Fresh groundwater lenses in the Arabian Peninsula: formative, stability and management assessments, The

2019 Fall.Includes bibliographical references.The formation of fresh groundwater lenses (FGLs) overlying denser, saline or brackish groundwater is a fascinating hydrologic phenomenon that creates groundwater supplies of great potential value for humans and ecosystems in several formation settings, such as coastal areas, atoll islands, riverine floodplains, and subterranean oases in arid regions. In particular, FGLs in subterranean oases are a critical source of freshwater supply in arid regions, due to a general lack of perennial rivers and lakes. These FGLs are in danger of salinization due to natural events and anthropogenic stresses. Although extensive research has been conducted on FGLs in general, the FGLs in subterranean oases in arid regions have received less attention. Key knowledge gaps include the quantity and frequency of natural recharge to these FGLs; reliable estimates of environmental aquifer dispersivity at the scale of subterranean FGLs; the timing of lens development; and the impact of anthropogenic activities on lens dynamics. This dissertation focuses on the FGLs of subterranean oases in the Arabian Peninsula (AP), using the Rawdatain FGL in Kuwait as a case study. Among the FGLs in the AP, the Rawdatain FGL in Kuwait is perhaps a unique candidate because of its size and the availability of extensive subsurface data for the pre-development period. The main objectives of this study are as follows: (1) estimate long-term average annual recharge for the Rawdatain FGL and investigate the timing of lens depletion due to climate change; (2) provide a realistic range of longitudinal (αL), horizontal transverse (αh), and vertical transverse (αv) dispersivity values for the aquifer; and (3) assess the impacts of historical and future anthropogenic activities and evaluate artificial recharge alternatives for lens recovery storage (LSR). In this study, a 3D density-dependent groundwater flow and solute transport model using the SEAWAT modeling code is developed using the following pre-development period calibration targets: (1) groundwater head, (2) spatially-variable total dissolved solids (TDS) groundwater concentration, (3-5) three groundwater volume targets, (6-8) three vertical thickness targets of stored groundwater of three different water quality TDS ranges (0−700, 700−1000, and 1000−2000 mg/L), and (9) geometrical shape features of the lens along cross-sections. In addition, groundwater age data of the Rawdatain FGL was used as an independent factor to constrain the dispersivity and recharge rate during the simulated period of lens development. Moreover, a sensitivity analysis was performed to explore the effects of the hydraulic conductivity, boundary conditions, and vertical transverse dispersivity on lens geometry. Based on a comparison of twelve annual recharge amount scenarios using a constant recharge mechanism (CRM) (R1 to R12: 0.2 to 5.0 million m³/year) with data targets, the R5 (0.5 million m³/year) recharge scenario is selected to represent the long-term average annual recharge. These results demonstrated that the annual natural replenishment of the Rawdatain FGL is minimal compared with its size. A macro-scale stability assessment shows that a 50% reduction in annual recharge within a 100-year time frame would reduce the lens volumes by 21%, 17% and 9% for the three water quality categories. A multi-criteria score-based method was performed to rank the best performance of 28 dispersivity sets (D1 to D28: 1 to 500 m) among all of the targets with an equal weight, on a scale of 0 to 300 x 106 m3. The results illustrated that the D16 dispersivity set (αL = 50 m: αh = 5 m: αv = 0.1 m) represents the best large-scale environmental dispersivity values for the Rawdatain FGL and can be used for analyzing the natural mixing between the ambient brackish water and fresh water. A new baseline model for the predevelopment period using a pulse recharge mechanism (PRM) was established to assess the recharge frequency along with the longitudinal dispersivity. The results revealed that the 50 m longitudinal dispersivity set and one pulse recharge every two years had the best performance, and they were selected to simulate the effects of the infrequent rainfall events and anthropogenic impacts simultaneously. During the groundwater abstraction from 1963 to 2018, the reduction in the stored volumes was 28%, 17% and 12% for the three quality categories. The future pumping scenarios (2019-2100) suggested that the 0.16×106 m3/year is a suitable alternative for long-term use, 0.5×106 m³/year)is an appropriate option for short-term use, and extraction scenarios greater than 1.0×106 m³/year will cause a remarkable degeneration of the Rawdatain FGL. Artificial recharge scenarios (2019-2028) imply that a successful LSR for the Rawdatain FGL depends on selecting appropriate well locations and amounts of injected water. For instance, the I2 alternative could achieve a 100% storage recovery within 7.5, 8 and 9 years for the three water quality categories. This study provides a first attempt to model the formation of a FGL, assess the historical anthropogenic stresses, and evaluate future management scenarios in subterranean oases in arid regions. Implementing multiple data targets and water age is a unique process of calibration that was helpful in eliminating several non-unique calibration parameters and in decreasing the uncertainty of the calibrated parameters. The methodology presented herein provides a general approach that can be extrapolated to other FGLs with similar climatic and environmental circumstances. The outputs of this dissertation enhance the understanding of the formation, stability, and management of these lenses and will be very valuable to water managers for establishing appropriate water supply plans for these valuable water reserves, leading to preferable future water security in the AP

