Viewing our HIstory of Trash and Tire Removal planning future cleanups
GIS mapPING TO visualize our accomplishments
Clean Jordan Lake has taken advantage of the Capstone Project offered in the master’s degree in Geospatial Information Science & Technology (MGIST) at the Center for Geospatial Analytics at North Carolina State University. In their last semester, students work directly with community and industry partners to apply the knowledge and skills they have developed to real-world problems. Sue King developed the first GIS database in 2017. Click here to see her final product. In Spring 2020, Kelsey Little developed the first version of a mobile phone APP to enable our cleanup leaders to enter cleanup data and the length of shoreline while in the field.
How to estimate impact of rainfall on trash ?
At least two cleanups are needed along the same length of shoreline to measure the trash amount arriving with rainfall. The first cleanup establishes a clean state for the shoreline. The trash collected per 100 ft in the next cleanup is divided by the number of significant rainfalls between the first and second cleanups. Lake level rise is the surrogate measure of rainfall available online from the USGS gauging station in Moncure. The same method of calculation applies to subsequent cleanups.In Fall 2020, Laurel Krynock improved the phone APP and the GIS database. Click here to watch her presentation of the project at the NCSU Geospatial Analytics Center. Click here to watch her short video about how to use the phone APP. She greatly increased the value of our database to public interest groups and local government agencies in the watershed by software that allows calculation of the amount of trash arriving from rainfall. Trash data were isolated for 45 small subsections of shoreline along the Haw River Arm and upwards a few miles on the New Hope Channel where recreation is only a minor contributor. Lake level rise is the net result of widely varying rainfall over 1,300 sq. mi. of watershed. Laurel wrote code to do data fetching, from the online graph of lake level at the USGS Gauging Station at Jordan Lake so as to identify the lake level rises above normal and their magnitude going back to 2009 when our cleanup work began. The dates of each cleanup at each shoreline subsection, the number of trash bags and the length of shoreline are in the GIS database. The number of LLRs and cumulative height of all LLRs between successive cleanups are retrieved from the data fetching. Dividing the amount of trash per 100 ft of shoreline by the either the number of LLRs of the total height of all the LLRs are two ways of connecting rainfall to the intensity of trash deposits.
GIS focuses on the Haw River Arm from the entrance of Robeson Creek to the dam and both sides of New Hope River Channel from the dam northward to New Hope Overlook at Jordan Lake State Park.
About 20 mi. were cleaned at least once. This section was selected because the main source of trash and tires comes from stormwater flows from the Haw River watershed after rainfalls rather than recreational use of the lake. The shoreline length was divided into 45 small subsections to show spatial variability in intensity of trash and tires and in volunteer effort to remove it.The public can access the Clean Jordan Lake Trash Cleanup Web Mapping Application and User Guide. In the example mapping below, the Average Trash Metric Tool in lb/100 ft was selected by clicking on the Toolbox icon. The Legend icon at the top right was selected to show the values of trash associated with each circle size. Trash loading is averaged across all cleanups conducted at each subsection of shoreline and the yellow triangles are located at the center of each subsection.
Choosing from the Toolbox icon the Average Trash Metric Tool of lb/100 ft/LLR (no.) relates the trash deposit to the rainfall events the caused it as depicted below. A mapping can also be generated for lb/100 ft/CLLR (ft) that accounts for the magnitude of each LLR and thus, the intensity-duration of rainfalls between successive cleanups.
Each time a new trash cleanup is entered either at the site with the phone APP or later with the ADMIN version of the Web Mapping Application, the trash metrics are updated automatically.
The public can also query the Web Mapping Application to look at the trash removed for each cleanup in each specific subsection of shoreline. Clicking on the Bar Graph Icon and choosing a subsections (HRA E2) results in the mapping below. The general decline in trash loadings per 100 ft from the early years of cleanups is because our volunteers were faced with removing a legacy of 28 years of trash deposited since the lake had been filled in 1981. The loadings also vary from date to date because of the intervening number of rainfall events, i.e., the more rainfalls, generally the more trash.
