A hierarchical approach to fisheries planning and modeling in the Columbia River Basin

Abstract

/ The Columbia River Basin is the scene of a massive effort to restore populations of Pacific salmon (Oncorhynchus spp.) and steelhead (O. mykiss). Efficient restoration is confounded by a high level of complexity, competing sociopolitical goals and values, and uncertainty about key system properties. Simulation models and other tools of systems analysis are important to development oi a comprehensive, regionally acceptable strategy. Hierarchy theory provides a useful paradigm for organized complexity within the Columbia Basin and the basis for a trilevel hierarchical structure for organizing and integrating models. Life-stage models compose the most basic simulation units at the lowest level in the proposed hierarchical modeling structure, Each ~ife-stage model simulates a distinct period in the life cycle of anadromous salmonids. Population models at the intermediate level simulate the complete life cycles of salmon and steelhead populations. At the highest level in the hierarchy, interpopulation mode~s simulate extensive, long-term processes that affect multiple species and stocks. A hierarchical system of models is preferable to a single model or to a group of models lacking formal structure. A principal advantage is that models have the correct spatial and temporal resolution for analyzing questions at different scales. A hierarchical structure also facilitates the flow o1 information among models, and aids in understanding the impacts of uncertainty. Constructing a hierarchy of models should involve both bottom-up and top-down perspectives that maintain iogical consistency among models, while allowing unique model structures appropriate for each level in the hierarchy.The Columbia River Basin in the northwestern United States is the scene of a grand effort to rebuild populations of Pacific salmon (Oncorhynchus spp.) and steelhead (0. mykiss). The Columbia Basin is a large, complex area of over 670,000 km 2 that serves a wide diversity of uses--many of which compete directly with the salmon and steelhead's needs for copious amounts of clean, cool, fast-moving water. Salmon and steelhead are anadromous fish that spawn and rear as juveniles in freshwater streams, migrate to the ocean as smolt, and spend one to several years in the ocean before returning to their natal streams to spawn.Historically, salmon and steelhead have suffered dearly when competing with other users of the watershed (Chancy 1978; Neblsen and others 1991, Ray-

Characterizing the Spatial Structure of Mangrove Features for Optimizing Image-Based Mangrove Mapping

“…The central concept of this theory focuses on the differences in structure and process rate between hierarchical levels. Based on these differences, ecosystems are viewed as being stratified into discrete levels of interacting subsystems, with attributes and processes occurring at specific spatial and temporal scales [7,[10][11][12]. Remote sensing is a tool able to deliver information on mangrove characteristics at specific spatial and temporal scales.…”

Relationships Between Landscape Habitat Variables and Chinook Salmon Production in the Columbia River Basin, 1999 Annual Report.

“…A huge effort has been undertaken by various federal, state, and tribal agencies to restore populations of anadromous salmonids within the Columbia River Basin in the northwestern United States -a complex area that accomodates a variety of uses and pressures on its natural resources, including those that are incompatible with the needs of anadromous salmonids (Lee and Grant 1995). In fact, exploitation of fish and degradation of their freshwater habitats within the Columbia River Basin over the past century has reduced numbers of salmon and steelhead from an estimated 10-16 million adults to 1.5-4 million adults (Northwest Power Planning Council 1986, Lee andGrant 1995).…”

“…In fact, exploitation of fish and degradation of their freshwater habitats within the Columbia River Basin over the past century has reduced numbers of salmon and steelhead from an estimated 10-16 million adults to 1.5-4 million adults (Northwest Power Planning Council 1986, Lee andGrant 1995). The entire basin covers approximately 670,000 km 2 in portions of seven states (mainly Idaho, western Montana, most of eastern Washington and Oregon with smaller portions in Wyoming, Utah, and Nevada) in the northwestern United States, as well as the southeastern part of British Columbia, Canada (Krutilla 1967).…”

Remote sensing for multi-scale mangrove mapping

“…The central concept of the theory focuses on the differences in structure and process rates between levels. Based on these differences, ecosystems are viewed as being stratified into discrete levels of interacting subsystems, with attributes occurring at specific spatial and temporal scales (Delcourt et al 1983;Müller 1992;Lee & Grant 1995;Farnsworth 1998). Geospatial technology and analysis tools, including remote sensing data and its mapping techniques, are required to address emerging issues in spatial ecology from local to global scales (Naveh & Lieberman 1994;Skidmore et al 2011).…”

“…The central concept of this theory focuses on the differences in structure and process rate between hierarchical levels. Based on these differences, ecosystems are viewed as being stratified into discrete levels of interacting subsystems, with attributes and processes occurring at specific spatial and temporal scales (Delcourt et al 1983;Müller 1992;Lee & Grant 1995;Farnsworth 1998). Remote sensing is a tool able to deliver information on mangrove characteristics at specific spatial and temporal scales.…”