Linked-Model Simulations

SRBEX is the first of several planned regional experiments which are to be undertaken in our interdisciplinary EOS research program. The Susquehanna River Basin (SRB) is a 62,419 km² watershed covering portions of New York, Pennsylvania, and Maryland. The overarching goals of SRBEX are to understand the hydrologic cycle of the basin through modeling and the analysis of observed data, and -- as a result of this understanding -- to develop capabilities for monitoring and projecting changes in basin hydrology (Yarnal, 1994a and 1994b) and their impact on the landscape and human activities.

The hydrologic cycle of this basin reflects the complex interaction of a variety of physical and biological systems, including: atmospheric circulation; transfers of energy and moisture between the atmosphere, vegetation, and soil; transport of energy and moisture within the soil; surface and underground storage and channeling of water; and chemical and erosional processes associated with the circulation of water below and above ground.

To improve our understanding of the complex dynamics of the SRB, we have set up one or more models for each of these systems, and are linking them together to simulate the complete hydrologic cycle of the entire SRB and of selected sub-basins and watersheds within it. The linked models will first be tested by simulating historical weather events and sequences, and then used to investigate the effects of changes in climatic conditions and land surface characteristics such as vegetation.

We have defined three initial tests of the linked models:

The results of each of these tests will be used to improve the models and the linkages between them.

For the first test, we have attempted to simulate the storm event from 9-11 April 1980. This particular storm was chosen because it is a climatologically representative event for the northeastern U.S. We have obtained simulated precipitation fields over the entire SRB, but have not yet completed comparisons with fields obtained from objective analysis of the observed precipitation, nor comparisons of simulated hydrographs with discharge rates recorded at gaging stations.

The planned multiple-event simulation will extend over a period which includes several storm events and dry periods. The scope of the doubled carbon dioxide simulation is not yet fully defined.


Last change: 11 May 1995, R. A. White / raw@essc.psu.edu