Influence of riparian forest composition and land use on watershed performance and management planning

Background/Question/Methods

The rapid development and change of land use is constantly altering the hydrology and ecosystem function within a watershed, many times leading to the impairment of surface and groundwater. Currently, the roles of forests in the management of watersheds are uncertain and should be thoroughly investigated to provide a comprehensive understanding of their effects. This study investigates how erosion and water absorption patterns can be predicted by soil and forest structure within the Upper Raritan Watershed, New Jersey, and aims to update our current prediction methods and serve as a tool for scientists and policymakers in managing the water quality and quantity within individual watersheds. Using ArcGIS software, analyses were performed to determine any correlation between percent forest cover near streams and water quality. New Jersey Department of Environmental Protection’s (NJDEP) designated riparian buffer zones of three hundred feet were used along streams and rivers to calculate the percentage of forest located within the buffer. These calculations were used to compare the New Jersey Impairment Score (NJIS) and the Habitat Quality Score, both used in ESEPA Rapid Bioassessment Protocol in evaluating waters, and its correlations to forest percentage within the buffer zone. 

Results/Conclusions

The resulting data indicates that watershed areas with a higher percentage of forest area within the buffer zone had higher water quality levels in a significant number of cases (P < 0.05). Given the diversity of forests, this data must be further tested using different buffer zones and forest type categories to observe their effects on water quality; such a tool will be most useful in waters designated for consumption and could influence land development patterns. The results of this study may provide a more comprehensive understanding of watershed function based on land usage and forest landscape. Future exploration will lead to improved prediction and management of water quality through monitoring the spatial distribution of forested landscapes in the watersheds.