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Harvard Forest REU Symposium Abstract 2005
- Title: Hydrology of Prospect Hill Tract at Harvard Forest
- Author: Safina Singh (Mount Holyoke College)
- Abstract:
This summer we initiated Long-Term Hydrological Studies at Harvard Forest. The objectives of my study were to examine the response of stream flow, evapotranspiration and ground water to precipitation events; to observe the effects of wetlands on stream discharge and to estimate the water balance of the Prospect Hill Watershed at Harvard Forest. The watershed consists of three minor watersheds called Nelson Watershed (44 ha), Lower Bigelow Watershed (65 ha) and Upper Bigelow Watershed (24 ha). I collected stream discharge measurements from weirs and pipes at Nelson Brook and Bigelow Brook; wetland water stages from gages at the respective sites and ground water depths from the Lyford Wells. In addition, I analyzed the data from eddy flux towers called Hemlock Tower and Little Prospect Hill Tower for evapotranspiration. We found that stream discharge; water stages at Black Gum Swamp, Beaver Swamp and ground water wells were highly correlated with precipitation events. The stream discharges at the watersheds were proportional to their sizes as illustrated by Figure 1. However, Nelson Watershed showed a delayed release of water displaying the greater buffering effect of Black Gum Swamp covering 25% of the Nelson Watershed in comparison to Beaver Swamp covering 5% of Lower Bigelow Watershed. We also found the water table at Beaver swamp fluctuating remarkably with rain events. The eddy flux data showed lower evapotranspiration of hardwoods during spring than in summer which is consistent with the foliation of hardwoods in summer. However, the daily averages of stream discharge, evapotranspiration, ground water and precipitation did not summed up to zero but -0.9mm for spring and 0.1mm for summer suggesting either overestimation or underestimation of inputs and outputs of the system in the water balance calculations.
- Research Category:
