[关键词]
[摘要]
利用黄河源区9个气象站1997—2018年的逐日气温、地表温度和冻土深度资料,使用线性趋势分析法,基于ArcGIS的反距离权重插值法、高程插值法和相关系数法,对黄河源区温度和季节性冻土最大冻结深度以及封冻期起止时间进行分析,研究最大冻结深度与温度的相关关系。结果表明:黄河源区季节性冻土的最大冻结深度分布具有较明显的纬度分带性和垂直分布性,纬度较高地区大于纬度较低地区,海拔较高地区大于海拔较低地区。同时纬度高海拔高的地区相较于纬度低海拔低的地区来说,冻土冻结起始日出现的更早,解冻日出现的更晚,封冻期更长;黄河源区季节性冻土的冻结起止时间均发生了变化,大致表现为冻结起始时间延后,冻结消融时间提前,封冻期缩短,不同地区变化幅度有所不同,源区平均缩短速率为8 d/(10 a)。近20年来,源区绝大部分地区气温、地温和负积温均呈现不同程度的上升趋势,冻土最大冻结深度呈波动减小的趋势,最大冻土深度和冬季平均气温地温、周期内平均气温地温、负积温均呈负相关关系,其对负积温的响应最为显著,相关系数R=-0.762 7。这说明负积温每上升100 ℃,最大冻土深度将减少7.07 cm
[Key word]
[Abstract]
As the climate warms,permafrost degradation becomes progressively serious in cold regions.The changing characteristics of the frozen depth of permafrost have become the focus of many hydrologists and ecologists,and also become the hot and difficult point of hydrology research in cold regions.It is of great significance to study the variation characteristics of permafrost in the source region of the Yellow River for understanding the rules of alpine hydrological science,exploring the regional ecohydrological process and building the ecological civilization in the cold region. Use of 9 weather stations data from 1997 to 2018 of daily temperature,surface temperature and frozen soil depth data,and using the linear trend analysis,inverse distance weighted interpolation method based on ArcGIS,elevation interpolation method and the correlation coefficient method,the temperature and seasonally frozen soil of Yellow River source area maximum freezing depth and start-stop time freeze cycle are analyzed.The relationship between maximum freezing depth and temperature was also studied. The distribution of the maximum freezing depth of seasonally frozen soil in the source region has obvious latitude zoning and vertical distribution,and the higher latitude area is greater than the lower latitude area,and the higher altitude area is greater than the lower altitude area.At the same time,compared with the regions with high latitude and high altitude,the freezing start date of frozen soil appears earlier,the thawing date appears later,and the freezing period is longer in the regions.The starting and ending time of seasonal permafrost in the source region has changed,which generally showed the starting time of freezing is later,the thawing time is earlier,and the freezing period is shorter.The variation range is different in different regions,and the average shortening rate in the source region is 8 d/(10 a). Interpretation: In recent 20 years,the temperature in most of the source area rise to a different extent,and maximum freezing depth showed a decrease trend of permafrost.The maximum frozen soil depth and winter average temperature geothermal ground temperature,average temperature cycle,the negative accumulated temperature is a negatively correlated relationship.It′s response to the negative accumulated temperature is the most significant,the correlation coefficient R=0.762 7.It shows that the maximum permafrost depth will decrease by 7.07 cm when the negative accumulated temperature rises by 100 ℃.
[中图分类号]
[基金项目]