甘肃环县沙漠化时空演变及风险性预测分析

Spatial-temporal evolution of desertification and prediction analysis of desertification risk in Huan County,Gansu Province

结合甘肃环县1975-2015年的遥感卫星影像,1981-2015年的植被指数数据和气象数据,通过目视解译、线性回归模型拟合等方法,得到环县40a来沙漠化时空演变过程及未来35a不同时期不同气候变化情景下沙漠化风险预测结果.结果表明,从沙漠化的时空演变来看,环县沙漠化总面积在1975-1995年呈增加趋势,1995-2015年呈减少趋势;沙漠化程度在1975-1985年以中度沙漠化为主,1995-2015年以轻度沙漠化为主.环县未来沙漠化风险呈东南高、西北低的特点.从气候变化情景来看,在代表路径浓度(RCP)为4.5情景下,环县未来沙漠化风险最大,RCP 6.0情景下风险最小.

Combining the remote sensing satellite image from 1975 to 2015,NDVI data and meteorological data from 1981 to 2015 in Huan County,Gansu Province and,by means of visual interpretation and linear regression model fitting,the spatial-temporal evolution of desertification in the past 40 years and a prediction of desertification risk under different climate change scenarios in the next 35 years were obtained for this place.The results were shown as follows:from the perspective of spatial-temporal evolution of desertification,the total area of desertification increased from 1975 to 1995,and decreased in 1995-2015.The degree of desertification was mainly moderate in 1975-1985 and was mainly light in 1995-2015.The risk of desertification was higher in the southeast and lower in the northwest of the county.From the perspective of climate change scenarios,the risk of desertification will be the highest under the scenario of representational concentration of path(RCP)4.5,with the lowest under the scenario of RCP 6.0 in Huan County.