基于样方分析的甘肃省白龙江流域景观生态风险演变

Evolution of Landscape Ecological Risk in the Bailongjiang Basin of Gansu Province Based on Sample Analysis

为解决白龙江流域土地资源的可持续利用和生态环境保护等问题,通过景观指数和景观生态风险研究样方的选取,改进了景观生态风险评价模型,研究了2000—2020年白龙江流域景观生态风险演变规律,分析景观生态风险变化的潜在特征。结果表明:在研究期内耕地面积减少最多,草地面积增加最多。白龙江流域景观生态风险在3000 m海拔是一个重要节点,中风险区和较高风险区在小于3000 m的空间内明显增加,在3000 m以上是低风险区和较低风险区得以保存的空间。在时间尺度上,低风险区和较低风险区随时间变化面积递减,较高风险区随时间变化面积递增。通过对研究样方分析可知,耕地的扩张是景观生态风险增加的主要原因;耕地向草地的转变是景观生态风险降低的主要原因。可见在白龙江流域耕地和草地成为了景观生态风险变化的风向标,通过对风险演变影响因素的分析,为流域风险识别和治理提供了新途径。

In order to solve the problems of sustainable use of land resources and ecological environmental protection in the Bailong River Basin,the landscape ecological risk evaluation model was improved through the selection of landscape indices and landscape ecological risk research samples,and the landscape ecological risk evolution pattern in the Bailong River Basin from 2000 to 2020 was studied to analyse the potential characteristics of landscape ecological risk changes.The results showed that the area of arable land decreased the most and the area of grassland increased the most during the study period.The landscape ecological risk of the Bailong River Basin was an important node at 3000 m altitude,and the medium-risk and higher-risk zones increase significantly in the space less than 3000 m,and above 3000 m was the space where the low-risk and lower-risk zones were preserved.On the time scale,the area of low-risk and lower-risk zones decreased with time,and the area of higher-risk zones increased with time.Through the analysis of the study sample,it can be seen that the expansion of arable land is the main reason for the increase of the ecological risk of the landscape;the transformation of arable land to grassland is the main reason for the decrease of the ecological risk of the landscape.It can be seen that in the Bailong River Basin,arable land and grassland have become the wind vane of landscape ecological risk change,and the analysis of the influencing factors of risk evolution provides a new way for the identification and management of basin risk.