Greetings Everybody, ...

Greetings Everybody, continuing to investigate the methods of estimating the recharge to groundwater, I've worked on Building and Simulating a groundwater model using the GIS as follows;

Building a Groundwater Model using GIS to estimate the Recharge:

This approach records the process used to calculate the groundwater infiltration in the urban areas. The groundwater model will provide insights into the effectiveness and appropriate locations for groundwater drainage and water use strategies.

The Groundwater Model should be simulated for the target protection year and urban recharge input files were thus calculated for the target year.

Existing data sets are used to calculate the urban recharge and are calibrated against current water balance data. The development and change in urban recharge are then calculated for the target year.

Core Data Sets:

The data used to prepare each of the component groundwater infiltration input files is as follows:

1. Project Boundary.
2. Grid 1 km x 1 km, Cover 1km buffer area of boundary
3. Shape Files of Landuse data.
4. Shape Files of Road Data.
5. Shape Files of Population Data.
6. Shape Files of Sewer Data.
7. Shape Files of Clean Water.
8. Shape Files of TSE.
9. Shape Files of Municipal Irrigation.
10. Shape Files of Building.
11. Shape Files of Parcel Data.
12. Shape Files of Road Irrigation.
13. Shape Files of Septic Tank.

Preparation of Grid:

The grid is prepared with a size of 1 km x 1 km area covering the Model Boundary with an extra 1 km buffer area around the peripheral edge. It must cover the entire area of study.

The population data is assigned to each grid based on percentage area of Traffic Analysis Zones (TAZ).

This is a methodology that has been previously developed and used within the Drainage Master Plan of Qatar. Each cell had the sum of the percentage of population of the TAZs which coincided with the grid as shown in the figure below.

It is assumed that the population is spread equally across the entire area of the population TAZ boundaries. The development factor is based on the projected population growth and is prepared by identifying the peak year with the highest population which is assigned a value of 1 on the assumption that it will have maximum development.

The remaining years are assigned a factor [Population of Year to be calculated]*1/ [Peak year Population]. So, for example, if 2062 has the highest population, 2012 will have a development factor = [Pop2012]*1/ [Pop2062]

It will found that, there is increasing trends with peak population achieved. There are as well a few cases of decreasing trend in areas where significant industry developments or mega projects were planned for implementation.