考虑局地因素坡向影响的青藏高原工程走廊冻土分布与制图研究

通过Pearson相关性分析,选取对青藏高原工程走廊多年冻土分布影响较大、在GIS技术支持下较容易量化的坡向因子,结合走廊内2000-2010年29个钻孔点的地温监测数据,建立了年均地温与坡向、纬度和高程的关系模型.根据高原冻土工程地温分带指标,制作了工程走廊内符合实际的冻土分布图,由面积统计结果知:多年冻土区占整个区域的94.06％,其中,低温稳定带占多年冻土区面积的15.94％,主要分布在风火山和可可西里的高山基岩区;低温基本稳定带占16.97％,主要分布在风火山及可可西里丘陵地带;高温不稳定带占48％,主要分布于可可西里和北麓河盆地东缘;高温极不稳地带占19.09％,主要分布于北麓河盆地和楚玛尔河高平原.

Permafrost Modeling and Mapping along the Qinghai-Tibet Engineering Corridor Considering Slope-Aspect

The permafrost in the Qinghai-Tibet Plateau was resulted from the interaction of the Earth-Atmosphere System.The atmosphere controlled the macrostructure of the permafrost.However,some local factors such as slope-aspect,also greatly affected the permafrost status.However,the study of the small area′s larger scale and considering the local factors for permafrost distribution and mapping is still uncommon in China.According to the consequence of Pearson correlation analysis,some factors were selected greatly influencing the permafrost distribution in a section from the Chumaer River to the Fenghuo Mountain in the Qinghai-Tibet Engineering Corridor.The factors which can be easily quantified by GIS are latitude,elevation and slope-aspect.Based on records of the mean annual ground temperature from 29 boreholes in the section between 2000 and 2010,the relationship model with the mean annual ground temperature,the elevation,latitude and slope-aspects was constructed using regression analysis method.When multiple correlation coefficient was significant with a value of 0.936.Then a simulated map of permafrost distribution was produced through the indices for cold region engineering purpose.Every zone′s area was also calculated.As a result,permafrost regions occupy 94.06% of the whole area,among which low temperature stable zone accounts for 15.94% mainly in alpine bedrock area of Fenghuoshan and Hoh Xil,low temperature basically stable zone is 16.97% mainly in Fenghuoshan and Hoh Xil′s foothills,high temperature unstable zone is 48%,mainly in Hoh Xil and the east edge of Beilu River Basin,and high temperature extremely unstable zone is 19.09%,mainly in Beilu River Basin and Chumaer River planalto.