半干旱草地能量分配长期变化特征  

Characteristics of Long-Term Changes in Energy Partitioning in Semi-Arid Grassland

作　　者：李溪盈 

机构地区：[1]成都信息工程大学大气科学学院,四川 成都

出　　处：《地球科学前沿（汉斯）》2023年第12期1369-1385,共17页Advances in Geosciences

摘　　要：为了解中国黄土高原半干旱地表能量分配及蒸散生物物理控制长期变化的驱动机制,本文用榆中站点2006年5月至2012年12月的观测数据,分析了研究期黄土高原半干旱草地地表各主要能量分量(净辐射、地表土壤热通量、感热通量、潜热通量和波文比)的月、年变化特征,及其受气候和生物因子(植被指数NDVI和气孔导度)的影响。结果表明:(1) 地表能量随季节变化,感热和潜热均是春季高、秋季低,波文比在冬季较大,因为冬季感热的增长速度大于潜热的增长速度。(2) 半干旱草地生态系统中的各气象要素的变化有很明显的季节性,夏季大、冬季小。净辐射随季节波动变化;土壤含水量总体上是夏季大冬季小,波动较小;空气湿度夏季高冬季低,变化较快;空气温度呈波动变化,最大值几乎不变,最小值有起伏变化;土壤温度的变化与空气温度十分相似。(3) 气候条件中辐射、温度、土壤温度、风速四个变量与波文比呈较弱的正相关;湿度和波文比呈较强的负相关;土壤含水量和波文比呈较弱的负相关。(4) 生物因素中植被指数和气孔导度与波文比是负相关,波文比随着它们的升高而降低。(5) 各气象要素和生物因素对波文比产生影响的路径系数不同。净辐射对波文比的正向影响最大,土壤温度和地面风速次之,空气湿度对波文比的负向影响最大,其次是气孔导度。In order to understand the driving mechanism of long-term changes in semi-arid land-surface energy distribution and Biophysical control of evapotranspiration on the Loess Plateau of China, this paper uses the observations from May 2006 to December 2012. By analyzing the monthly and annual variation characteristics of the main energy components (net radiation, surface soil heat flux, sensible heat flux, latent heat flux and bowen ratio) during the research period, and the influence of climate and biological factors (vegetation index NDVI and stomatal conductivity), the results indicate that: (1) Surface energy varies with the season, and both sensible heat and latent heat are high in spring and low in autumn. The value of Bowen ratio is larger in winter, because the growth rate of sensible heat in winter is greater than that of latent heat. (2) The variation of various meteorological elements in the semi-arid grassland ecosystem is obviously seasonal, large in summer and small in winter. Net radiation changes with seasonal fluctuations;soil water content is large in summer and small in winter, the fluctuation is relatively small;air humidity is high in summer and low in winter, but changes very quickly with no obvious rules;the air temperature fluctuates, the maximum value is almost constant, and the minimum value fluctuates;soil temperature is very similar to air temperature. (3) The four variables of radiation, temperature, soil temperature and wind speed showed a weak positive correlation with the Bowen ratio;humidity and Bowen ratio showed a strong negative correlation;soil water content and Bowen ratio showed a weak negative correlation. (4) Vegetation index and stomatal conductance are negatively correlated with the Bowen ratio, which decreases with the increase. (5) The path coefficients of the influence of various meteorological elements and biological factors on the Bowen ratio differ. The net radiation has the greatest positive effect on Bowen ratio, followed by soil temperature and ground wind speed, an

关 键 词：黄土高原 半干旱草地 能量 对比分析 

分 类 号：G63[文化科学—教育学]