Aplikasi teknik remote sensing bagi terbitan maklumat hasilan air di Semenanjung Malaysia

Satellite remote sensing techniques have found wide applications in hydrology including water-yield determination. This however requires the localization to area-of-interest that are influenced by the local climate and biophysical factors. This study focussed to develop a method for determining the water-yield information through full satellite-based data for Peninsular Malaysia from the public domain sources, for a period of 10 years (July 2000 - June 2010). The specific objectives were to investigate on: (i) derivation of information on monthly rainfall from Tropical Rainfall Measuring Mission Multisatellite Precipitation Analysis (TMPA) satellite data; (ii) derivation of monthly Actual- Evapotranspiration (AET) from Moderate Resolution Imaging Spectroradiometer (MODIS) satellite with Normalized Differential Vegetation Index (NDVI) data product; (iii) derivation of water yield from fully satellite-based information using water balance analysis; and (iv) water yield variation, with respect to changes of corresponding land cover and land use. Results, indicated good correlation between monthly rainfall TMPA with the corresponding rain gauge records (r2=0.71: p<0.001, n=1337) with accuracy (RMSE) of +83 mm (n=2308). The TMPAcalibrated annual averaged rainfall for the entire study area is 2357mm, which is - 5.3% compared with independent studies undertaken by an international consultant appointed by the government. The bio-physical parameters based on MODIS used NDVI as an indicator of AET to represent the land use, reported good match-up (r2=0.55: p<0.001, n=1664) with accuracy (RMSE) of +15 mm (n=864). The NDVIcalibrated annual averaged AET throughout the study area was determined at 1153mm, which is -9.9% compared with the same independent research report. Annual averaged water-yield for the entire study area is 1204mm, with -0.5% and 1.6% variations when compared to the two independent studies, the same independent research report and, Drainage and Irrigation Department respectively. But at state level, the estimated rainfall, AET and water-yield varies with larger magnitudes. Analysis at selected basin level, the annual water-yield is determined at 1393mm, in access of 9.5% compared to the independent studies water flowrate, with a standard deviation of 22%. The regression analysis between water-yield and land use cover changes, clearly indicated strong relationship (r2=0:51, p<0.0001; n=151), and independent accuracy (RMSE) of 8.3% (n=154). The main findings in this study, especially the devised techniques indeed have contributed significantly as an alternative method for the determination of water-yield in Peninsular Malaysia based on fully satellite-driven data. The devised method could be accustomized to other areas through localised calibration approach thus, could serve as a guideline for the relevant authorities to have accurate and comprehensive water-yield information

Experimental and numerical studies on the water balance of the Upper Mega Aquifer system, Arabian Peninsula

Besides a few perennial rivers, like the Euphrates, surface water resources are scarce and often not reliable in its temporal availability on the Arabian Peninsula. Consequently, the region relies on its mainly fossil groundwater reserves, which are predominantly stored in the sedimentary formations of the Arabian Platform. One of its major groundwater reservoirs is the Upper Mega Aquifer (UMA) system. The present thesis comprises three major studies on this aquifer system. The first one deals with a specific type of groundwater recharge: the accumulation of surface water and its discharge into karst features like open shafts and sinkholes. In order to quantify the amount of recharge, a combined approach of time-lapse camera monitoring and water balance modelling was applied. Finally, an average groundwater recharge rate of about 5 mm a-1 could be estimated for the As Sulb plateau, which constitutes an outcrop area of the Umm Er Radhuma karst aquifer. Moreover, this study discusses the non-linearity of recharge processes in arid environments. The second study deals with the groundwater evaporation from salt pans. During this study, different methods are used to provide a comprehensive picture of this process. These methods include satellite image analysis for the mapping of salt pan areas, isotopic investigations in order to distinguish between groundwater and seawater dominated salt pans, and a column experiment for the quantification of evaporation rates. A combination of these methods suggests a total annual groundwater loss of 1.3 km3 for the UMA system caused by the evaporation from salt pans. The third study encompasses the set-up and the calibration of a numerical groundwater flow model. In the course of this study, the phenomenon of fossil groundwater gradients is discussed and a novel calibration scheme is introduced. The final part of this thesis applies the model and three different development scenarios for groundwater abstraction are simulated and discussed

