地球信息科学学报 ›› 2017, Vol. 19 ›› Issue (5): 635-645.doi: 10.3724/SP.J.1047.2017.00635

• 地理空间分析综合应用 • 上一篇    下一篇

西藏高原积雪覆盖空间分布及地形影响

除多1,2,*(), 达珍3, 拉巴卓玛2   

  1. 1. 中国气象局 成都高原气象研究所拉萨分部,拉萨 850000
    2. 西藏高原大气环境科学研究所,拉萨 850000
    3. 西藏自治区气象局气象服务中心,拉萨 850000
  • 收稿日期:2015-10-21 修回日期:2016-11-21 出版日期:2017-05-20 发布日期:2017-05-20
  • 通讯作者: 除多 E-mail:chu_d22@hotmail.com
  • 作者简介:

    作者简介:除 多(1969- ),男,西藏白朗县人,博士,正研级高级工程师,主要从事卫星遥感应用研究。E-mail:chu_d22@hotmail.com

  • 基金资助:
    国家自然科学基金项目(41561017);公益性行业(气象)科研专项(GYHY201206040、GYHY201306054)

Spatio-temporal Distribution Patterns of Snow Cover on the Tibet and Orographic Impacts

CHU Duo1,2,*(), DA Zhen3, LABA Zhuoma2   

  1. 1.Lhasa Campus of Institute of Plateau Meteorology, CMA, Lhasa 850000, China
    2. Tibet Institute of Plateau Atmospheric and Environmental Science, Lhasa 850000, China
    3. Meteorological Service Center of Tibet Meteorological Bureau, Lhasa 850000, China
  • Received:2015-10-21 Revised:2016-11-21 Online:2017-05-20 Published:2017-05-20
  • Contact: CHU Duo E-mail:chu_d22@hotmail.com

摘要:

利用2000-2014年MOD10A2积雪产品和数字高程模型DEM数据,以积雪覆盖率为指标,在分析西藏高原积雪空间分布特点的基础上,定量研究了高程、坡度和坡向等地形要素对高原积雪时空分布的影响。主要结论有:① 西藏高原积雪的空间分布差异显著,具有中东部念青唐古拉山和周边高山积雪丰富,覆盖率高,而南部河谷和羌塘高原中西部积雪少,覆盖率低的特点。② 海拔越高积雪覆盖率越高,积雪持续时间越长,年内变化越稳定。海拔2 km以下积雪覆盖率不足4%,海拔6 km以上覆盖率达75%。海拔4 km以下年内积雪覆盖呈单峰型分布特点,海拔越高,单峰型越明显;而海拔4 km以上则为双峰型,海拔越高,双峰型越明显。海拔6 km以下积雪覆盖率最低值出现在夏季,而6 km以上则出现在冬季。③ 总体上,高原地形坡度越高积雪覆盖率越高。不同坡向中,北坡积雪覆盖率最高,南坡最低,年内分布呈双峰型,而无坡向的平地积雪覆盖率要小于有坡向的山地,其年内变化呈单峰型分布特点。

关键词: 积雪覆盖率, 时空分布, MODIS, 地形, 西藏高原

Abstract:

Snow cover on the Tibet is a vital water source in western China and Himalayan regions. In addition, it is very sensitive to climate change and closely related to hydrological processes in the Tibet and downstream areas. Understanding snow cover dynamics and spatial distribution pattern is very important for regional water resources, environment management and climate change. Therefore, in this study, the spatial and temporal distribution patterns of snow cover and the impact of topography (elevation, aspect and slope) on snow cover distribution of the Tibet are analyzed based on snow cover fraction (SCF) derived from MODIS 8-day snow cover product (MOD10A2) from 2000 to 2014 and digital elevation model (DEM) using GIS spatial analysis and statistic methods. Results are as follows: (1) the spatial distribution of snow cover on the Tibet is spatially uneven, which is generally characterized by rich snow and high SCF on Nyainqentanglha Mountain ranges and surrounding high mountains and less snow and low SCF in southern valley and middle part of northern Tibet. Annual mean SCF is 16%, with 22% of SCF in spring and winter, 16% in autumn and 5% in summer. (2) Snow cover on the Tibet presents that the higher altitude the higher the SCF and the longer the snow cover duration and the more stable in intra-annual variations. Average SCF below 2000 m above sea level (masl) is less than 4% while it reaches to 75% above 6000 masl. (3) Intra-annual snow cover distribution below 4000 masl is characterized by unimodal patterns with the higher the altitude the more obvious single-peak type. Above 4000 masl, it is characterized by bimodal patterns with the higher altitude the more obvious double-peak types. The lowest SCF below 6000 masl occurs in summer while above 6000 m which occurs in winter. (4) For different slopes, monthly mean snow cover presents bimodal patterns with generally the higher slope the higher SCF. (5) For different aspects, SCF is highest in north aspect and lowest in south aspect, and is between the two of them in east and west aspects. The distribution pattern of intra-annual snow cover in different aspects is double-peak type, whereas it is single-peak type in flat terrain and its SCF is less than that in mountains with aspects.

Key words: snow cover fraction, spatio-temporal distribution, MODIS, DEM, Tibet