The assessment of groundwater recharge and conservation area of pintung plain

Assessing groundwater recharge area is an important issue for regional groundwater management. The Law on Geological and Mining Activities has recently issued, groundwater recharge area becomes a part of geological sensitivity district which is required higher level survey and protection. This study uses factor analysis to assess the groundwater recharge area and conservation area. To validate the recharge area identified, 2D electrical resistivity and water quality are adopted. The total measurement length of the 2D electrical resistivity survey is 7,240 m and the water quality index is dissolved oxygen. The assessment first focuses on shallow aquifer for recharge area and then evaluates the entire groundwater aquifer for groundwater conservation area. The factor analysis adopts seven factors to identify the groundwater recharge area. After the recharge area is identified, a factor related to the storage of deep aquifer is added to determine the groundwater conservation area. The identified groundwater recharge area is compared with the results obtained from the 2D electrical resistivity survey and the water quality examination. All three methods show consistent result, which indicates that ninety-six percent of identified area is overlapped between the factor analysis and the 2D electrical resistivity survey as well as the concentration level of the dissolved oxygen in the identified area is higher than the outside area. This study proposed a methodology to identify the groundwater recharge and conservation area. The identified area provides important reference for groundwater management and designation of geologic sensitive.