DECLINE TREND OF GROUNDWATER LEVEL IN THE MEKONG RIVER DELTA PLAIN

Abstract

Groundwater resources (NDĐ) play a very important role in the water supply of the Mekong Delta. Groundwater is being exploited about 2,000,000 m³/day, of which 70 - 80% of rural people use groundwater. The total number of pumping wells is about 553,135. Since 1990, the Government has invested in building a national monitoring network of ground water resources. So far there have been 246 monitoring wells in 8 aquifers in the Mekong Delta. Observation results show that groundwater levels in the Mekong Delta tend to decline and are differentiated to varying degrees, especially in the main aquifers. Monitoring results from 2005 to 2018 showed that maximum rate of water level in the the upper Pleistocene aquifer (qp₃) is up to 0.45 m/year; 0.46 m/year in the upper middle Pleistocene (qp_2-3) 0.51 m/year in the lower pleistencen aquifer (qp₁); 1.0 m/year in the middle Pliocene aquifer (n₂²) and 1.02 m/year in the middle Pliocene aquifer (n₂¹). The water levels will decline. Which increases saltwater intrusion.