Brief Introduction

The ultimate goal of the project is building a Decision Support System (DSS) that will facilitate the decision-makers to deal and manage the water resources and wellfields in 24 catchment areas throughout sultanate of Oman. In this report we will describe the role of the GIS in designing an important part of the DSS. An ArcView enterprise-wide GIS based facility management system is used in putting together various color-coded maps in a simple design that will be later on integrated with other special package to construct the DSS. The design will describe and display the whole hydrogeological setting of each catchment area that contains the wellfields required protection.

Sohar wellfields in Jizzi catchment area will be implemented as a pilot project. The work had been based on the final report of Sohar Wellfield Protection Plan produced by the Water Resources Protection Department. The wellfield protection plan aimed to protect the groundwater used for water supply from contamination and over abstraction. Various data collected and used in the project to perform different hydrogeological analysis. Different maps representing the geology, soil type, potential contaminants, location of wells, rain station, wadi gauge, protection zone, and others had been produced in CAD format for the report.

The main databases of the project either in digital and non-digital formats had been used from the final report to construct the GIS component of the DSS. The GIS design will facilitate the role of decision-makers at the MWR to be able to get the precise information data about the water resources, wellfield in each catchment area, and other related information to the hydrogeological setting and groundwater protection.

The DSS will facilitate the professionals and the decision-makers to perform many tasks.

Each decision at the higher management level related to the wellfield protection will be made better, fast, and more suitable for the MWR. The system will help the planner if necessary to locate a best location for a new wellfield and monitoring wells. It will demonstrate how many potential contaminants are near the wellfields and their effects.

To design the system many files in digital and non-digital format had been used. Initially the obtained databases were available primarily in CAD and excel spreadsheet formats. The databases were converted and translated from the AutoCAD and excel formats into GIS format. The database conversion was of great important in order to perform spatial analysis in GIS environment. The conversion was extremely timed consuming and involved various steps, but was a significant and profound step. The AutoCAD layers and the point features associated with coordinate system in excel formats were translated into shapefiles, which is the GIS ArcView format. The converted files are in adequate quality and ll of them projected into the same coordinate system, which is UTM zone 40.

The data was analyzed, which usually involves querying attributes, feature locations, storing, retrieving, and displaying. The result of the analysis had been produced various color-coded maps. The maps represent Jizzi catchment, wellfields, monitoring wells, aflaj, geology, soil, wadi, protection zones and other information necessary for building the GIS component of the DSS.

The final step was used to design a system that classified and organized all the produced maps in five divisions. The divisions were labeled as General View, Monitoring Wells, Contaminants, Developments, and Regulations.

Each division is associated with number of maps that illustrate certain information. This approach was designed in order to simplify the work and assist the decision-makers who have different levels of experience in dealing with maps to communicate easily the results of the analysis. The design doesn’t require GIS experience to run it. In addition to that the GIS system will review various aspects of the project, including user need assessment, and portability of GIS system design to facilitate use the model at various departments of the MWR.