多源土壤湿度数据的比较及土壤湿度对降水的影响研究

发布时间：2019-04-19 02:07

【摘要】：利用中国区域1992-2010年的土壤湿度观测资料,对欧洲航天局(European Space Agency)的卫星遥感反演(以下简称ESA)和ERA-Interim再分析(以下简称ERA)的两套土壤湿度数据在典型区域的可靠性进行了评估。结果表明;两种土壤湿度均能较好的描述观测区域的总体土壤干湿变化,但均值和趋势一致性存在时间和空间差异。ESA、ERA资料都能较好的描述中国区域春、夏、秋三个季节土壤湿度的干、湿分布格局。在干湿程度上,ESA在北方地区较观测偏干,在江淮和西南较观测偏湿;ERA在北方和西南地区较观测偏湿,在江淮较观测偏干;在江淮、华北部分区域,ERA与观测数据的相关性要高于ESA。三个季节,ESA、ERA与观测数据都有较高的相关性,秋季时,相关性最好;在全国大部分区域,ESA偏差要小于ERA且在大部分地区都表现出与观测一致的变化趋势。在空间上,ERA在东北、华北、西南变化趋势的空间范围与观测有明显差异,变干的范围明显大于观测;然而,ERA能更好的体现观测土壤湿度的年际变化。相对于西部地区,东部地区ERA与观测的一致性最好,而ESA在受降水、植被、地形等因素影响较小的时段或区域与观测的一致性最好,对秋季土壤湿度的描述比春、夏季更准确。另外,我们通过利用美国气候变率与可预测性研究计划干旱工作组数值模式模拟的结果,探讨土壤湿度对陆地降水的影响。分析了全球6个主要干旱区,结果如下:北美、南美干旱区受海温型影响最大,PcAw土壤湿度更湿,降水差值也更大,北非干旱区与之相反,PwAc土壤湿度更湿,降水差值更大,波恩比差值在北非不能代表降水的变化,澳大利亚PwAc土壤湿度更湿,降水差值却相对PcAw要小,南非干旱区季节变化最大,也受海温影响,却无季节规律,中国西北干旱区除冬季外,土壤湿度差值越大,降水差值也越大。
[Abstract]:Based on the observed data of soil moisture in the China region from 1992 to 2010, The reliability of two sets of soil moisture data from European Space Agency (European Space Agency) satellite remote sensing retrieval (ESA) and ERA-Interim reanalysis (ERA) in typical regions was evaluated. The results show that; Both soil moisture and soil moisture can well describe the change of soil moisture in the observed area, but there are temporal and spatial differences in mean and trend consistency. ESA and ERA data can well describe the spring and summer in China. Dry and wet distribution pattern of soil moisture in three seasons of autumn. In the degree of dry and wet, ESA is drier than observation in northern area, wetter than observation in Jianghuai and southwest, ERA is wetter than observation in north and southwest, and drier than observation in Jianghuai. In some regions of Jianghuai and North China, the correlation between ERA and observed data is higher than that of ESA.. In the three seasons, the correlation between ESA,ERA and observed data is high, and in autumn, the correlation is the best. In most regions of China, the deviation of ESA is smaller than that of ERA, and the variation trend is consistent with observation in most areas. In space, the spatial range of the variation trend of ERA in Northeast, North China and Southwest China is obviously different from that observed, and the range of drying is obviously larger than that of observation. However, ERA can better reflect the interannual variation of observed soil moisture. Compared with the western region, the ERA of the eastern region is the best agreement with the observation, and the ESA is the best agreement with the observation in the period or region which is less affected by precipitation, vegetation, topography and so on. The description of soil moisture in autumn is more accurate than that in spring and summer, and the soil moisture in autumn is more accurate than that in spring and summer. In addition, the effects of soil moisture on land precipitation are discussed by using the numerical simulation results of the drought working Group of the Climate variability and predictability Program in the United States. Six main arid regions in the world are analyzed. The results are as follows: the arid regions of North America and South America are most affected by sea temperature type, the soil moisture of PcAw is wetter and the difference of precipitation is bigger, and the difference of precipitation is also larger in arid region of North Africa, the soil humidity of PwAc is wetter and the difference of precipitation is bigger. The Bonn ratio difference does not represent the change of precipitation in North Africa, the soil moisture of PwAc in Australia is wetter, the precipitation difference is smaller than PcAw, the seasonal variation is the largest in the arid area of South Africa, but it is also affected by SST, but there is no seasonal rule. In arid areas of northwest China, the greater the soil moisture difference is, the greater the precipitation difference is except in winter.
【学位授予单位】：成都信息工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S152.71

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