Abstract: Due to the complex terrain in gulch area, and mostly mountainous terrain in the area of water collection with fast collecting flow speed, it is essential to consider the volume of small watershed's flood peak flow in choosing and designing of tailing pool in gulch area. After studying the flood peak flow calculation method adopted generally at present, the calculation formula of small watershed's flood peak flow suiting to the gulch area is selected. Meanwhile, taking the mine tailing pool in a certain gulch area of Yunnan province for example, the field calculation on the flood peak flow is carried out. With the actual survey, the calculation result approaches the actual situation. This calculation method is worthy of popularizing in other gulch area.

Key words: Gulch Area, Address selection of mine tailing pool, Watershed, Flood peak flow