右江干热河谷典型芒果经济林实际蒸散量尺度扩展及影响机制研究

作为广西特色产业和千亿元产业，芒果经济林的种植和生产是区域经济和社会发展的重要支撑。右江河谷是全国三大“天然温室”之一，具有得天独厚的芒果等经济作物种植气候条件。本研究首先通过使用大型称重式蒸渗仪不间断监测不同生长时期芒果经济林水分变化情况，研究水分收支量及变化过程，得到对应阶段的芒果作物系数。其次，使用能够满足区域尺度观测地表特征的遥感技术，对SEBAL模型所需的地表反照率、地表温度、比辐射率等要素反演，估算研究区的净辐射通量、土壤热通量及显热通量。根据能量平衡得到潜热通量后估算瞬时蒸散量。在实测作物系数的基础上将瞬时蒸散量扩展到日、月、年尺度。并使用涡度相关仪实测数据对各个能量分量估算结果进行验证。最后，分析气象因子、下垫面条件和植被类型等对蒸散量的影响及响应规律，探讨蒸散量影响机制。同时明确蒸散量变化特征与分布规律，探索芒果经济林在不同生长时期的耗水特点，为合理灌溉提供科学依据。

As the specialty industry and '100 Billion Yuan' industry of Guangxi, the planting and production of mango plantation plays an important role in supporting the development of regional economy and society. The Youjiang River Valley is one of the three “natural greenhouses” of our country, with exceptional advantages of climate conditions for the cultivation of cash crops such as mangoes. In this study, the large weighing lysimeter is used to continuously monitor the water change of the mango plantation at different growth stages to explore the water balance and the change process, as well as the crop coefficients mango plantation at the corresponding growth stages. Secondly, the surface albedo, surface temperature, emissivity and other components required by the SEBAL model are calculated to estimate the net radiation flux, soil heat flux and sensible heat flux. And the instantaneous evapotranspiration was estimated after figuring out the latent heat flux according to the energy balance. Based on the filed measured crop coefficients, the instantaneous evapotranspiration is extended to daily, monthly, and annual scales. The eddy covariance is applied to verify the estimation results of each energy component. Finally, the effects of meteorological factors, underlying surface conditions and vegetation types on evapotranspiration and their responses are analyzed, and the influence mechanism of evapotranspiration is discussed. At the same time, the characteristics and distribution of evapotranspiration are investigated and the water consumptions of mango plantation in different growth periods are explored to provide a scientific basis for reasonable irrigation.