中文摘要：

借助ArcGIS空间分析工具，以嫩江流域1978年、1990年、2000年和2008年4期遥感湿地分布图为基础，采用SWAT（SoilandWaterAssessmentT001）水文模型将嫩江流域划分为43个子流域，并以沼泽湿地类型为例，将各个子流域内降水和径流信息与湿地退化遥感信息作对比筛选，对全流域以及湿地面积减少严重所在子流域作进一步分析。另外，利用两期土地利用类型数据生成嫩江流域土地利用转移矩阵。结果表明：1978--2008年间嫩江流域沼泽湿地退化严重，尤其以1990--2000年间最为显著。这与流域内降水、径流的变化密切相关，并受到土地利用类型转化以及水利工程建设等人类活动的影响。其中，沼泽湿地面积变化与流域径流系数变化在0．01水平上呈极显著正相关，pearson相关系数为0．90。气候变化和人类活动影响下对湿地水文过程以及水资源的变化，导致湿地日益萎缩，对流域内湿地生态系统平衡产生了负面影响。

英文摘要：

Based on ArcGIS spatial analysis tools and four wetland remote sensing images from 1978, 1990, 2000 and 2008, the Nenjiang River basin can divided into 43 subbasins using the Soil and Water Assessment Tool （SWAT） model. A eontrastive analysis is performed on marsh wetlands to investigate the differences between information on rainfall and runoff and wetland degradation provided by remote sensing images. Further analysis is done on the subba- sins with serious issues on wetland loss and degradation. On the other hand, two land-use maps are used to generate the land-use transition matrix of the Nenjiang River basin. The result shows that the marsh wetlands in the f Nenjiang River basin have degraded seriously during the period 1978--2008, especially between 1990 and 2000. This can be closely related to the changes in precipitation and runoff, as well as the influence of human activities such as the con- version of land-use changes and water conservancy constructions. Furthermore, the variation of marsh areas and the basin runoff coefficient exhibit a significant positive correlation at the level of 0.01 , and the Pearson correlation is 0.90. Under the influences of climate changes and human activities on the hydrological processes and water re- sources, the wetland areas have gradually been shrinking over the years, causing a negative impact on the balance of the wetland ecosystem in the Nenjiang River basin.