A practical method for the management of road runoff

摘要

In this paper we outline a conceptual and methodological approach to evaluating the impacts off unsealed forest roads on in-stream water quality based upon the principal of hydrological connectivity,. The methodology is based on the Vbt5 model of Hairsine et al (2002) and makes use of simple empirical relationships that only require input data that are generally available or relatively easily to obtain, such as the road contributing area to drains and the distance from drain outlets to the streams. Using a plantation forestry catchment in the Australian Capital Territory, we demonstrate that the degree of connectivity along a road network is affected by the spatial distribution of the runoff delivery pathways Furthermore, we illustrate how the methodology can be used to extract practical guidelines for appropriate drain spacing and to develop risk assessment maps to assist in prioritizing roads for removal or relocation.