The evolution of semi-nomadism in non-desert environment: The case of Galilee in the 19th century

This paper attempts to reconstruct the way of life of a Palestinian Bedouin group living in Galilee, N Palestine, during the 19th century and established as semi-nomads. The term semi-nomadic is used here to indicate a distinctive life-style that is an amalgam of both pastoral nomadic and sedentary habits.The paper is based largely on primary sources, notably the narratives of 19th century European travellers-authors in Palestine. It introduces to the study of the cultural geography of Palestine and nomadism a methodological approach in which fragmentary pieces of information recorded in historical literature are utilized in order to evaluate spatial changes and processes.Paper originally presented at the International Conference of Historical Geographers, Cukanzus, Oxford '83 Oxford 17–23 July 1983.     

Identification of hydrogeochemical processes and their influence on groundwater quality for drinking and agricultural usage in Wadi Nisah,Central Saudi Arabia

Groundwater quality of a region is often controlled by the geochemical processes that operate with respect to the aquifer-water interaction, especially in arid regions where rainfall recharge is minimal. The goal of the present research was to understand the hydrochemical processes influencing groundwater chemistry and to evaluate groundwater quality for drinking and agricultural usage in Wadi Nisah and Wadi Al-Awsat, south of Riyadh. Twenty-nine groundwater samples were analyzed for major physio-chemical parameters. Ionic plots, chloro-alkaline indices, and modified Piper plots point towards reverse ion exchange. Saturation indices and correlation coefficients indicate halite, calcite, and dolomite dissolution. The Piper plot shows that most of the groundwater samples (82.76%) are of the (Ca + Mg)–(Cl-SO₄) type. The groundwater quality is not good for drinking due to its high total dissolved solid (TDS) content. The groundwater is found to be suitable for irrigation in terms of residual sodium carbonate, sodium adsorption ratio, soluble sodium percentage, Kelly’s index, and magnesium hazard. The high salinity is unsuitable for irrigation; however, this can be overcome by using salinity-resistant crop varieties.     

Hydrochemical classification and multivariate statistical analysis of groundwater from Wadi Sahba area in central Saudi Arabia

The central region of Saudi Arabia is underlain by thick sedimentary formations belonging to the Mesozoic and Cenozoic era. These sedimentary formations form a prolific aquifer supplying groundwater for agricultural and domestic usage in and around Riyadh. The region south of Riyadh City is well known for agricultural activities. Wadi Sahba, which is an eastward extension of Wadi Nisah, has readily available groundwater resources in the Cretaceous Biyadh sandstone aquifer to sustain agricultural activities. The objective of the present study was the hydrochemical assessment of groundwater in the area to understand the main hydrological processes which influence groundwater chemistry. To achieve this objective, 20 groundwater samples were collected from agricultural farms in the Wadi Sahba in central Saudi Arabia, and the major physiochemical constituents were analyzed and interpreted. The average TDS value of the analyzed samples is 1578.05 mg/l, whereas the average EC concentration is 3220.05 μS/cm. Groundwater facies classification inferred from the Piper plot shows that groundwater in the study area belongs to the Ca-SO₄-Cl type and Ca-Na-SO₄-Cl type. The Ca-SO₄-Cl type of groundwater facies is influenced mainly by gypsum dissolution and base ion exchange, whereas the Ca-Na-SO₄-Cl type is influenced by gypsum and halite dissolution. All the groundwater samples are undersaturated with respect to these two principal mineral phases. The Q-mode cluster analysis results in two main groups of groundwater samples, mainly based on the TDS content. Cluster 1 has an average TDS value of 1980 mg/l, whereas cluster 2 has an average TDS of 1176 mg/l. The groundwater facies identified through the Piper plot reflects the major hydrological processes controlling groundwater chemistry in the area and was found to be more useful in this study as compared to cluster analysis.     

Probabilistic tsunami hazard assessment along Oman coast from submarine earthquakes in the Makran subduction zone

The Sultanate of Oman is among the Indian Ocean countries that were subjected to at least two confirmed tsunamis during the twentieth and twenty-first centuries: the 1945 tsunami due to an earthquake in the Makran subduction zone in the Sea of Oman (near-regional field tsunami) and the Indian Ocean tsunami in 2004, caused by an earthquake from the Andaman Sumatra subduction zone (far - field tsunami). In this paper, we present a probabilistic tsunami hazard assessment for the entire coast of Oman from tectonic sources generated along the Makran subduction zone. The tsunami hazard is assessed taking into account the contribution of small- and large-event magnitudes. Results of the earthquake recurrence rate studies and the tsunami numerical modeling for different magnitudes were used through a logic-tree to estimate the tsunami hazard probabilities. We derive probability hazard exceedance maps for the Omani coast considering the exposure times of 100, 250, 500, and 1000 years. The hazard maps consist of computing the likelihood that tsunami waves exceed a specific amplitude. We find that the probability that a maximum wave amplitude exceeds 1 m somewhere along the coast of Oman reaches, respectively, 0.7 and 0.85 for 100 and 250 exposure times, and it is up to 1 for 500 and 1000 years of exposure times. These probability values decrease significantly toward the southern coast of Oman where the tsunami impact, from the earthquakes generated at Makran subduction zone, is low.     

Trace Element Determination of Single Fluid Inclusions in Quartz by Laser Ablation ICP-MS

Single fluid inclusions in quartz from a Pb-Zn-Ag carbonate replacement deposit were selected for trace element determination by laser ablation ICP-MS. Spikes in element intensities were noted between first breached fluids versus subsequent analyses, suggesting that accurate element concentrations may not be determined in smaller fluid inclusions when only one analysis is obtained before the fluid is exhausted. Elemental concentrations in the fluid inclusions were determined by external standardisation using solutions sealed in microcapillary tubes. Standards and single natural inclusion analyses give repeatabilities (%RSD) of ˜ 20% for Rb and Sr. Rubidium and strontium concentrations range from 0.56-5.07 μg ml^-1 and 1.12-27.4 μg ml^-1, respectively, whereas Zn and Ag are below detection limits (< 10 ng ml^-1). The results suggest that nearly all Zn and Ag are removed by the time hydrothermal fluids precipitate gangue minerals.