Analysis of velocity groundwater in unconfines aquifer zone using infiltration measurement

The presence of ground water is strongly influenced by the presence of recharge zones. Changes in land use can affect the availability of ground water due to changes in the rate of groundwater flow into the ground. One of the causes of flooding and inundation, this occurs because the reduction in the catchment area is accompanied by a decrease in the infiltration rate coupled with an uneven distribution of rainfall throughout the year, thus triggering inundation problems. In this study by analyzing the value of groundwater flow velocity in the free aquifer zone. The study area has various hydraulic conductivity values with values ranging from 0.69 cm / minute to 0.02 cm / minute. The very high category is in the southern part of the research area with an area of 150 Ha, the high category is in the West, East, South and North research area with an area of 21,355 Ha, and the rather high category is in the northern part with an area of 740 Ha. The study area has various infiltration velocity values ranging from 0.22 cm / minute to 1.41 cm / minute. The fast category is in the South and North parts of the research area with an area of 17,355 Ha, the rather fast category is in the North and West parts of the research area with an area of 4152 Ha. Potential groundwater catchment areas are limited by areas consisting of breccia's, pasufufaan, or clay tuffs, fast infiltration rates - rather fast, and high hydraulic conductivity - very high. The main groundwater catchment potential zone has an area of 10,417.63 Ha, while the additional groundwater catchment potential zone has an area of 11,673.24 Ha.