A GIS Framework for Collecting, Managing, and Analyzing Multiscale Landscape Variables across Large Regions for River Conservation and Management

摘要

We describe a geographic information systems (GIS) framework for conducting research related to the functional linkages between rivers and multiscale landscape descriptors. Our purpose in presenting this framework is to provide a template for those wishing to conduct their own research and to encourage the adoption of standardized GIS methodologies when conducting stream ecological research. A standardized framework will strengthen the abilities of stream ecologists to communicate and reach broad conclusions regarding the relationships between rivers and conditions in the surrounding landscape and ultimately will improve conservation and management efforts. The GIS framework consists of three spatial units: stream reaches, riparian buffers, and catchments. The basic spatial unit is a stream reach, which is defined primarily as interconfluence stretches of water. A riparian buffer is that portion of the landscape within a bounded distance (e.g., 60 m) of a reach, while a catchment is the total landarea draining to a reach. We distinguish between two forms of riparian buffers and catchments, reach and network, which helps with variable attribution and provides a method for differentiating between local and accumulative upstream conditions. Each ofthese spatial units can be delineated from the national hydrography and elevation data sets using Arclnfo GIS functions. Variables that are attributed to the spatial units either occur in preexisting GIS data sets (e.g., land use) or else are calculated(e.g., reach sinuosity) or statistically modeled (e.g., river temperature) using attributes available in preexisting GIS data sets. Several potential applications (landscape-based statistical modeling of reach-scale characteristics, identification of conservation gaps, and environmental impairment assessment and management) of this GIS framework are described to illustrate the benefits and flexibility of this approach in addressing common river conservation and management objectives.