Water-quality data collected at 20 stations in Michigan were used to develop regression equations relating discharge to loads of 19 dissolved and suspended substances measured at each station. These equations and mean daily discharge were used to estimate long-term loads, which then were converted to estimates of drainage basin yields. These yields were compared to measured yields and to previous estimates. Fifty percent of the equations had standard errors of 22 percent or less; 90 percent had standard errors of 80 percent or less. Regression exponents indicate that the load increases as discharge increases in all cases, but for about two-thirds of the substances or properties the increase is less rapid than that of discharge. Seventy-eight percent of the nitrogen, phosphorus, and sediment loads, taken as a group, increase more rapidly than discharge. With respect to concentration, about 63 percent of the substances or properties decrease as discharge increases.
Additional publication details
USGS Numbered Series
Estimates of dissolved and suspended substance yield of stream basins in Michigan