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<br />14 <br /> <br />method of error estimation assumes that we identifiedthe boundaries. correctlY; <br /> <br />and that aerial error is the result of map scale only. <br /> <br />Stratigraphy and Dendrochronology <br /> <br />Stratigraphy was analyzed by excavating part of the active floodplain <br /> <br />near. tfJe present cableway. Root crown elevations were noted for a number of <br /> <br />buried saltcedar exposed during excavation. Slabs were removed throughout <br /> <br />the root croWn area and were sanded and polished. Tree fings were counted to <br /> <br />determine the approximate age of the tree, and the age of the sedimentary layer <br /> <br />at that level was assigned the same age as the tree. Comparisons were made <br /> <br />between cross-section data and tree-ring data to corroborate conclusions about <br /> <br />the timing of bank aggradation. <br /> <br />Channel Cross-Section Monumenting <br />and Surveying <br /> <br />Eight semipermanent cross sections were established near the present <br /> <br />cableway. Detailed surveys of the cross sections were completed over a range <br /> <br />of discharges from 98.8 to 801.4 m3/s on both the rising and falling limbs of the <br /> <br />1995 snowmelt flood (Table 3). Each channel cross section was monumented <br /> <br />by driving 1.5-meter metal fence posts into the banks. These posts also served <br /> <br />as semipermanent benchmarks. All benchmarks were surveyed from a common <br /> <br />point to provide relative coordinates and elevations. Cross sections were <br /> <br />surveyed using a geodetic total station for all areas that were above water or <br />