Summary of Cottonwood Monitoring and Research

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B. Spring - 2002- (Surveying, Sampling, and Photography -- Temporal Sections) Data collection in support of the temporal intensive monitoring component of the protocol was initiated March 28, 2002. At this time a subset of the intensive monitoring and research sections were resurveyed and bed material resampled at these sections. These resurveys included 2 sections in the Input reach, 3 in the Managed, and a1125 sections in the Output reach. These resurveys and samples are intended to document natural intra-year variability in bed elevation and bed-material grain size. While only 3 sections are typically surveyed at the Output section, a1125 were surveyed and additional surveyed detail including longitudinal profiles, bank, island and bar points were collected for comparison and validation of an experimental LIDAR (Light Detection And Ranging) system flown over the entire Cottonwood Ranch. C. Summer - 2002 -(Surveying, Sampling, and Photography -- Temporal Sections, General Monitoring Sections) On July 16, 2002 we revisited the same subset of intensive monitoring sections as were resurveyed and resampled in March. These resurveys included 2 sections in the Input reach, 3 in the Managed, and 3 sections in the Output reach. The General Monitoring component was also completed at this time. A total of 5 additional cross-sections that traverse the entire width of the Platte River (include all channels) were resurveyed. While all of these sections are located downstream of the intensive research reaches, 3 are located upstream of the Elm Creek Bridge and 2 below the bridge (Figure 2). The sections located downstream of the Elm Creek Bridge were placed on NPPD property and do not require special permissions for access. However, the three sections above the Elm Creek Bridge are located on private property and permission to access that property was granted by the landowners. The General Monitoring transects were surveyed and sampled in approximately the same manner as the intensive sections described above. Survey lines for the General sections were pre-selected in the office with GIS software and the endpoints of these lines entered into the GPS data collector. The endpoints of these lines were navigated to in the field and the section monumented and surveyed in the same manner as the intensive sections. While the total number of bed material samples collected in the General Monitoring transects is similar to the number collected in the intensive sections, 10- 15 verticals, the sampling was not as intensive as a whole along the sections with multiple channels. A minimum of three or four bed material samples were taken at equal intervals across each of the North and South channels. It was decided that the center channel would be sampled with greater intensity than the both the North and South channels because a larger proportion of the flow is conveyed through this channel. We took ground photographs from the left bank of the river to the right bank in a manner similar to that described above for the intensive sections.