Earth Science and Climate Change

Hydrological Sciences

Submit Abstract Register Now

Hydrological Sciences

Hydrology encompasses the study of the availability, distribution, movement and quality of water on Earth and its relationship with the environment within every phase of the water cycle. This cycle consists of a delicate balance of processes of water precipitation, evaporation, freezing, melting and condensation. These processes are highly dependent on temperature, and with climate change and atmospheric warming happening on a global level, the impacts are felt in the hydrologic balance and hydrological systems everywhere.

There are three key variables that determine the health and balance of hydrological systems: (a) soil moisture, which is a primary control on vegetation and ecosystems; (b) groundwater recharge, which feeds groundwater reserves; and (c) runoff, which feeds rivers and causes floods. Areas of research in hydrological sciences focus on these variables while studying, the quality of the water, the movement of water between its various states or within a given state, or a quantification of the amounts in the different states in a given region. 

Warmer temperatures increase the rate of evaporation of water into the atmosphere, resulting in less snow formation, as well as changes in mean rainfall, rainfall intensity, and rainfall seasonality. With the relationship between rainfall and runoff being non-linear, the response of runoff generated by rainfall is magnified. This leads tovarious climate change effects such as increased flooding and drought. The frequency of heavy precipitation events will very likely increase in most regions, with consequences for the risk of rain-generated floods. At the same time, the proportion of land surface in extreme drought at any one time is also projected to increase.

In a warmer environment, more precipitation will materialize as rain rather than snow, which means there will be an increased occurrence of water shortages. Because rain flows faster than melting snow, higher levels of soil moisture and groundwater recharge are less likely to occur. When rain falls, reservoirs fill quickly to capacity, which can also result in excess water runoff that can’t be stored. Higher water temperatures and changes in extremes, including floods and droughts, are also projected to affectwater quality.Intense rainfall, for example, leads to an increase in suspended solids in lakes and reservoirs, as well as an enhanced transport of pathogens and other dissolved pollutants.

These changes in water quantity and quality due to climate change are expected to affect food availability, stability, access and utilization. These adverse effects of climate change on hydrological systems in turn aggravate the impacts of other stresses, such as population growth, changing economic activity, land-use change and urbanization. With a predicted global growth in water demand over the coming decades, it is essential to develop and implement long term lasting solutions for the conservation of water resources. This includes adaptation procedures and risk management practices that incorporate the projected hydrological changes, improve water-use efficiency and water access for all of adequate quality and quantity.