滇西北高山峡谷典型区土地利用变化与生态安全评价研究

Research of land use change and ecological security of typical area of alpine canyon in Northwest Yunnan

以滇西北高山峡谷典型区香格里拉市为研究对象,对该区域1974—2017年土地利用变化和土地生态安全状况进行分析。结果表明:1974—2017年间,研究区耕地、灌草地、建设用地、未利用地都有增加,林地和水域有不同程度的减少,建设用地变化幅度是最大的,林地变化幅度是最小的,1999—2003年间土地利用变化是最剧烈的,2013—2017年间土地利用变化是最小的;1974—2017年间,研究区土地生态安全指数呈现先降后升的趋势,生态安全状况转变情况为“中度预警—轻度预警—安全—较安全”;通过线性回归模型趋势拟合分析发现,研究区土地生态安全综合指数呈增长趋势;研究区生态安全等级为南部、海拔较低的五境乡、上江乡、金江镇、虎跳峡镇、三坝纳西族乡、洛吉乡等区域较高,北部海拔较高的东旺乡、尼西乡、格咱乡等区域较低。

We took Shangri-La,a typical alpine canyon area in Northwest Yunnan,as the research area to analyze the land use changes from 1974 to 2017,to construct a land ecological security evaluation system,and to reveal the overall change of land ecological security in Shangri-La.The results showed that between 1974 to 2017,the cultivated land,shrub-grass land,construction land,and unused land in the study area all increased,forest and waters were decreased,the change in construction land was the largest,and the change in forest was the smallest.Between 1999 to 2003,the land use change was the most dramatic,and the land use change was the smallest between 2013 to 2017.From 1974 to 2017,the land ecological safety index of the study area showed a trend of decreasing first and then increasing,and the change in the ecological security situation was"moderate warning-mild warning-safety-safer".Through linear regression model trend fitting analysis,it was found that the comprehensive index of land ecological security in the study area showed an increasing trend.The ecological security level of the study area was higher in the southern towns as Wujing,Shangjiang,Jinjiang,Hutiaoxia,Sanba Naxi and Luoji,but that of the towns as Dongwang,Nixi and Geza with higher elevation in the north was lower.