Groundwater is found underground in rock, sand and soil. It’s an important international resource with a significant role in most economies. Environmentally, groundwater plays an important role in river flow. In order to receive maximum benefit from ground water, nations need to become knowledgeable in its occurrence, development and protection.
In the United States, groundwater:
- Supplies drinking water for 51% of the population.
- 64% is used for crop irrigation.
- It’s important to many industrial processes.
- Is a source of recharge for lakes, rivers, and wetlands.
- Represents 30% of the world’s fresh water.
- Ground water accounts for roughly 1/3 of the fresh water consumed by humans, but in some parts of the world, it can reach 100%.
Digital elevation models (DEMs) are used to locate and manage groundwater. This includes the development of thematic maps from remote sensing data, topographic maps, hydro-geological data and well data. Thematic maps based on hydro-geomorphology and lineaments should also be prepared to better understand groundwater resources.
Drainage maps leverage elevation data and are prepared from large scale topographic maps and satellite data. Drainage maps play a critical role in groundwater management.
Surface vegetation coverage and density can indicate soil moisture conditions by using the Normalized Difference Vegetation Index (NDVI). Availability and depth of groundwater can then be predicted by looking at the relationship between land surface reflectance and the NDVI index.
GIS software plays a critical role in producing the above maps and the final groundwater potential zone map which can be validated through ground-truthing for yield. Polygons can show probability levels of groundwater occurrence. This data is all compiled and evaluated to better manage a nation’s groundwater resources, and digital elevation models play a key role.
These are just a few examples of how DEMs are used in groundwater hydrology. Can you think of some other industries that could use terrain profiles?
Add you thoughts and comments below.