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2017 behaved and consistent for the Arkansas River at Las Animas (and the Purgatoire River, as well,) there is considerably more scatter fur the Arkansas River below the dam. The correlation coefficient for the AIkansas River below the dam is considerably less, 0.69, compared to the Arkansas River at Las Animas, 0.85, and the Purgatoire River at Las Animas, 0.86 for the total data sets. For the monthly analyses, the Arkansas and Purgatoire Rivers at Las Animas show reasonable curve fits, with correlation coefficients of 0.65 to 0.95 and 0.77 to 0.90, respectively, while the Arkansas River below John Martin Dam values range from 0.00 to 0.78. The graphs further illustrate this latter point - for the months of May through September the fitted lines show a marked difference in slope, with May and July sloping in the opposite direction from the others (Qss decreasing for increasing Q) and September showing a near -horizontal line. This indicates that the suspended load is being dispersed in a different manner during the summer months. Additionally, Colby showed a correlation between suspended sediment concentration and bed material transport capacity. The reduction in the wash load component could be having an impact on the sands carried by the river downstream of the dam. This, coupled with a reduction in the peak discharges in the river as a result of operation of the dam for flood control, would be expected to cause .deposition without an equa1izing change in the river hydraulics (e.g. channel geometry) or bed material load. It is assumed that the reservoir also traps a significant quantity of bed material, but it is not readily apparent whether the reduced peak discharges or reduced sediment load is dominant. Furthermore, the scour which generally occurs immediately downstream of a dam often causes deposition at some point farther downstream. All of these factors indicate that the river has been placed in a state of non -equilibrium as a result of John Martin Dam. Additionally, Degradation Range Surveys were analyzed from nine survey periods ranging from December 1943-February 1944 to March 1987. The cross-sectional areas were compared by choosing an arbitraIy elevation above all of the section points and calculating the areas between this line and the ground surface. These were then compared to get changes in area. The resulting areas were also multiplied by the channel distances between ranges using the average-end-area method to arrive at volumes. These were also compared to get volume changes. The results of these analyses show the areal changes for Degradation Ranges 1 through 3 alternate between aggradation and degradation. Ranges 4 and 5 show only degradation. Ranges 6 and 7 indicate predominantly aggradation, and Range 8 alternates between aggradation and degradation. Range 9 shows aggradation for all surveys. Range 10 shows degradation for all surveys except 1972. Range 11 shows all aggradation Ranges 12 and 13 alternate between aggradation and degradation. The volwnetric changes for the individual sub-reaches between adjacent Degradation Ranges show low magnitude (=100 acre feet) changes in both directions for John Martin Dam to Range I, Ranges I to 2, and Ranges 2 to 3. Ranges 3 to 4, 4 to 5, and 5 to 6 all show degradation, up to a maximum of about 600 acre feet between Ranges 4 and 5. Ranges 6 to 7, 7 to 8, and 8 to 9 show predominantly aggradation, up to a maxinmm of approximately 1,200 acre feet between Ranges 7 and 8. BetWeen Ranges 9 and 10, there was mostly degradation to a maximum of about 600 acre feet, although net aggradation ofapproximately 800 acre feet was indicated from the 1972 survey. The sub-reaches between Ranges 10 and II, II and 12, and 12 and 13 show mostly aggradation to a maximum of about 3,700 acrefeet between 11 and 12.