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This relation was determined for each of six sampling sites located at streamflow gaging stations as shown in figure 17. A relation similar to equation 4 exists between suspended-sediment transport rate and water discharge. This relation is: Qs = aQb (5) where: Qs = suspended-sediment transport rate, in tons per day, and a and b = regression coefficients. Equations 4 and 5 are shown in table 6 for the six sites where sufficient data existed to regress the relations. A comparison of figure 17 and the correlation coefficients in table 6 shows that generally the stations with larger suspended-sediment con- centration have relations with larger correlation coefficients while those with smaller concentrations have relations with smaller correlation coefficients. Station 09216000, Big Sandy River below Eden, and station 09216050, Big Sandy River at Gasson Bridge, near Eden, are exceptions to this general relationship. The smaller correlation coefficients probably are due to the variations in streamflow at the stations. Both these stations are downstream from Big Sandy Reservoir, and occasionally streamflow consists of relatively large flows with relatively small suspended-sediment concentrations from reservoir releases. Streamflow at these stations also consists of relatively large flows with relatively large suspended-sediment concentrations from Little Sandy Creek. There- fore, streamflow at these stations may have two very different suspended- sediment concentrations for the same magnitude of discharge. The larger suspended-sediment concentrations occur as a result of greater availability of finer, more easily eroded and transported materi- al in the Pacific Creek drainage basin, which is underlain principally by sandstone, mudstone, and 'siltstone (fig. 8). In summary, for areas of the basin where fine-grained materials are available for erosion and transport, suspended-sediment concentrations tend to be large. Using equation 4, which was defined on the basis of periodic sam- ples, a long-term record of the suspended-sediment transport rate may be developed for a site. Such computations were made using the relation (DeLong, 1977): _ d L = (b/d) X CjQj j =j (6) 24