The state science and technology support program--- “Adaptability of regional water resources and distributional structure of irrigated crop in North China Plain” (2007BAD69B02), which is undertaken by the Institute of Hydrogeology and Environmental Geology, CAGS, has been selected as the 2009 annual “Top Ten scientific and technological progress” of CAGS.
Aiming at substantially solving the issue of over-exploitation of groundwater in North China Plain, the project team set their primary objects to the impact and mechanism of irrigated farmland crop distribution structure, scale and their water consuming intensity on regional groundwater under different climate conditions, and some important findings were brought forward. The inhomogeneous drastic changing process of groundwater flow field in resent 50 years and its causation was found; the phase and distribution characteristics and the mechanism of irrigated agriculture’s impact on groundwater was elucidates; an ‘inverse response law’ between groundwater recharge and exploitation intensity and precipitation was found; with the improvement of irrigation water saving technology, the increment of groundwater exploitation was decreased. Furthermore, the relationship between the deterioration of regional groundwater flow field, climate and the changes of agriculture activity intensity was elucidated.
Based on the “modulus” concept in hydrogeology and fine unit subdivision, a technical support system for water-balance and transforming analysis in regional and sectional “groundwater-precipitation-farmland irrigation” was built up. Quantitative coupling and analysis among meteorological, agriculture and groundwater data in different spatial scale was achieved; distribution and structure of grain, vegetable and water-consuming fruit trees and their relationship to regional groundwater over-exploitation were found out; adjustment strategies of crop distribution and structure aiming to save overexploited groundwater were brought forward.
The impact of drought on groundwater is greater than that of the increase of rainfall. This difference is 3.96% of the storage variable quantity. According to conclusion, we need to pay more attention to the impact of continuous drought on groundwater.
researcher Zhang Guanghui giving directions on water saving experients in the field