基于卫星遥感和再分析数据的青藏高原土壤湿度数据评估

doi:10.11821/dlxb201809013

摘要/Abstract

摘要：

土壤水是地表与大气在水热交换方面的关键纽带,是关键水循环要素,更是地表产汇流过程的关键控制因子。青藏高原是地球第三极,也是亚洲水塔,探讨青藏高原土壤水变化对于探讨青藏高原热力学特征变化及其对东亚乃至全球气候变化的影响具有重要意义,而获取高精度长序列大尺度土壤水数据集则是其关键。本文利用青藏高原100个土壤水站点观测数据,从多空间尺度（0.25°×0.25°,0.5°×0.5°,1°×1°）、多时间段（冻结和融化期）等角度,采用多评价指标（R、RMSE、Bias）,对多套遥感反演和同化数据（ECV、ERA-Interim、MERRA、Noah）进行全面评估。结果表明：① 除ERA外,其他数据均能反映青藏高原土壤水变化,且与降水量变化一致。而在那曲地区,遥感反演和同化数据均明显低估实测土壤水含量。从空间分布来看,MERRA和Noah与植被指数最为一致,可很好地反映土壤水空间变化特征;② 青藏高原大部分地区土壤水变化主要受降水影响,其中青藏高原西部边缘与喜马拉雅地区土壤水变化则受冰雪融水和降水的共同影响;③ 除阿里地区外,大部分遥感反演和同化数据在融化期与实测土壤水相关性高于冻结期,其中在那曲地区,遥感反演和同化数据均高估冻结期土壤含水量,却低估融化期土壤含水量。另外,遥感反演和同化数据对中大空间尺度土壤水的估计要好于对小空间尺度土壤水的估计。本研究为青藏高原土壤水研究的数据集选择提供重要理论依据。

关键词: 卫星遥感数据, 再分析数据, 土壤湿度, 青藏高原

Abstract:

Soil water is the key link between land surface and atmosphere in water-heat exchange and it is the key element of water cycle. It is also the key control factor affecting the process of surface runoff. The Himalayan-Tibetan Plateau (HTP), also known as the "Asian Water Tower", is the source region of many Asian rivers. Meanwhile, HTP has direct impacts on its surrounding climate via hydro-meteorological processes, and on establishment and maintenance of Asian monsoon. This study collected observed soil moisture data from 100 in-situ soil moisture observatory stations and evaluated applicability of the available remote sensing and reanalysis soil moisture datasets such as ECV, ERA-Interim, MERRA, and Noah at different spatial resolutions (0.25°×0.25°, 0.5°×0.5°, 1°×1°) during different time intervals such as non-freezing and freezing periods. Statistical indicators such as R, RMSE and Bias were used to evaluate the performances of these remote sensing and reanalysis soil moisture datasets. The results indicated that: (1) All remote sensing and reanalysis soil moisture datasets except ERA can well estimate soil moisture changes of the Tibetan Plateau and the soil moisture changes are in generally good line with precipitation changes. In the Naqu region, however, the remote sensing and reanalysis soil moisture datasets substantially underestimate observed soil moisture. In space, MERRA and Noah are mostly consistent with the change of vegetation index, and can well estimate spatial distribution of soil moisture changes. (2) Soil moisture changes across most parts of the Tibetan Plateau are greatly influenced by precipitation changes. In addition, soil moisture changes in the western flank of the Tibetan Plateau and Himalayas are the combined results of melting snow/glaciers and precipitation. (3) Except in the Ngari region, soil moisture during non-freezing period is usually higher than that during freezing period. In the Naqu region, all remote sensing and reanalysis soil moisture datasets overestimate soil moisture amount during freezing periods, while they underestimate it during non-freezing periods. Besides, from a spatial scale viewpoint, at medium and large scales, remote sensing and reanalysis soil moisture datasets can better evaluate soil moisture availability compared with at small scale. This study provides a theoretical basis for selection of the right remote sensing and reanalysis soil moisture datasets for evaluation and analysis of soil moisture of the Tibetan Plateau.

Key words: remote sensing dataset, reanalysis dataset, soil moisture, Tibetan Plateau

范科科,张强,史培军,孙鹏,余慧倩. 基于卫星遥感和再分析数据的青藏高原土壤湿度数据评估[J]. 地理学报, 2018, 73(9): 1778-1791.

FAN Keke,ZHANG Qiang,SHI Peijun,SUN Peng,YU Huiqian. Evaluation of remote sensing and reanalysis soil moisture products on the Tibetan Plateau[J]. Acta Geographica Sinica, 2018, 73(9): 1778-1791.

参考文献

[1]	Zeng J, Li Z, Chen Q, et al.Evaluation of remotely sensed and reanalysis soil moisture products over the Tibetan Plateau using in-situ observations. Remote Sensing of Environment, 2015, 163: 91-110.http://linkinghub.elsevier.com/retrieve/pii/S0034425715001042
[2]	Guo Weidong, Ma Zhuguo, Yao Yonghong.Regional characteristics of soil moisture evolution in northern China over recent 50 years. Acta Geographica Sinica, 2003, 58(Suppl.): 83-90.
[2]	[郭维栋, 马柱国, 姚永红. 近50年中国北方土壤湿度的区域演变特征. 地理学报, 2003, 58(Suppl.): 83-90.]
[3]	Chahine M T.The hydrological cycle and its influence on climate. Nature, 1992, 359(6394): 373-380.http://www.nature.com/doifinder/10.1038/359373a0
[4]	Zhuo Ga, Deji Zhuoma, Nima Ji.Distribution of soil moisture over the Qinghai-Tibetan Plateau and its effect on the precipitation in June and July over the mid-lower reaches of Yangtze River Basin. Plateau Meteorology, 2017, 36(3): 657-666.
[4]	[卓嘎, 德吉卓玛, 尼玛吉. 青藏高原土壤湿度分布特征及其对长江中下游6, 7月降水的影响. 高原气象, 2017, 36(3): 657-666.]
[5]	Zhuo Ga, Chen Tao, Zhou Kanshe, et al.Spatial and temporal distribution of soil moisture over the Tibetan Plateau during 2009-2010. Journal of Glaciology and Geocryology, 2015, 37(3): 625-634.
[5]	[卓嘎, 陈涛, 周刊社, 等. 2009-2010 年青藏高原土壤湿度的时空分布特征. 冰川冻土, 2015, 37(3): 625-634.]
[6]	Dan L, Ji J, Liu H.Use of a land surface model to evaluate the observed soil moisture of grassland at the Tongyu reference site. Advances in Atmospheric Sciences, 2008, 25(6): 1073-1084.http://link.springer.com/10.1007/s00376-008-1073-6
[7]	Shukla J, Mintz Y.Influence of land-surface evapotranspiration on the earth's climate. Science, 1982, 215(4539): 1498-1501.http://www.sciencemag.org/cgi/doi/10.1126/science.215.4539.1498
[8]	Wang Chenghai, Dong Wenjie, Wei Zhigang.Anomaly feature of seasonal frozen soil variations on the Qinghai-Tibet Plateau. Journal of Geographical Sciences, 2002, 12(1): 99-107.http://link.springer.com/10.1007/BF02837433
[9]	Nicolai-Shaw N R. Climate research applications of remote-sensing based soil moisture: Spatial representativeness, predictability and drought response [D]. Zurich: ETH Zurich, 2016.
[10]	Brocca L, Moramarco T, Melone F, et al.Assimilation of surface- and root-zone ASCAT soil moisture products into rainfall-runoff modeling. IEEE Transactions on Geoscience and Remote Sensing, 2012, 50(7): 2542-2555.http://ieeexplore.ieee.org/document/6112677/
