Journal of Geo-information Science >
Analysis of Spatial-Temporal Variations of Snow Depth over the Qinghai-Tibetan Plateau during 1979-2010
Received date: 2013-09-23
Request revised date: 2013-11-29
Online published: 2014-07-10
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Snow depth is an important parameter to characterize snow features, and it is also one of the most sensitive factors of regional response to climate change. Based on the daily dataset of snow depth from 1979 to 2010, the spatial and temporal variations and distribution anomaly of snow depth over the Qinghai-Tibetan Plateau in China were analyzed with the use of spatial and statistics analysis function of GIS. The results showed that, during the period from 1979 to 2010, snow depth increased obviously and significantly with the rate of 0.26 cm/(10a) in the Qinghai-Tibetan Plateau, and especially the snow depth in the alpine desert zone in Kunlun Mountains increased most obviously with the rate of 0.73 cm/(10a), and it decreased most clearly with the rate of -0.34 cm/(10a) in the montane evergreen broad-leaved forest in south side of eastern Himalayas. Snow depth gradually increased from the 1980s to the 1990s, while it changed stably in the early 21th century. The results indicated that monthly average snow depth started to rise from September, reached a maximum in January, and then declined to the minimum in August. From the perspective of seasons, snow depth rose, particularly in winter with the rate of 0.57 cm/(10a), and increased most obviously in Ali, north of Kunlun Mountains and the alpine desert zone in Kunlun Mountains. Among the four seasons, spring mean snow depth contributed most significantly to the annual situation, with the correlation coefficient between them up to 0.885. As far as the spatial distribution is concerned, the deeper snow depth lied in the southeast, the western and southern areas of the Qinghai-Tibetan Plateau; the area with an annual upward trend accounted for 67.1%, of which 91.3% is the mild and moderate increase which mainly occurred in the north and west of Qinghai-Tibetan Plateau; moreover, the maximum snow depth varied between -0.1 and 0.1 cm/a, which was on the rise in the north wing of the Kunlun Mountain, the mountainous region of the Qaidam Basin, and south of Qiangtang Plateau where the snow depth mildly increased; the sensitive areas of distribution anomaly of snow depth were in the alpine shrub of Guoluo-Naqu region, south Qinghai and the Qiangtang Plateau.
Key words: Qinghai-Tibetan Plateau; snow depth; spatial-temporal variations
BAI Shuying , SHI Jianqiao , GAO Jixi , BU Jun . Analysis of Spatial-Temporal Variations of Snow Depth over the Qinghai-Tibetan Plateau during 1979-2010[J]. Journal of Geo-information Science, 2014 , 16(4) : 628 -637 . DOI: 10.3724/SP.J.1047.2014.00628
Fig.1 Variation trend of snow depth and its 5-year moving average in the Qinghai-Tibetan Plateau during 1979-2010图1 1979-2010年青藏高原雪深及5年滑动平均变化趋势 |
Fig.2 Monthly variation of snow depth in the Qinghai-Tibetan Plateau图2 青藏高原雪深逐月分布曲线图 |
Tab.1 Tendency rate of seasonal snow depth in the Qinghai-Tibetan Plateau表1 青藏高原四季雪深变化倾向率( cm/10a)分布 |
地区 | 春季 | 夏季 | 秋季 | 冬季 |
---|---|---|---|---|
青藏高原 藏南山地 阿里山地 果洛那曲地区 川西藏东地区 羌塘高寒地区 青南高寒地区 昆仑高寒地区 柴达木山地地区 青东祁连山地地区 昆仑北翼山地地区 东喜马拉雅南翼山地 | 0.24 0.33* 0.71* -0.03 -0.43 0.54** 0.34* 0.83** 0.38** 0.09 0.51** -0.63** | 0.01 -0.01 0.10 -0.00 -0.05** 0.03 0.00 0.20** -0.01* -0.01 0.05 -0.08* | 0.26** 0.29** 0.90** 0.07 -0.05 0.33* 0.37* 0.70** 0.23** 0.16** 0.48** -0.24* | 0.57* 0.44 0.99 0.00 0.22 0.69 0.32 1.17** 0.94** 0.65** 1.21** -0.34 |
注:*,**分别表示通过0.05、0.01显著性检验 |
Fig.3 Spatial distribution of annual mean snow depth in the Qinghai-Tibetan Plateau during 1979-2010图3 1979-2010年青藏高原多年平均雪深分布 |
Tab.2 Change tendencies of mean snow depth and maximum snow depth in the Qinghai-Tibetan Plateau表2 青藏高原平均雪深、最大雪深变化趋势统计 |
Slope | 趋势变化等级 | 像元总数 | 面积比例(%) | |
---|---|---|---|---|
年 均 积 雪 深 度 | <-0.1 -0.1~-0.05 -0.05~-0.01 -0.01~0.01 0.01~0.05 0.05~0.1 >0.1 | 明显减少 中度减少 轻度减少 基本不变 轻度增加 中度增加 明显增加 | 94 194 426 635 1419 1090 239 | 2.29 4.74 10.40 15.50 34.64 26.60 5.83 |
最 大 积 雪 深 度 | <-0.5 -0.5~-0.3 -0.3~-0.1 -0.1~0.1 0.1~0.3 0.3~0.5 >0.5 | 明显减少 中度减少 轻度减少 基本不变 轻度增加 中度增加 明显增加 | 8 69 569 1863 1502 57 29 | 0.20 1.68 13.89 45.47 36.66 1.39 0.71 |
Fig.4 Spatial distribution of mean snow depth and maximum snow depth change trends in the Qinghai-Tibetan Plateau during 1979-2010图4 1979-2010年青藏高原年均雪深和最大雪深变化趋势空间分布 |
Tab.3 Anomaly variations of mean snow depth and maximum snow depth in the Qinghai-Tibetan Plateau表3 青藏高原年均雪深和最大雪深异常变化统计 |
异常等级 | 年均积雪深度异常变化 | 最大积雪深度异常变化 | ||||
---|---|---|---|---|---|---|
(cm) | 像元数 | 百分比(%) | (cm) | 像元数 | 百分比(%) | |
无异常 轻微异常 轻度异常 中度异常 重度异常 | 0 <1 1~2 2~3 >3 | 2 1926 1886 269 14 | 0.05 47.01 46.03 6.57 0.34 | 0 <3 3~6 6~9 >9 | 2 1672 1729 459 235 | 0.05 40.81 42.20 11.20 5.74 |
Fig.5 Spatial distribution of the RSME of mean snow depth and maximum snow depth in the Qinghai-Tibetan Plateau during 1979-2010图5 1979-2010年青藏高原年均雪深和最大雪深距平均方根差空间分布 |
The authors have declared that no competing interests exist.
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