DEGRADATION OF SPRINGS IN THE ARAVA VALLEY: ANTHROPOGENIC AND CLIMATIC FACTORS H. J. BRUINS 1 *, Z. SHERZER 1 , H. GINAT 2 AND S. BATARSEH 1 1 The Jacob Blaustein Institutes for Desert Research, Swiss Institute for Dryland Environmental Research, Ben-Gurion University of the Negev, Sede Boker Campus, 84990, Israel 2 Dead Sea and Arava Science Center, Tamar Regional Council, Neve Zohar, Dead-Sea mobile post 86910, Israel Received: 22 March 2011; Revised: 10 September 2011; Accepted: 13 September 2011 ABSTRACT Groundwater pumping in the hyper-arid Arava Valley began in 1936 for industrial use, south of the Dead Sea, and since 1949 for domestic and agricultural use with the establishment of Eilat. Pumping gradually increased with the founding of 19 rural villages throughout the Arava Valley. Groundwater levels dropped as a result, and springs in the Arava Valley began to deteriorate. Their status had not been studied for decades, and we conducted comprehensive fieldwork of virtually all the known springs on the Israeli side of the Arava Valley, 31 springs, within the period 2008–2010. Our objectives were (i) to determine the current condition of each spring, (ii) to study spring deterioration through time in relation to historical data and (iii) to evaluate anthropogenic and climatic factors through time. Our results reveal that only 13 springs discharged water on the landscape surface and 18 springs were found dry. Detailed evaluations and time-series analyses are presented for the springs: ‘Ein Tamar, ‘Ein Mashak, ‘Ein Evrona and ‘Ein Netafim, selected on the basis of geodiversity. Climatic trends in the region were studied using the novel P/PET aridity index (P = annual precipitation, PET = annual potential evapotranspiration). We calculated yearly P/PET values since 1970 for five meteorological stations in Israel and six stations in Jordan. All stations, without exception, show a negative downward trend toward increasing aridity, often with significant p values (below 010). The change to a drier climate in the region should be considered as an important factor regarding sustainable groundwater management in the Arava Valley. Copyright © 2012 John Wiley & Sons, Ltd. keywords: spring degradation; Arava Valley; groundwater pumping; anthropogenic impact; increasing aridity; Israel; Jordan; climatic impact INTRODUCTION The Arava Valley, or Wadi Arabah, forms part of the Great Rift Valley, running from northern Syria to Mozambique in southern Africa over a distance of ca. 6000 km. The Hashemite Kingdom of Jordan and the State of Israel share the Arava Valley, which lies between the Dead Sea in the north and the Red Sea in the south (Figures 1 and 2). The Arava Valley is about 180km long and 10–20 km wide, enclosed by the impressive Edom Mountains in the east (Jordan) and the Negev Hills in the west (Israel). Occasional earthquakes can affect temporarily the discharge of springs in the Arava Valley (Yechieli and Bein, 2002), underlining the complex tectonic setting with many faults that may enable mix- ing of groundwater from different aquifers (Adar et al., 1992). There are many archaeological remains in the Arava Valley (Cohen, 1983; Gichon, 1993; Avner, 2006; Bienkowski and Galor, 2006; Bruins, 2006; Hirschfeld, 2006; Levy et al., 2008), despite the harsh desert climate. Indeed, the numerous springs in the Arava Valley must have functioned as critical water sources since time immemorial in this hyper-arid region, where summer temperatures are regularly above 40  C. The mean annual temperature is 23  C to 24  C, and the mean annual rainfall ranges from less than 30 mm in the south to 50 mm in the northern Arava (Goldreich and Karni, 2001; Goldreich, 2003). The warm climate in the Rift Valley (Goldreich, 2003) and its south–north orientation enabled the penetration of tropical plant species northward through this corridor. Hence, the vegetation in the Arava Valley is classified as the Sudanian phytogeographical region (Danin, 1983). For example, the northernmost occurrence in the world of the doum palm (Hyphaene thebaica) is near Eilat (Figures 1 and 2). Also, various other tree species, whose principal habitat is in the East African savannas, are found in Israel only in the Rift Valley (Danin 1983). In terms of topography, the lowest point of the Arava Valley is near the Dead Sea at about 390 m below mean sea-level (MSL). Here, the Wadi Arava streambed enters the evaporation pans of the Arab Potash Company (wadi is the Arabic name for stream or ephemeral stream channel). Going southward, the Arava Valley gradually rises to its highest point at 203m above-sea level, near Ar Risha (Figure 2). The northern drainage system runs from here down to the *Correspondence to: H. J. Bruins, The Jacob Blaustein Institutes for Desert Research, Swiss Institute for Dryland Environmental Research, Ben-Gurion University of the Negev, Sede Boker Campus, 84990, Israel. E-mail: hjbruins@bgu.ac.il Copyright © 2012 John Wiley & Sons, Ltd. land degradation & development Land Degrad. Develop. (2012) Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/ldr.2149