Impact of climate change on groundwater recharge and salinity distribution in the Vientiane basin, Lao PDR

Abstract

Groundwater is widely used for domestic, agricultural, and industrial purposes in the Vientiane basin. The trend of groundwater use is increasing but the usage of the mentioned groundwater is without proper study and monitoring. Six climatic scenarios from three General Circulation Models (GCMs) under Representative Concentration Pathways (RCPs) 4.5 and 8.5 were used to project rainfall and temperature in the future (2021–2050) periods. The numerical models HELP3, MODFLOW, and MT3D were used for groundwater recharge estimation, groundwater potential, and salinity distribution, respectively. The study found that during the following 30 years (2050), rainfall is expected to rise by 16, 17.52, and 49.93% for the MPI-ESM-MR, MIROC5, and CNRM-CM5 (under RCPs 4.5 and 8.5), respectively. Groundwater recharge is estimated to rise from baseline throughout all future climate conditions. Climate change's impact on salinity distribution in depth aquifers, the area with the water with the TDS between 500 and 1,500 mg/l will tend to decrease, whereas the freshwater (TDS <500 mg/l) area will tend to increase. Annual groundwater replenishment is expected to increase from current levels in all future climate scenarios in the range of 334–401 MCM/year or approximately 22.7–47.5%.

Predictive analysis of groundwater balance and assessment of safe yield using a probabilistic groundwater model for the Dead Sea Basin

“…It may be observed that several past studies used projected climate data to estimate recharge and applied it in numerical groundwater models to estimate changes in groundwater levels and fluxes (Reinecke et al, 2021;Soundala and Saraphirom, 2022). Depending on the complexity of the recharge models, they use computationally complex solution of Richard's equation or simpler approaches like UZF1 or Hydrus 1D coupled to MODFLOW in which 1D solution of Richard's equation was used.…”

Remote sensing data for monitoring water mirror of lake ecosystems

“…In doing so, the state of the lake can be seen as an indicator of the processes occurring in and around the lake, which are influenced by both human actions and climate [4]. Climate change is a global phenomenon, but its effects are felt regionally and locally [5]. The variability of lake ecosystems can be monitored by a continuous monitoring system, which for a number of reasons, both economic and geographical, is not feasible, and monitoring networks are in decline worldwide [6].…”