Experimental Study for the Effect of Rainfall and Surface Runoff on Sediment Load

Rasha Mohammad Al-Salem, Moayad Sa'ad Allah Kaleel, Mohammad Ezz-Aldeen Mohammad

Abstract


The impact of several factors on detachment and transport of soil particles due to rainfall and surface runoff have been studied. The role of flow depth, the Kinetic energy of rainfall, surface discharge, type of soil and soil surface slope on sediment concentration were evaluated using the Basic Hydrologic System apparatus of the hydraulic laboratory, (Mosul University). This system is employed to simulate the rainfall and surface run off on selected soil samples to obtain the required flow depths of water.
Soil samples were taken from four locations in Mosul city, Al-Ghabbat, Mosul University, Al-Kafaat, and Al-Sukkar. The percent of clay of the samples varies from 8 to 40%, and the median particle size (D50) varies from 0.009 to 0.057mm. Three soil surface slopes 2.5, 5, and 7.5% were selected to investigate their effect on soil erosion. The applied rainfall intensities were ranging between 1.25 and 3.5 mm/min. The test was divided into two main stages. At the first stage: surface runoff was applied only and the effective factors on detachment and transport soil particles were considered. At the second stage the simulated rainfall was applied along with selected intensities to achieve different surface flow depths.
Finally factors affecting the detachment and transport of soil particles as a result of rainfall (through rainfall kinetic energy and flow depth) were investigated only.

Keywords


Rainfall Detachment, Sediment Concentration, Surface Flow

Full Text:

PDF

Refbacks

  • There are currently no refbacks.