江淮分水岭区域植被覆盖与人类活动强度的时空动态演化

Spatial and temporal dynamic evolution of vegetation cover and human activity intensity in the Yangtze-Huaihe River divide region

利用江淮分水岭区域2000—2015 NDVI月合成数据、降水与气温数据、高程数据以及社会经济数据,采用一元线性趋势分析法、残差分析法分析江淮分水岭区域16 a植被覆盖情况以及变化趋势与人类活动强度的关系。结果表明:1)江淮分水岭区域的植被覆盖指数在16 a内呈现整体上升趋势,但合肥、六安这两个经济发展速度较快的中心城区,植被覆盖指数有所降低。2)通过计算与分析可知,0.0061<slope<0.0479为植被的改善区域,占所研究区域的39.97%,主要分布在明光市、来安县、全椒县、凤阳县的山区;0<slope<0.0061为植被覆盖基本不变,占所研究区域的52.67%,主要分布在偏远农村地区;-0.0278<slope<0为植被退化区域,占所研究区域的7.36%,主要分布在合肥市与六安市的中心区域。3)将NDVI的残差值与人类活动强度、人口、农业机械总动力、GDP进行回归分析,结果可得回归相关系数r=0.5311,说明人类活动因素与植被覆盖具有较高的相关性。其中,人类活动强度通过1%的显著性水平检验,且相关系数为-5.37,得出人类活动强度越大,NDVI值越小,人类活动强度越小,NDVI值越大。

Based on NDVI monthly synthetic data,precipitation and temperature data,elevation data and socio-economic data from 2000 to 2015,the relationship between spatial distribution of vegetation cover,temporal variation trend and human activity intensity in the Jianghuai watershed region in 16 years was analyzed by trend analysis and residual analysis.The result shows that:a)The vegetation index of the Jianghuai watershed area showed an overall upward trend in the last 16 years,but the two central urban areas with a faster economic development rate in Hefei and Lu’an had a lower vegetation index.b)According to the calculation and analysis,the area with 0.0061<slope<0.0479 had an improvement in vegetation cover,accounting for 39.97%of the study area,and mainly distributed in the mountainous areas of Mingguang City,Lai'an County,Quanjiao County and Fengyang County;the area with 0<slope<0.0061 had basically the same vegetation cover with before,accounting for 52.67%of the study area,which mainly distributed in remote rural areas;the area of-0.0278<slope<0 indicted a degradation in vegetation cover,accounting for 7.36%of the study area,and mainly distributed in the central area of Hefei City and Lu’an city.c)Regression analysis was conducted on the residual value of NDVI,human activity intensity,population,total power of agricultural machinery and GDP,and the regression correlation coefficient r=0.5311 was obtained,indicating that human activity factors had a high correlation with vegetation cover.Among them,the intensity of human activity was tested by a 1%significance level,and the correlation coefficient was-5.37.It is concluded that the higher the human activity intensity is,the smaller the NDVI value is,and the lower the human activity intensity,the larger the NDVI value.