Tree health mapping with multispectral remote sensing data at UC Davis, California |
| |
Authors: | Qingfu Xiao E Gregory McPherson |
| |
Institution: | (1) Department of Land, Air, and Water Resources, University of California, Davis;(2) Center for Urban Forest Research, Pacific Southwest Research Station, USDA Forest Service, USA;(3) CUFR, c/o Department of Plant Sciences, University of California, Mail Stop 6, One Shields Avenue, Davis, 95616-8780, CA |
| |
Abstract: | Tree health is a critical parameter for evaluating urban ecosystem health and sustainability. Traditionally, this parameter
has been derived from field surveys. We used multispectral remote sensing data and GIS techniques to determine tree health
at the University of California, Davis. The study area (363 ha) contained 8,962 trees of 215 species. Tree health conditions
were mapped for each physiognomic type at two scales: pixel and whole tree. At the pixel scale, each tree pixel within the
tree crown was classified as either healthy or unhealthy based on vegetation index values. At the whole tree scale, raster
based statistical analysis was used to calculate tree health index which is the ratio of healthy pixels to entire tree pixels
within the tree crown. The tree was classified as healthy if the index was greater than 70%. Accuracy was checked against
a random sample of 1,186 trees. At the whole tree level, 86% of campus trees were classified as healthy with 88% mapping accuracy.
At the pixel level, 86% of the campus tree cover was classified as healthy. This tree health evaluation approach allows managers
to identify the location of unhealthy trees for further diagnosis and treatment. It can be used to track the spread of disease
and monitor seasonal or annual changes in tree health. Also, it provides tree health information that is fundamental to modeling
and analysis of the environmental, social, and economic services produced by urban forests. |
| |
Keywords: | Urban forestry tree health index tree health mapping remote sensing data |
本文献已被 SpringerLink 等数据库收录! |
|