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Evaluating the Effectiveness of Floodplain Restoration on the North Fork of the John Day River

出版	U.S. Department of Agriculture, Forest Service, Remote Sensing Appllications Center, 2008
URL	http://books.google.com.hk/books?id=QA_9uQEACAAJ&hl=&source=gbs_api

註釋Over the last decade, hundreds of river restoration projects have been implemented to maintain, protect, and restore watersheds, rivers, and habitat for native species in the Pacific Northwest. Monitoring has generally focused just on the site, using field-based methods that are often expensive and limited. Remote sensing and GIS technologies show great promise, especially for large-scale projects; however, most organizations undertaking projects don't have enough budget and staff for monitoring and require simple, low-cost techniques that can use readily available imagery. This study used 1:24,000 digitized and orthorectified resource imagery from 1995 and National Agriculture Imagery Program (NAIP) digital orthophotography from 2005 to evaluate the effectiveness of floodplain restoration on a 15-kilometer stretch of the North Fork of the John Day River. Between 1993 and 1997, the Umatilla National Forest undertook an extensive restoration project to remove, reshape, and revegetate cobble tailings left from dredge mining along this section of the river. Restoration intended to improve floodplain function (inundation, riparian habitat) directly and instream habitat (pools, spawning) indirectly by reconnecting the active river channel with a reconstructed floodplain. The study objectives were to field-verify remote sensing measurements of selected stream characteristics to test whether available remote sensing imagery is effective for project monitoring and to quantify changes along the river using a case-study approach. The postproject NAIP image interpretation produced mixed results due to resolution and sampling methods, but overall positive changes in sinuosity, vegetation cover, and depositional area were apparent. A reduction in the active channel width was interpreted as a natural stage of evolution from a confined to an open channel. Mapped high-flow evidence indicated that the total functional floodplain area had increased by 8 hectares or about 10 percent.