Spatial Optimization of CoCoRAHS Network in Tennessee

CoCoRaHS (Community Collaborative Rain, Hail and Snow Network) is a non-profit, all-volunteer, community-based network of thousands of observers of all ages and backgrounds working together in all fifty states and Canada to measure and map precipitation, By using low-cost rain gauges, incorporating training and education, and taking advantage of an interactive Web-site, high quality daily rainfall data is available for natural resource, education and research applications. CoCoRAHS was established in Tennessee in 2007 and the reported rainfall data have been important to augment the information available for monitoring droughts and floods. However, the distribution of stations is less than ideal; there are no observers in 9 out of 95 counties, only 1 observer in another 13 counties, and several counties have more than 20 observers. Recruitment of volunteers has been very haphazard, with no statewide coordination to optimize the spatial distribution of the observers. Sustained and reliable observation of daily rainfall has also been a problem, with about 450 consistent observers out of more than 1500 who registered as volunteers; more than 500 observers never reported at all. In addition, very little education and outreach have taken place due to lack of involvement by teachers and schools. Logistically, there is too much redundancy and overlap with other rain gauges such as National Weather Service (NWS) Cooperative Observer and other rainfall data reported to the NWS such as ASOS (Automated Surface Observing System). To help improve the network and enhance the educational benefits, a spatial analysis was conducted to 1) find the optimal new locations for CoCoRAHS using spatial information such as topography, currently reporting CoCoRAHS locations, NWS rain gauges, and UT mesonet stations, and 2) recruit new observers for CoCoRAHS, using other spatial information relative to ideal new locations: such as schools, fire halls, master gardens, community gardens, utility plants, UT Extension offices, libraries, transportation offices, city engineering offices, and other organizations that might be interested in the educational aspects, or are open 24/7. The resulting spatial analysis has provided a list of ideal contacts to possibly recruit in this rapidly expanding program.