Water cycles exist in all processes of water resources utilization, including water-saving irrigation. Due to the complex water cycle process of irrigation, the ecological effects and safety of large-scale water-saving irrigation have received increasing attention. This paper analyzed both the positive and negative ecological effects of water-saving irrigation and the scale effects from the plant-scale to the watershed-scale. Based on the Vensim and GMS (Groundwater Modeling System) models, a quantitative evaluation method of ecological safety of large-scale water-saving irrigation was proposed. The case study in Changma Irrigation District in the arid inland river basin of Northwest China showed that the ecological safety of large-scale water-saving irrigation was sensitive to the combination of water source condition, water distribution technology and water-saving irrigation technology in field. In terms of the positive effects, large-scale water-saving irrigation can reduce the percolation loss of irrigation water, increase the environment water flow for the downstream, and slow down the salinity accumulation. As for the negative effects, large-scale water-saving irrigation could reduce the groundwater recharge, decrease the environment water supply in local farmland, and cut down the soil salinity leakage. The research results have positive significance for guiding the sustainable development of water-saving irrigation and conservation of ecosystem in an arid inland river basin.
Scale Effects of Ecological Safety of Water-Saving Irrigation: A Case Study in the Arid Inland River Basin of Northwest China
