Arid regions, that have a terrestrial share of 30 %, heavily rely on groundwater for do-mestic, industrial and irrigation purposes. The reliance on groundwater has partly turned into a dependency in areas where the increasing population number and the expansion of irrigated agricultural areas demand more groundwater than is naturally replenished. Yet, spatial and temporal information on groundwater are often scarce induced by the facts that groundwater is given a low priority in many national budgets and numerous (semi-) arid regions in the world encompass large and inaccessible areas. Hence, there is an urgent need to provide low-cost alternatives that in parallel cover large spatial and temporal scales to gain information on the groundwater system. Remote sensing holds a tremendous potential to represent this alternative. The main objective of this thesis is the improvement of existing and the development of novel remote sensing applications to infer information on the scarce but indispensable resource groundwater at the example of the Dead Sea. The background of these de-velopments relies mainly on freely available satellite data sets. I investigate 1) the pos-sibility to infer potential groundwater flow-paths from digital elevation models, 2) the applicability of multi-temporal thermal satellite data to identify groundwater discharge locations, 3) the suitability of multi-temporal thermal satellite data to derive information on the long-term groundwater discharge behaviour, and 4) the differences of thermal data in terms of groundwater discharge between coarse-scaled satellite data and fine-scaled airborne data including a discharge quantification approach. 1) I develop a transparent, reproducible and objective semi-automatic approach us-ing a combined linear filtering and object based classification approach that bases on a medium resolution (30 m ground sampling distance) digital elevation model to extract lineaments. I demonstrate that the obtained lineaments have both, a hydrogeological and groundwater significance, that allow the derivation of potential groundwater flow-paths. These flow-paths match results of existing groundwater flow models remarkably well that validate the findings and shows the possibility to infer potential groundwater flow-paths from remote sensing data. 2) Thermal satellite data enable to identify groundwater discharge into open water bodies given a temperature contrast between groundwater and water body. Integrating a series of thermal data from different periods into a multi-temporal analysis accounts for the groundwater discharge intermittency and hence allows obtaining a representa-tive discharge picture. I analyse the constraints that arise with the multi-temporal anal-ysis (2000-2002) and show that ephemeral surface-runoff causes similar thermal anomalies as groundwater. To exclude surface-runoff influenced data I develop an au-tonomously operating method that facilitates the identification. I calculate on the re-maining surface-runoff uninfluenced data series different statistical measures on a per pixel basis to amplify groundwater discharge induced thermal anomalies. The results reveal that the range and standard deviation of the data series perform best in terms of anomaly amplification and spatial correspondence to in-situ determined spring dis-charge locations. I conclude on the reason that both mirror temperature variability that is stabilized and therefore smaller at areas where spatio-temporal constant groundwater discharge occurs. 3) The application of the before developed method on a thermal satellite data set spanning the years 2000 to 2011 enables to localise specific groundwater discharge sites and to semi-quantitatively analyse the temporal variability of the thermal anomalies (termed groundwater affected area - GAA). I identify 37 groundwater discharge sites along the entire Dead Sea coastline that refine the so far coarsely given spring areas to specific locations. All spatially match independent in-situ groundwater discharge observations and additionally indicate 15 so far unreported discharge sites. Comparing the variability of the GAA extents over time to recharge behaviour reveals analogous curve progressions with a time-shift of two years. This observation suggests that the thermally identified GAAs directly display the before only assumed groundwater discharge volume. This finding provides a serious alternative to monitor groundwater discharge over large temporal and spatial scales that is relevant for different scientific communities. From the results I furthermore conclude to observe the before only assumed and modelled groundwater discharge share from flushing of old brines during periods with an above average Dead Sea level drop. This observation implies the need to not only consider discharge from known terrestrial and submarine springs, but also from flushing of old-brines in order to calculate the total Dead Sea water budget. 4) I present a complementary airborne thermal data set recorded in 01/2011 over the north-western part of the Dead Sea coast. The higher spatial resolution allows to refine the satellite-based GAA to 72 specific groundwater discharge sites and even to specify the so far unknown abundance of submarine springs to six sites with a share of <10 % to the total groundwater discharge. A larger contribution stems from newly iden-tified seeping spring type (24 sites) where groundwater emerges diffusively either ter-restrial or submarine close to the land/water interface with a higher share to the total discharge than submarine springs provide. The major groundwater contribution origi-nates from the 42 identified terrestrial springs. For this spring type, I demonstrate that 93 % of the discharge volume can be modelled with a linear ordinary least square re-gression (R2=0.88) based on the thermal plume extents and in-situ measured discharge volumes from the Israel Hydrological Service. This result implies the possibility to determine discharge volumes at unmonitored sites along the Dead Sea coast as well that can provide a complete physically-based picture of groundwater discharge magni-tude to the Dead Sea for the first time.

