Change of wetland pattern and regulating capacity of forest hydrology in burned area of northern great Hingan mountains

Hydrological condition and terrain are the key factors to generate the wetland, besides permafrost. The Yuying and Fendou farms are located in Tuqiang forestry bureau, which is one of the mainly burned area in 1987 fire, were selected as the study area to reveal the wetland pattern change after 1987 catastrophic fire, the restoration of regulating capacity of forest hydrology post-fire and the change of permafrost active layer, using GIS software. The results show that the total area of wetland increased obviously with convergence tendency compared to that of pre-fire; the average regulating capacity of forest hydrology has already restored, but the area of high regulating capacity of forest hydrology decreased, and the permafrost active layer in the burned area is thicker than that in unburned area. Regulating capacity of forest hydrology, terrain factors and permafrost active layer related to the wetland pattern change. The increase of wetland was remarkable in valley, gentle slope and the area with thick permafrost active layer, and also in area of regulating capacity of forest hydrology decreasing.