在黑龙江、松花江和乌苏里江,尤其是松花江的源头与汇合口,散布着许许多多的湿地。这是因为黑龙江流域的这些河流,流淌在低缓的高差不大的地区,并且这些地区有的属于永久冻土区,河水切割不下去,河床平缓,水流迂回曲折,尤其是支流汇入主流的地方,水流速度更缓,所携带泥沙容易沉积成沙洲、成岛、成湿地。湿地是水体与陆地之间的相互浸 In Heilongjiang, the Songhua River and the Wusuli River, especially the source and convergence of the Songhua River, scattered with many wetlands. This is because these rivers in Heilongjiang River flow in areas of low elevation difference, and some of these areas belong to permafrost areas, the river can not cut off, the riverbed is gentle and the flow of twists and turns, especially the tributaries into the mainstream Where, water flow more slowly, easy to sediment sediment into a sand island, into the island, into a wetland. Wetlands are the mutual immersion of water and land