Monitoring Network for Selected Mississippi-Atchafalaya River Subbasins with Varied Sizes, Hydrology, Land Use, and Geographic Location

Figure 1. Locations of 21 subbasins in the Mississippi-Atchafalaya River Basin with varied size, hydrology, land use, and geographic location that are used for estimating and studying nutrient fluxes. (Subbasin number is identified in table 1.) (Click on image for larger version)

In addition to the stations that are used to estimate delivery to the Gulf of Mexico, and the stations used to estimate nutrient fluxes of major Mississippi River subbasins, monitoring is conducted at stations located within 21 subbasins that vary in size, hydrology, land use, and geographic location. These subbasin drainage areas vary from 16,200 to 630,700 square kilometers.

The drainage areas of the 21 subbasins are shown in figure 1, and pertinent station information that defines these subbasins is provided in table 1. Sampling is active for 12 of the 21 selected subbasins as of 2006 as indicated in table 1. Six of the 21 subbasins are currently part of the National Stream Quality Accounting Network (NASQAN) Program network, which is currently designed to collect data for larger subbasins.