THE EFFECTS OF CLIMATE-CHANGE DUE TO GLOBAL WARMING ON RIVER FLOWS INGREAT-BRITAIN

Global warming due to an increasing concentration of greenhouse gases in the atmosphere will affect temperature and rainfall, and hence rive r flows and water resources. This paper presents results from an inves tigation into potential changes in river flows in 21 catchments in Gre at Britain, using a daily rainfall-runoff model and both equilibrium a nd transient climate change scenarios. Annual runoff was simulated to increase by 2050 by over 20% in the wettest scenarios and decline by o ver 20% in the driest scenarios - and different catchments respond dif ferently to the same change scenario. Monthly flows change by a greate r percentage than annual hows, and under all the scenarios considered there would be a greater concentration of flow in winter. Snowfall, an d hence snowmelt, would be almost entirely eliminated. Progressive cha nges in river flows over the next few decades would be small compared with year-to-year variability, but would be noticeable on a decade-to- decade basis.