中国农业气象 ›› 2020, Vol. 41 ›› Issue (09): 575-586.doi: 10.3969/j.issn.1000-6362.2020.09.004

• 论文 • 上一篇    下一篇

 TRMM 3B43降水数据在云南地区的降尺度适用性评价

 玉院和,王金亮   

  1.  云南师范大学旅游与地理科学学院/云南省高校资源与环境遥感重点实验室/云南省地理空间信息工程技术研究中心,昆明 650500
  • 出版日期:2020-09-20 发布日期:2020-09-13
  • 作者简介:玉院和,E-mail:14787870652@163.com
  • 基金资助:
     国家重点研发计划政府间/港澳台重点专项项目(2018YFE0184300);云南基础研究重点项目(2019FA017);国家自然基金项目(41561048);云南省高校高原山地资源环境遥感监测与评估科技创新团队

 Applicability Evaluation of TRMM 3B43 Precipitation Data for Downscaling in Yunnan Province

 YU Yuan-he, WANG Jin-liang   

  1.  College of Tourism and Geographic Sciences, Yunnan Normal University/Key Laboratory of Resources and Environmental Remote Sensing for Universities in Yunnan/Center for Geospatial Information Engineering and Technology of Yunnan Province, Kunming 650500, China
  • Online:2020-09-20 Published:2020-09-13
  • Supported by:
     

摘要:  借助云南省2009?2018年25个气象站点逐月降水量分析TRMM 3B43降水数据特征,利用相关系数(R)、偏离率(BIAS)、均方根误差(RMSE)和平均绝对误差对TRMM 3B43月降水数据和各站点进行适用性分析,并探讨该数据与海拔、坡度、坡向之间的关系,最后将TRMM 3B43月降水数据降尺度至季、年尺度,并对其进行适用性评价,为复杂地形地区开展区域降水研究、水文预报等提供可靠降水产品数据。结果表明:(1)TRMM 3B43降水数据与实测降水数据变化趋势基本一致,降水量均表现为西多东少、南多北少,且大致随海拔高度呈阶梯式分布;(2)TRMM 3B43月降水量与实测降水量具有极显著相关性,R高达0.9392,BIAS接近0,且TRMM 3B43降水数据在25个站点R值均超过0.735,大多数站点的偏离度和误差较小,其整体精度较高;(3)TRMM 3B43数据精度受坡度的影响比海拔、坡向大,但多数站点在不同海拔高度、坡度和坡向的精度均较高,适用性较强,尤其是海拔位于1000-2000m、坡度小于4°、坡向位于160°-240°的站点数据适用性更强;(4)降时间尺度后的TRMM 3B43数据相关系数稍有降低,误差变大,尤其是在冬季和年尺度适用性稍差。TRMM 3B43月降水数据在云南地区具有较高的精度,可为地面降水数据提供有效补充。

关键词:  TRMM 3B43, 降水数据, 适用性评价, 地形因子, 云南地区

Abstract:   Precipitation exerts an important role in the exchange of matter and energy in the global water cycle, affecting soil moisture, vegetation growth, and surface runoff. By employing existing station data, the spatial distribution of precipitation obtained by the meteorological observation method was obtained by interpolation. However, the interpolation results of a small number of meteorological stations are challenging to accurately analyze the spatial variation characteristics of actual precipitation. Launched on 28 November 1997, the Tropical Rainfall Measuring Mission (TRMM) was jointly developed by the United States National Aeronautics and Space Administration (NASA) and the Japan Aerospace Exploration Agency (JAXA), thus providing long time series and covering most regions of the world with precipitation rate data. Nevertheless, TRMM was obtained by indirect precipitation measurement. Meanwhile, there were related errors and uncertainties. As a result, TRMM accuracy evaluation was the primary work of regional precipitation research. The terrain of Yunnan Province is complex, and the altitude difference is large. In addition, it is affected by the southwest monsoon and southeast monsoon. Complex factors such as the uneven distribution of precipitation may affect the detection capabilities of TRMM satellites. However, the current evaluation of the applicability of TRMM data in Yunnan Province is only a simple analysis of the coefficient of determination. Besides, the research on the factors affecting the accuracy of TRMM precipitation data and errors such as deviation rate is still lacking. In the present study, the accuracy of TRMM 3B43 precipitation data was evaluated in Yunnan, where the terrain was complex, aiming to provide reliable precipitation product data for regional precipitation research and hydrological forecasting. Monthly precipitation from 25 meteorological stations in Yunnan province from 2009 to 2018 provided by the China Meteorological Data Service Center was used to analyze the characteristics of TRMM 3B43 precipitation data. The correlation coefficient(R), BIAS, root mean square error (RMSE) and mean absolute error (MAE) were used to analyze the applicability between TRMM 3B43 monthly precipitation data and meteorological station data. Then, the relationship between the TRMM 3B43 precipitation data corresponding to each station and the elevation, slope, and aspect was discussed in this study. Finally, the data was downscaled to the seasonal and annual scales. At the same time, its applicability was evaluated. Some results the current study showed that: (1) the mean difference between TRMM 3B43 precipitation data and measured precipitation data was small, especially at Luxi station, where the difference was only 0.02mm. The TRMM 3B43 precipitation data was basically in consistence with the measured precipitation data, showing that there were more in the west and south and less in the east and north. It was roughly distributed step by step with the altitude. However, the difference in the spatial distribution of precipitation caused by the difference in altitude and latitude of each station also revealed the difference between TRMM 3B43 and the measured precipitation. Therefore, it is of much necessity to evaluate its applicability before using TRMM data.(2) With an R as high as 0.9392, BIAS close to zero, RMSE as low as 32.9776mm, and MAE as low as 20.5730mm, TRMM 3B43 displayed an extremely significant correlation between monthly precipitation and measured precipitation. In the range of TRMM 3B43 monthly precipitation less than 250mm, the accuracy of the fitting was relatively higher. The TRMM 3B43 precipitation data exceeded 0.735 at 25 stations, which passed the significance test at the 0.01 level, and the deviation and error of most stations were small with high overall accuracy. However, due to the different geographical locations of the stations, the deviation and error of the data presented certain differences. (3) The accuracy of TRMM 3B43 data was more affected by the slope than the altitude and aspect. The correlation coefficients of slope and R, RMSE and MAE were 0.8167, 0.7071 and 0.6865 respectively, showing strong quadratic function relationship characteristics. Except for the TRMM 3B43 precipitation data at Gongshan station and Weixi station, the accuracy of most stations at different altitudes, slopes and aspect was higher, having stronger applicability. Particularly, the data applicability was stronger for sites located at an altitude of 1000-2000m, slope less than 4°, and slope direction of 160°-240°. (4) The correlation coefficient of TRMM 3B43 data after time downscaling was slightly reduced. The error was slightly larger, especially in the winter and the annual scale slightly remained less suitable. With the largest error in summer, the RMSE and MAE of the TRMM 3B43 precipitation in Yunnan Province and the measured precipitation in each season were both less than 97mm and 78mm, respectively. The transmissibility of errors caused the RMSE and MAE of the annual scale TRMM data to become larger, and the applicability was the worst compared to other time scales. Therefore, the TRMM 3B43 monthly precipitation data had high accuracy in Yunnan region, which could thus provide effective supplement to the surface precipitation data.

Key words:  TRMM 3B43, Precipitation data, Applicability evaluation, Topographic factor, Yunnan Province

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