SUMMARY OF NOMINATED STUDIES FOR THE PRIZE
Topic: Coastal Aquifer management
Water Section
Center for Environment and Water
Research Institute, King Fahd University of Petroleum and Minerals
Dhahran, Saudi Arabia

King Fahd University of Petroleum and minerals is located in Dhahran on top of Dammam Dome which is an important part of the hydro geological system of the coastal aquifers in the Eastern Province.  This location propelled the researchers and scientists interest and diligent research activities at the University since the early eighties towards development of new and advanced techniques to improve the understanding and management of the coastal aquifers world wide using the developed knowledge of coastal aquifers in the Eastern Province. 

The coastal aquifers which extend along the eastern coasts of the Eastern Province of the Kingdom consist of confined multi-aquifer system.  This confined multi aquifer system is characterized by the presence of confining units.  The major water-bearing units of the area in descending order are: the limestone and Dolomite of Umm Er Radhuma aquifer (UER), the limestone and dolomite of Khobar and Alat members, the clastics of the Neogene complex. The aquicludes are represented by the shales and the marls of the upper part of the Wasia formation, the varicolored shales and marls of the top of the Al-Ullia. The fine clastics and evaporates of the Rus formation and Midra and Saila shale at the top of UER, the marls and shales (orange marls) of the base of Alat member, and the shales of the Hadruk formation and marls of the Dammam formation.  The three main productive coastal aquifers in the Province are: the Umm Er Radhuma (UER), the Dammam (Khobar and the Alat members) and Neogene (mainly productive in Al Hassa).  These coastal aquifers supply more than 95% of the water demands in the Eastern Province for domestic, agricultural and domestic purposes.  The province includes nine cities and towns such as Dammam, Khobar, Dhahran, Jubail, Khafji, and Qateef.  Further, it contains main oil production and processing sites in addition to three industrial cities which include major petrochemical industries. These aquifers have been subjected to excessive pumping to satisfy the growing demands for fast growing developments in all sectors.  This has been experienced especially during the last three decades which have witnessed the rise in population from less than 1.5 millions to 3.2 millions.  The total groundwater withdrawal has increased from less than 400 million cubic meter 1975 to about 1800 MCM in 2004.  Negative impacts have been experienced in parts of these aquifers such as salt water intrusion, rise in groundwater salinity and decline in water levels.  The major challenges in coastal aquifers management in the Eastern Province can be defined as:

• The coastal aquifers are dominated by complex features in geological structures such anticlines, synclines and dominal units. These features have important impacts on the hydrogeological properties of these aquifers in specific localities and on regional levels.  Understanding these features on local and regional levels is a major challenge towards proper management of these aquifers. 
• With the expected growth in water demands in the province, these coastal aquifers will be subjected for more excessive groundwater pumping.  This will result in more deterioration of groundwater levels and qualities under negligible replishments by natural recharge.
• These coastal aquifers will be more vulnerable to saltwater intrusion through several pathways by upward intrusion from deeper more saline zones of a groundwater system. This can result in the abandonment of groundwater supply wells with high rise of concentrations of dissolved salts. 
• Developments of proper management schemes of these coastal aquifer means making decisions on: 1) rates of pumping and artificial recharge (if practiced), 2) spatial distribution of pumping and injection wells and 3) measures for water demand reduction.

The above challenges have been taken as priorities in the research programs of the University to protect the sustainability of coastal aquifers in the Eastern Province and to conserve the finite groundwater resources in these aquifers.  The primary objectives of the University in coastal aquifers research programs have included:

• In-depth understanding of the highly complicated nature of the hydrogeology of coastal aquifers in the Eastern Province on local and regional levels especially those supplying urban and agricultural areas with groundwater.
• Quantitative assessments of the salt water intrusion, leakages under different pumping schemes and knowledge of the aquifer’s natural replenishment (from precipitation and through aquifer boundaries). 
• Assessment of the response of the aquifers (water levels and salt concentrations) to the implementation of any management alternative using numerical modeling tools. 
• To define optimal decisions for water withdrawal from the aquifer in terms of locations of pumping fields, pumping quantities and pumping programs. 

