Adapting Water Scarcity for River Basin: Optimization of Land Uses

Water scarcity is a hot issue in river basin management, especially in ecologically fragile areas with arid climate, such as the Heihe River Basin (HRB) in Northwest China, where water availability is at the core of sustainable socioeconomic development and ecological conservation and the effects of land use changes on the hydrological process are crucial to rational allocation of water resources. In this chapter, first, we identified that the severity of water scarcity problems can be associated with imbalance between water supply and demand, irrational water consumption structure and low water efficiency, deficient systems and institutions for water management, as well as unreasonable water allocation scheme. Further, we investigated the hydrological responses to land use changes in the upper and middle reaches of the HRB based on scenario analysis. In one case, the results indicated that the forest land has “sponge” effects on the water resource in the upper reach of the HRB; in the other case for the upper and middle reaches, the results showed that the forest land and grassland will expand with increase in water utilization ratio, and further the quick-response surface runoff would decrease significantly due to forest and grassland expansion, which may cause an overall decreasing trend of the water yield. This indicated that water resources should be reasonably allocated for different land use demand, which is critical for sustainable development. The results of this chapter will be informative to decision-makers for sustainable water resource and land management.