Study On Temporal-Spatial Patterns Of Extreme Climate And Vegetation Over The Tibetan Plateau

Tibetan Plateau is a sensitive area for global climate change;slight changes of climate elements will result in extreme events,and increased the frequency of extreme events.The change of extreme events will have a great influence on the social economy and environment.The research will be help for preventing extreme meteorological disaster events from happening and stably developing agriculture and animal husbandry in Tibetan Plateau.The present study used GIS and RS technologies to explore the temperal-spatical pattern of meteorological and NDVI documents via data mining,At different time and spatial scales,the distribution characteristics of extreme climate and extreme vegetation are analyzed.Through the experimental analysis results show that:The extreme maximum and minimum temperature showed a significant increased trend,the rate of temperature separately are 0.55 ?/10a and 0.75 ?/10a form 1980-2013yr.The extreme minimum precipitation showed a slow increased trend 0.27mm/a year by year.The trend of extreme highest precipitation is not significant.The spatial distribution of the extreme maximum and temperature threshold all presented high in the Southeast-Northwest,followed by Northeast-Northwest,then the lowest value in middle region;The threshold value of the extreme maximum precipitation and relative extreme minimum precipitation presented a rising trend in the Northwest-Southeast region with stripe characteristic;Meanwhile,The spatial distribution of extreme NDVI mainly presents the trend of decreasing from the east to the west,with shows a certain degree of latitudeThree different vegetation types of typical research sites of extreme temperature has been founded obviously different,the extreme temperature of Alpine Desert Steppe is highest,then it is Alpine Meadow,last is Alpine Steppe;But the extreme precipitation of Alpine Meadow is highest,then it is Alpine Steppe,last is Alpine Desert Steppe;The extreme NDVI shows same with extreme precipitation.The extreme maximum NDVI of Alpine Meadow and Alpine Steppe affected by extreme maximum precipitation,the Alpine Desert Steppe is mainly affected by extreme maximum temperature;Alpine Meadow and Alpine Steppe extreme minimum NDVI is affected by extreme minimum temperature,Alpine Desert Steppe extreme minimum NDVI is affected by extreme minimum precipitation.