Analysis on the trends of groundwater level changes in the allusive plain of Taihang Mountain piedmount region suggested that:①the dropping-down of groundwater level was mainly caused by water use in wheat growing season,which is the dry season of the year.②The amount of precipitation in wheat growing season,corn growing season and the whole year are strongly correlated with the dropping-down of groundwater level in the corresponding period. Statistic analysis indicated that when precipitation increased by 100mm in wheat growing season,corn growing season and the whole year,the dropping-down of groundwater level decreased by 0.365m,0.436m and 0.56m respectively. The difference in different levels of dropping-down during different periods was possibly resulted from the difference in recharge of groundwater in different seasons and the effectiveness of rainfall for the crops.③The analysis also implied that the accelerated dropping-down of groundwater level was mainly caused by decrease of groundwater recharge. Before 1985,the groundwater level usually raised over 0.8m in contrast with less than 0.4m after 1986.④Compared to 1970s′,the amount of water use in wheat growing season could be decreasing suggested by a gradual decrease in groundwater dropping-down during this period. On the other hand,water use in corn growing season could be increasing.⑤Based on the analysis of groundwater level changes,it was suggested that,in order to keep the sustainable use of groundwater in this region,150 mm of irrigation has to be saved each year in the future. Considering an annual 250mm of soil evaporation was not used for crop growth and some results from water-saving experiments,to achieve this target is possible.
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