic index of land use in the Guangxi areas of Sino-Vietnam border is 3.40%,and the land use changes are quite drastic.(2)The information entropy of land use structure increases from 0.832 Nat in 1995 to 0.877 Nat in 2018,and the spatial structure characteristics of land use change greatly.(3)There are 30 types of mutual transformation of land use in the studied areas,and there are significant differences in the number of land use transfers in different regions.The transfer land is mainly construction land and grassland.(4)The annual average value of the ecological risk index of land use in the studied areas rises from 0.187 of a low risk in 1995 to 0.196 of a moderate riskin 2018.(5)The land ecological security has regional differences.From the perspective of the average land use ecological risk index of each county(city and district)from 1995 to 2018,the studied areas present a similar W-shaped ecological risk level from the southeast to the northwest.The ecological risks in the central and southern regions are higher.Since the implementation of the national policy of rejuvenating the border and enriching the people,the rapid social and economic development and the acceleration of urbanization in the Guangxi areas of Sino-Vietnamese border have led to significant changes in land use types.However,while pursuing economic development,we should also pay attention to the ecological security and achieve the synchronization ecological protection and high-quality economic development.