The groundwater resources sustainability of the Upper -Middle Pleistocene aquifer in Ca Mau peninsula under impact of climate change and some of adaptive solutions

Abstract

Ca Mau peninsula covers an area of 16,940 km2, including Ca Mau, Bac Lieu, Soc Trang, Hau Giang, Can Tho, and a part of Kien Giang provinces, which have agriculture is the mainly activities of the people. Groundwater resource was extracted with large quantities and have not yet controlled, combine with climate change in Ca Mau peninsula reduced groundwater levels and saltwater intrusion in the aquifers. Therefore, to predict groundwater sustainability under climate change impacts, this research used the results of the groundwater flow model, the salinity transportation model, and the recharging model to calculate the Total groundwater abstraction/Groundwater recharge Indicator (Indicator 1); Groundwater depletion Indicator (Indicator 2); Groundwater salinity indicator (Indicator 3). Calculated results show that the increase of Indicator 1: in 2015 there are 13/43 sustainable districts, 1/43 relatively sustainable districts, and 29/43 unsustainable districts. To the 2090 this index has changed 33/43 unsustainable districts, 1/43 relatively sustainable districts, and 9/43 sustainable districts. Indicator 2 in the 2015 there are 21/43 sustainable districts, 10/43 relatively sustainable districts, and 12/43 unsustainable districts. To the 2090 there are 7/43 sustainable districts, 12/43 relatively sustainable districts, 24/43 unsustainable districts. Indicator 3: in the 2015 there are 11/43 low salinity districts, 10/43 medium salinity districts, and 22/43 high salinity districts. To the 2090 there are 7/43 low salinity districts, 11/43 medium salinity districts, and 25/43 high salinity districts. Study results show that the climate change has impacted to all aquifers in Ca Mau peninsula, which increase the areas of unsustainable districts for the period from 2015 to 2090. This study contributes to support the groundwater managers in activities of planning, management and exploitation of groundwater resources more reasonable in Ca Mau peninsula.