【作者】 李修仓；

【导师】 姜彤；

【作者基本信息】 南京信息工程大学 ， 3S集成与气象应用， 2013， 博士

【摘要】 在联络气候系统的大气过程和陆面过程的水文循环中,蒸散发过程是殊为关键的环节。蒸散发研究对于理解气候变化及气候变化的影响具有重要的意义,其准确测定和估算,对水资源、农业、生态环境等方面都具有十分重要的应用价值。本文选择珠江、海河和塔里木河等三个典型流域作为研究区,分别作为中国湿润地区、半湿润半干旱地区及干旱地区等三种气候类型的代表流域,计算并分析了实际蒸散发及其时空变异特征,在此基础上对实际蒸散发的时空变异进行了归因研究,获得的主要研究成果如下：(1)分别采用闭合流域水量平衡方程和Penman公式计算了珠江、海河、塔里木河等三个典型流域的年实际蒸散发及潜在蒸散发,验证了下垫面供水条件变化下实际蒸散发与潜在蒸散发存在互补相关关系。通过建立下垫面供水条件与蒸散发之间的联合回归方程,并对回归系数进行显著性T检验的方法判定实际蒸散发与潜在蒸散发互补关系的非对称性,得出相关流域蒸散发关系的从属属性,即珠江流域的韩江、柳江及盘江等三个子流域实际蒸散发与潜在蒸散发呈现严格互补相关关系,而东江、西江、北江以及海河流域的滦河、官厅水库子流域和塔里木河的阿克苏河、和田河子流域都呈现非对称性互补相关关系。研究了非对称条件下的互补相关理论模型形式,对平流-干旱实际蒸散发模型参数α赋予了更多的物理意义,使其适用范围扩展至“非对称互补相关”范围。在珠江、海河及塔里木河三个流域对平流-干旱模型进行了率定,结果表明该模型在三个流域都是适用的。(2)1961-2010年,珠江流域和海河流域实际蒸散发呈现显著的下降趋势,塔里木河流域实际蒸散发呈现显著的增加趋势。在三个流域中,夏秋季节实际蒸散发的变化趋势非常明显,春冬季节的变化趋势略显平缓。从三个流域之间年内实际蒸散发的比较来看,珠江和海河流域夏秋季节实际蒸散发的峰值非常接近,两个流域实际蒸散发的差异主要体现在春冬季节,而海河和塔里木河两流域在春冬季节实际蒸散发的谷值非常接近,两个流域实际蒸散发的差异主要体现在夏秋季节。从空间变化特点上看,珠江流域实际蒸散发等值线呈现东北-西南走向,海河流域实际蒸散发等值线基本呈现西北-东南走向,塔里木河流域实际蒸散发的空间分布特点则是在流域北部(天山南麓)和流域西部及西南部实际蒸散发较高,流域中部及东南部较低。(3)珠江流域实际蒸散发的下降是辐射能量项的下降和空气动力学项的增加共同作用的结果。其中辐射能量项的下降是由于气温日较差、日照时数下降引起的；空气动力学项的增加是由于平均气温、最高、最低气温的上升引起的；同时平均风速的下降减缓了空气动力学项的增加幅度。海河流域实际蒸散发的下降原因主要是辐射能量项的下降。辐射能量项的下降是由气温日较差、日照时数下降引起的。塔里木河流域实际蒸散发的增加则是辐射能量项的增加和空气动力学项的下降共同作用的结果。其中辐射能量项的增加主要是由于气温(含平均气温、最高、最低气温)以及实际水汽压的上升引起的；日照时数的下降减缓了辐射能量项的增加幅度。空气动力学项的下降主要是由于平均风速的下降引起。根据1961-2010年间各气象要素的实际变幅计算了各气象要素具体的贡献量,发现在三个流域日照时数的下降贡献了实际蒸散发绝大部分的变化,其他气象要素的贡献量相对来说非常弱。(4)通过对Budyko及傅抱璞水热耦合实际蒸散发模型以及基于互补相关理论的实际蒸散发计算结果的分析,指出两种理论在根本上是一致的。借助基于互补相关理论的珠江、海河和塔里木河流域实际蒸散发计算结果,拟合得出Budyko-傅抱璞水热耦合曲线的参数,从而定量化分析了降水量变化对实际蒸散发的影响,结果表明：珠江流域平均每增加5%的降水,实际蒸散发约增加2.3%;海河流域平均每增加5%的降水,实际蒸散发约增加4.5%,远远大于珠江流域；塔里木河流域每增加5%的降水,实际蒸散发将增加近5%；根据1961-2010年间降水量的实际变化,得出珠江流域降水变化对实际蒸散发的贡献量为+4.3mm,海河流域为-92mm,而塔里木河流域为+32.5mm。更多还原

