Forestry Drought Monitoring Research Based On Spatio-temporal Data

Aridity is a hot scientific issue in the global climate change research,drought will cause huge damage to the local forestry,agriculture industry,economic development.There is a possibility for forestry drought every year,it will be large threaten caused by drought and its secondary disaster in Hunan province forestry development,due to the large economic losses of drought in natural disasters.There is no enough information about spatiotemporal evolution feature,uncertainty in remote sensing disaster monitor,modelling a forestry drought monitor with effective geography information technology,remote sensing image information extractive technique,data mining technology combing with drought-inducing factors analysis technics,which increase the extract accuracy of forestry drought information,supervise drought in time,the research achievements can be basis of drought emergency management.This study is mainly based on the MODIS remote sensing data,analyze the mechanism of forestry drought in Hunan province through spatiotemporal features and data,building the forestry monitor model with GIS technics,realize dynamic monitor and warning and forecasting.The main works are as follows:(1)The drought remote sensing monitoring indicators were analyzed,and the currently used for hunan forest arid space-time distribution characteristics,selecting suitable for monitoring forest land of drought monitoring index of NDVI?LST and TVDI.(2)Based on the MODIS vegetation index data and MODIS surface temperature from remote sensing which is large-scale and high effectiveness,the corresponding NDVI and LST build the NDVI-LST model and TVDI at the same time.The forestry drought monitor model based on the TVDI with GIS technology,using the ArcMap models connect to ArcPY functional interface.(3)Combing the climate feature and forestry resource district distribution in Hunan,investigated the spring in 2014 to 2015 and autumn in 2013 to 2015 drought degree with TVDI model.Confirmed the Hunan province drought degree according the year TVDI data.Evaluating the 14 cities in Hunan developing trend with location and TVDI.(4)The analysis of the drought in forest land in 2014 and 2015 is typically seen as a result of different levels of drought in March to may.For 2013 and 2014,forest land autumn drought analysis,woodland autumn drought in hunan province is basically with the passage of time,increasing,more special,2013,a severe summer drought,September,October autumn drought trend to return to normal.Combined with level city of hunan province distribution and based on the analysis of spatio-temporal data woodland TVDI index drought situation,spring drought of 14 cities in hunan province,the development trend of autumn drought conditions are analyzed.So far,the forests to specific application of drought monitoring and early warning research are relatively few,this paper built the drought monitor model which suit for forestry,with TVDI.This model has high effective in organizing time-space data,is specific in drought detection,the monitor of drought is fast and accurate,but it's limit in selecting data.It is necessary to improve the model according to the different forest.