Pollutant pathways and travel times at catchment scale: a tool to include groundwater in modelling

Introduction

The development of many industrial enterprises, the water industry, agriculture, transportations, discharges for abandoned mines, urban infrastructures directly harm the quality of water and have the potential to pollute water. In addition, the impact of past activities especially on groundwater systems polluted the water. Pollutant may arise as point sources or may be dispersed and diffuse. Pollutant from these activities may enter surface and groundwater directly then may move slowly within the groundwater and eventually emerge in surface water. In order to continue using the surface and groundwater water resources, there is a need to model or predict the influenced of pollutant pressure, to distinguish where actually this pressure came from, the pathway of the pollutant and the interaction with surface and groundwater system.

The general aims of this study is to develop a tool (embedded GIS based model) in order to understand the fate of pollutant (pathway and travel times) from the catchment at surface, in the groundwater flow and attain to the surface water bodies. To work towards the aim, objectives should be addressed here are;

• To model the flow and transport of pollutant in groundwater system.
  • Develop embedded GIS based model of flow in groundwater. This model will provide a tool to track the pollutant transfer
• To test GIS based model for surface - groundwater risk assessment.
  • Develop integrated GIS based groundwater - pollution risk model.
  • To apply the integrated GIS surface-groundwater model to Don catchment.
  

Approach

GIS is an important tool for monitoring and modelling the flow of water and pollutants at the surface at the regional scale. Due to complexity of geographical distributions of groundwater and lack of tools for modelling in three dimension using GIS; groundwater modelling is typically done only at the aquifer scale. However, this study is to explore the possibility of extending GIS based modelling for pollutant tracking which include the assessment for groundwater at a catchment scale. A various effects (such as topography control of flow, aquifers properties and nature of pollutants) will be considered in order to understand the flow and pollutant transport in a groundwater system. Then the model will be integrated with the pollution risk model to look if the combination of integrated surface and groundwater model provide better results. Integrated model will be applied to Don catchment as this catchment will be my case study. This study hopefully will provide a simplified tools for priotisation and risk analysis of a catchment.