Digital Coast In Action
Prediction of Runoff and Erosion Will Aid Land Managers in Hawaii
The Hanalei River, located on the Hawaiian island of Kauai, is one of the lengthiest rivers in the state and a critically important feature of the Hanalei Bay Watershed. The health of this watershed is essential to the local economy because it supports a variety of cultural and recreational activities and provides water to many taro farms. This watershed, like many in the tropics, is threatened by stormwater runoff, which can increase nutrient transport and sediment that degrades coral reef ecosystems. What’s more, Mount Wai‛ale‛ale, which drains into the Hanalei River, is one of the rainiest places on Earth, increasing the runoff potential.
The Process
To better understand hydrologic processes in the Hanalei Bay Watershed, researchers at the University of Hawaii applied the Nonpoint-Source Pollution and Erosion Comparison Tool (N-SPECT), which was developed by the NOAA Coastal Services Center. N-SPECT is a geographic information system (GIS) extension that uses land cover, elevation, precipitation, and soils data to create quantitative predictions.
Using N-SPECT enabled researchers to glean accurate estimates of both the volume and spatial location of predicted stormwater runoff. State and local land managers can use this information to prioritize the locations of management actions and evaluate a variety of management scenarios.
The image at left shows Coastal Change Analysis Program (C-CAP) land cover in the Hanalei Bay Watershed on the Hawaiian island of Kauai. The image at right adds information on predicted surface water runoff.
Partners in This Effort
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