地理科学 ›› 2015, Vol. 35 ›› Issue (9): 1164-1169.doi: 10.13249/j.cnki.sgs.2015.09.1164

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TRMM降水数据的空间降尺度方法研究

李净1(), 张晓2   

  1. 1. 西北师范大学地理与环境科学学院, 甘肃 兰州 730070
    2. 中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室, 甘肃 兰州 730000
  • 收稿日期:2014-03-27 修回日期:2014-08-10 出版日期:2015-09-25 发布日期:2015-09-25
  • 作者简介:

    作者简介:李 净(1978-),女,甘肃会宁人,博士,副教授,主要研究方向为定量遥感。E-mail:li_jinger@163.com

  • 基金资助:
    甘肃省科技计划项目(1308RJZA141) 资助

Downscaling Method of TRMM Satellite Precipitation Data

Jing LI1(), Xiao ZHANG2   

  1. 1.College of Geography and Environment Science, Northwest Normal University, Lanzhou, Gansu 730070, China
    2.State Key Laboratory of Cryosphere Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China
  • Received:2014-03-27 Revised:2014-08-10 Online:2015-09-25 Published:2015-09-25

摘要:

以天山中段为研究区,以降水与高程(DEM)、植被指数(NDVI)、坡向(Aspect)、经纬度与之间存在的相关关系为基础,构建了TRMM卫星3B43降水数据与NDVI、DEM和坡向等相关因子的回归模型,对TsHARP统计降尺度算法引入DEM和局部Moran指数进行改进,得到2001~2006年研究区的250 m高分辨率降水空间分布数据。最后利用研究区气象站点降水数据对降尺度结果进行验证,得出降尺度的结果和实测值的误差明显小于原始降水数据和实测值的误差,年均降水最大改善程度是70 mm,因此构建的降尺度方法是合理可行的,可用于山区降水数据的降尺度研究。

关键词: 降水, TRMM 卫星, 降尺度, 天山中段

Abstract:

Precipitation is an essential input parameter for model research of hydrology, ecology and climate, and accurate precipitation data with high resolution are very important for the understanding of regional climate change. At present, TRMM satellite with resolution of 0.25 degree can provide global precipitation data, but the application of the lower resolution of TRMM 3B43 precipitation data are restricted in hydrological or climatic model of watershed scale. In mountain, precipitation data cannot be obtained by simple interpolation or extrapolation, so it is necessary to apply downscaling methodology to improve the resolution of TRMM precipitation data. In this article, the middle part of Tianshan Mountains is study area, based on the correlation of annual precipitation with the regression model between the TRMM 3B43 annual accumulated precipitation data and such factors as DEM, NDVI, aspect, longitude and latitude is built. TsHARP is a statistical downscaling algorithm, which is improved by introducing DEM and local Moran’s I index of NDVI, and the precipitation data with 250 m resolution in the studied area during 2001-2006 are obtained. From the results, it can be known that the internal precipitation in study area affected by the altitude is serious. The amount of precipitation in the western Tianshan Mountains is more than the eastern and the amount of precipitation in the northern slope is more than the southern slope. This conclusion and the previous research on the precipitation are consistent. The downscaled results are validated with observed precipitation data from meteorological stations in the studied area. It is obtained that 1) the errors of downscaled results are substantially less than those of original TRMM precipitation data, and the maximal improved value of annual average precipitation is 70mm; 2) the spatial distribution characteristics of precipitation in the middle section of Tianshan Mountain can be depicted in detail by downscaled results; 3) the correlation coefficient (R2) for TRMM 3B43 accumulated precipitation data and observed precipitation data is 0.618, while the one for downscaled results and observed precipitation data is 0.713. So the downscaling methodology built in this article is feasible, in a certain extent, which can provide technical support for the research of rigion with high altitude where human beings cannot monitor the precipitation area, and can provide spatial distribution of precipitation with detailed description of the results in mountains.

Key words: precipitation, TRMM satellite, downscaling, the middle of Tianshan Mountain

中图分类号: 

  • P426.1