近30年来内蒙古东部达赉诺尔湖泊地区沙漠化与湿地演变初探

沙地与湿地对气候变化都有敏感的响应。我国内蒙古东部的达赉诺尔湖泊地区位于气候年际变化显著的东亚季风区,其地貌类型包括浑善达克沙地与达赉诺尔湖泊湿地。通过野外考察和对不同时期卫星遥感数据的解译发现,近30年来达赉诺尔湖区湖面发生了先扩大后缩小、湖周的流沙先减少后增加的现象。相应的研究表明,以气温和降水为主的气候变化是引起达赉诺尔地区湖泊演化的主导因素;而目前人类活动对该地区沙漠化与湿地演变的影响保持在较低水平。

PRELIMINARY STUDIES OF DESERTIFICATION AND WETLAND CHANGES IN THE AREAS OF DALAI NUR LAKE OF EASTERN INNER MONGOLIA DURING THE LAST 30 YEARS

In general, the landscape of sandy lands and wetlands responds quite sensitively to climate fluctuations. The areas of the Dalai Nur Lake of eastern Inner Mongolia are located in the region of the East Asian monsoons, climatically charactedrized by a clear seasonality. The relief there includes the Hunshandake (Ortingdag) Sandy Land and the lacustrine plains around the lake Dalai Nur. The reserch method here is mainly digital image processing, supported by ground checks. The Data from the last three decades (1975,1989,1992 and 2001) indicate that the surface of wetlands was larger in 1975 and 1992 than that in 1989 and 2001. The area of mobile dunes varies in inverse proportion to the wetlands. The main process of desertification occurs with the form of the reactivation of the fixed sand dunes in the landscape. The trends of the wetlands are consistent with the variations of local precipitation, suggesting that the climate might be the key factor for the landscape evolutions in the study area. Thanks to a low population density in the study area the human impact on the process of desertification and on wetland changes appears still limited.