Groundwater accounts for roughly 99% of all liquid freshwater on our planet. It has the potential to provide societies with tremendous social, economic, and environmental benefits and opportunities.
What is Hydrogeology?
Hydrogeology is a very exciting, interdisciplinary field. In the simplest terms, it is the branch of geology that deals with groundwater, principally:
- How water gets into the ground.
- How it flows in the subsurface.
- How it interacts with the surrounding soils, rocks, pollutants present, and more.
Hydrogeology generally involves a combination of multiple disciplines such as microbiology, chemistry, and isotope geochemistry. Additionally, we have recently witnessed a lot of benefits from trans-disciplinary approaches such as socio-hydrogeology.
Hydrogeologists are helping to unlock the enormous potential that groundwater offers. We are delivering these benefits to our clients and our societies by working closely together with colleagues from other disciplines, especially civil and environmental engineers.
What benefits are there from utilising groundwater reserves?
Most people rarely think about groundwater resources as they are “beneath our feet”, “out of sight” and consequently “out of mind”. Combating these views is the worldwide hydrogeological community who are actively trying to “make the invisible visible”. This is important because groundwater has many benefits. Groundwater is relatively cheap to utilise as not only is it the cleanest source of water, it is also very commonly found and widespread. Additionally, it is a reliable source of water even in times of drought due to the large amounts stored in the subsurface.
In many parts of the world groundwater is the main source of water. Groundwater already provides half of the volume of water withdrawn for worldwide domestic use. Approximately 70% of all global groundwater withdrawals are used in the production of food, fibres, livestock, and industrial crops.
What challenges are faced when utilising groundwater?
There are many challenges but the most important are linked to groundwater resource management and degradation of groundwater quality. Increasing withdrawals to meet growing human needs have led to a significant depletion of this resource within areas of major population and agriculture. Contamination of groundwater with fertilizers, pesticides, pathogens, pharmaceuticals, and various chemicals is a massive challenge. Side effects of the excessive groundwater development as well as numerous pollution impacts include land subsidence and degradation, loss of flow to ecologically important wetlands, impacts on ecosystems, escalating water treatment, drilling, pumping costs, and many more.
Are there any other applications for groundwater and what role does hydrogeology play in them?
The potential for using groundwater as a renewable geothermal source is enormous. Its use could contribute to our ambitions of cutting greenhouse gas emissions to as close to zero as possible. This is particularly true for deep aquifers, but also applies to shallow aquifers. Typical geothermal systems consist of two or more wells: hot water is collected from production wells, while injection wells are used to re-inject water after heat has been extracted, allowing sustainable energy production.
Moving forward, reliance on groundwater will only increase due to the growing water demand by all sectors. This, combined with climate change impacts, will result in the need for more hydrogeologists to take an important role in the fight against poverty, to provide food and water security. Groundwater is a critical factor in the future of socio-economic development and creation of jobs.