Reservoir: Advantages: large storage capacity, time and space distribution of water, stable water source and good water quality. Disadvantages: easy siltation, large amount of work, destruction of ecological original appearance and high maintenance cost; Advantages: providing water source for agricultural development, small evaporation area, saving water and regulating regional water shortage caused by topography; Disadvantages: it leads to salinization of land and diffusion of agricultural chemical fertilizer and pesticide pollution, and its self-purification ability is low; Advantages: good water storage and excellent water quality in mountainous areas; Disadvantages: small water storage capacity, benefiting rivers with small population; Advantages: Comprehensive development has great economic benefits.