Agricultural water-saving and sustainable groundwater management in Shijiazhuang Irrigation District, North China Plain

摘要

North China Plain (NCP) is one of the most important agricultural production regions in China. A severe water shortage, due to intensive irrigation, exists in the plain. In NCP, crop water-use accounts for 70% of total groundwater use in the floodplains and over 87% in the piedmont regions. Surface water in the plain is limited and restricted for urban water supply. Agricultural production therefore heavily relies on groundwater irrigation; the main driver of groundwater depletion in the region. To address the water shortage issue, a flexible and sustainable water management method is proposed. The method integrates crop-growth and groundwater model, and ensures groundwater recovery via agricultural water-saving. The method is successfully tested for the 4763km~2 Shijiazhuang Irrigation District in the piedmont region of Mount Taihang. The model results show that 29.2% or 135.7mm reduction in irrigation could stop groundwater drawdown in the plain. An additional 10% reduction in irrigation pumping (i.e., a total of 39.2% or 182.1mm) would induce groundwater recovery and restoration to the pre-development hydrologic conditions of 1956 in about 74years. The farmers' current irrigation practices are inefficient and wasteful of the limited water resources. Under appropriate irrigation schemes therefore, grain yield loss as a result of the 39.2% agricultural water-saving is less than 10%. This minimal agronomic loss is economically acceptable, giving the ecological and environmental benefits of groundwater recovery in the study area. However, successful agricultural water-saving requires not only practical feasibility of models, but also sufficient political commitment, promotion of water-saving incentives and efficient water-saving technologies, and enforcement of sustainable water management policies.