Study Of Remote Sensing About Surface Temperature Spatiotemporal Variability In Da Hinggan Mountains Permafrost Region, Northeast China

AuthorLiang Min TutorXing LixinUnder the influence of global warming,especially the shocking terperature and the human actixities of the northern hemisphere in recent decades, the permafrost of China is in a strong state of degradation whose overall performances are the maximum of permafrost depth is decreasing, freezing time is delaying, melting time is aheading, frozen duration time is shorting, permafrost area is shirnking and the lower bound of permafrost is on the rise in general.In order to better plan and solve the problems existing in the permafrost regions and more clearly understand the present distribution and the evolution law of permafrost, it is particularly important to study the temperature distribution of permafrost. So accurate detemination of the spatial distribution and time evolution of the land surface temperature has a very important meaning for global climate change research,disaster monitoring and resource management.It has become an important field of remote sensing that using thermal infrared technology to retrieval the land surface temperature. Thermal infrared remote sensing is currently the only means for retrievaling land surface temperature of regional or global. It has wide coverage,large amount of information,good dynamics and high resolution,etc obvious advantages. Using thermal infrared remote sensing to study region distribution of land surface temperature has a important application value in some research fields, such as climate change, vegetation ecology, environmental monitoring and urban heat island, etc. On the basis of the study of radiative transfer equation algorithm, single window algorithm, split window algorithm, generalized single-channel temperature algorithm,etc four common methods with retrievaling temperature, and integrated retrieval accuracy and applicability for Landsat 5,Landsat 7,and Landsat 8 data, this paper uses radiative transfer equation algorithm to retrieval the land surface temperature of study area, deviding the temperature retrivaling results of different time phase into temperature grades, studies the transformation law of land surface temperaturre in space distribution and time scales, and analysis the driving factors of changing the temperature distribution.The study area is located in the south of Da Hinggan Mountains in Northeast China, and permafrost land surface temperature changes of time and space in this region is resulted as regional climate,geomorphology,soils,hydrology, vegetation and human activities,etc. Based on the terrain conditions, climate factors and vegetation index,etc three aspects, this paper analysis the driving factors that cause spatiotemporal variability of permafrost land surface temperature in Da Hinggan Mountains, and reveals the main reasons for permafrost land surface temperature variation in temporal and spatial aspects in the south of Da Hinggan Mountains.The main achievements of this paper are as follows:1. Over 25 years, the surface temperature of Da hinggan mountains permafrost regions is on the rise, and the temperature level distribution of study area has a tendency to gradually moving northwest.2. The changes of surface temperature are negatively related with altitude, but the time and space distribution changes of surface temperature are less affected by terrain conditions;The changes of surface temperature are negatively related with vegetation coverage, but the interannual variability of vegetation coverage is small in this region.3. Under the influence of global climate warming, especially the rising temperature and increasing human activities of northeast China in recent decades, the surface temperature of Da hinggan mountains permafrost regions appears consistent with climate warming.Therefore, the main driver resulting in the spatiotemporal variation of the surface temperature in Da hinggan mountains permafrost regions might be climate warming or the increasing human activities.We should strengthen the specialized scientific research in permafrost regions. And protecting the ecological environment is our duty.