怒江流域中上游地表冻融特征及时空分布

发布时间：2018-07-23 11:49

【摘要】：冻土水文过程的复杂性使其分析及模拟较为困难,在研究青藏高原冻土退化水文效应的过程中,需要明确流域内土壤冻结和融化状态的时空变化特征。利用被动微波遥感数据反演获得的地表冻融状态,系统地辨识怒江流域中上游地表冻融状态时空变异特征。结果表明:1.怒江流域贡山水文站以上年平均地表冻结天数270 d的区域占研究区总面积的32.0%,而180~270 d的则约占62.3%,海拔高度每升高1 000 m,年地表冻结天数平均增长约62 d;2.研究区不同年份持续冻结的开始和结束时间差异较大,融化-冻结阶段的9—10月平均气温与阶段末10月地表冻结面积的相关系数为-0.80,而冻结-融化阶段的4—6月平均气温与阶段末6月地表冻结面积的相关系数则为-0.87,均在0.01水平上显著负相关,研究区气温的年际波动导致地表冻结面积、冻结日期、融化日期及冻结持续时间等的年际变化;3.被动微波遥感反演获得的高时间分辨率冻融状态数据,可为气候变化背景下,缺资料高原山地流域大范围地表冻融状态变化分析、流域尺度水文过程模拟等提供良好的数据支撑。
[Abstract]:It is difficult to analyze and simulate the hydrological process of frozen soil because of its complexity. In the process of studying the hydrological effects of frozen soil degradation in the Qinghai-Tibet Plateau, it is necessary to clarify the temporal and spatial characteristics of the frozen and thawed soil in the basin. The temporal and spatial variation characteristics of surface freeze-thaw state in the upper and middle reaches of the Nujiang River Basin were systematically identified by using the passive microwave remote sensing data inversion of the surface freeze-thaw state. The result shows that 1: 1. The area above Gongshan Hydrological Station accounts for 32.0 days of the total area of the study area, while the area with 180 days of 270 days accounts for 62.3 meters. For every 1 000 m elevation, the average annual surface freezing days increase about 62 days. The beginning and end time of continuous freezing varies greatly in different years of the study area. The correlation coefficient between the average temperature in September-October period and the frozen area in late October is -0.80, while the correlation coefficient between the average temperature in April and June in the frozen-thawing stage and the frozen area in the end of June in the stage. It was -0.87, which was significantly negative at 0.01 level. The interannual fluctuation of air temperature in the study area resulted in the interannual variation of surface frozen area, freezing date, melting date and freezing duration. The high time resolution freeze-thaw state data obtained by passive microwave remote sensing inversion can be used to analyze the freeze-thaw state change of large scale land surface in the mountainous watershed of plateau under the background of climate change. Watershed scale hydrological process simulation provides good data support.
【作者单位】：云南大学亚洲国际河流中心/云南省国际河流与跨境生态安全重点实验室;
【基金】：国家自然科学基金项目(41601026) 喜马拉雅地区气候变化适应性研究项目(挪威外交部和瑞典国际发展署)~~
【分类号】：P642.14

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