Considering that a large area of Pinus tabulaeformis suffers from Dendrolimus tabulaeformis in West Liaoning
this study monitored Dendrolimus. tabulaeformis disaster promptly
efficiently
and precisely through remote sensing technology. Information on the influencing factors
such as geography and meteorology
was collected to provide a reference for future prediction. This study adopted the method of Thematic Mapper(TM)
Enhanced TM Plus data source
and Geographic Information System technology to examine the image gray histograms of injured Pinus tabulaeformis with various damage degrees and monitor the damage degrees by using the Ratio Vegetation Index(RVI) [near infrared(NIR)/red]. To analyze the imposing factors
the classification results from RVI analysis were overlapped with geography and meteorology statistics
with cross reference to previous studies on the biological characteristics of Dendrolimus tabulaeformis. By analyzing the image gray histograms
this study determined that in the Pinus tabulaeformis spectrum
the NIR band shows high sensitivity to mild infection
whereas the red band shows high sensitivity to severe infection. Therefore
using RVI
which combines the two bands
prompts the disaster monitoring. The monitoring results are in accordance with the biological characteristics of Dendrolimus tabulaeformis
which prefer dry and warm environments
thus proving the efficiency of the remote sensing monitoring. For the factors that influence the damage
Dendrolimus tabulaeformis prefers south gentle slopes. Areas with long sunshine time
minimal rain
and low accumulative temperature suffer from severe damage. This finding provides a basis to predict the probability of disaster outbreak. By applying a novel converse method to test the reliability and accuracy of monitoring results
this study showed that researchers could take advantage of the biological and ecological characteristics of remote sensing objects to assess the reliability of results when forestry damage field investigations are lacking and there isno access to fieldwork sample statistics to estimate the monitoring results. This procedure could reduce the load and difficulty of field investigations.