Assessment of a Dynamic Watershed via Field Studies and GIS-Based Erosion Model

This paper presents a one-year-long study of the baseline hydrologic conditions of the Geus Watershed in the tropical island of Guam, through field observations. Data analyses show a strong correlation between stream level, turbidity, and rainfall within the watershed, suggesting a highly dynamic nature of Geus watershed. Field data were then used to create a stage discharge curve, which increases the efficiency of future watershed management by providing an estimate of stream flow from a simple measure of water level. The supplemental analyses based on the test results of soil samples and a GIS-based erosion model identified areas within the watershed with higher contributions to erosion potential. In addition, synthesis of the information in this watershed study will allow for future recommendations for effective and sustainable watershed management strategies, thereby opening a way for evaluating progress within the Geus watershed with continued monitoring.