Abstract: As a major hazard source of mine， flood discharge capacity of tailings pond drainage system has a direct impact on its stability. In order to solve the problem of low efficiency and poor precision of traditional methods in flood discharge capacity assessment of tailings pond in deep cutting area， taking a tailings pond in the alpine valley region of western Sichuan Plateau as an example， the high-resolution remote sensing was used to obtain the water catchment area information of tailings pond firstly， then UAV photogrammetry and 3D laser scanning were used to extract the current body length of the reservoir， establish tailings pond DEM， and calculate the capacity of the flood control reservoir， and the flood control check calculation was finally conducted to construct a method of flood discharge capacity assessment of the tailings pond drainage system in deep cutting region based on "integration of space， sky and ground". The results show that the maximum discharge flow of the flood discharge system of the tailings pond occurs at time sequence 3.15 h， and the discharge flow is 21.58 m³/s. The required flood discharge capacity of the tailings pond is 35 200 m³， which is less than 46，200 m³ of the flood discharge capacity of the tailings pond， and it means that the discharge capacity of the discharge system meets the requirements of the corresponding grade of flood discharge. Meanwhile， it also reveals that the "integration of space， sky and ground" method has advantages and reproducibility in the assessment of discharge capacity of the tailings pond discharge system in dissecting area.

Key words: High-resolution remote sensing, UAV photogrammetry, 3D laser scanning, Integration of space, sky and ground, Dissecting area, Flood discharge capacity, Tailing pond