THE RED RIVER DELTA, LAKE TEXOMA: A REMOTE SENSING STUDY OF DELTA

The Red River is a classic braided stream, and carries a very high sediment load. Because the river is mostly uncontrolled, this high sediment load is deposited where the Red River flows into Lake Texoma, forming a rapidly changing delta. This delta has grown since the Denison Dam was completed in 1944.

We used ASTER and Landsat satellite imagery to study the highly dynamic growth of this delta. It has a classic river-dominated "bird foot" type morphology, with sub-lobes formed due to protrusion of terminal distributary channels into Lake. Delta morphology has changed with growth. Satellite images collected from 1984 to 2001, show the Red River delta prograded into Lake Texoma more than 8 km.

Study of turbidity in front of the delta suggests that the river outflow is hyperpycnal at discharges less than 1000 ft3/s but homopycnal at discharges more than 1000 ft3/s. For calculation of suspended concentrations in the water, we used bands 1, 2 and 3 Landsat TM data and band 2 and 3 ASTER data. Transformation of digital numbers yielded estimates of suspended sediment concentrations between 0 and 800 mg/l, but the method has some limitation for concentrations higher than 600mg/l. The remote sensing data sets we used were obtained during relative low discharge of the Red River, but for a discharge of 3500 ft3/s (July 2nd 1997) suspended sediments are visible as far as 8 km away from the delta front.