Geoscience Reference
In-Depth Information
large basin runoff model (DLBRM) and then discusses procedures for processing
and deriving nutrient loadings from both point and nonpoint sources. These loading
estimates are then used as input to the water quality model to quantify the transport-
ation of combined loadings of livestock manure and fertilizers and CSOs to storages
of upper soil zone, lower soil zone, groundwater, and surface water in the Saginaw
Bay Basin and to enable management agencies to target critical areas for imple-
mentation of water quality programs.
6.2 The Study Area
The study area of this research is the Saginaw Bay Basin with a drainage area
of about 23,300 km
2
, subdivided into four sub-watersheds: the Saginaw River
(16,680 km
2
) west of the bay, the AuGres-Rifle (2,777 km
2
) to the North,
Kawkawlin-Pine (1,409 km
2
) in the center, and Pigeon-Wiscoggin (2,425 km
2
)to
the East (Fig.
6.1
). The Saginaw Bay Basin, covering portions of 22 counties, and
hosts a number of cities such as Bay City, Flint, Midland, and Saginaw, etc. It is an
important base for industrial supply, food production, warm water fishing, and
navigation, with agriculture and forests being the two major land uses. Soils in
the watershed consist mainly of loamy and silty clays and sands, and are poorly
drained in much of the area. Major crops in the watershed include corn, soybeans,
