Study hydrology if you want to help everyone to have access to clean drinking water. If you want to define a sustainable approach to groundwater reservoirs. Or if you want to know what changes in water cycles mean for ecosystems and vice versa.Clean drinking water is a luxury for large part of the world?s population. Irrigating agricultural areas as a way of combating hunger may seem like the best solution in the short term but what about the long term? Will there be precipitation excess? Will groundwater supplies be exhausted? And what will be the influence on the local climate if land is irrigated? These are the kinds of issues you will be dealing with. Hydrology is an applied natural scientific discipline with a strong measure of social engagement.Water is one of the few resources on earth that we simply cannot do without. It is and will always remain a primary necessity of life, so there will always be work for you as a hydrologist, whether you opt to manage water supplies and groundwater in dry areas or study the influence of changes in the water cycle on delta areas.