Long-term climatic data (maximum temperature, minimum temperature, rainfall and evaporation) for Big Bend in the Lowveld, a semi-arid region of Swaziland, were analysed for any changes or variations. Evaporation and...Long-term climatic data (maximum temperature, minimum temperature, rainfall and evaporation) for Big Bend in the Lowveld, a semi-arid region of Swaziland, were analysed for any changes or variations. Evaporation and rainfall data were analysed to assess water resources availability in the region. Analysis of the available data shows that there is no indication of decrease in rainfall with time, but the results show that there has been a steady increase in minimum temperatures over the last 25 years. The average effective water resources index, measured as the difference between mean annual rainfall and mean annual evaporation, for the region in the period from 1965 to 2001 was -1,500 mm. The large negative index implies low available water for the region, a situation that is likely to affect agricultural, hydropower and other water related development activities in the region. The negative effective water index implies deficits in the region's water resources which call for better management of the region's water resources. In the agriculture sector, this requires promoting technologies and practices that provide for water saving, improved water use performance and high water productivity. These include soil conservation tillage, wastewater reuse, runoff harvesting and soil fertility interventions through application of fertilizers, manures and mulches, and agronomic management. There is need for more analysis for the other regions in order to get a countrywide picture of the climate as well as water resources situations.展开更多
South Africa’s water resources are limited and unevenly distributed. To overcome the uneven spread of water resources and to manage floods and drought, more than two thirds of the country’s mean annual rainfall is c...South Africa’s water resources are limited and unevenly distributed. To overcome the uneven spread of water resources and to manage floods and drought, more than two thirds of the country’s mean annual rainfall is currently stored in dams. The paper reviews the current water storage capacity of the country at national and provincial levels. Data from a list of registered dams in the country were used to analyse the water storage capacity of the country. Water storage capacity is highest in Free State Province and lowest in Gauteng Province. The results also show that, while it is clear that the country has invested a lot in developing water storage infrastructure, there is potential for the development of additional infrastructure. However, since most of the major rivers are transboundary, the country needs to develop additional storage with full consideration of its ecological requirements and international obligations.展开更多
文摘Long-term climatic data (maximum temperature, minimum temperature, rainfall and evaporation) for Big Bend in the Lowveld, a semi-arid region of Swaziland, were analysed for any changes or variations. Evaporation and rainfall data were analysed to assess water resources availability in the region. Analysis of the available data shows that there is no indication of decrease in rainfall with time, but the results show that there has been a steady increase in minimum temperatures over the last 25 years. The average effective water resources index, measured as the difference between mean annual rainfall and mean annual evaporation, for the region in the period from 1965 to 2001 was -1,500 mm. The large negative index implies low available water for the region, a situation that is likely to affect agricultural, hydropower and other water related development activities in the region. The negative effective water index implies deficits in the region's water resources which call for better management of the region's water resources. In the agriculture sector, this requires promoting technologies and practices that provide for water saving, improved water use performance and high water productivity. These include soil conservation tillage, wastewater reuse, runoff harvesting and soil fertility interventions through application of fertilizers, manures and mulches, and agronomic management. There is need for more analysis for the other regions in order to get a countrywide picture of the climate as well as water resources situations.
文摘South Africa’s water resources are limited and unevenly distributed. To overcome the uneven spread of water resources and to manage floods and drought, more than two thirds of the country’s mean annual rainfall is currently stored in dams. The paper reviews the current water storage capacity of the country at national and provincial levels. Data from a list of registered dams in the country were used to analyse the water storage capacity of the country. Water storage capacity is highest in Free State Province and lowest in Gauteng Province. The results also show that, while it is clear that the country has invested a lot in developing water storage infrastructure, there is potential for the development of additional infrastructure. However, since most of the major rivers are transboundary, the country needs to develop additional storage with full consideration of its ecological requirements and international obligations.