Specific sediment yield based on different decades for the Lower Missouri

 
Sediment data behind the dams in the Missouri basin based on the last survey for each dam is used to develop a sediment yield map.  These dams were built in different years and were surveyed in different years. For sub-basin 1, where most of the sediment originated, 85 sediment survey data behind the dams for different decades are used to examine the temporal pattern of sediment yield. For this sub-basin, survey data were available from the 1930s to the 1960s. It can be seen that Ks decreases by increasing the decades (Figure 13). This is due to the fact that the Missouri has experienced a major shift in land management through the implementation of soil conservation methods.  Maps of unit area yield based on both the most recent survey data for each dam and the entire available data are shown in Figure 14. This Figure shows that the differences in unit area yield data are smoother in the most recent surveys. The standard deviations of differences between these maps are illustrated in Figure 15. This Figure shows that the most significant changes have occurred at locations with very high unit area yield based on the entire available data.