Method for comprehensive prevention and treatment of water and soil loss and effective utilization of runoff in soft sandstone soil covering area

The invention provides a method for comprehensively preventing and controlling water and soil loss and effectively utilizing runoff in a soft sandstone soil covering area, which comprises the following steps of: (1) treating an upper slope surface by adopting an intercepting transverse ditch and longitudinal ditch combined retaining mode: excavating an intercepting transverse ditch along a contour line, excavating longitudinal ditches at two ends of the intercepting transverse ditch, and arranging the longitudinal ditches at two ends of the intercepting transverse ditch; longitudinal ditches are dug downwards along the slope from the highest position of the slope top every 5m in the left-right direction of the transverse flow intercepting ditches, and the transverse flow intercepting ditches are connected in series to form a trapezoidal ditch net; (2) three-dimensional cultivation is carried out, fish-scale pits are dug in each closure transverse ditch, the fish-scale pits in every two adjacent closure transv