Publication Date:
2014-12-07
Description:
ABSTRACT Much of the water and sediment flux in semi-arid catchments is found to be highly concentrated in localised pathways. Identifying the location of these pathways in the landscape is important for management and restoration. Measures can then be targeted so as to minimise the potential for erosion and sediment flux along these pathways. A method of repeat field mapping of flow and sediment pathways suitable for Mediterranean type agricultural catchments is presented. Several small catchments in Cárcavo basin, SE Spain, differing in topographic and land use characteristics, were monitored under several events. Morphometric properties of pathways were analysed and compared with rainfall characteristics. Number and length of pathways varied with rainfall characteristics but also antecedent conditions. In low rainfall events, runoff sources and main pathways were disconnected, but in a larger event the network of pathways became fully connected. The pathway patterns showed that man-made lines such as terrace embankments and tracks have a major influence on sediment connectivity. Micro-topographic factors, soil moisture and the presence of vegetation are highly influential on pathways and the frequency of water and sediment fluxes. Runoff and erosion hotpots for the development of pathways were identified, which should be targeted for mitigation and restoration measures using vegetation. The relevance of local scale factors emphasises the importance of repeat field observations to understand connectivity and pathways development in the landscape. This article is protected by copyright. All rights reserved.
Print ISSN:
1085-3278
Electronic ISSN:
1099-145X
Topics:
Geography
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
