闪电河流域中游区长时间序列土地利用动态变化对植被的影响

摘要

基于闪电河流域中游区1985、1990、1995、1999、2004、2010和2014年7期中高分辨率的遥感影像数据,利用ENVI 5.1和ArcGIS 10.1解译土地利用和植被覆盖信息,分析闪电河流域中游区土地利用与植被覆盖度长时间序列的动态变化,并利用回归分析法,探索土地利用变化对植被覆盖度的影响.结果表明:(1)研究区内土地利用发生明显变化,土地利用变化有较强的时空分异特征.裸地和耕地面积均有大幅度的增加,林地和草地面积有一定程度的下降,增加和减少的总幅度基本一致.土地利用程度强度变化较大,2000年前土地利用基本处于调整期,2000年后土地利用程度不断增加,处于发展期.(2)植被变化有较强的波动性和异质性.研究区始终以植被高级覆盖和中高级覆盖为主,但中低级覆盖、低级覆盖以及裸地面积比都表现为上升趋势,同时植被高级覆盖与中高级覆盖面积比不断下降,特别是植被高级覆盖面积比于2010年后明显下降.(3)各土地利用类型对植被覆盖度的贡献各异,其中林地＞草地＞耕地.综上,研究区的土地利用类型变化和土地利用程度变化均不利于植被恢复和持续发展,土地利用变化是植被变化的先决因素,决定了植被变化的趋势、强度与过程.%Based on the remote sensing data of 1985,1990,1995,1999,2004,2010 and 2014 seven periods,make an interpretation of land use and vegetation coverage information was made by ENVI 5.1 and ArcGIS10.1,the change of long time series of land use and vegetation coverage in the middle reaches of the Shandian river basin was analyzed.The effect of land use change on vegetation coverage was explored by regression analysis.The results are as follow:(1) There are obvious changes in land use in the study area,and the change of land use is characterized by strong spatial and temporal differentiation.Cultivated land,grassland and bare land are the main types of change.The area of bare land and cultivated land increased greatly,and the area of woodland and grassland decreased to a certain extent,and the total range of increase and decrease was basically the same.The intensity of land use changed greatly.The land use was basically in the adjustment period before 2000,and the land use degree increased continuously after 2000,and it was in the period of development.(2) The change of vegetation has strong fluctuation and heterogeneity.The main part of study area was high coverage vegetation and medium high coverage vegetation,but the area ratio of medium low coverage vegetation,low coverage vegetation and bare land showed an uptrend,while the area ratio of high coverage vegetation and medium high coverage vegetation continue to decline,especially the area ratio of high coverage vegetation dramatic decline than that after 2010.(3) The contribution of various types of land use to vegetation coverage is different,in which woodland ＞ grassland ＞ cultivated land.The results showed that the change of land use type and land use degree in the study area were not conducive to vegetation restoration and sustainable development,land use change is a prerequisite factor of vegetation change,determine the trend,strength and process of vegetation change.