180.
The groundwater table has been declining at a rate of 0.65 m/yr in Luancheng County since large scale groundwater extraction
carried out in the 1960s. The drop of precipitation, substantial increase in agricultural output, variations of crop planting
structure and construction of water conservancy projects in the headwater area all tie up with the decline of the groundwater
table. On the basis of analyzing the hydrogeological conditions and the water resources utilization of Luancheng County, a
three-dimensional groundwater flow model was developed to simulate the county’s groundwater flow through finite-difference
method using Visual Modflow software. We divide the research field into four parts after analyzing the hydrogeological condition.
Based on parameter calibration and adjustment using measured data, the hydraulic conductivity and specific yield were simulated.
Using the calibrated model, we analyze the agricultural water saving potentiality and its influence on the groundwater. The
results are as follows: (1) if we decrease the amount of water extracted by 0.14xl0
8 m
3, the average groundwater table of the five observation wells in December will rise by 0.33 m; (2) if we decrease the water
by 0.29x 10
8m
3, the average groundwater table of the five observation wells in December will rise by 0.64 m; and (3) if we increase the
water by 0.29 x 10
8m
3, the average groundwater table of the five observation wells in December will decline by 0.45 m. So we can draw a conclusion
that controlling the agricultural water use is an important way to prevent the decline of groundwater table.
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