Die vorliegende Studie befasst sich mit einer hydrochemischen Untersuchung des Aquifersystems auf der Westseite des Toten Meeres. Für die Untersuchungen der Grundwasserressourcen der kreidezeitlichen Grundwasserleiter, insbesondere Grundwasserherkunft, Mischprozesse, Identifizierung von Wasser-Gesteins- Wechselwirkungen, Datierung von Grundwasseraltersbereichen, Identifizierung der Herkunft des Quellen an der Küste des Toten Meeres und Abtrennung quartärer Grundwassermuster, wurde eine Tracerkombination auf Wasser- und Gesteinsproben angewendet. Die hier vorgestellte Multitracer-Methodik ist auch in anderen datenarmen Gebieten mit komplexer Hydrogeologie (Karst oder Störungen) unter anthropogenem Einfluss anwendbar. / The present study deals with a hydrochemical investigation of the aquifer system on the western side of the Dead Sea. To examine the groundwater resources of the Cretaceous aquifer, particularly groundwater origins, mixing processes, identification of water-rock interaction, dating of groundwater age ranges in the aquifers and identification of spring water origins at the Dead Sea coast and separation of Quaternary groundwater patterns, a combination of tracer is applied on water and rock samples. The multi-tracer method presented here is also applicable in other data-poor areas with complex hydrogeology (karst or fracture) under anthropogenic influence.

Arid regions, that have a terrestrial share of 30 %, heavily rely on groundwater for do-mestic, industrial and irrigation purposes. The reliance on groundwater has partly turned into a dependency in areas where the increasing population number and the expansion of irrigated agricultural areas demand more groundwater than is naturally replenished. Yet, spatial and temporal information on groundwater are often scarce induced by the facts that groundwater is given a low priority in many national budgets and numerous (semi-) arid regions in the world encompass large and inaccessible areas. Hence, there is an urgent need to provide low-cost alternatives that in parallel cover large spatial and temporal scales to gain information on the groundwater system. Remote sensing holds a tremendous potential to represent this alternative. The main objective of this thesis is the improvement of existing and the development of novel remote sensing applications to infer information on the scarce but indispensable resource groundwater at the example of the Dead Sea. The background of these de-velopments relies mainly on freely available satellite data sets. I investigate 1) the pos-sibility to infer potential groundwater flow-paths from digital elevation models, 2) the applicability of multi-temporal thermal satellite data to identify groundwater discharge locations, 3) the suitability of multi-temporal thermal satellite data to derive information on the long-term groundwater discharge behaviour, and 4) the differences of thermal data in terms of groundwater discharge between coarse-scaled satellite data and fine-scaled airborne data including a discharge quantification approach. 1) I develop a transparent, reproducible and objective semi-automatic approach us-ing a combined linear filtering and object based classification approach that bases on a medium resolution (30 m ground sampling distance) digital elevation model to extract lineaments. I demonstrate that the obtained lineaments have both, a hydrogeological and groundwater significance, that allow the derivation of potential groundwater flow-paths. These flow-paths match results of existing groundwater flow models remarkably well that validate the findings and shows the possibility to infer potential groundwater flow-paths from remote sensing data. 2) Thermal satellite data enable to identify groundwater discharge into open water bodies given a temperature contrast between groundwater and water body. Integrating a series of thermal data from different periods into a multi-temporal analysis accounts for the groundwater discharge intermittency and hence allows obtaining a representa-tive discharge picture. I analyse the constraints that