ACCESS NUMBER: 30660-19965 

STUDY TITLE: Coastal Marine Environmental Modeling: Part III 

REPORT TITLE: High-Resolution Integrated Hydrology-Hydrodynamic Model: 

Development and Application to Barataria Basin, Louisiana 

CONTRACT NUMBER: 14-35-0001-30660-19965 

SPONSORING OCS REGION: Gulf of Mexico 

APPLICABLE PLANNING AREA(S): Northern Gulf of Mexico 

FISCAL YEAR(S) OF PROJECT FUNDING: 1999; 2000; 2001 

COMPLETION DATE OF REPORT: October 2004 

COST(S): FY 1999: $115,134; FY 2000: $104,472; FY 2001: $118,080; 

CUMULATIVE PROJECT COST: $337,686 

PROJECT MANAGER(S): Masamichi Inoue 

AFFILIATION: Coastal Studies Institute and Dept. of Oceanography & Coastal 

Sciences, Louisiana State University 

ADDRESS: Coastal Studies Institute, Louisiana State University, Baton Rouge, 

Louisiana 70803 

PRINCIPAL INVESTIGATOR(S): Masamichi Inoue, Dongho Park, William Wiseman, 

Jr., Dubravko Justic, and Gregg Stone 

KEY WORDS: Barataria Basin, Louisiana estuaries, hydrology-hydrodynamic 

modeling, salinity distribution, freshwater diversion, estuarine circulation 

BACKGROUND: The Barataria Basin, a bar-built estuarine system located directly 

west of the Mississippi Delta, has been experiencing a significant land loss, especially 

since the leveeing of the Mississippi River for flood control purposes in early 20th

century. Recent efforts to alleviate the land loss problem includes the construction of 

man-made freshwater diversion structure in order to divert river water as well as its 

associated suspended sediments from the Mississippi River into the Barataria Basin. A 

major consequence of man-made freshwater diversions in estuarine environments such 

as Barataria Basin is its impact on salinity distribution. Salinity gradients, such as those 

within Barataria and Terrebonne estuaries have a significant influence on the 

distribution of estuarine flora and fauna. In order to establish modeling capability usable 

for responsible management purposes, an integrated hydrology-hydrodynamic model, 

that simulates local runoff and circulation inside the bay, is needed. 
ACCESS NUMBER: 30660-19965 

OBJECTIVES: To establish an integrated hydrology-hydrodynamic model of Barataria 

Basin that can be useful for management purposes. The model should; 1) account for 

local hydrological cycle including evaporation and precipitation, in particular local runoff 

from the surrounding drainage basins; 2) be high-resolution in order to simulate very 

accurately salinity changes in the complex network of channels and bayous within the 

basin; 3) be thoroughly tested and calibrated against real observed data to be useful. 

The direct contribution of this project would be to demonstrate feasibility of an integrated 

hydrology-hydrodynamic model that can be used to simulate anticipated changes in bay 

salinity distribution in response to various diversion scenarios within the framework of 

various local weather and climatic conditions. 

DESCRIPTION: Development of a high-resolution integrated hydrology-hydrodynamic 

model of Barataria Basin is presented. First, a hydrology model that explicitly accounts 

for the local hydrological cycle over the surrounding drainage basins for the Barataria 

Basin is developed. Using observed precipitation and estimated evaporation over the 

surrounding drainage basins, the hydrology model provides estimates of local runoff. 

The hydrology model is coupled to a high-resolution (O (100m)) two-dimensional depthintegrated hydrodynamic model of the Barataria Basin in order to simulate the 

hydrodynamic response of Barataria Basin to hydrological, tidal, and wind forcing. The 

coupled model was used to simulate the flood event during tropical storm Allison in 

June 2001 that resulted in significant rise in sea-level heights especially in the upstream 

region of the basin, thus, providing a rare opportunity to test the model. The integrated 

model was also used to simulate a typical dry summer condition, namely the 30-day 

period during the summer of 1999. The model was then used to simulate potential 

impact of freshwater diversions at Naomi, West Pointe à la Hache, and Davis Pond. 

SIGNIFICANT CONCLUSIONS: A high-resolution (O (100m)), integrated hydrologyhydrodynamic model of the Barataria Basin can be developed to simulate explicitly local 

hydrological cycle over the surrounding drainage basin and hydrodynamics within the 

basin in response to hydrological, tidal and wind forcing. The integrated model appears 

to be able to simulate the observed sea-level variations during the flood event due to 

the tropical storm Allison in June 2001. The model appears to do reasonable job of 

simulating time evolution of salinity fields inside the bay during a typical dry summer 

condition, namely the 30-day period during the summer of 1999. Model simulations to 

depict potential impact of freshwater diversions at Naomi, West Pointe à la Hache and 

at Davis Pond suggest that even at reasonable diversion rates, notable impacts on 

water level and salinity should be observable. The results of this study highlight the 

need to use high model resolution, sufficiently high enough to resolve many of the 

important complex morphological features of the basin in order to achieve reasonable 

simulation capability of salinity distribution for morphologically complex basins such as 

Barataria Basin. 

