Vegetation activities sensitively response to topological conditions and a changing climate. To better understand vegetation dynamics under varying environmental conditions, we analyze observations of vegetation indices, Land Surface Temperature (LST), air temperature, and precipitation of a Korean forest over an 11. year period from year 2000 to 2010. While a positive relationship between EVI (Enhanced Vegetation Index) and LST is established for all seasons, independent of elevation, the EVI-LST relationship exhibits a threshold above which the rate of EVI increase over LST increase changes significantly. This transitional point is associated with the condition that the air temperature triggers the start of the growing season. The EVI-LST relationship above the threshold exhibits a hysteresis loop, i.e., rising limb differs from falling limb. We identify two types of hysteresis patterns, i.e., a single loop and a twisted loop. The variation in loop width between the ascending and descending paths contains a signature in annual precipitation of concurrent year. In our analysis, annual precipitation above 1600. mm is associated with LST difference more than 5. °C in the loop width.
Bibliographical noteFunding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (Grant Number 2012R1A2A2A01015355 ) and AusAID as a contributor to scholarship to the first author. We would like to thank to Dr. Chunwoo Baek for his assistance for precipitation data for the Suncheong catchment. The MODIS data were obtained through the online Data Pool at the NASA Land Processes Distributed Active Archive Center (LP DAAC), USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota ( https://lpdaac.usgs.gov/get_data ).
- Surface temperature
- Vegetation index
ASJC Scopus subject areas
- Water Science and Technology