Climate Change

Providing services in climate data analysis and prediction, climate change scenario development, climate change impact studies.

Water circulates in the hydrosphere through a variety of complex paths to form the hydrologic cycle. The global hydrologic cycle can be divided into three components: 1) the atmospheric water system containing the process of precipitation, evaporation, interception and transpiration; 2) the surface water system comprising overland flow, surface runoff, and runoff into streams and the ocean; 3) the subsurface water system consisting of infiltration and ground water flow. Perturbation on any of the subsystems can trigger changes in the cycle, leading to significant impacts on hydrology and in particular flood events. Climatic processes constitute a major part of the hydrologic cycle, and hence the study of climatic variabilities and changes and their potential impacts on hydrologic systems cannot be overemphasized.

It is now widely accepted that sound hydrologic engineering analysis, planning, design and management should account for the potential impacts of climatic variability and change on extreme precipitation magnitudes and frequencies and associated flood and drought episodes. Traditionally, extreme hydrologic statistics were based on the assumption that the climate system would be time invariant. Such assumptions may not hold because of expected potential climate change due to global warming.

To quantify the response of the climate system to changes in natural and anthropogenic forcings, numerical models of the climate system, referred to as General Circulation Models (GCMs), are used. In spite uncertainties embedded in these models, most GCMs predict significant increases in temperature arising from enhanced greenhouse gases and consequently changes in the global climate. By implication, such changes could have considerable impact leading to extreme hydrologic events like storms and floods. Warmer temperatures have the potential to lead to a more vigorous hydrological cycle, which can translate, into prospects for more severe hydrologic events. Several GCMs indicate an increase in precipitation intensity in diverse parts of the globe, suggesting a possibility for more extreme rainfall events which in turn can lead to increased flood magnitudes.

AqCESo has over the years developed expertise and tools for assessing climate variability/ change and the potential impacts on the aquatic environment among others.