The Environmental Impacts of the Gulf War 1991

The environmental consequences of the Gulf War in 1991 affected the air, the marine environment, and the terrestrial ecosystem. Various scenarios and forecasts had been made before the war about the possible and probable impacts under different conditions. The follow-up studies have showed a rather different picture than what had been forecasted. When considering the various aspects of air and atmospheric pollution, in brief summary, the following observations have been made: In early 1991 more than 800 oil wells were blown up, of these more than 600 caught fire and burned with flames and about 50 wells gushed oil onto the ground. During the period up to October 1991 all the wells were capped. The maximum amount of oil and gas in the oil fires was about 355,000 tons and 35 million m3 respectively per day. The soot emissions for the burning oil and gas has been estimated to about 20,000 tons per day and the total SO2 emission about 24,000 tons per day. The CO2 emission from the burning oil and gas in Kuwait has been estimated to about 130 to 140 million tons corresponding to 2-3% of the global annual anthropogenic contribution from the use of fossil and recent fuels and only 0.1% of the total global CO2 emission. Levels of particles in the air a few kilometers from the burning oil fields was in the order of about 10 5 per cm3. this corresponds to 10% of the global contribution from anthropogenic burning of recent and fossil fuels. Most of the soot particles accumulated at altitudes between 1000 and 3000 meters and very little contamination reached higher than 5000 meters. As a result the soot did not spread over large areas but fell out with rain and dew mostly over the Arabian Peninsula. The high volume of particles in the air had a very pronounced effect on the climate in Kuwait and in the neighboring countries. Temperatures were up to 10 degrees C lower than under normal years. Soot and oil covered extensive areas in Kuwait, Northern Saudi Arabia and the Gulf. the vegetation as well as wildlife was exposed to this fallout but no or very scattered information is available about environmental aspects. The oil from the oil wells formed networks of rivers and lakes on land. The total volume of oil din these lakes and rivers has been estimated to between 10 and 20 million tons. During 1991, up to 200 km2 of ground was covered with oil forming about 250 lakes. In 1992 the figure had decresaed to about 50 km2, partly due to weathering, penetrating of oil into the ground, coverage of oil by dust and sand, and physical removal. The oil has subsequently the ground to varying depth, depending on the nature of underlying soil. The total area of oil lakes calculated based on satellite image in 1998 was about 24 km2. However, at that stage much of the surface area of the oil lakes were covered by sand and could hardly be observed from the sky. The "marine environment" was exposed to large quantities of petroleum hydrocarbons, the volume of the spills has been estimated to between 1 and 1.7 million tons. the oil was released from tank farms on land (Al Ahmadi North), oil loading terminals (Sea Island and Mina Al-Bakr (Iraq)) and from oil carriers anchored along the Kuwait coast. the spill was broken up from several smaller spills which contaminated most of the Saudi Arabian coastline. About 700 km of Saudi Arabian shoreline consisting of sand, gravel, wetlands, lagoons, and muddy tidal flats and a total of the surfacve area of about 34 km2 was contaminated. Some oil ended up on the beaches of Kuwait, Iran, Bahrain, and Qatar but generally these countries were less affected. The oil on the SAudi Arabian coastline ende up in shallow lagoons, wetlands and flats covered with vegetation. Here the oil caused considerable damage and caused primarily by the physical characteristics of the oil on the vegetation and on animals in the intertidal zone. Hence most of the mangroves and marshes in the wetlands along the affected coast was destroyed by the oil. Fifty to 90% of the fauna of these areas, mainly crabs, amphipoda and molluscs, were also killed by the oil. Already within a year natural cleanup process had removed most of the oil from hard surfaces and decresed the quantities considerably in areas with sand and mud. About three years after the spill most of the fauna had re-colonized the lower sections of the beach, and the recovery on the upper sections were underway. About 10 years after the spill, weathered and underground oil were still present on some beaches. The large-scale clean-up that was carried out after the spill in many areas did contribute to incresing the damage and spreading the oil into previously unaffected areas. Studies from different subtidal areas along the Saudi Arabian coast on sand, mud and rock bottoms and in sea-grass beds showed minor or no effects at all among the fauna and flora at 1 to 6 meters depth and deeper areas. Several investigations were carried out to study the impacts on soral reefs along the coast but these studies did not reveal any significant effects, particularly in the reefs off the Saudi coast. Also the fish fauna appeared to have survived intact. About 75 to 80% of the sun's radiation was absorbed and the remainder was scatttered by the smoke in the super composite plume and this resulted in a drop in the temperature by up to 10 degrees C in Kuwait and in the Northern Saudi Arabia. Also as far away as 250 km from the burning Kuwait oil fileds a reduction in mid day temperature of 5-8 degrees C was recorded. Also seawater temperatures in the Gulf were considerably lower during 1991 as conpared to previous years. This drop of seawater temperature during spring-summer period of 1991 was considered more damaging to fish and prawns than the oil spills. Seabirds and waders were affected by direct oiling of feathers and due to intake of oil primarily through preening. It has been estimated that between 22 and 50% of the populations of several species of cormorants and grebes died as a result of the spill. Investigations of the presence of waders on the shores made during the acute phase of the war a reduction by almost 100% and most of the birds found were contaminated by oil. It was estimated that about 100,000 waders were killed directly or indirectly by the oil spill in 1991. Investigations of the marine turtles showed that green turtles nested at normal rates and with a hatching success similar to the figures for the figures for the years previous to the spill. For hawksbills the number of nests were normal but the hatching rate was much lower than normal. Approximately 50 dugongs and several times as many dolphins were found dead on the beaches of Saudi Arabia after that spill. In total over 84,000 tons of bombs were dropped over an area of about 4,000 square miles during 43 days of war. The military casualties and the allied side was 149 dead and another 513 wounded. In the years after the war between 50 and 100 allied soldiers were killed in connection with mine clearance. The total loses of Iraqi soldiers were much higher, probably more than 100,000 during 43 days of war. Nearly 25,000 died during the mass retreat. In addition at least another 100,000 Iraqi military were wounded, the majority of whom later died due to lack of medical facilities and medicine. Between 400 and 600 Kuwaiti civilians were killed directly during the war. In addition an astimated 2,000 died due to consequences of the war. Between 15,000 and 16,000 civilians spent time in prison during and after the war. In additio there have been more than 1,500 civilian mine and ammunition victims in Kuwait since August 1990. Furthermore a large portion of the Kuwaiti population suffered various psychosomatic disorders, so called Post-Traumatic Stress Disorder (PSTD) several years after the war. Another consequence of the war is that crime and violence has become more common in Kuwait. Between 2,500 to 3,000 Iraqi civilians died directly as a result of the allied bombardment. However, Iraqi civilians suffered much larger casualties as indirect consequences of the war dring the period 1991-2001. Figures are not known but several hundred thousand civilian, including infants and children, have probably died due to the lack of medicine, hospital supplies, and medical services. Other studies indicate that more than 46,900 children under five years age died between January and August 1991 due to the war and its aftermath. In addition about 100,000 Kurds in the north and Shiites in the south of Iraq died and many more suffered from heavy repression in the civil unrest immediately after the war. Other reports indicate increseased child mortality among children in Iraq, in excess of 40,000 per year during the period 1992-1998

