Impacts of off-road vehicle tracks on runoff, erosion and sediment delivery - A combined field and modeling approach

摘要

Assessing the effects of land disturbance on sediment yield requires quantification of erosion and sediment connectivity. Off-road vehicle (ORV) tracks represent sources of sediment pollution to coral reefs and coastal wetlands in a dry tropical setting of Southwestern Puerto Rico. This study assesses their contribution through a combined empirical and modeling approach. Rainfall simulation experiments and sediment accumulation in detention ponds indicate that ORV track erosion rates are 31-83 Mg ha(-1)yr(-1) and these are one to two orders of magnitude greater than background erosion rates. A new sediment connectivity model predicted a watershed-scale sediment yield of 2.7 Mg ha(-1)yr(-1) from a 11.9 km km(-2) of ORV track network, and this exceeds those from comparable watersheds in the Caribbean. The spatially explicit nature of the model outputs allows for site-specific quantification of sediment contributions and for an evaluation of the effectiveness of mitigation methods such as detention ponds.