arise with the multi-temporal anal-ysis (2000-2002) and show that ephemeral surface-runoff causes similar thermal anomalies as groundwater. To exclude surface-runoff influenced data I develop an au-tonomously operating method that facilitates the identification. I calculate on the re-maining surface-runoff uninfluenced data series different statistical measures on a per pixel basis to amplify groundwater discharge induced thermal anomalies. The results reveal that the range and standard deviation of the data series perform best in terms of anomaly amplification and spatial correspondence to in-situ determined spring dis-charge locations. I conclude on the reason that both mirror temperature variability that is stabilized and therefore smaller at areas where spatio-temporal constant groundwater discharge occurs. 3) The application of the before developed method on a thermal satellite data set spanning the years 2000 to 2011 enables to localise specific groundwater discharge sites and to semi-quantitatively analyse the temporal variability of the thermal anomalies (termed groundwater affected area - GAA). I identify 37 groundwater discharge sites along the entire Dead Sea coastline that refine the so far coarsely given spring areas to specific locations. All spatially match independent in-situ groundwater discharge observations and additionally indicate 15 so far unreported discharge sites. Comparing the variability of the GAA extents over time to recharge behaviour reveals analogous curve progressions with a time-shift of two years. This observation suggests that the thermally identified GAAs directly display the before only assumed groundwater discharge volume. This finding provides a serious alternative to monitor groundwater discharge over large temporal and spatial scales that is relevant for different scientific communities. From the results I furthermore conclude to observe the before only assumed and modelled groundwater discharge share from flushing of old brines during periods with an above average Dead Sea level drop. This observation implies the need to not only consider discharge from known terrestrial and submarine springs, but also from flushing of old-brines in order to calculate the total Dead Sea water budget. 4) I present a complementary airborne thermal data set recorded in 01/2011 over the north-western part of the Dead Sea coast. The higher spatial resolution allows to refine the satellite-based GAA to 72 specific groundwater discharge sites and even to specify the so far unknown abundance of submarine springs to six sites with a share of <10 % to the total groundwater discharge. A larger contribution stems from newly iden-tified seeping spring type (24 sites) where groundwater emerges diffusively either ter-restrial or submarine close to the land/water interface with a higher share to the total discharge than submarine springs provide. The major groundwater contribution origi-nates from the 42 identified terrestrial springs. For this spring type, I demonstrate that 93 % of the discharge volume can be modelled with a linear ordinary least square re-gression (R2=0.88) based on the thermal plume extents and in-situ measured discharge volumes from the Israel Hydrological Service. This result implies the possibility to determine discharge volumes at unmonitored sites along the Dead Sea coast as well that can provide a complete physically-based picture of groundwater discharge magni-tude to the Dead Sea for the first time.:1 Introduction 1.1 Remote sensing applications on groundwater 1.1.1 Classical aspects 1.1.2 Modern aspects 1.2 Motivation and main objectives 1.3 Why the western catchment of the Dead Sea? 1.4 Overview 2 The western catchment of the Dead Sea 2.1 Geological and Structural Overview 2.2 Groundwater system 2.3 Groundwater inputs 2.4 Dead Sea 3 Groundwater flow-paths 3.1 Prologue 4 Method development for groundwater discharge identification 4.1 Prologue 5 Localisation and temporal variability of groundwater discharge 5.1 Prologue 6 Qualitative and quantitative refinement of groundwater discharge 6.1 Prologue 7 Conclusion and Outlook 7.1 Main results and implications 7.2 Outlook References Appendix

