I am currently working on a research project examining the potential contribution of fecal indicator bacteria (FIB) to the water column from streambed sediment sources. The main goal is to identify the impact of bed sediment to water quality impairment. Briefly, I am collecting sediment samples from four different sites which are one mile apart from one another. The top most upstream site has direct access to cattle while other three downstream sites do not have cattle access. The result shows highest FIB concentrations and variability observed in the upstream which has access to cattle. FIB concentrations gradually decreased towards downstream sites. Now my question is how I can use this field study of a small portion (around 4 miles) of a river to a watershed scale? How might I can assess the impact of sediment sources on a watershed scale?