Tukman Geospatial logo
Mark Tukman and colleague mapping

Featured Projects

Horry County Vegetation Mapping Project

Team Members: Kass Green and Associates and Fugro Earthdata, Inc.

Description: Horry County needed an accurate land cover layer to use as one of the inputs to their storm water models. Fugro Earthdata, the prime contractor on the project, was in an excellent position to collect and provide Horry County with high resolution imagery. They turned to Tukman Geospatial and KGA to help them to develop a vegetation map using the high-resolution imagery.

Tukman Geospatial, working closely with KGA and Fugro-Earthdata, used the high resolution imagery (ADS40), along with LIDAR data also collected by Fugro-Earthdata, to automatically label polygons created in Definien’s Ecognition. The processed utilized CART (Classification and Regression Tree Analysis), field work to collect training data and to verify the models, and lots of photo interpretation.

For the field work, Tukman Geospatial developed a customized field data collection form, which was programmed in Visual Basic for Applications to run within ArcMap. The field form ensured that accurate, consistent field data was collected.

To help improve the accuracy of the vegetation map, Tukman Geospatial derived a vegetation canopy height layer from the LIDAR derived digital terrain model and digital surface model. The height layer was used both as in input to CART and as an aid during photo interpretation.

The end product of this project was a GIS layer that divided Horry County into hundreds of thousands of polygons, each representing contiguous blocks of relatively homogenous land cover. Each polygon received a label representing its land cover type. The land cover classification was a modified Anderson Level II classification, with classes such as shrub, wetland evergreen forest, wetland deciduous forest, upland evergreen forest, cropland, etc.

Horry County had very accurate planimetric data representing building footprints and roads. Tukman Geospatial used this existing planimetric data to add percent impervious labels to all mapped polygons.

For the manual editing (photo interpretation) phase of the project, Tukman Geospatial implemented an SQL geodatabase with SDE to accommodate multiple editors in multiple locations.

This project was completed on time and on budget; the client was very pleased with the work completed by the team.