Ein transversales Störungssystem im Nahen Osten, die Dead Sea Transform (DST), trennt die Arabische Platte von der Sinai-Mikroplatte und erstreckt sich von Süden nach Norden vom Extensionsgebiet im Roten Meer über das Tote Meer bis zur Taurus-Zagros Kollisionszone. Die sinistrale DST bildete sich im Miozän vor etwa 17 Ma und steht mit dem Aufbrechen des Afro-Arabischen Kontinents in Verbindung. Das Untersuchungsgebiet liegt im Arava Tal zwischen Totem und Rotem Meer, mittig über der Arava Störung (Arava Fault, AF), die hier den Hauptast der DST bildet.<br /> <br /> Eine Reihe seismischer Experimente, aufgebaut aus künstlichen Quellen, linearen Profilen über die Störung und entsprechend entworfenen Empfänger-Arrays, zeigt die Untergrundstruktur in der Umgebung der AF und der Verwerfungszone selbst bis in eine Tiefe von 3-4 km. Ein tomographisch bestimmtes Modell der seismischen Geschwindigkeiten von P-Wellen zeigt einen starken Kontrast nahe der AF mit niedrigeren Geschwindigkeiten auf der westlichen Seite als im Osten. Scherwellen lokaler Erdbeben liefern ein mittleres P-zu-S Geschwindigkeitsverhältnis und es gibt Anzeichen für Änderungen über die Störung hinweg. Hoch aufgelöste tomographische Geschwindigkeitsmodelle bestätigen der Verlauf der AF und stimmen gut mit der Oberflächengeologie überein. <br /> <br /> Modelle des elektrischen Widerstands aus magnetotellurischen Messungen im selben Gebiet zeigen eine leitfähige Schicht westlich der AF, schlecht leitendes Material östlich davon und einen starken Kontrast nahe der AF, die den Fluss von Fluiden von einer Seite zur anderen zu verhindern scheint. Die Korrelation seismischer Geschwindigkeiten und elektrischer Widerstände erlaubt eine Charakterisierung verschiedener Lithologien im Untergrund aus deren physikalischen Eigenschaften. Die westliche Seite lässt sich durch eine geschichtete Struktur beschreiben, wogegen die östliche Seite eher einheitlich erscheint. Die senkrechte Grenze zwischen den westlichen Einheiten und der östlichen scheint gegenüber der Oberflächenausprägung der AF nach Osten verschoben zu sein.<br /> <br /> Eine Modellierung von seismischen Reflexionen an einer Störung deutet an, dass die Grenze zwischen niedrigen und hohen Geschwindigkeiten eher scharf ist, sich aber durch eine raue Oberfläche auf der Längenskala einiger hundert Meter auszeichnen kann, was die Streuung seismischer Wellen begünstigte. Das verwendete Abbildungsverfahren (Migrationsverfahren) für seismische Streukörper basiert auf Array Beamforming und der Kohärenzanalyse P-zu-P gestreuter seismischer Phasen. Eine sorgfältige Bestimmung der Auflösung sichert zuverlässige Abbildungsergebnisse.<br /> <br /> Die niedrigen Geschwindigkeiten im Westen entsprechen der jungen sedimentären Füllung im Arava Tal, und die hohen Geschwindigkeiten stehen mit den dortigen präkambrischen Magmatiten in Verbindung. Eine 7 km lange Zone seismischer Streuung (Reflektor) ist gegenüber der an der Oberfläche sichtbaren AF um 1 km nach Osten verschoben und lässt sich im Tiefenbereich von 1 km bis 4 km abbilden. Dieser Reflektor markiert die Grenze zwischen zwei lithologischen Blöcken, die vermutlich wegen des horizontalen Versatzes entlang der DST nebeneinander zu liegen kamen. Diese Interpretation als lithologische Grenze wird durch die gemeinsame Auswertung der seismischen und magnetotellurischen Modelle gestützt. Die Grenze ist möglicherweise ein Ast der AF, der versetzt gegenüber des heutigen, aktiven Asts verläuft. Der Gesamtversatz der DST könnte räumlich und zeitlich auf diese beiden Äste und möglicherweise auch auf andere Störungen in dem Gebiet verteilt sein. / The Dead Sea Transform (DST) is a prominent shear zone in the Middle East. It separates the Arabian plate from the Sinai microplate and stretches from the Red Sea rift in the south via the Dead Sea to the Taurus-Zagros collision zone in the north. Formed in the Miocene about 17 Ma ago and related to the breakup of the Afro-Arabian continent, the DST accommodates the left-lateral movement between the two plates. The study area is located in the Arava Valley between the Dead Sea and the Red Sea, centered across the Arava Fault (AF), which constitutes the major branch of the transform in this region.