[11]	Brocca L, Melone F, Moramarco T, et al.Improving runoff prediction through the assimilation of the ASCAT soil moisture product. Hydrology and Earth System Sciences, 2010, 14(10): 1881.http://www.hydrol-earth-syst-sci.net/14/1881/2010/
[12]	Miralles D G, Holmes T R H, De Jeu R A M, et al. Global land-surface evaporation estimated from satellite-based observations. Hydrology and Earth System Sciences, 2011, 15(2): 453.http://www.hydrol-earth-syst-sci.net/15/453/2011/
[13]	Dharssi I, Bovis K J, Macpherson B, et al.Operational assimilation of ASCAT surface soil wetness at the Met Office. Hydrology and Earth System Sciences, 2011, 15(8): 2729-2746.https://www.hydrol-earth-syst-sci.net/15/2729/2011/
[14]	Chen Y, Yang K, Qin J, et al.Evaluation of AMSR-E retrievals and GLDAS simulations against observations of a soil moisture network on the central Tibetan Plateau. Journal of Geophysical Research: Atmospheres, 2013, 118(10): 4466-4475.http://doi.wiley.com/10.1002/jgrd.50301
[15]	Ye Qinyu, Chai Linna, Jiang Lingmei.A disaggregation approach for soil phase transition water content using AMSR2 and MODIS products. Journal of Remote Sensing, 2014, 18(6): 1147-1157.
[15]	[叶勤玉, 柴琳娜, 蒋玲梅, 等. 利用AMSR2和MODIS 数据的土壤冻融相变水量降尺度方法. 遥感学报, 2014, 18(6): 1147-1157.]
[16]	Zhu Liping, Xie Manping, Wu Yanhong.Quantitative analysis of lake area variations and the influence factors from 1971 to 2004 in the Nam Co basin of the Tibetan Plateau. Chinese Science Bulletin, 2010, 55(13): 1294-1303.
[16]	[朱立平, 谢曼平, 吴艳红. 西藏纳木错1971-2004年湖泊面积变化及其原因的定量分析. 科学通报, 2010, 55(18): 1789-1798.]
[17]	Nie Yong, Zhang Yili, Liu Linshan, et al.Monitoring glacier change based on remote sensing in the Mt. Qomolangma National Nature Preserve, 1976-2006. Acta Geographica Sinica, 2010, 65(1): 13-28.
[17]	[聂勇, 张镱锂, 刘林山, 等. 近30 年珠穆朗玛峰国家自然保护区冰川变化的遥感监测. 地理学报, 2010, 65(1): 13-28.]
[18]	Shi Yafeng, Liu Shiyin.Estimate of the response of glaciers in China to the global warming-up in the 21st century. Chinese Science Bulletin, 2000, 45(4): 434-438.
[18]	[施雅风, 刘时银. 中国冰川对21世纪全球变暖响应的预估. 科学通报, 2000, 45(4): 434-438.]
[19]	Bianduo, Yang Zhigang, Li Lin, et al. The response of lake area change to climate variations in north Tibetan Plateau during last 30 years. Acta Geographica Sinica, 2006, 61(5): 510-518.
[19]	[边多, 杨志刚, 李林, 等. 近30年来西藏那曲地区湖泊变化对气候波动的响应. 地理学报, 2006, 61(5): 510-518.]
[20]	Zhang Y, Li T, Wang B.Decadal change of the spring snow depth over the Tibetan Plateau: The associated circulation and influence on the East Asian summer monsoon. Journal of Climate, 2004, 17(14): 2780-2793.http://journals.ametsoc.org/doi/abs/10.1175/1520-0442%282004%29017%3C2780%3ADCOTSS%3E2.0.CO%3B2
[21]	Ding Y, Wang Z, Sun Y.Inter-decadal variation of the summer precipitation in East China and its association with decreasing Asian summer monsoon. Part I: Observed evidences. International Journal of Climatology, 2008, 28(9): 1139-1161.http://doi.wiley.com/10.1002/joc.v28%3A9
