TRANSPORTATION AND FORMATION PROCESSES OF INFILTRATING WATER IN SOILS

一部分降水在土壤中的流动包气带中转化为地下水。在这一过程中，降水中的水质通过入渗水转化为地下水中的水质，大气压力在土壤气体溶于地下水的过程中起一定的作用。研制了一套能自动测量一定深度土壤气压并定时数字化记录的系统，选取了三个测场进行了观测。研究的领域和主要科目是;南九州大学的农田土壤中的大气压力和温度波动BGRL的测量场，京都大学大气压力和土壤温度波动BGRL附近陆侧地区降水和渗透水的取样和记录（大原）对各种地下沃茨的采样和记录，利用自动采样系统可以观测到土壤中的气压异常事件，在野外观测中，我们可以估计入渗水和地下水水质的形成过程如下：降水侵入土壤，使Ca和HCO 3突然增加。随着土壤入渗过程的进行，Ca的比例降低，Na的比例增加。地下水通过阳离子交换过程具有较高的Na比率。

Some part of precipitation turns into ground water in traveling unsaturated zone in soils. In such process, water qualities in precipitation change themselves into those in ground water through the infiltrating water.The atmospheric pressure takes some role in dissolving process of soil gasses into ground water. We made the system that can measure the atmospheric pressure in soils in the certain depth automatically and record digitally in the fixed time intervals.We took three measuring field and carried out the observation. The fields and the main subjects of study are; the farming ground of Minamikyushu University atmospheric pressure and temperature fluctuations in soils the measuring field in BGRL, Kyoto University atmospheric pressure and temperature fluctuations in soils the sampling and record for precipitations and infiltrating water the landside area near BGRL (Otobaru) the sampling and record for various ground waters.We could observe some events of atmospheric pressure anomaly in soils with the automatic sampling system.In the field observation, we could estimate the forming process of qualities in infiltrating water and ground water as follows: Precipitation intrudes into soils with sudden increase in Ca and HCO3. With infiltration process in the soils, Ca decreases and Na increases in ratio. The ground water has high ratio of Na by the cation exchange process.