Assessment of the Groundwater Quantity Resulting from Artificial Recharge by Ponds at Ban Nong Na, Phitsanulok Province, Thailand

Abstract

Ban Nong Na Phitsanulok Province, has been facing continuous groundwater level decreases, from 1-2 m below ground surface in the past 25 years to 7-8 m in the present due to overexploitation for irrigation. This area was selected as a pilot site to construct and conduct the recharge experiment. The objective of this research is to quantify groundwater mound resulting from the recharge experiment using MODFLOW2000. Two recharge ponds A and B, which have an area of 660 and 600 m², respectively, were constructed in the selected site of the study area. The experiment duration was July to November, 2010 using raw water with turbidity less than 100 NTU. The total recharge amount is 25,797 m³. The results showed that under the experiment conditions the designed recharge pond can provide a moderately good analysis of the recharge water. The mounding results of the simulations were compared with the field observation; both were found to be compatible. After 5 days of the fifth test, the maximum rise of the mound was 3.33 m and covers an area of approximately 6,000 m².