Impact of Land Use on River Basin Water Balance: A Case Study of the Modder River Basin, South Africa

Abstract

"The study was conducted in the Upper and Middle Modder River Basin (UMMRB) which is located in the semi-arid area of central South Africa. About 35 percent of the basin consists of a communal-farming area where subsistence farmers have difficulty in growing enough food for themselves because of the marginal conditions for crop production. The limiting factors are low and erratic rainfall and excessive water losses due to runoff and evaporation from the predominantly duplex and clay soils. In an attempt to improve the crop production potential of the area the Institute for Soil, Climate and Water of the Agricultural Research Council (ARC-ISCW) introduced a crop production technique called the Infield Rainwater Harvesting (IRWH), which increased the yields of maize and sunflower by around 30–50 percent compared to the yield obtained through conventional tillage."