A study of the measuring factors and analyzing model to judge variation in groundwater circumstances

表征地下水环境的典型因子有：(1)地下水位，(2)径流量和(3)水质，它们受含水层常数及其地层的影响，也受邻近河流补给的影响。另一方面，近年来大规模的地面工程对水情的影响令人担忧。从我们的案例研究中，可以得出以下结论。(1)地下水流速难以测量。对于小丘中的地下水，观测到的速率是基于综合研究预测的速率的10倍。(2)抽水试验测得的含水层常数难以正确采集/重新整理/重新评估，对了解地下水流非常重要。(3)水质形成机制取决于三个因素：(1)与河流的距离；(2)原始地下水的质量；(3)含水层的土壤构成和渗透性。(4)宜比河补给。约占河流流量的10%和年降雨量的7-10%。并对岐阜市小河流下地表三分之一的渗透率进行了评价。(5)提出的“简化模型”有助于消除降雨对水位自然变化的影响，判断地面施工是否违反水环境。

The typical factors to express groundwater circumstances are(1)groundwater level, (2)rate of discharge and (3)water quality, which are effected by the aquifer constants and its stratum, and also by recharge from neighboring river. On the other hand, a kind of impact of large scale of ground works on water circumstances is worried recently. From our case studies, next conclusions are obtained.(1)The rate of groundwater flow is difficult to measure. For the groundwater in a hillock, ten times greater rates are observed than the rate predicted based on the synthetic research.(2)Aquifer constants measured by pumping test are difficult to collect/rearrange/re-evaluate correctly, and very important to know the groundwater flow.(3)The mechanism of water quality formation depends on three factors : (1)distance from river, (2)quality of original groundwater, and(3)soil constitution and transmissibility of aquifer.(4)For the recharge from the Ibi-river. about 10% of the river discharge and 7-10% of annual rainfall are supplied. And one-third of permeability of srtatum under small river is evaluated in Gifu city.(5)Proposed "simplified model" is useful to eliminate the rainfall effect on the natural variation in water level for judging whether ground construction work does violate the water circumstance or not.