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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #319928
Title: Application of advanced remote sensing techniques to improve modeling estuary water quality

Author
item AZAD,, HOSSAIN - University Of Mississippi
item JIA, YAFEI - University Of Mississippi
item CHAO, XIAOBO - University Of Mississippi
item ALTINAKAR, MUSTAFA - University Of Mississippi

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 5/1/2014
Publication Date: 9/1/2014
Citation: Azad,, H., Jia, Y., Chao, X., Altinakar, M. 2014. Application of advanced remote sensing techniques to improve modeling estuary water quality. In: Finkl, C.W. and Makowski, C. editors. Remote Sensing and Modeling: Advances in Coastal and Marine Resources. New York, NY: Springer International. pp 295-313. DOI: DOI 10.1007/978-3-319-06326-3_12.

Interpretive Summary: The goal of this research was to advance the application of remote sensing technology to study the estuarine water quality. Specific focus was given on the integration of remote sensing technology with the numerical water quality model to map and monitor estuarine water quality at high spatial and temporal resolution. A time series of Landsat 5 TM imagery and digital image processing techniques were used to estimate and map suspended sediment concentrations, chlorophyll-a concentration and salinity in the Lake Pontchartrain during the Bonnet Carre´ Spillway event in 1997. CCHE2D WQ, a numerical water quality model developed at NCCHE was used to model the dynamics of the lake water quality during and after the spill way opening event. The Landsat imagery derived water quality data were used to initialize, calibrate and validate the numerical model. Although both remote sensing and numerical model based methods have weaknesses when used together, they can become a powerful tool to study water quality in estuary. The results obtained in this research clearly demonstrate this capability. This research is still evolving. Inspired by the outcome of this study, it is being considered to develop a system based on the integration of remote sensing technology and numerical model to study estuarine water quality. This system is expected to be capable of (1) generating different water quality data from multi-sensor satellite platforms, (2) using satellite observed water quality estimation to initialize, calibrate and validate the numerical water quality model to generate estuarine water quality data at high spatial and temporal resolution, and (3) visualizing estuary water quality dynamics in the web based GIS environment.

Technical Abstract: Estuaries, the interface between terrestrial and coastal waters are an important component of complex and dynamic coastal watersheds. They are usually characterized by abrupt chemical gradients and complex dynamics, which can result in major transformations in the amount, chemical nature and timing of the flux of material along these river–sea transition zones. The ecological functioning of these areas is considered to be of major concern, as estuaries offer the last opportunity to manage water quality problems before they become uncontrollable in the coastal waters. Numerical models can provide hydrodynamically computed water quality data to study estuary water quality, but they have problems with initializations, boundary conditions, calibration, and validation. Another way is to use remote sensing technology, but they provide only surface observations and there are challenges related to cloud coverage, ground truthing, and variable spatial and temporal resolution. Although both methods have weaknesses when used together, they can become a powerful tool to study water quality in estuary. This has been demonstrated through recent application of this capability to study water quality problem in Lake Pontchartrain. This study evaluated the use of Landsat 5 TM multispectral imagery to generate spatially distributed water quality data for use in CCHE2D Water Quality model to improve its performance in this estuary to simulate sediment transport, predict algal bloom and monitor salinity after the Bonnet Carre´ Spillway opening event in 1997. The outcome of this research clearly indicates that the application of remote sensing techniques for estuarine water quality study can be advanced by integrating them with numerical water quality models.