1980-2000年松嫩平原耕地变化及其对干旱的影响

Change of cultivated land in Songnen Plain during 1980-2000 and its impacts on drought

基于1980-2000年的降水数据资料和TM影像,利用趋势面、残差异常值等方法对这20年里松嫩平原耕地面积变化对干旱机率的影响进行了分析。结果表明,(1)1980-2000年松嫩平原耕地面积整体呈增加趋势,自西向东逐步递减;干旱频率在空间分布上也自西向东呈逐步递减趋势,与耕地的空间分布相吻合。(2)干旱频率正残差异常值所覆盖的面积明显大于负残差异常值覆盖的面积;在正残差异常值中转入耕地的面积大于转入为其他土地利用类型的面积。松嫩平原耕地的增加是导致干旱情况加剧的因素之一。对于耕地变化可能引起干旱加强的现象应该引起人们的关注。

The effect of cultivated land change in Songneng Plain during 1980 -2000 on drought probability was analyzed using rainfall data and TM images and tendency plane and residual abnormal value methods. Results show that, the cultivated land area of the Songneng Plain presents an overall increasing trend from 1980 to 2000, and the increased area progressively diminishes from west to east; drought frequency also shows a gradually declining trend from west to east in spatial distribution, corresponding to the spatial distribution of the cultivated land. The area covered by positive residual abnormal values of drought frequency is significantly larger than that covered by negative residual abnormal values; the area of the cultivated land converted from positive residual abnormal values is larger than the area of other land use types converted from the positive residual abnormal values. The increase in the cultivated land of the Songneng Plain is one of the factors that have brought about serious drought, which should have people＇s attention.