Estimating groundwater recharge using the chloride mass-balance method in the West Bank, Palestine

Abstract

The quantification of natural recharge rate is a prerequisite for efficient and sustainable groundwater resources management. Since groundwater is the only source of water supply in the West Bank, it is of utmost importance to estimate the rate of replenishment of the aquifers. The chloride mass-balance method was used to estimate recharge rates at different sites representing the three groundwater basins of the Mountain Aquifer in the West Bank. The recharge rate for the Eastern Basin was calculated as between 130.8 and 269.7 mm/year, with a total average replenishment volume of 290.3 Â 10 6 m 3 /year. For the Northeastern Basin, the calculated recharge rate ranged between 95.2 and 269.7 mm/year, with a total average recharge volume of 138.5 Â 10 6 m 3 /year. Finally, the recharge rate for the Western Basin was between 122.6 and 323.6 mm/year, with a total average recharge volume of 324.9 Â 10 6 m 3 /year. The data reveal a replenishment potential within the estimated replenishment volumes of previous studies for the same area. Also, the range was between 15 and 50% of total rainfall, which is still within the range of previous studies. The geological structure and the climate conditions of the western slope were clearly play an important role in the increment of total volume. In some cases, such as the geological formations in the Northeastern Basin, the interaction between Eocene and Senonian chalk formations result in minimum recharge rates.Key words mountain aquifer; chloride-mass balance; recharge rate; groundwater replenishment Estimation de la recharge hydrogéologique par la méthode du bilan massique des chlorures en Cisjordanie, Palestine Résumé La quantification de la recharge naturelle est un pré-requis pour une gestion efficace et durable des ressources en eaux souterraines. Puisque l'eau souterraine est la seule source pour l'alimentation en eau de la Cisjordanie, il est primordial d'estimer le taux de renouvellement des aquifères. Nous avons utilisé la méthode du bilan de masse des chlorures afin de calculer la recharge en différents sites du Mountain Aquifer en Cisjordanie, représentatifs des trois bassins hydrogéologiques. La recharge du bassin Est a été estimée entre 130.8 et 269.7 mm/an, avec un volume total de 290.3 Â 10 6 m 3 /an. Pour le bassin Nord-Est, la recharge se situe entre 95.2 et 269.7 mm/an, avec un volume total de 138.5 Â 10 6 m 3 /an. La recharge du bassin Ouest, finalement, s'échelonne entre 125.7 et 323.6 mm/an avec un volume de 324.9 Â 10 6 m 3 /an. Ces données révèlent un potentiel de renouvellement plus important que les volumes estimés lors d'études antérieures dans la même région. La structure géologique et les conditions climatiques sur le versant ouest jouent manifestement un rôle important pour la contribution significative de ce versant au volume total de recharge. Dans certains cas, les formations géologiques, comme la craie Eocène et Sénonienne du bassin Nord-Est, ne favorisent pas la recharge ce qui se traduit par valeurs inférieures.Mots clefs aquifère de ...

Recharge estimation and soil moisture dynamics in a Mediterranean, semi-arid karst region

“…Methods include knowledge GIS-based mapping (Andreo et al, 2008), multiple linear regression (Allocca et al, 2014), conceptual models (e.g. Hartmann et al, 2013a), coupled water-balance groundwater models (Sheffer et al, 2010), and chloride mass balances (Marei et al, 2010;Schmidt et al, 2013). However, these studies treat karst systems as units, including both the unsaturated and the saturated zones, and are limited in temporal and spatial resolution.…”

“…Later, groundwater flow models were used to establish empirical rainfall-recharge relationships (Baida and Burstein, 1970;Guttman and Zukerman, 1995;Zukerman, 1999). Average recharge rates were assessed by a simple water balance approach (Hughes et al, 2008) and by a chloride mass balance (Marei et al, 2010). Sheffer et al (2010) coupled a water budget model with a groundwater flow model for the entire western part of the Mountain Aquifer and used spring discharge and groundwater level data for calibration.…”

Mapping the Stable Isotopes to Understand the Geo-Structural Control of Groundwater Recharge and Flow Mechanisms (Case Study From the Northeastern Basin of the West Bank)

“…Recharge process for both aquifer systems takes place wherever the rock formation is outcropped and exposed directly to the rainfall or underlying thin soil layers. Marei et al estimate the groundwater recharge rate, by using chloride mass balance method for the study area, of about 95.2 and 269.7 mm/year, with a total average recharge volume of 138.5 MCM/year (Figure 4) [14], while the total calculated recharge rate by the previous study of the authors is 107.1 MCM/a [14]. Recharge rate can be higher than estimated when karstic and high fractured rock layers are cropped out at the surface such as the formation of the Upper and Lower Mountain aquifer system at the two anticline flanks in the west and in the east, in the other hand ground recharge decrease to about zero from Abu Dis formation "Chalky Unit".…”

Assessment of Hydrogeochemistry and Environmental Isotopes in Karst Springs of Makook Anticline, Kurdistan Region, Iraq

“…The CMB method has often been used for recharge estimation [17,18] and is applicable in semi-arid regions when additional sources of chloride are absence [19,20]. The precipitation in the area of interest was sampled 10 times during hydrological year (2011-2012).…”