The amount of rainfall in Japan is more than 2.5 times or more of the world average, however most of rainfall flows and goes down to the sea because of steep geographical characteristic. Recently as social infrastructure develops, situation of water usage in urban area is vital. Consequently, shortage of water causes serious problem in many area in Japan IKOMOA city, Nara pref. Japan is typical area since necessity of water supply for population increased rapidly. Therefore development of groundwater has been focused. Reasonable pumpage plan, carefully considering geographic and geological condition, is indispensable because ground water as a resource is not infinite. This paper focuses on TAKAYAMA area IKOMA city, Nara prefecture and mentions the results of investigating geographical and hydrological characteristic. Then we mention the appropriate amount of pumping in standpoint of water expenditure by quasi3-dimensional analysis (Finie Element Method) modeling ground water basin for this area.
We can't rely to groundwater in order to secure life water in the area where most of river water flows into Ocean, and in the area of basin area where irrigation condition is bad. A quantity and quality of existing groundwater greatly on the weather condition, ground condition of the layer constitution, thickness of aquifer and hydrogeology condition. Unplanned pumping of groundwater causes hastening of a well life and bad influence such a ground subsidence influenced by water level lowering. In other works we need to predict the proper pumping discharge, which considered behavior of subsurface water by pumping and the water balance into development of subsurface water precisely. It is confirmed that this area meets the requirement for secure of groundwater as supply water. As results of investigation and examination of ground layer constitutions, thickness of aquifer, permeability and water quality.