<br /> <br /> A set of seismic experiments comprising controlled sources, linear profiles across the fault, and specifically designed receiver arrays reveals the subsurface structure in the vicinity of the AF and of the fault zone itself down to about 3-4 km depth. A tomographically determined seismic P velocity model shows a pronounced velocity contrast near the fault with lower velocities on the western side than east of it. Additionally, S waves from local earthquakes provide an average P-to-S velocity ratio in the study area, and there are indications for a variations across the fault. High-resolution tomographic velocity sections and seismic reflection profiles confirm the surface trace of the AF, and observed features correlate well with fault-related geological observations.<br /> <br /> Coincident electrical resistivity sections from magnetotelluric measurements across the AF show a conductive layer west of the fault, resistive regions east of it, and a marked contrast near the trace of the AF, which seems to act as an impermeable barrier for fluid flow. The correlation of seismic velocities and electrical resistivities lead to a characterisation of subsurface lithologies from their physical properties. Whereas the western side of the fault is characterised by a layered structure, the eastern side is rather uniform. The vertical boundary between the western and the eastern units seems to be offset to the east of the AF surface trace.<br /> <br /> A modelling of fault-zone reflected waves indicates that the boundary between low and high velocities is possibly rather sharp but exhibits a rough surface on the length scale a few hundreds of metres. This gives rise to scattering of seismic waves at this boundary. The imaging (migration) method used is based on array beamforming and coherency analysis of P-to-P scattered seismic phases. Careful assessment of the resolution ensures reliable imaging results.<br /> <br /> The western low velocities correspond to the young sedimentary fill in the Arava Valley, and the high velocities in the east reflect mainly Precambrian igneous rocks. A 7 km long subvertical scattering zone reflector is offset about 1 km east of the AF surface trace and can be imaged from 1 km to about 4 km depth. The reflector marks the boundary between two lithological blocks juxtaposed most probably by displacement along the DST. This interpretation as a lithological boundary is supported by the combined seismic and magnetotelluric analysis. The boundary may be a strand of the AF, which is offset from the current, recently active surface trace. The total slip of the DST may be distributed spatially and in time over these two strands and possibly other faults in the area.

Die folgende Arbeit ist Teil des multidisziplinären Projektes DESERT (DEad SEa Rift Transect), welches seit dem Jahr 2000 im Nahen Osten durchgeführt wird. Dabei geht es primär um die Struktur der südlichen Dead Sea Transform (DST; Tote-Meer-Transformstörung), Plattengrenze zwischen Afrika (Sinai) und der Arabischen Mikroplatte. Seit dem Miozän beträgt der sinistrale Versatz an dieser bedeutenden aktiven Blattverschiebung mehr als 100 km. Das steilwinkelseismische (NVR) Experiment von DESERT querte die DST im Arava Tal zwischen Rotem Meer und Totem Meer, wo die Hauptstörung auch Arava Fault genannt wird. Das 100 km lange Profil erstreckte sich von Sede Boqer/Israel im Nordwesten nach Ma'an/Jordanien im Südosten und fällt mit dem zentralen Teil einer weitwinkelseismischen Profillinie zusammen. <br><br> Steilwinkelseismische Messungen stellen bei der Bestimmung der Krustenstruktur bis zur Krusten/Mantel-Grenze ein wichtiges Instrument dar. Obwohl es kaum möglich ist, steilstehende Störungszonen direkt abzubilden, geben abrupte Veränderungen des Reflektivitätsmuster oder plötzlich endende Reflektoren indirekte Hinweise auf