Influence of relief dismemberment on surface – water infiltration and erosion conditions in Merkys River tributaries catchments

Abstract

The information necessary for assessment of water resources may be obtained by investigating the constituents of water systems: precipitation, runoff, infiltration. The latter two are largely affected by relief: its genesis, lithological structure, relief morphometric indices. The river catchments include relief complexes of variable genesis which differ also in their morphometric indices. This largely determines the surface runoff and infiltration properties of catchment and quantity of groundwater. The surface inclination is one of factors affecting infiltration capacity. In sloping surfaces a considerable amount of precipitation flows down at a high speed. For this reason water infiltration in the upper part of the slope is by far lower than at the foot. Besides, the downstreaming water may accumulate in closed depressions. During rain-falls, it is possible to determine the amount of water, which gets into rivers and other water basins and in groundwater. The energy of running water determines its impact on the slope, i.e. the actual slope erosion. It is determined by water mass and its flowing ratio. As a mass index we may take the largest amount of precipitation which falls down during a rainfall per unit of area. The smallest energy of flowing water, which does erode the slope, equals 0.001 kg/m². In all other cases slope erosion takes place. The energy of water flowing down steep slopes is sufficient to start an intensive slope erosion and development of linear forms of erosion. The linear forms of erosion later stimulate a more rapid rain water flow into small river basins and, concomitantly, change the infiltration environment of the basin. The aim of paper – evaluate of relief dismemberment influence on surface–water infiltration in Šalcia and Spengla Rivers catchments and flowing water impact on surface: rivers valley and hill slopes.