The following are five selected major original scientific research studies of the Water Section which have contributed significantly to improving the understanding and management of coastal aquifers in the Eastern Province and World wide:

1. Development and management of the Dammam Aquifer in Eastern Province.
This research study has dealt with the development of better management plan for Dammam aquifer.  It has used advance numerical techniques in groundwater flow simulation model for the aquifer.  Further, it has defined the optimal groundwater pumping in terms of pumping quantities and pumping fields from this coastal aquifer on regional level.  The Dammam aquifer is capable of meeting the projected water demands in the region for reasonable period of time if a proper management plan is implemented. The data presented in this study has become a useful base for further research and management actions.

2. Numerical Modeling of a Multi-Aquifer System in Eastern Province.
This comprehensive study was carried out to improve the management of the coastal multi aquifer system on regional level that included the Umm Er Radhuma aquifer in addition to Dammam (considering khobar and Alat as separate units) mainly in Greater Dammam-Khobar-Dharan-Abqiaq Metropolitan areas.  A numerical quasi-three-dimensional groundwater flow model was constructed for the multi- aquifer system to determine the hydraulic properties of the system including interactions among them, and to evaluate the consequences of various development and pumping alternatives.  The model results indicated that the adoption of a demand management strategy, by gradually introducing a comprehensive program of conservation measures, would be more effective in ensuring the long-term productivity of the aquifers.  The original modeling approaches and findings of this study have contributed to the improvement of understanding of the coastal aquifers in the Province on regional level.  
3. Regional Coastal Aquifers Management in Eastern Province. 
A regional numerical simulation model of a multi-aquifer system of a larger scale in the Province covering an area of about 76,000 Km2 was developed to assess the behavior of the aquifer system under long-term water stresses over a planning horizon of 31 years (1995-2025). The study has included the Dammam (as single unit) and Umm Er Radhuma (UER) aquifers. The main objective of the study was to have better understanding of the hydraulic features of the multi aquifer system on larger scale and assess the impacts of long-term stresses on future groundwater. This was to help in selecting the best management scheme which protects the aquifer productivity concurrent with the comprehensive development of the Kingdom.  The area selected for the study includes more urban centers such as Qatif, AI-Hassa, AI-Fadhli, As-Sarrar, Wadi AI-Miyah and AI-Hunay. It contains more than 80% of the population of eastern Saudi Arabia, who are mainly concentrated in Dammam, Dhahran, Jubail, AI-Khobar, AI-Hofuf, Abqaiq and Qatif municipalities. This area contains the largest portion of the Kingdom's oil fields and refineries.  Model results postulate that dewatering of the Dammam aquifer will occur at low productivity sites and along the outcrop with the current trend towards increasing abstraction. The UER will exhibit significant cones of depression at large irrigation projects. Aquifer dewatering and drawdowns will be minimal with the conservation alternative. This management scheme was a guide for the future development and protection of groundwater in the province.  The study showed that water recharging in these coastal aquifers is insignificant. Results of the groundwater management model indicate that the implementation of conservation methods with a 30% reduction in the well fields of the agricultural, industrial and municipal sectors will be more effective in reducing the drawdowns by the end of 2025. The methodology used in this study can also be extended to other coastal sites in the Kingdom and elsewhere in the arid countries to improve groundwater management in coastal aquifers and to protect the quality of groundwater and the productivity of the depletable aquifers.