Transformbewegung. Da bis zum DESERT Experiment keine anderen reflexionsseismischen Messungen über die DST ausgeführt worden waren, waren wichtige Aspekte dieser Transform-Plattengrenze und der damit verbundenen Krustenstruktur nicht bekannt. Mit dem Projekt sollte deshalb untersucht werden, wie sich die DST sowohl in der oberen als auch in der unteren Kruste manifestiert. Zu den Fragestellungen gehörte unter anderem, ob sich die DST bis in den Mantel fortsetzt und ob ein Versatz der Krusten/Mantel-Grenze beobachtet werden kann. So ein Versatz ist von anderen großen Transformstörungen bekannt. <br><br> In der vorliegenden Arbeit werden zunächst die Methode der Steilwinkelseismik und die Datenverarbeitung kurz erläutert, bevor die Daten geologisch interpretiert werden. Bei der Interpetation werden die Ergebnisse anderer relevanter Studien berücksichtigt. Geologische Geländearbeiten im Gebiet des NVR Profiles ergaben, dass die Arava Fault zum Teil charakterisiert ist durch niedrige Steilstufen in den neogenen Sedimenten, durch kleine Druckrücken oder Rhomb-Gräben. Ein typischer Aufbau der Störungszone mit einem Störungskern, einer störungsbezogenen Deformationszone und einem undeformierten Ausgangsgestein, wie er von anderen großen Störungszonen beschrieben worden ist, konnte nicht gefunden werden. Deshalb wurden zur Ergänzung der Reflexionsseismik, welche vor allem die tieferen Krustenstrukturen abbildet, ASTER (Advanced Spacebourne Thermal Emission and Reflection Radiometer) Satellitendaten herangezogen, um oberflächennahe Deformation und neotektonische Aktivität zu bestimmen. / Following work is embedded in the multidisciplinary study DESERT (DEad SEa Rift Transect) that has been carried out in the Middle East since the beginning of the year 2000. It focuses on the structure of the southern Dead Sea Transform (DST), the transform plate boundary between Africa (Sinai) and the Arabian microplate. The left-lateral displacement along this major active strike-slip fault amounts to more than 100 km since Miocene times. The DESERT near-vertical seismic reflection (NVR) experiment crossed the DST in the Arava Valley between Red Sea and Dead Sea, where its main fault is called Arava Fault. The 100 km long profile extends in a NW&mdash;SE direction from Sede Boqer/Israel to Ma'an/Jordan and coincides with the central part of a wide-angle seismic refraction/reflection line. <br><br> Near-vertical seismic reflection studies are powerful tools to study the crustal architecture down to the crust/mantle boundary. Although they cannot directly image steeply dipping fault zones, they can give indirect evidence for transform motion by offset reflectors or an abrupt change in reflectivity pattern. Since no seismic reflection profile had crossed the DST before DESERT, important aspects of this transform plate boundary and related crustal structures were not known. Thus this study aimed to resolve the DST's manifestation in both the upper and the lower crust. It was to show, whether the DST penetrates into the mantle and whether it is associated with an offset of the crust/mantle boundary, which is observed at other large strike-slip zones. <br><br> In this work a short description of the seismic reflection method and the various processing steps is followed by a geological interpretation of the seismic data, taking into account relevant information from other studies. Geological investigations in the area of the NVR profile showed, that the Arava Fault can partly be recognized in the field by small scarps in the Neogene sediments, small pressure ridges or rhomb-shaped grabens. A typical fault zone architecture with a fault gauge, fault-related damage zone, and undeformed host rock, that has been reported from other large fault zones, could not be found. Therefore, as a complementary part to the NVR experiment, which was designed to resolve deeper crustal structures, ASTER (Advanced Spacebourne Thermal Emission and Reflection Radiometer) satellite images were used to analyze surface deformation and determine neotectonic activity.

No description available.

