Informace o publikaci
The present stage of Fluvio-Geomorphological research in context of Euro-American Collaboration (Exemples of Sacramento River). Longitudinal and temporal evolution of the Sacramento River between Red Bluf and Colusa, California, USA (1942-1999)
| Autoři | |
|---|---|
| Rok publikování | 2009 |
| Druh | Konferenční abstrakty |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | Historic and archival aerial images hold a important information which offers the potential to enhance our understanding of long term channel change in both natural and anthropogenically impacted settings. We analyzed historical channel changes from archival aerial photographs to document the evolution of the main channel and floodplain lakes over a 140-km reach of the Sacramento River, from Red Bluff to Colusa, California, from 1942 to 1999. This period spans the construction of Shasta Dam in 1944, and thus effects of altered flow regime on lateral channel and floodplain morphology should be visible in the aerial imagery. Multivariate analysis on the results of the historical analysis demonstrated that whilst channel geometry was simplified after the construction of Shasta dam, long-term channel evolution was not dominated by dam-induced channel changes, but affected more by other anthropogenic impacts. Since the mid 19th century, anthropic bank stabilisation in the downstream part of the study reach have hindered lateral channel migration, and have thus significantly affected channel evolution. In the upstream part of the study reach, bank stabilisation works were limited and nearly absent. By using catchment-scale, time dependent data, the key factors of channel change can be isolated, thus leading to an understanding of the long term evolution of the channel and oxbow lakes. |