Role of hydrological forecasts and river flow modelling in rational agricultural water management in the perspective of a climate change — A case study of the Rivers Upper Nile and Niger
Abstract An international scientific conference under the auspices of WMO, UNEP and ICSU on the role of CO 2 and other greenhouse gases in climate variation made a statement that, if the concentration of CO 2 in the atmosphere doubles in the near future as present trends indicate, the global mean surface temperature would increase by 1.5–4.5°C. The paper discusses the impact such a climate change may have on water resources and on their management in agriculture. It stresses the importance of the possible increase in variance and frequency of extreme climatic events and subsequent water yield. It further outlines the ways of exploring the consequences of such development by using hydrological and water management models. It also proposes that real-time hydrological forecasting systems, able to produce forecasts with long, medium and short lead times, are one of the most effective measures to offset possible negative effects of the climate change, by increasing the effectiveness of storage management. These propositions are documented by means of case studies from developing countries using models on the River Nile, in particular in the basin of Lake Victoria, and of a hydrological forecasting system on the River Niger. It is proposed that it is important to develop a simulation model of the whole River Nile, together with a real-time forecasting system on the river in order to operate efficiently existing and future storages. Modelling of climate change impact on the water yields of River Niger is also discussed.
RECENT RESEARCH ON EFFECTS OF CLIMATE CHANGE ON WATER RESOURCES
: Concentrations of atmospheric CO2 and other radiatively active trace gases have risen since the Industrial Revolution. Such atmospheric modifications can alter the global climate and hydrologic cycle, in turn affecting water resources. The clear physical and biological sensitivities of water resources to climate, the indication that climate change may be occurring, and the substantial social and economic dependencies on water resources have instigated considerable research activity in the area of potential water resource impacts. We discuss how the literature on climate change and water resources responds to three basic research needs: (1) a need for water managers to clearly describe the climatic and hydrologic statistics and characteristics needed to estimate climatic impacts on water resources, (2) a need to estimate the impacts of climate change on water resources, and (3) a need to evaluate standard water management and planning methods to determine if uncertainty regarding fundamental assumptions (e.g., hydrologic stationarity) implies that these methods should be revised. The climatic and hydrologic information needs for water resource managers can be found in a number of sources. A proliferation of impact assessments use a variety of methods for generating climate scenarios, and apply both modeling approaches and historical analyses of past responses to climate fluctuations for revealing resource or system sensitivities to climate changes. Traditional techniques of water resources planning and management have been examined, yielding, for example, suggestions for new methods for incorporating climate information in real-time water management.
A study of the local tissue reactions in man to cortisone and compound F. VI. Histopathological studies of the local effect of compound F in normal and pathologic skin of man.
After our previous negative studies (1) of the local effect of cortisone acetate in the skin of man, a year ago, a parallel study of 17-hydroxycorticosterone-21-acetate, Compound F, was outlined. Theoretically, Compound F should be the active steroid. It was so suggested by Rothman (2), that in all probability Compound F and not cortisone would be active locally in the skin of man.