Groundwater is the only fresh water resource in the semi-arid to hyper-arid Western Dead Sea catchment. Due to exploitation of groundwater the water level is decreasing in the surrounding Cretaceous aquifer system and sustainable water management is needed in order to prevent the progressive yields and contamination of those water resources. In addition, the water level of the Dead Sea decreases dramatically by at least one meter per year. This is connected to channel off the water from the Jordan River to supply intensive agriculture in the semi-arid to hyper-arid region. Hydrological and hydro-geological analysis and modelling in arid regions, like the study area, frequently suffer from data scarcity and uncertainties regarding rainfall and discharge measurements. The study showed that spatial and temporal interpolations as well as additional methods (e.g. empirical relationships and simultaneous numerical approaches) were suitable tools to overcome data shortage for modelling. Water balances are the result of a calibrated model and are the basis for sustainable management of surface and subsurface water resources. The present study investigates beside the hydrological characterisation of selected sub-catchments (wadis) also the hydro-geology of the Judean limestone aquifer and calculates a comprehensive water balance of the entire western flank of the Dead Sea by the application of two numerical open source codes: OpenGeoSys (OGS) and J2000g. The calibrated two-dimensional hydrological model J2000g provides a 33 years time series of temporal and spatial distributed groundwater recharge for the numerical groundwater flow model of OGS. The mean annual groundwater recharge of 139.9 · 10^6 m^3ˑ a^-1 is nearly completely depleted by abstractions from pumping wells close to the replenishment area in the Judea Mountains.

Groundwater is the only fresh water resource in the semi-arid to hyper-arid Western Dead Sea catchment. Due to exploitation of groundwater the water level is decreasing in the surrounding Cretaceous aquifer system and sustainable water management is needed in order to prevent the progressive yields and contamination of those water resources. In addition, the water level of the Dead Sea decreases dramatically by at least one meter per year. This is connected to channel off the water from the Jordan River to supply intensive agriculture in the semi-arid to hyper-arid region. Hydrological and hydro-geological analysis and modelling in arid regions, like the study area, frequently suffer from data scarcity and uncertainties regarding rainfall and discharge measurements. The study showed that spatial and temporal interpolations as well as additional methods (e.g. empirical relationships and simultaneous numerical approaches) were suitable tools to overcome data shortage for modelling. Water balances are the result of a calibrated model and are the basis for sustainable management of surface and subsurface water resources. The present study investigates beside the hydrological characterisation of selected sub-catchments (wadis) also the hydro-geology of the Judean limestone aquifer and calculates a comprehensive water balance of the entire western flank of the Dead Sea by the application of two numerical open source codes: OpenGeoSys (OGS) and J2000g. The calibrated two-dimensional hydrological model J2000g provides a 33 years time series of temporal and spatial distributed groundwater recharge for the numerical groundwater flow model of OGS. The mean annual groundwater recharge of 139.9 · 10^6 m^3ˑ a^-1 is nearly completely depleted by abstractions from pumping wells close to the replenishment area in the Judea Mountains.:Acknowledgements Abstract Nomenclature Content List of Figures List of Tables 1 Introduction 1.1 Motivation 1.2 State of the Field 1.3 General research questions 1.4 Challenges 1.5 Structure of the Thesis 2 Theory and Methods 2.1 Data analysis 2.2 Governing equations 2.2.1 Surface Flow - Hydrological Model: J2000g 2.2.2 Subsurface Flow - Groundwater Flow Model: OpenGeoSys 2.3 Groundwater recharge 3 Study area 3.1 Study site selection 3.2 Geography 3.2.1 Climate 3.2.2 Soils 3.2.3 Vegetation 3.2.4 Land use 3.3 Hydrology 3.3.1 Wadis 3.3.2 Flashfloods 3.3.3 Dead Sea 3.4 Geology 3.5 Hydro-geology 3.5.1 Springs 3.5.2 Well fields 4 Hydrological Model 4.1 Conceptual Model 4.2 Hydrological Model J2000g 4.2.1 Data base 4.2.2 Simulation results from J2000g 5 Structural geological model 5.1 Stratigraphy 5.2 Database 5.3 Workflow 6 Numerical groundwater flow model 6.1 Work flow of 2D and 3D meshing 6.2 Parametrisation 6.3 Boundary conditions 6.4 Model Set-up 6.5 Calibration of Steady-State model 6.6 Transient Model 6.6.1 Model assumptions 6.6.2 Challenges 6.6.3 Preliminary results 7 Conclusions and Outlook 7.1 Important results from the hydrological model 7.2 Important results from the geological structural model 7.3 Important results from the hydro-geological model 7.4 Deficiencies 7.5 Outlook References 8 Enclosed Publications