Several studies and assessments have been conducted of areas exposed to pollution, especially areas that contain aquifer. The final extraction of the vulnerability map of the groundwater was constructed through the use of the DRASTIC method by applying the linear equation of the seven coefficients in the Arc GIS software program (Version 10.4). The aim of the study to assess aquifer vulnerability to pollution. Results, vulnerability map range between 75-126 (very low, low, and medium), the study area consists of very low and low vulnerability, except some areas medium vulnerability close to the center of the sub-basin in the standard vulnerability map (s) and 91-149 (very low, low, and medium) for the agriculture or pesticide vulnerability map (p), the medium vulnerability occupies a greater area the center of the sub-basin.

The groundwater is an intrinsic and vital capital for providing water supplies in rural and urban areas. Climate change poses a strong threat to the world; especially in Iraq is considering one of the arid and semi-arid regions. The climatic changes lead to an increase in the demand for groundwater, especially with low rainfall and an increase in the population. It is very important to model groundwater potential for the sub-basin. This paper aims to produce a map defining the potential groundwater zones of the Shwan sub-basin. By Geographic Information System and remote sensing data, the required data or six factors (geology, elevations, slope, drainage density, soil, and land uses/land covers) are available to be collected through weighted overlay for creating groundwater potential map. The result was five zones for groundwater potential from very low towards the eastern parts and also end of the western boundary to very high towards the western parts of the sub-basin. The geological formations of the sub-basin such as conglomerate, low elevations, low slope and low drainage density consider as high groundwater potential zones.

It is possible to determine the risks through the existence of contaminated groundwater in some drinking wells. Most of the recent applied studies by groundwater scientists are the exposure of groundwater or aquifers to pollution, especially in areas that contain polluted groundwater due to human use of land. This work intends to produce a map to identify the areas of groundwater at risk. The groundwater risk map is dependent on applying the equation that exemplifies the combination of the map of vulnerability with the map of land uses and land covers using Geographical Information Systems (Version 10.4) and QGIS (Version 3.12) software. In addition, validation work for groundwater risk map with nitrate concentrations have been carried out. The results showed that the area risk map ranges from 117 to 218 (low, medium, high, and very high). The majority of up Al-Sanaf Marsh sub-basin are of low and medium risk, except for some southern, southeastern, northern, and eastern parts the groundwater is high and very high risk.