[22]	Shi Lei, Du Jun, Zhou Kanshe, et al.The temporal-spatial variation of soil moisture over the Tibetan Plateau during 1980-2012. Journal of Glaciology and Geocryology, 2016, 38(5): 1241-1248.
[22]	[石磊, 杜军, 周刊社, 等. 1980-2012 年青藏高原土壤湿度时空演变特征. 冰川冻土, 2016, 38(5): 1241-1248.]http://d.wanfangdata.com.cn/Periodical/bcdt201605007
[23]	Su Z, Wen J, Dente L, et al.The Tibetan Plateau observatory of plateau scale soil moisture and soil temperature (Tibet-Obs) for quantifying uncertainties in coarse resolution satellite and model products. Hydrology and earth system sciences, 2011, 15(7): 2303-2316.https://www.hydrol-earth-syst-sci.net/15/2303/2011/
[24]	Su Z, Rosnay P, Wen J, et al.Evaluation of ECMWF's soil moisture analyses using observations on the Tibetan Plateau. Journal of Geophysical Research: Atmospheres, 2013, 118(11): 5304-5318.http://doi.wiley.com/10.1002/jgrd.50468
[25]	Zeng J, Li Z, Chen Q, et al.Evaluation of remotely sensed and reanalysis soil moisture products over the Tibetan Plateau using in-situ observations. Remote Sensing of environment, 2015, 163: 91-110.http://linkinghub.elsevier.com/retrieve/pii/S0034425715001042
[26]	Bi H, Ma J, Zheng W, et al.Comparison of soil moisture in GLDAS model simulations and in situ observations over the Tibetan Plateau. Journal of Geophysical Research: Atmospheres, 2016, 121(6): 2658-2678.http://doi.wiley.com/10.1002/2015JD024131
[27]	Sun Honglie, Zheng Du, Yao Tandong, et al.Protection and construction of the national ecological security shelter zone on Tibetan Plateau. Acta Geographica Sinica, 2012, 67(1): 3-12.
[27]	[孙鸿烈, 郑度, 姚檀栋, 等. 青藏高原国家生态安全屏障保护与建设. 地理学报, 2012, 67(1): 3-12.]
[28]	Zheng Du, Zhang Rongzu, Yang Qinye.On the natural zonation in the Qinghai-Xizang Plateau. Acta Geographica Sinica, 1979, 34(1): 1-11.
[28]	[郑度, 张荣祖, 杨勤业. 试论青藏高原的自然地带. 地理学报, 1979, 34(1): 1-11.]
[29]	Chen Y Y, Yang K, Tang W J, et al.Parameterizing soil organic carbon's impacts on soil porosity and thermal parameters for eastern Tibet grasslands. Science China Earth Sciences, 2012, 55(6): 1001-1011.http://link.springer.com/10.1007/s11430-012-4433-0
[30]	Gao Zhigang, Luo Jingxin, Liu Kexiu, et al.Evaluation of ERA-Interim reanalysis data along coast of China. Marine Science, 2015, 39(5): 92-105.
[30]	[高志刚, 骆敬新, 刘克修, 等. ERA-Interim再分析数据在中国沿海的质量评估. 海洋科学, 2015, 39(5): 92-105.]
[31]	Yang K, Chen Y Y, Qin J.Some practical notes on the land surface modeling in the Tibetan Plateau. Hydrology and Earth System Sciences, 2009, 13(5): 687-701.http://www.hydrol-earth-syst-sci.net/13/687/2009/
[32]	Chen Y, Yang K, Qin J, et al.Evaluation of AMSR-E retrievals and GLDAS simulations against observations of a soil moisture network on the central Tibetan Plateau. Journal of Geophysical Research: Atmospheres, 2013, 118(10): 4466-4475.http://doi.wiley.com/10.1002/jgrd.50301