As described in the Task Force Science Assessment Topical Report 3, historical data on streamflow and concentrations of dissolved nitrogen (N), phosphorous (P), and silica (Si)(nutrients), were used in regression models to estimate the daily, monthly, and annual flux and yield of nutrients at 36 sites on smaller rivers within the Mississippi Basin and at 9 sites on the Mississippi River or its major tributaries. Six sites on smaller rivers that were included in the CENR report did not have daily streamflow data and are not included here. The total flux and yield estimates for the Mississippi River, which include the diversion into the Atchafalaya River at the Old River Outflow, are listed under "the Mississippi at St. Francisville" in the data files. The total flux and yield estimates from the Mississippi-Atchafalaya-Red River Basin, which includes the Mississippi, Atchafalaya, and Red Rivers are listed under "Total to Gulf" in the data files. The period of record for most sites and constituents extends from the mid-1970’s to the mid-1990’s, but varies some by station.

Data (Excel files) generated during the preparation of the CENR topic 3 report are provided below. First are estimates of the average annual flux and yield for 1980-96, of nitrate, total nitrogen, ortho-phosphorus, total phosphorus, silica, and chloride for the 9 sites. Second are estimates of the annual flux and yield of nitrate, total nitrogen, ortho-phosphorus, total phosphorus, silica, and chloride for both the 36 sites and 9 sites. Third are estimates of the monthly flux and yield for both the 36 sites and 9 sites.

Flux-yield-80-96average-9sites.xls ­ Average annual nutrient flux estimates for the 1980-96 time period, for the 9 sites
Flux-yield-annual-9sites.xl ­ annual (January-December) nutrient flux estimates for the 9 sites
Flux-yield-monthly-9sites.xls ­ monthly nutrient flux estimates for the 9 sites
Flux-yield-annual-36sites.xls ­ annual (January-December) nutrient flux estimates for the 36 sites
Flux-yield-monthly-36sites.xls ­ monthly nutrient flux estimates for the 36 sites

 

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