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II. Field Activities <br />A. Fall 2000 -(Surveying, Sampling, and Photography -- Spatial Cross Sections) <br />Monitoring and research in support of the spatial intensive research component of the <br />work plan was initiated September 21, 2000 with the placement of 11, 21 and 25 <br />cross-section pins along each bank of the Input, Managed and Output Reaches <br />respectively of the middle channel of the Platte River within the Cottonwood Ranch <br />(Figure 1). A survey-grade global positioning system was used to make topographic <br />measurements along each cross-section by defining the slope breaks occurring <br />between riverbanks. Topography along a1157 cross-sections was measured during this <br />first round of data collection. Additional detailed topographic data was collected <br />along riverbanks, island and bar edges and along longitudinal profiles to supplement <br />the cross-section data collected at the Managed and Output reaches. This data has <br />been used to create detailed maps of bed elevation along these reaches for input to <br />multi-dimensional computational flow models. <br />Bed material was sampled at almost every other cross-section surveyed. Bed material <br />was collected at equal intervals (verticals) across a cross-section. The number of <br />samples collected at a section varied as a function of the width of the section. The <br />spacing of the verticals was on the order of one per approximately 10 to 12 meters, <br />although shorter sections were sampled with greater intensity to give a larger <br />statistical population. A total of 62, 119, and 108 bed-material samples were collected <br />at the Input, Managed and Output reaches respectively. <br />Originally, it was anticipated that two samples from each bank would be collected. <br />Recognizing that the riverbank is not homogeneous we divided the bank profile into <br />stratigraphic units. These units were identified by recognizing the differences in <br />sediment color and/or texture present between the top of the bank and the water <br />surface at the time of sampling. Each stratigraphic unit was sampled, photographed, <br />and a sketch made showing the measured thickness of each layer. A single riverbank <br />profile was selected at the Input, Managed, and Output reaches for stratigraphic <br />analysis. It is anticipated that additional bank sampling will be repeated in each reach <br />using the same procedures outlined above. <br />We took ground photography along each cross-section by standing over the left pin <br />and sighting the right pin in the center of the frame. Photographs were also made of <br />the left riverbank immediately upstream and downstream of each section by standing <br />on or around the left pin of the section and turning both upstream and downstream to <br />sight the bank in the center of the frame. <br />B. Spring - 2001- (Surveying, Sampling, and Photography -- Temporal Sections / <br />General Monitoring) <br />Data collection in support of both intensive monitoring and research and general <br />monitoring components of the protocol was initiated May 1, 2001. At this time a