Assessing urban riverscapes: A multiscale approach designed for management application

Abstract

Abstract Urban riverscapes are integral to the livability and sustainability of cities and suburbs. Conserving and restoring these riverscapes requires assessing their condition over a broad range of spatial scales, from watershed to planning segment to reach scale. Any riverscape assessment must examine the hydrogeomorphic and ecological characteristics and behaviors in order to provide decision-making information to resource managers. The novel assessment method introduced in this article, Urban Riverscape conditions-Based Assessment for management Needs (URBAN), provides a framework to characterize the physical condition of and the social-ecological values within a watershed, as well as the anthropogenic impacts affecting those functions and values, that can inform restoration planning and riverscape management. URBAN is founded upon the third tier of the Urban Riverscapes Assessment Framework – “How should we assess the values and functions of an urban riverscape?” Assessment of physical conditions and characteristics in urban riverscapes using the URBAN indicators and metrics provides critical information about the underlying watershed system status and stream evolution trajectory. URBAN includes both data collection and the evaluation of desktop and field data to determine stream characteristics. Data collection emphasizes reach-typing (or stream classification) and related or relevant aspects of stream physical condition. URBAN is unique in its emphasis upon stream “values,” which links the physical processes of a stream and its social-ecological values to anthropogenic stressors that may influence the long-term recovery of degraded streams. These linkages also provide critical information for planning instruments, regulatory requirements, and community conversations. Coupled with GIS tools, urban riverscape studies at multiple scales, like URBAN, provide objective methods to understand and interpret multi-causal mechanisms and trends that influence the physical condition and potential recovery of degraded urban riverscapes. This article provides a summary of those methods and the tools applied by way of remote and rapid field assessments, through the lens of an urban watershed assessment conducted in the Colorado Front Range. The outcome of this work advances the scientific basis underlying applied riverscape management and broad-scale preservation and renovation planning.