Earth retaining and drainage system at front edge of gully in high-cold region and implementation method of earth retaining and drainage system

The invention relates to the technical field of slope gully treatment, in particular to an alpine region gully front edge soil retaining and drainage system and an implementation method thereof.The alpine region gully front edge soil retaining and drainage system comprises a retaining wall and a concave retaining wall which are sequentially arranged at intervals in the gully extending direction, the retaining wall is arranged at the slope position of the gully front edge, and the concave retaining wall is arranged at the slope toe position above the retaining wall; a soil modification area is formed above the side slope between the retaining wall and the concave retaining wall; the soil change area is sequentially filled with a subsoil layer, a waterproof layer, an inverted filter layer and a nutrient soil layer from bottom to top, and the upper end of the nutrient soil layer is flush with the retaining wall and forms a cold-resistant plant planting area; a first water guide pipe is further pre-buried in the