A methodology for investigating fresh water inflow requirements of a Texas estuary




Lambert, Walter P. and E. Gus Fruh

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Center for Research in Water Resources, Environmental Health Engineering Research Laboratory, Civil Engineering Department, University of Texas at Austin


This study addressed the water resource management problem of determining fresh water inflow requirements for a Texas estuary. A computer-oriented methodology was developed for assessing those requirements. The methodology provided a general, rational approach to the inflow problem without being dependent upon specific machines and computer programs. Viability of the methodology was demonstrated using existing computer models within an estuarine management scenario developed for Corpus Christi Bay, Texas. The methodology has a two-step structure. STEP 1 translates qualitative, ecologically-oriented management policy goals for an estuary into a set of net fresh water inflow requirements. STEP 2 produces the set of upstream fresh water release schedules required to satisfy those net inflow requirements. Execution of STEP 1 depends on the identification of a set of indicator organisms which, in some sense, characterized the desired estuarine environment. Indicator organisms must be responsive to a set of abiotic control parameters, e.g. salinity, which are controllable by upstream fresh water releases. Control parameter behavior within the estuary is modeled on a computer. Experiments with the models determine net fresh water inflow requirements for maintaining control parameter levels within acceptable bounds. STEP 2 uses computer models of upstream fresh water systems tributary to the estuary. Flow control structures are assumed to exist. Inputs to STEP 2 include legal, sociological, physical, hydrologic, and meteorological characteristics of the upstream region and surface water user community. Computer experiments with STEP 2 models produce upstream fresh water release schedules. These schedules provide necessary information for assessing regional impact of a particular estuarine management policy.


2 volumes


freshwater inflow, estuary, management, computer, methodology, water quality management, data processing, mathematical models