Evaluation of Ephemeral Surface Flow at Ibiekuma Watershed in South Central Nigeria

O. A. Ehigiator

《Research Journal of Environmental and Earth Sciences》 1卷1期 (2009/07) Pp. 1-5

並列摘要

The primary objective of this effort is the application at Ibiekuma watershed of lessons derived from a large number of published and ongoing research projects on dry season surface flow and sediment yield at the International Institute for Tropical Agriculture (IITA) Ibadan in South western Nigeria. The period covered spans September through November which generally constitute the second growing season. The effect of the spatial distribution of rainfall on runoff generation becomes increasingly important with the aridity often experienced during this period and which necessitates an accurate assessment of available water, crucial to the determination of crop water irrigational requirement. Runoff measurement was obtained through water collection system aligned with a Gerlach type trough draining a twin plot of 10.71 ha within Ibiekuma watershed in south-central Nigeria. The study validated an exponential depth-averaged rainfall intensity formulation developed at IITA for application in runoff and erosion modeling .There was a reasonably close agreement between predicted storm s kinetic energy using the exponential distribution and values obtained from the Revised universal soil loss equation (RUSLE) with a coefficient of performance (CP) and an estimation difference (ED) of 0.81 and 7.35% respectively. Average depth of runoff for the entire period was less than a millimetre.

並列關鍵字

rainsplash ； intensity ； runoff ； erosivity ； aridity ； ferrasol