Development of an environmental health risk and socio-economic perception framework to critically assess the management of TWW reuse practice and options in Kuwait

This thesis introduces a new methodological approach to provide a framework for environmental health and socioeconomic perception that critically assesses the management of treated wastewater (TWW) reuse practice and options. The methodology combines Multi-Criteria decision Making (MCDM) and Rapid Impact Assessment Matrix (RIAM). The approach uses expert opinion to assess TWW reuse options and converts the qualitative subjective evaluation of experts into quantitative objective and numeric output. The methodology includes the use of a Driver Force, Pressure, State, Impact and Response (DPSIR) framework to analyse the current situation in a specific case study (Kuwait). The research identified the best available TWW reuse options for Kuwait and determined the essential environmental health and socioeconomic criteria affected by the practice of selected TWW reuse options. The latter include recreational and agricultural irrigation, firefighting and industrial and ruses, oil depressurization and groundwater recharge. Options where the public had direct contact with TWW, such as showering, cooking and drinking were rejected. Environmental health criteria were found to be the most significant criteria associated with TWW reuse practice and options, but given current heavy subsidies of wastewater treatment, distribution and transportation, the economic burden was also significant. Further research in this area is recommended to enable a reduction of pressures on freshwater resources through TWW reuse practice and this should be included within a wider context of integrated water management (IWM)