The Lower Jordan River: River Salinization, Relationship with Adjacent Groundwater and Future Management
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The Lower Jordan River: River Salinization, Relationship with Adjacent Groundwater and Future Management Thesis submitted in partial fulfillment of the requirements for the degree of “DOCTOR OF PHILOSOPHY” by Efrat Farber Submitted to the Senate of Ben-Gurion University of the Negev Approved by the advisor _____________________ Approved by the Dean of the Kreitman School of Advanced Graduate Studies ______________________ November 2005 Beer-Sheva This work was carried out under the supervision of Dr. Avner Vengosh In the Department of Geological & Environmental Sciences Faculty of Natural Sciences Title: The Lower Jordan River: River Salinization, Relationship with Adjacent Groundwater and Future Management By: Efrat Farber Supervisor: Dr. Avner Vengosh Abstract: The objective of this study was to investigate the geochemical system of the lower Jordan River and associated groundwater in order to evaluate the origin of river salinization, the relationship with adjacent groundwater, and consequent suitable management activities required to maintain or improve river water quality. The study is comprised of a general introduction, three separate discussion papers, and a general summary. The Introduction (1.1) discusses the global phenomena of river salinization processes, the hydrological and hydrogeological background of the Jordan Valley, and analytical procedures employed during this study. The following chapters present the results from the lower Jordan River and regional groundwater, and implications for groundwater management. Although each can be read independently, with its introduction, results and discussion, the sections in Chapter 2 are arranged such that each one defines a different way of looking at the hydrological system of the lower Jordan River and its vicinity. The first section (2.1) discusses the origin and mechanisms of salinization in the lower Jordan River, and has been published in Geochimica Cosmichimica Acta (Farber et al., 2004). The second (2.2) deals with the geochemistry of groundwater resources in the Jordan Valley and evaluates the impact of the Rift Valley brines. It has been accepted to Applied Geochemistry. The third section (2.3) aims to predict the future salinity variations of the lower Jordan River under several different management scenarios that are included in the peace treaty between Israel and Jordan. It can be found in Applied Geochemistry (Farber et al., 2005). The Summary (Chapter 3) provides a comprehensive framework combining all the conclusions regarding the chemical and isotopic variations along the lower Jordan River, the different sources that control the river water's quality and the impact of those findings for future management of the lower Jordan River. Preface The objective of this study was to investigate the geochemical system of the lower Jordan River and associated groundwater in order to evaluate the origin of river salinization, the relationship with adjacent groundwater, and consequent suitable management activities required to maintain or improve river water quality. The study is comprised of a general introduction, three separate discussion papers, and a general summary. The Introduction (1.1) discusses the global phenomena of river salinization processes, the hydrological and hydrogeological background of the Jordan Valley, and analytical procedures employed during this study. The following chapters present the results from the lower Jordan River and regional groundwater, and implications for groundwater management. Although each can be read independently, with its introduction, results and discussion, the sections in Chapter 2 are arranged such that each one defines a different way of looking at the hydrological system of the lower Jordan River and its vicinity. The first section (2.1) discusses the origin and mechanisms of salinization in the lower Jordan River, and has been published in Geochimica Cosmichimica Acta (Farber et al., 2004). The second (2.2) deals with the geochemistry of groundwater resources in the Jordan Valley and evaluates the impact of the Rift Valley brines. It has been accepted to Applied Geochemistry. The third section (2.3) aims to predict the future salinity variations of the lower Jordan River under several different management scenarios that are included in the peace treaty between Israel and Jordan. It can be found in Applied Geochemistry (Farber et al., 2005). The Summary (Chapter 3) provides a comprehensive framework combining all the conclusions regarding the chemical and isotopic variations along the lower Jordan River, the different sources that control the river water's quality and the impact of those findings for future management of the lower Jordan River. Contents Preface ....................................................................................................................... I 1. Introduction........................................................................................................... 1 1.1. River salinization in the world.................................................................... 1 1.2. Hydrology and Hydrogeology of the Jordan Valley.................................... 8 1.3. Methods................................................................................................... 12 1.3.1.Fieldwork 12 1.3.2.Analytical techniques: major and minor ions……………………………..12 1.3.3.Analytical techniques: 87Sr/86Sr, δ34S, δ11B, δ15N and δ18O Isotopes. 12 1.3.4.Drilling procedure 14 2. Results and Discussion ........................................................................................ 15 2.1. The origin and mechanisms of salinization of the lower Jordan River ........... 15 2.1.1. Introduction…...………………………...………………………………..15 2.1.2. Results and Discussion 15 2.1.3. Conclusion 36 2.2. The geochemistry of groundwater resources in the Jordan Valley: impact of Rift Valley brines ................................................................................................ 38 2.2.1. Introduction 38 2.2.2. Results 44 2.2.3. Discussion 56 2.2.4. Summary and conclusion 70 2.3. Management scenarios for the Jordan River salinity crisis............................. 71 2.1.1. Introduction 71 2.1.2. Methodology 74 2.1.3. Results and Discussion 76 2.1.4. Conclusions 96 3. Summary............................................................................................................. 99 4. References..........................................................................................................103 5. Appendix I: analytical results…………..……………………………………….. 110 1. Introduction 1.1. River salinization throughout the world River salinization is a phenomenon that has shaped human history since at least the fourth millennium BC. New evidence suggests that the rise and collapse of early civilizations (e.g., the Akkadian, 4200 BC) were affected by the salinization of their rivers (e.g., the Tigris and Euphrates rivers; Cullen et al., 2000; deMenocal, 2001). While prehistoric salinization is associated with both climatic changes and man’s activity through irrigation practice, modern salinization is caused primarily by direct and indirect human activities. The water quality of many rivers in arid and semiarid areas is deteriorating due to a combination of extensive land-use changes, diversion and damming of rivers, generation of saline agricultural return flows, and sewage dumping. The results are striking: the rise in salt content causes a decrease in biodiversity, a replacement of the halo-sensitive biota with halo-tolerant species, soil salinization, and diminishing water resources (Williams, 2001). The dominant factor determining the river quality in water-scarce areas is the balance between freshwater withdrawal, groundwater discharge, and agricultural return flow. As more fresh surface water is diverted, the impact of the agricultural return flow increases (Pillsbury, 1981). The rise in the salt content of rivers such as the Colorado and Arkansas rivers in the United States is derived from a combination of upstream diversion of fresh water, intensive irrigation, and formation of saline agricultural return flow, which enters the river (Pillsbury, 1981; Gates et al., 2002). Similarly, saline agricultural drainage increases the salt contents of the Nile (Kotb et al., 2000), Euphrates and Tigris rivers (Robson et al., 1983; Beaumont, 1996). In contrast, the source of the dissolved salts in the Murray River in South Australia (Allison et al., 1990; Herczeg et al., 1993) and the Rio Grande in the United States (Phillips et al., 2003) is geogenetic and derived from the discharge of saline groundwater. Despite the importance of river salinization in dryland environments, only a few studies have investigated the full chemical and isotopic compositions of salinized rivers (e.g., Herczeg et al., 1993; Phillips et al., 2003). The lower Jordan River is located in the semiarid region of the Jordan Valley, along the border between Israel and Jordan. The water discharge and the size of the Jordan 1 River are relatively small, compared to other rivers in the ME, such as the Nile, Euphrates and Tigris Rivers. The Jordan River has historical and religious importance and it serves as a borderline throughout history. Its importance to the neighboring communities rises from these facts not less and perhaps more than its importance as a water resource. The flow rate of this river changed dramatically during the second half of the 20th century. The severe reduction in water flow during the last few decades has