【Abstract】 Evapotranspiration is a key link combining atmospheric process and land surface process in the hydrological cycle of the climate system. Evapotranspiration research has an important significance for the understanding the climate change and the impact of climate change. Meanwhile, the evapotranspiration research has very important application in many subjects such as water resources, agriculture, and ecological environment. This paper taked three typical river basins, the Pearl, Haihe and Tarim River basins, as research area. As the representatives of wet area, semi-wet and semi-arid area, and arid area, the Pearl River basin, the Haihe River basin, and the Tarim River basin were selected as the research areas of this paper. The spatio-temporal variation of the evapotransipiration in the three river basins were analysed, based on which the paper also tried to find the reasons to explain why the variation existed. The main findings are showed as follows:(1) Water balance equation and Penman formula were used to calculate annual actual evapotranspiration (ETa) and annual potential evapotranspiration (ETp) of the three river basins. Results demonstrate that ETa has an obviously complementary relationship with ETp under the condition of surface water supply changing. After the regression equation between the water supply conditions of underlying surface (P) and the evapotranspiration (ET) was constructed, the T-test method was used to determine that the complementary relationships between ETa and ETp were symmetrical in three subbasins of the Pearl River basin such as Hanjiang, Liujiang and Panjiang. But asymmetrical complementary relationships between ETa and ETp were found Dongjiang, Xijiang and Beijiang, which are subbasins of the Pearl River basin and same situations were found in Haihe and Tarim River basin. The form of complementary relationship model of asymmetric conditions was discussed. More physical significance was given to the parmmeter "a" of the Advection-Aridity model thus the applicable scope extended to "asymmetric complementary relationship". In the Pearl River, the Haihe River and the Tarim River Three River Basin of Advection-Aridity model was calibrated. The results show that the model is applicable in the three basins. (2) The actual evapotranspiration have significantly decreased trend in Pearl River, Haihe over the past50years from1961to2010, but has a significant increasing trend in the Tarim River Basin. In the three basins, the decreased (increased) trend of actual evapotranspiration in summer and autumn is very obvious, but slightly in spring and winter. ETa of the Pearl River was very close to the peak with the ETa of the Haihe River Basin, and the difference between the ETa of the two river basins is mainly reflected in the spring and winter. ETa in Spring and Winter of the Haihe River Basin was close to the ETa in the Tarim River basin, so the difference between the ETa of the two river basins is mainly reflected in the Summer and Autumn. The ETa isoline showed a direction from northeast to southwest in the Pearl River basin and showed a direction from northwest to southeast in the Haihe River basin. In the Tarim River Basin, the spatial distribution characteristics of ETa is that higher ETa values occurred mainly in northern, western and southwest of the basin (root of the Tianshan Mountains and Kunlun Mountains), low ETa values occurred mainly in the hinterland of Taklimakan Desert which is located at the center area of the basin.(3) The temporal trend of the ETa results from the variation of the radiation energy term and the aerodynamic term, but different terms gave different impact on the ETa. According to the Adevection-Arid Model, negative (or positive) trends of ETa related to the negative (or positive) trends of the radiation energy term or related to the positive (or negative) trends of aerodynamic term. In the Pearl River Basin decrease of daily range of temperature, sunshine hours caused decrease in radiation energy, contribute to the actual evapotranspiration decrease; the increase of the average temperature, maximum and minimum temperatures, caused the increase of aerodynamic term, contributed to ETa decrease; decline of average wind speed decrease aerodynamic item, actually slow down decrease degree of ETa. In the Haihe River Basin decrease of daily range of temperature, sunshine hours caused decrease in radiation energy, contributed to the decline trend of ETa. The temperature in the Tarim River Basin (including average air temperature, maximum, minimum temperature rise) and actual water vapor pressure gave more obvious contribution to the increase of the radiation energy; decreased sunshine duration caused a decrease in radiation energy, in turn reduces ETa; decline in average wind speed is contributing to the aerodynamics item, turn on strengthening increased degree of ETa. According to the actual amplitude of variation of all the climate factors, we found that the sunhour contribute the most variation of the ETa in all river basins.(4) Based on review of the Budyko and Fu Baopu water heat coupling actual evapotranspiration model and analysis of the ETa results calculated from the complementary relationship theory, this paper pointed out such two kinds of theories are fundamentally identical. Used the results of ETa in the Pearl River, Haihe River and the Tarim River Basin, the paper fitting parameters of Budyko-Fu Baopu water heat coupling curve. Thus quantitative analysis can be done to explain how the suface water content conditions impact on the actual evapotranspiration:in the Pearl River Basin average each5%increase in precipitation, can caused ETa increased by about2.3%; in Haihe River Basin, the average increase of5%precipitation, actual evapotranspiration increased by about4.5%, far greater than the Pearl River Basin; and in the Tarim River Basin every additional5%of precipitation, actual evapotranspiration will increase nearly5%. According to the actual amplitude of variation of precipitation from1961to2010, we found that the actual contribution of the precipitation on the ETa is about+4.3mm in the Pearl River basin,-92mm in the Haihe River basin and+32.5mm in the Tarim River basin.更多还原