STUDY RESULTS: First, a hydrology model that explicitly accounts for the local 

hydrological cycle over the surrounding drainage basins for the Barataria Basin is 

developed. Using observed precipitation and estimated evaporation over the 

surrounding drainage basins, the hydrology model provides estimates of local runoff. 
ACCESS NUMBER: 30660-19965 

The hydrology model is coupled to a high-resolution (O (100m)) two-dimensional depthintegrated hydrodynamic model of the Barataria Basin in order to simulate the 

hydrodynamic response of Barataria Basin to hydrological, tidal, and wind forcing. A 

flood event during tropical storm Allison in June 2001 resulted in significant rise in sealevel heights especially in the upstream region of the basin, thus, providing a rare 

opportunity to test the model. It is shown that the integrated model is capable of 

capturing a significant portion of the observed sea-level variations during the flood. The 

integrated model was also used to simulate a typical dry summer condition, namely the 

30-day period during the summer of 1999. Despite the relatively crude salinity initial 

condition used (based on only eight observations), the model appears to do reasonable 

job of simulating time evolution of salinity fields inside the bay. The model was then 

used to simulate potential impact of freshwater diversions at Naomi, West Pointe à la 

Hache, and Davis Pond. Those simulation runs suggest that even at reasonable 

diversion rates, notable impacts on water level and salinity should be observable in the 

multiply connected channels through the marsh in the vicinity of operating diversion 

structures within several days of freshwater release, and after 15 days or so even in the 

downstream regions of the basin. The largest impact of diversions should be felt in the 

mid-bay region where the ambient salinity gradients are the steepest. It is notable that 

the diversion signal propagates at shallow-water wave speed, like a tidal bore, due to its 

mass flux, that is much faster than the diffusion time-scale suggested for mixing of two 

water masses in estuaries (e. g., Elliot and Reid, 1976). It is interesting to note that 

even after day 30, some isolated areas still remain without noticeable influence of the 

diversion. Those observations highlight the need to use high model resolution, 

sufficiently high enough to resolve many of the important complex morphological 

features of the basin in order to achieve reasonable simulation capability for 

morphologically complex basins such as Barataria Basin. 

STUDY PRODUCTS: Inoue, M. and W. J. Wiseman, Jr. 2000. Transport, stirring and 

mixing process in a Louisiana estuary: A model study. Estuarine. Coastal and Shelf 

Science, 50:449-466. 

Park, D., M. Inoue, and W. J. Wiseman, Jr., 2000. Wind, tide, and buoyancy-driven flow 

in Barataria Bay, LA. Extended abstracts proceedings volume, edited by C. T. 

Friedrichs and A. Valle-Levinson, the 10th International Biennial Conference on Physics 

of Estuaries and Coastal Seas. 7-11 October 2000, Norfolk, Virginia, SRAMSOE 

Report No. 366, Virginia Institute of Marine Science, Gloucester Point, VA, U. S. A.

Park, D., M. Inoue, and W. J. Wiseman, Jr., 2001. Hydrodynamics and freshwater 

dispersion within Barataria Basin. ERF2001: An Estuarine Odyssey, Conference 

Abstracts, 106. 

Park, D. H. 2002. Hydrodynamics and freshwater dispersion within Barataria Basin. 

Ph.D. dissertation, Louisiana State University, Baton Rouge, Louisiana. 107 pp. 
ACCESS NUMBER: 30660-19965 

Park, D., M. Inoue and W. J. Wiseman, Jr., 2002. Salinity effects of riverine diversions 

to Barataria Basin, a bar-built estuary. Abstract submitted to the 11th International 

Biennial Conference on Physics of Estuaries and Coastal Seas in Hamburg, Germany. 

Park, D., M. Inoue and W. J. Wiseman, Jr., 2002. A high-resolution integrated 

hydrology-hydrodynamic model of the Barataria Basin system. Abstract submitted to 

OCEANS 2002 MTS/IEEE meeting held in Biloxi, Mississippi, October, 2002. 

Inoue, M., D. Park, D. Justic, and W. J. Wiseman, Jr., 2004. A High-Resolution 

Integrated Hydrology-Hydrodynamic Model of the Barataria Basin System. Abstract 

submitted to 7th International Marine Environmental Modeling Seminar to be held in 

Washington, DC, October 19-21, 2004.