Review on the use of environmental isotopes for groundwater recharge and evaporation studies in the GCC countries

A Critical Review of Groundwater Table Fluctuation: Formation, Effects on Multifields, and Contaminant Behaviors in a Soil and Aquifer System

“…Evaporation is a key component of groundwater drainage and contributes to the fluctuation of the groundwater table (Figure ). , The monthly evaporation loss of 916 reservoirs in China increased significantly for 33 years, and the total loss of evaporation reached 140.2 × 10 8 m 3 in 2018, which provided the evidence that evaporation played a non-negligible role in controlling the GTF zone’s drainage . The evaporation loss of small irrigation water reservoirs in Morocco also clarified the annual evaporation loss was ∼1.50 Mm 3 year –1 …”

“…Evaporation is a key component of groundwater drainage and contributes to the fluctuation of the groundwater table (Figure 1). 28,29 The monthly evaporation loss of 916 reservoirs in China increased significantly for 33 years, and the total loss of evaporation reached 140.2 × 10 8 m 3 in 2018, which provided the evidence that evaporation played a non-negligible role in controlling the 29 rainfall, 32 tide, 40 lateral recharge and drainage, 47 surface water, 49−51 irrigation, 63,64 and groundwater pumping 68 ). There is a mixing zone between freshwater and seawater in a coastal aquifer, and salinity drives high-salinity seawater into freshwater aquifers.…”

The Origin of Groundwater on The East Slope of Sumbing Vulcano Using Isotopic Methode

“…One of the main causes of changes in isotopic composition is evaporation. This occurs especially in arid and semiarid areas where the evaporation is also closely related to temperature, geological conditions, and relative humidity that determine the evaporation slope line [15][16] [17]. Therefore, the isotopic composition determines the recharge area and identifies the rate of precipitation and evaporation.…”

“…If the slopes of the groundwater samples are higher than the slope of the LMWL, it indicates a relatively low rate of evaporation and reflects high altitude recharge. The lower slope indicates a high rate of evaporation of surface water prior to infiltration [17].…”

“…There is a degree of evaporation or deuterium excess value (d-excess) that could be a secondorder parameter and reflects non-equilibrium fractionation during initial evaporation from the ocean, re-evaporation at the land surface, or re-evaporation and mixing along the water mass trajectory. Dexcess is defined in Equation 3 [17] [18]. Positive d-excess values indicate low evaporation and show that it forms from meteoric origin while negative d-excess indicate high evaporation.…”