The issues of groundwater Enviroment in Ca Mau peninsula

Abstract

Groundwater is an important resource of provinces in Ca Mau Peninsula. The water is supplied to household, industrial, agricultural and aquacultural activities. More important, in this area, as the majority of surface water is contaminated and requires further treatment to become usable, the main source of water supply is the groundwater. Under the impacts of socialeconomic development, the increase of population and the urbanization rate in the region, groundwater resource is under a pressure of exploitation and utilization. Yearly exploited amount of groundwater is larger than the replenishment amount in most aquifers, so the groundwater level is lowered gradually year by year. According to statistics from 2000 to 2010, the groundwater level has been lowered from 0 to -14m (in some places, the water level is lowered to -28m below sea level) in qp2-3 and qp1 aquifers, with the highest drops in Bac Lieu and Soc Trang provinces. The amount of pumped groundwater in the region has been increasing from 159.914 to 931.944 m3 / day, whereas the replenishment amount has been decreasing from 526.121 to 185.004 m3 / day. Stated otherwise, groundwater in the region is declining in both volume and quality under the impact of climate change and exploitation activities. This paper uses the DPSIR framework to assess causal relationships of factors that impact to the groundwater environment in the region, and thereby propose appropriate solutions under the impacts. In combination with groundwater environmental indicators to quantify the degradation impacts to groundwater resource, the results of this paper indicate that water supply used mainly in Ca Mau Peninsula is groundwater ( 85.74%); the capacity of renewable water per capita in the region is still very low (80.06 l / day / person); the water loss from aquifer systems is much larger than the amount of replenishment (141.02%), however the amount of water extraction for domestic service was still in permissible limits of the aquifers (8.71%). The numbers show that groundwater in Ca Mau Peninsula is in decline but still within safe limits. Results from this paper can give authorities a more intuitive view about the current situation of groundwater when planning and using water resources.