摘要
湖冰物候是反映气候变化的灵敏指示器.基于青藏高原126个湖泊1978～2016年湖冰物候数据集和气象数据,对青藏高原湖泊湖冰物候的时空变化特征及其影响因素进行分析.结果表明:(1)在全球变暖背景下,青藏高原1978～2016年湖冰物候指数的变化特征呈现出结冰时间显著推迟、融化时间显著提前、冰期显著缩短的变化趋势.(2)青藏高原湖冰物候指数变化趋势的空间差异较为显著,其中大多数湖泊的结冰时间、融化时间和冰期持续时间呈现出显著提前、推后和缩短趋势,仅有少数湖泊的湖冰物候指数变化趋势不显著.(3)青藏高原湖冰物候指数空间分布差异显著,从南到北呈现出湖泊结冰日期提前、融冰日期推迟、冰期持续时间延长的分布模式.(4)温度是影响湖冰物候指数的关键因素;降水、纬度和湖泊面积则对开始日结冰日和完全结冰日具有显著影响;开始融化日和完全融化日则主要受到风速、纬度和海拔的共同作用;而冰期和完全结冰期的长短则主要受到风速、降水、纬度和海拔的影响.因此,青藏高原湖冰物候的变化是气候变化和湖泊自身因素相互作用所导致的.
Abstract
The change in lake ice phenology is a sensitive indicator reflecting climate change.Lake ice phenology over the Qinghai-Xizang Plateau(QXP)is however rarely observed and recorded.The numerous lakes in the QTP have significant functions within the climate system,influencing the balance of water and energy in the region,and are additionally viewed as key indicators of local climate change.Based on lake ice phenology dataset from 126 lakes on the QXP and meteorological data,this article analyzes the changes of lake ice phenology and influencing factors in the QXP from 1978 to 2016.Some conclusions can be drawn as follows.(1)The freeze-up start(FUS)and freeze-up end(FUE)of lake ice appears in mid-November,and mid-December,respectively.The time of break-up start(BUS)and break-up end(BUE)of lake ice is relatively dispersed,and appears in early April and early June,respectively.The average freezing duration(IceD,between BUE and FUS),complete freezing duration(CID,between BUS and FUE)were 168 days and 114 days,respectively.(2)The spatial difference of the change trend of the lake ice phenology in the QXP is relatively significant.The freezing time,melting time and duration of the ice period of most lakes show an obvious trend of advancing,delaying and shortening,while some lakes have no obvious trend of change.(3)The spatial distribution characteristics of lake ice phenology in the QXP have obvious regional differences,but the spatial distribution characteristics of each index are relatively similar,that is,there is a spatial distribution pattern of early lake ice formation date,delayed ice melting date,and extended ice period duration from the south to the north.(4)The spatiotemporal variability of lake ice phenology is the result of the combined effects of climate change and lake conditions.Temperature is a key factor affecting lake ice phenology,while precipitation,latitude,and lake area are the main factors influencing the dates of ice-on and ice-off.On the other hand,the dates of beginning and complete ice melting are mainly influenced by wind speed,latitude,and altitude.Wind speed,precipitation,latitude,and altitude are the main factors affecting the duration of the ice period and complete ice cover.In summary,under the background of global warming,the formation,melting,and duration of the ice period in the lakes on the QXP are undergoing significant changes.
基金项目
国家自然科学基金(42163001)
贵州省科技计划(黔科合基础-zk[2021]一般189)
贵州财经大学校级科研项目(2020)(2020XJC04)
NETL
NSTL
万方数据