Impact of climate change on the groundwater sustainability in the lower Chao Phraya basin, Thailand

Abstract

Abstract. This research investigates the impact of climate change on the hydraulic heads of Thailand's Lower Chao Phraya basin. The research also determines the sustainability of groundwater as the result from climate change. In the study, the climatic scenario (IPSL-CM5A-MR) of the Representative Concentration Pathways (RCP) between 2.6, 4.5 and 8.5 were considered, and the simulations were carried out using the three-dimensional groundwater flow model (i.e. MODFLOW-2000) predicting the groundwater behavior between 2017 and 2036. The findings revealed that the impact of climate change on the hydraulic head fluctuation was positively correlated. Specifically, under the IPSL-CM5A-MR RCP 4.5 that has the highest average precipitation, the average hydraulic head increased. In conclusion, the sustainability of groundwater in the Lower Chao Phraya basin was sufficient during the simulated time. However, the groundwater budget was lower than the average groundwater budget during 2009 -2014 indicating, the groundwater storage was continuously decreased. Specifically, the 2 nd , and 3 rd (Phra Pradeang and Nakorn Luang) aquifers may be facing the groundwater shortage in the future.

Impact of Climate Change on Soil Erosion in the Lam Phra Phloeng Watershed

“…This model was selected, because the scenarios offered the minimum bias and root mean square error on annual precipitation [22]. RCP 2.6 and 8.5 represent the most severe climate changes, and RCP 4.5 was the most likely event [23]. Soil erosion and sediment yield, due to climate change, were then predicted using the USLE and SDR models.…”

“…Nguyen and Chen [7] showed that the Shihmen is to predict long-term soil erosion and predict sediment yield in the reservoir, due to climate change, to improve the declining capacity of the reservoir and water planning and management. A Global Climate Model (GCM), Institute Pierre Simon Laplace-Climate Model version 5A (IPSL-CM5A-MR) from Coupled Model Intercomparison Project-5 (CMIP5) and three scenarios, i.e., RCP 2.6, RCP 4.5, and RCP 8.5, in the LPP watershed, were used to predict future rainfall data via Sananmuang's method [21], from the correlation between rainfall and water surface in the central part of Thailand [22,23]. Field measurements and other methods were used to validate the USLE and SDR results.…”

Groundwater Vulnerability of Thailand’s Lower Chao Phraya Basin

“…The hydrogeology is Tertiary-Quaternary formation that the depositions are coastal and fluvial deposits [18,19]. The aquifers consists mainly of sands, gravels and clay lenses, that can be divided into eight confined aquifers -the Bangkok (BK), Phra Pradaeng (PD), Nakorn Luang (NL), Nonthaburi (NB), Sam Khok (SK), Phayathai (PT), Thonburi (TB), and Pak Nam (PN) aquifers [1,9].…”

“…The effect of drought on water resources has been studied by Wongsa and Rangsiwanichpong et al [7,8]. Tanachaichoksirikun et al [9] reported that groundwater affected climate change: especially, in Thailand's Lower Chao Phraya (LCP) basin, groundwater is still sustainable but shortage may be faced in some aquifers.…”

“…Therefore, we investigated the impact of climate change on the groundwater vulnerability, by combining climate change, history of drought persistent and FCF, to investigate critical areas that affect climate change. This is the first time, FCF has been used to evaluate the challenge of confined aquifers: it was applied to the LCP basin because it is a confined aquifer, that was affected by climate change [9].…”