Identification of aquifer system in the whole Red River Delta, Vietnam

Abstract

The Red River Delta is one of two biggest deltas in Vietnam. People living in the delta depend entirely on groundwater for their domestic water. However, the aquifer system in the whole Red River Delta remains poorly understood due to the lack of available data. Recently, we were nominated to construct a hydrogeological database. Using these valuable data contained in this database, this paper comprehensively analyzed the best number of 778 boreholes including well logs and their hydrogeological parameters obtained from pumping tests for the first time in order to identify the entire aquifer system and characterize hydrogeological conditions in the whole delta for potential groundwater resources. Great efforts have been made to establish and analyze hydrogeological maps, cross sections, and contour maps of main aquifers' thickness and transmissivity. As for the results, we found that groundwater mainly exists in Quaternary unconsolidated sediments as porous water forming the topmost Holocene unconfined aquifer (HUA) and the shallow Pleistocene confined aquifer (PCA) sandwiching the Holocene-Pleistocene aquitard (HPA), while cleft and karst water exist in consolidated Neogene formations and Mesozoic rocks constituting the Neogene water bearing layer (NWL) and Mesozoic fractured zones (MFZ), respectively. PCA is almost entirely distributed over the delta. It serves as the highest groundwater potential and the most important aquifer for water supply. HUA is also widely distributed about 88% over the delta and has a high groundwater potential. NWL and MFZ, placed below PCA but exposed on the surface outside the delta, are minor sources for local domestic water supply only. These findings are indispensable for further groundwater analyses needed to ensure the sustainable groundwater development for the high-security water requirements in the delta, but have never been completed sufficiently before due to the unavailability of large-scale basic data sets.

Hydrogeochemical Features of Thermal Water of South Trungbo

“…8). Про-цесс внедрения морских вод в геологическом прош-лом в осадочные толщи на территории континенталь-ного Вьетнама хорошо изучен на примере дельты Красной Реки, где отчетливо видна смена химических типов от минерализованных хлоридных натриевых, в том числе с повышенным содержанием кальция, к пресным гидрокарбонатным натриевым подземных вод по мере удаления от береговой линии внутрь кон-тинента [15,27,40,47], те же закономерности наблю-даются в дельте реки Меконг [11] и Южном Трангбо. По отношению rNa/rCl (около 0.87) наиболее близки к морским -воды более низкой минерализации с повы-шенным содержанием в составе кальция, изученные в прибрежных районах (источники Пхуок Тинь, Бинь- хау, Такой, Винь Пхуонг Нха Транг, Тусон, Модук и Кы Ке) (рис.…”

Economic Sustainability Assessment of Groundwater Resources: Case Study of Hanoi, Vietnam

“…Unfortunately, this groundwater recently become seriously degraded in both quantity and quality perspectives due to the rapid exploitation of the groundwater without an appropriate management. From a quantity point of view, the aquifer system and groundwater potential resources for Hanoi was explored [5] and the whole RRD (Red River Delta) where Hanoi is located [6] but also evidently showed the seriously declining groundwater levels in Hanoi central areas [7]. From a quality point of view, the hydrogeochemical characteristics of groundwater in Hanoi and the RRD were investigated [8,9], D DAVID PUBLISHING…”

Identification of spatio-seasonal hydrogeochemical characteristics of the unconfined groundwater in the Red River Delta, Vietnam

“…A great many hydrogeochemistry studies have been carried out to improve the understanding of groundwater systems; e.g., studies have been conducted in America (Quiroz Londoño et al, 2008;Oyarzún et al, 2013), Africa (Mojerezi et al, 2011), Europe (Dragon and G orski, 2009), and Asia (Sasamoto et al, 2011). The focus of this study is the Red River Delta (RRD) in Vietnam, where excessive groundwater withdrawal in the absence of the wise management and adequate understanding of the hydrogeochemical characteristics has caused serious problems, such as the unmitigated decline of groundwater levels and the deterioration of water quality (Bui et al, 2011).…”