Simulating Forest Cover and Climate Change Impacts on Historic New England Runoff

The majority of the world currently lacks the monitoring equipment necessary to estimate runoff values, even at annual timescales. Reconstructing historical runoff presents a similar challenge, where a paucity of data requires simple methods, and in a more practical context, a simple means of estimating evapotranspiration. Inquiries following the logic from this perspective are particularly useful for large-scale analyses, where large sets of data inputs are required and where regional results may shed insight into focusing efforts for efficient allocation of funds for important water management and policy plans. This paper presents one means of modeling runoff using observed temperature, precipitation and sunny day measurements, an educated range of uncertain land cover estimates and a plant-water use coefficient by means of a Budyko curve, a Markov Chain Monte Carlo and Hamon model approach. The median regional runoff was found to increase throughout the time period. Using these methods, the imprint of the runoff from the northeastern United States during the early part of the 19th century was projected onto the later part of the century to test the hydrologic system’s sensitivity to changes in land cover, potential evapotranspiration and precipitation. Preliminary results show that throughout the studied time period precipitation is the primary driver of regional runoff variability and that the runoff estimates strongly correlate with changes in precipitation but not with changes in forest cover or PET.