Ahmed Murad

Isotopic variations of oxygen and hydrogen in groundwater of carbonate aquifer in an arid environment

The stable isotopic characteristics were used together with the total chloride to assess changes in groundwater from recharge zones into the carbonate aquifer in an arid environment. The aquifer under study represents a major source of groundwater and thermal springs in Al-Ain city, which are located at the northern part of Jabal Hafit in the United Arab Emirates (UAE). The relationship between oxygen and hydrogen isotopic composition of groundwater is established and is described by δD = 2.2δ18O − 9.96. The lower slope and y-intercept of groundwater samples relative to the local meteoric waterline suggests that the isotopic enrichment is due to the evaporation of shallow groundwater after recharge occurs. The majority of the shallow groundwater samples have a negative deuterium excess (d-excess) which might be ascribed to high a degree of evaporation, while most of the groundwater samples from deep wells, have a positive value of d-excess which may be related to a low degree of evaporation. The δ18O values of the thermal waters suggest enrichment towards δ18O of the carbonate rocks because of the exchange with oxygen at higher temperatures. A possible mixing between thermal or hot water and shallow groundwater is evident in some samples as reflected by δD vs. Cl and d-excess vs. δ18O plots.

Radioactivity in groundwater along the borders of Oman and UAE

Characterizing the quality and radioactivity of groundwater is vital as it represents valuable resource in arid regions. Here we present radioactivity level in groundwater collected from wells in a region along the border between Sultanate of Oman and United Arab Emirates (UAE). The aquifers are alluvium deposits (silt, sand and gravel) and the measured groundwater radioactivity (including 232Th, 238U, 235U, 226Ra, 222Rn, gross-α and gross-β) indicates values below the WHO permissible limits for drinking water. The results also show large difference in radioactivity fingerprints, in particular for 226Ra and 222Rn within the investigated aquifers. The data further indicate lower radioactivity in groundwater of the alluviums compared to the carbonate aquifers in the region. This feature makes the alluvium aquifers valuable reservoirs that should be carefully exploited as a source of groundwater. As this is the first investigation on the radioactivity of groundwater in alluvial aquifers in the region, it suggests that other alluvial deposits, particularly those inland and far from the marine water intrusion or seepage from carbonate rocks would have low radioactivity fingerprints.

Quality assessment of groundwater from the south-eastern Arabian Peninsula

Assessment of groundwater quality plays a significant role in the utilization of the scarce water resources globally and especially in arid regions. The increasing abstraction together with man-made contamination and seawater intrusion have strongly affected groundwater quality in the Arabia Peninsula, exemplified by the investigation given here from the United Arab Emirates, where the groundwater is seldom reviewed and assessed. In the aim of assessing current groundwater quality, we here present a comparison of chemical data linked to aquifers types. The results reveal that most of the investigated groundwater is not suitable for drinking, household, and agricultural purposes following the WHO permissible limits. Aquifer composition and climate have vital control on the water quality, with the carbonate aquifers contain the least potable water compared to the ophiolites and Quaternary clastics. Seawater intrusion along coastal regions has deteriorated the water quality and the phenomenon may become more intensive with future warming climate and rising sea level.

Structural and Stratigraphic Parameters as Tools for the Geozoning Project of Al-Ain City, UAE

Rapid urbanization dramatically increases the demand for land that requires planning and zoning which allow the authorities to achieve safe, manageable and sustainable construction expansions. Geozoning represents an effective way of summarizing surface and subsurface land stability that can be used for setting out regulations for construction purposes. We present here a preliminary geozoning survey of Al Ain city as a first stage to build-up a database which divides the city into several stability zones.

Trend Detection in Annual Temperature and Precipitation Using Mann–Kendall Test—A Case Study to Assess Climate Change in Abu Dhabi, United Arab Emirates

Annual average temperature and precipitation can be considered as two important indicators to judge the possibility of future climate change. The main objective of this study is to analyze the possibility of trend in annual average temperature and precipitation for Abu Dhabi and Al Ain cities in the United Arab Emirates (UAE). Mann–Kendall non-parametric tests were run at 5% significance level on annual time series data obtained from two stations located in Abu Dhabi and Al Ain cities for the period of 1972–2014. Significant increasing trend in temperature and no significant trend in precipitation of both cities were detected. Thus, there is a possibility to have higher temperature, but not significant change in precipitation of Abu Dhabi and Al Ain cities in the long run.

Geoforensic and Legal Aspects of Site Investigations

Use of geological information as clue for identifying responsibility of an engineering problem related to construction, land use and water resource management can provide significant help to the legal system. Flooding of basements in several houses in a residential area located in Al Ain city occurred in a more or less chaotic pattern. Results of the geoforensic investigationindicate that houses that are accidently built on the gravel paleochannel had their basement flooded compared to those lying outside the channel. Thus when it comes to the legal aspect of the case, then the nature geological conditions have contributed to the damage and not the construction practices.

Prediction of spatial ET-fluxes using remote sensing and field data of selected areas in the Eastern Part of Abu Dhabi, United Arab Emirates

Evapotranspiration (ET) is a major source of water depletion in arid and semi-arid environments; and it is a poorly quantified variable in the hydrological cycle. Remote sensing has the potential application to quantify this variable especially at large scale. The present study reports methodology useful to determine whether derived variables from remotely sensed data, such as vegetation and soil brightness indices, could be used to predict ET. To achieve this goal, various regression analyses were conducted between data derived from satellites, field meteorological stations, and ET values. Selected sub-scenes of Landsat Enhanced Thematic Mapper images free of cloud were used to derive Normalized Difference Vegetation Index (NDVI) and Soil Brightness Index using ER-Mapper and JMP software packages. From the obtained relationship between NDVI and ET, it was observed that ET increases sharply with increase in NDVI. The predicted ET results obtained from the multiple regression functions of field ET, NDVI, solar radiation, wind velocity, and/or temperature are comparable with the ET values obtained by Penman-Monteith method. The results showed that a remotely sensed vegetation index could be used, indirectly, to determine ET values. However, there is still considerable work to be done before simple and full automated extraction of ET from the reported methods can be achieved for large-scale applications.