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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。
Based on precipitation data and TM images from 1980 to 2000, the influence of the change of cultivated land area on drought probability in Songnen Plain over the past 20 years was analyzed by means of trend surface and residual error. The results showed that: (1) The area of cultivated land in Songnen Plain increased from 1980 to 2000 and gradually decreased from west to east. The spatial distribution of drought frequency also gradually decreased from west to east, which accorded with the spatial distribution of arable land. (2) The area covered by the anomaly of positive frequency of drought frequency is obviously larger than the area covered by the anomalous value of negative residual; the area transferred to arable land in the anomalous value of positive residual is larger than the area transferred to other types of land use. The increase of cultivated land in the Songnen Plain is one of the factors leading to the aggravating drought situation. The phenomenon that the change of arable land may cause the drought to be intensified should draw people’s attention.