Effect of farming methods on rivers

Perennial rivers are a source of livelihood to many rural people in the sub-humid tropics, where villages are often strategically situated along the river banks. The rivers provide water for irrigation and income from fishing, as well as a means of transportation and communication. However, this way of life is now under threat due to the changing climate brought about by deforestation, mainly due to slash-and-burn shifting cultivation. The resulting shortening of the rainy season and poor distribution is now having very serious implications on river flow and water supplies. In October 1994 at an Agriculture Extension Workshop in Northern Zambia, the District Forestry Officer reported that about thirty rivers in the eastern part of the district which used to be perennial a few decades ago are now completely dry, or flow only briefly during the rainy season. In Mansa District west of Luwingu, the main river from which the district derives its name, is almost dried up apart from a small muddy stream in an otherwise dry river bed. The district authorities can no longer pump water for domestic and industrial use and instead have to transport water by tanker from an inland lake 100km east of the district. Thirty-five years ago this river flowed throughout the year. To the rural people in the area what is happening appears to be the result of natural calamity; they do not connect it with their own actions and their farming of recent decades. (See Spore 58 Main Feature). Alfred Mkonda Sod Productivity Research Programme Misamfu Regional Research Centre PO Box 410055 Kasama ZAMBIAPerennial rivers are a source of livelihood to many rural people in the sub-humid tropics, where villages are often strategically situated along the river banks. The rivers provide water for irrigation and income from fishing, as well as a means of..