The effect of raindrop impact and initial soil conditions on surface crust formation
2005
Asgedom, G.G.(Hokkaido Univ., Sapporo (Japan)) | Hasegawa, S.
This study focused on the effect of raindrop impact on the crust formation processes using two clay loam soils, Hokudai and Biei from Hokkaido, Japan. Four different treatments AD (air dried), PS (large aggregate), BD (bulk density) and WET (wet) have been prepared from disturbed samples in a laboratory. A miniature type rainfall simulator with rainfall intensity of 63mm/hr was used for duration of one hour from a height of 170cm to measure the impact of raindrop on bare soils. The final infiltration rates were PSADWETBD by raindrop impact. Therefore, the impact of raindrop in impeding infiltration was high in smaller aggregates of AD and WET treatments compared with PS. Furthermore, the impact was higher for Biei soil than for Hokudai soil. The hydraulic conductivity of the crust layer for Hokudai and Biei had different trends. The order of reduction for Hokudai soil was WETPSADBD. The reason for this trend could be the aggregate stability or resistance to breakage. While the magnitude of reduction in Biei was ADPS WETBD. The initial moisture content appears to be more important factor for Biei soil.
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