INTEGRATING SCIENTIFIC AND INSTITUTIONAL ASPECTS OF WATER RESOURCES MANAGEMENT: A CASE STUDY OF THE BRANDYWINE BASIN (PENNSYLVANIA)

Different mathematical methods have been successfully applied in water resource planning and management. However, systems modeling has not been sufficiently and adequately linked with the institutional decision making in resolving water problems for the following reasons: (1) the water policies and evolution of institutional arrangements in the United States have resulted in decomposing the hydrologic regime into components; (2) hydrologic models are always developed in the deterministic fashion and lack the capability of forecasting the stochastic behavior of hydrologic responses for decision making under uncertainty; and (3) most of the developed hydrologic models are difficult to use due to insufficiency of data and the enormous effort needed to calibrate model parameters. The systems concept is incorporated in this research in order to provide a holistic approach to water issues and at the same time to apply mathematical methods to the decision making process. That is, the institutional aspects of water management and currently applied mathematical techniques are integrated using an interdisciplinary problem solving paradigm. A case study of the Brandywine Basin is applied to demonstrate the applicability of the interdisciplinary paradigm for water resource management. Emphasis is placed upon developing a deterministic hydrologic model. The deterministic model, composed of the hydrologic regime and all water uses, is developed by integrating empirically derived component equations. The output of the deterministic model is the response of the hydrologic regime to various inputs especially including land use characteristics and policy decisions. Institutional arrangements are analyzed and linked with the deterministic model in order to detect the effects of decisions/plans on the hydrologic cycle. A stochastic model is developed by using Markov process to simulate daily precipitation. The coupling of the stochastic and deterministic aspects of hydrology constitutes an advance in the field of systems modeling for water resources management. Such an effort is achieved by using simulated daily precipitation from the stochastic model as input to the deterministic model. The deterministic model is validated by comparing the simulated and recorded streamflows; the stochastic model is tested by comparing the generated daily precipitation with the historical events. Examples of land use change and reservoir construction further demonstrate the applicability of the proposed interdisciplinary paradigm. This modeling effort is applicable to watersheds smaller than 1000 square miles and useful to regional and county level institutions in predicting the hydrologic reliability of the consequences of the proposed changes