长武塬区实际蒸散发变化及驱动因素分析

Study on the variation regulation and influencing factors of farmland evapotranspiration in Gully region of Changwu tableland

以大型称重式蒸渗仪系统的实测农田蒸散量数据为基础,分别从年、月、日和生长季4个尺度分析长武塬区农田蒸散量的变化特征,采用相关分析和主成分分析法探究其影响因素,建立实测蒸散与影响因素之间的定量关系。结果表明:农田蒸散的变化特征与作物生长进程一致,高蒸散期均出现于作物生育旺期,且受到降水、气温、风速、太阳辐射、日照时数、空气相对湿度和土壤含水量的共同作用,其中,气温和太阳辐射是蒸散的主要驱动因素。

The study analyzed the variation characteristics of farmland evapotranspirationin Changwu tableland from four scales： yearly,monthly,daily and growing seasonbased on observation datafrom large scale lysimeter system and explore the influencing factors by using correlation analysis and principal component analysis method. The quantitative relationship between measured evapotranspiration and influencing factors is established. The results show that the variation characteristics of farmland evapotranspiration are consistent with the growth process of the crops and the high evapotranspiration occurs in the booming period. The evapotranspiration is affected by precipitation,air temperature,wind speed,solar radiation,sunshine hours,air relative humidity and soil water content. Temperature and solar radiation are the main driving factors of evapotranspiration.