The influence of climate variability on flood risk in the //Khara Hais municipality (Upington area): a GIS-based approach

English: The climate of the continents and the world is controlled by complex maritime and terrestrial interactions that produce a variety of climates across a range of regions and continents. Climate influences agriculture, environment, water and even the economy of countries all over the world. The climate of the world varies from one decade to another and a changing climate is natural and expected. However, there is a well-founded concern that the unprecedented human industrial and development activities of the past two centuries have caused changes over and above natural variation. Climate change is the natural cycle through which the earth and its atmosphere accommodate the change in the amount of energy received from the sun. A hazard is a physical situation with a potential for human injury, damage to property, damage to the environment or some combination of these. It is important to distinguish between the terms disaster and hazard. A disaster is seen as a serious disruption of the functioning of a community or society, causing widespread human, material or economic losses which exceed the ability of the affected community to cope, using its own resources. Disasters can be either natural, for instance a flood, or human induced, such as a nuclear accident. Disasters may furthermore be classified as slow-onset disasters, such as a drought, or sudden disasters, such as an earthquake . The word risk is one of the most notable examples of words with multiple and disparate meanings that may not be commonly acknowledged. Risk may have a technical meaning, referring to a chance or probability, such as risk from exposure, a consequence or impact, an example being the risk from smoking, or a perilous situation like a nuclear power plant that creates a risk. This study examines the influence of climate variability on flood risk in the //Khara Hais Municipality in the Northern Cape. The area that was investigated included the entire Orange River and Vaal River catchment areas where monthly rainfall data, as well as runoff data were used to produce a flood model for predicting a flood event within a two-month period, giving enough warning time to farmers and the inhabitants of the areas that may be influenced by this flood event. Maps were produced to show the high and low rainfall amounts in the these two catchment areas where randomly selected years and months were taken, as well as showing the one-month and two-month periods before these selected dates. Examples of the highest rainfall recorded, which was in 1988, the medium amount in 1977, and the lowest amount in 1997 were selected. Furthermore, five other such examples were taken to examine the rainfall and climate variation between the years and months ranging from 1950 to 1999.