Chemical and isotopic methods for confirming the roles of wadis in regional groundwater recharge in a regional arid environment: a case study in Al Ain, UAE

Abstract

Abstract:In arid environments groundwater may represent the most important source of water for sustaining life. The timing and nature of precipitation may induce infiltration and recharge on a small scale. The Al Ain region, UAE was chosen and from 1996 to 1997 studies were conducted to illustrate spatial distribution of recharge for groundwater by using chemical and isotopic methods. According to the field survey, UAE can be hydrogeologically classified into five parts: mountain area, wadis, sand dunes, inland sabkhas and coastal sabkhas, respectively. In this report, we studied a typical wadi, Wadi Mieshiq area. Upstream of the wadi, it was found that the groundwaters were characterized by low salinity. Stable isotopes of groundwaters in the wadi were lighter than those of the stream waters in the mountain area, since stream water was affected by evaporation before it infiltrated into the ground. The isotopes of recharged water into the wadi must have isotopically light values. From the results above, groundwater along the wadi was mainly derived from not only water from the mountain area but also infiltrated water during the flood period. Wadis are an important recharge region for groundwater.

Parameterization and evaluation of a three-dimensional modelling approach to water table recharge from seepage losses in a ditch

“…Lloyd, 1986;Gee and Hillel, 1988;Parissopoulos and Wheater, 1992;Tang et al, 2001). Because of the difficulty of monitoring flash flood events and of the large uncertainty in measuring recharge, modelling approaches appear to be an alternative to estimate groundwater recharge generated by seepage in the stream bed.…”

Southwestern Intermittent and Ephemeral Stream Connectivity

“…Chemical and isotopic tracers have confirmed that ephemeral streams are cumulatively important areas for floodwaters to recharge groundwater aquifers in desert regions (Tang et al. ). In a synthesis of research into groundwater recharge in the Southwestern and Western U.S., Phillips et al.…”

“…If restricting soil or geologic layers underlying the channel do not substantially inhibit downward motion, channel transmission losses will recharge either the regional or alluvial groundwater (Tang et al. ; Constantz et al. ; Harrington et al.…”

Spatio-temporal variations of δ2H and δ18O in precipitation and shallow groundwater in the Hilly Loess Region of the Loess Plateau, China

“…Retaining spatio-temporal variations in hydrogen and oxygen isotopes in precipitation and groundwater, in conjunction with hydrologic observations and hydrochemistry, has been widely used to identify origins of water bodies (Vrbka et al 1993;Lambs 2000), infiltration modes of precipitation (Douglas 1997;Gazis and Feng 2004;Li et al 2007), the interactions between groundwater and other waters (Simpson and Herczeg 1991;McDonnell et al 1991;Mook 2000;Lamontagne et al 2005;Song et al 2006) and groundwater recharge mechanisms (Clark and Fritz 1997;Tang et al 2001;McGuire et al 2002;Rademacher et al 2003;Demlie et al 2007;Gates et al 2008). Limited isotopic studies have been performed in the Loess Plateau, mainly at profile or point scales.…”