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The role of unpaved roads in the sediment budget of a semiarid mesoscale catchment
Author(s) -
Farias Teresa Raquel Lima,
Medeiros Pedro Henrique Augusto,
Araújo José Carlos de,
NavarroHevia Joaquín
Publication year - 2021
Publication title -
land degradation and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 81
eISSN - 1099-145X
pISSN - 1085-3278
DOI - 10.1002/ldr.4120
Subject(s) - surface runoff , sediment , hydrology (agriculture) , erosion , environmental science , sedimentary budget , universal soil loss equation , drainage basin , rill , soil loss , sediment transport , geology , geography , geomorphology , ecology , geotechnical engineering , cartography , biology
High erosion and runoff rates have been measured on road infrastructure, indicating that unpaved roads might be significant sources of sediment in catchments. In this paper, the production of surface sediments from unpaved rural roads is assessed in Northeastern Brazil, in a semiarid area of the caatinga biome, vulnerable to desertification. Sediment production data from road surface segments were monitored for 2 years (2013–2014) under conditions of natural precipitation. By using hydrosedimentological modeling and a geographical information system (GIS), the sediment budget was calculated at the meso‐scale catchment (aprox. 930 km 2 ), in order to identify the relative contribution of roads to the sediment balance. The universal soil loss equation (USLE) associated with Maner's sediment delivery ratio (SDR) equation, proved to be an adequate approach for predicting sediment yield on the road segment scale. The best results were obtained for the road without traffic, due to the non‐interference in this segment of external factors, such as traffic and maintenance activities, not explicitly considered in the model formulation. The modeling procedure showed that the roads, which occupy only 0.7% of the catchment surface, were responsible for approximately 7% of soil loss in the area. Furthermore, sediment connectivity might be enhanced by roads, which cross the river network and, therefore, deliver more directly the sediment generated at hillslopes. This is particularly important in the studied environment, where sediment connectivity is low due to limited runoff and the existence of a dense network of surface water reservoirs.