4. Management of Coastal Aquifers Under Complex Structural Geological Features of Dammam Dom

This study was carried out as a necessity for understanding the hydrogeology of specific complex geological structures within specific localities such as Greater Dhahran Area on top of Dammam Dom.  The use of numerical techniques to define the detailed groundwater budget analysis for each individual aquifer in a multi-aquifer system under steady state and transient conditions has not been well established in the literature prior to this research study. In this work, numerical analysis has been used to define the water budget for each individual aquifer in a multi-aquifer system in the complex locality of Greater Dhahran Area. This area represents a complex hydrogeological system due to its complicated geological structures.  Each aquifer like the Alat, the Khobar and the Umm Er Radhuma were considered as an individual unit within a multi-aquifer system. USGS groundwater model MODFLOW was used to calculate the total volumetric groundwater budget in terms of inflows and outflows for the whole multi-aquifer system during steady state and transient conditions. Then, a special program MODCELL was used to calculate the volumetric inflows and outflows of each cell of individual aquifer within the modeled area under steady and transient conditions. This program utilizes the output of MODFLOW to calculate the groundwater budget of each cell. Finally, a utility module CONVML was used to convert the output data files of MODCELL which contain the detailed budget of each aquifer from binary to ASCII formats. In this research work, a special program was developed in order to make the output files of MODCELL compatible with CONVML format requirements.  The outcome and findings from this study was important addition to the scientific knowledge of the complex hydrogeology of these specific coastal localities.  It has been of great help in developing sound schemes for groundwater pumping from different localities within Greater Dhahran-Dammam areas. The developed study tools have been used by other specialists to understand the complex hydrogeological features.

5. Dynamic and Computerized Decision Support System for Management of Groundwater from Coastal Aquifers for Irrigation Purposes in the Eastern Province

Proper management of fragile coastal aquifers is important for long-term sustainability of groundwater resources and agriculture developments. This requires effective decision support system based on aquifer characteristics to forecast the short-term and long-term impacts of different groundwater pumping scenarios for irrigation on aquifer conditions. This helps in adaptation of suitable cropping and irrigation policies for small and large irrigation scheme on the basis of the aquifer productivity and the negative impacts on its properties.  This is necessary to avoid unacceptable impacts on coastal aquifers in terms of quality and production.  Furthermore, proper irrigation water scheduling and operation results in minimizing water demands and fuel use and reduction in the costs of irrigation operation.  Minimizing water losses and reduction of irrigation water demands by the use of advanced and proper techniques in the management of groundwater resources and irrigation water at farm level is essential to protect groundwater resources and agricultural activities.  This includes the advance selection of type of crops to be cultivated and the area of each irrigated field from each well and the number and spacing between wells on the bases of proper assessment of groundwater conditions in local aquifers, and according to their long-term capabilities for irrigation water production at well and farm level, which results in minimal negative impacts on groundwater level and quality.  This should also be coupled with effective irrigation water scheduling according to the actual crop water requirements to avoid excessive irrigation water use and losses.   In this study a new dynamic computerized Decision support system was developed to operate and manage the pumping of groundwater from multi-aquifer system in a large coastal agricultural project. The System consists of two integrated parts namely: the Groundwater Simulation Model (GSWM) and the Computerized and Dynamic Irrigation Management System (CDIMS).  The CDDSSGM system defines in advance, the suitable size of cultivated fields, the well distribution and pumping policies, to avoid negative impacts on water level and quality on the basis of groundwater flow simulation model of the local aquifer.  The CDIMS defines the irrigation water requirements of various crops and fields and the doses and timings between irrigation applications for the cultivated crops at farm level.  It can be used for different types of irrigation methods, with possible water supply shortages and considering different soil types and contributions from rainfall and shallow groundwater table for the selected agricultural region; and the farming practices.  The developed system was implemented to reduce and minimize the pumping of groundwater from the coastal aquifers for irrigation in the Eastern Province.  The implementation of the study has resulted in significant reduction in groundwater pumping (about 25% to 35%) in large agricultural projects from the coastal aquifers in the Province.  The developed new scientific techniques have also been utilized by other specialists to improve water management in other large agricultural projects locally and internationally. 

The gained scientific experiences and developed tools and models have been used by water researchers and specialists for similar studies in the Kingdom and world wide in the area of coastal aquifer management.  Further, the implementations of the recommendations of these studies have important benefits to local water authority in the Province and in the Kingdom in protection of groundwater resources in coastal aquifers.