闪烁仪法测算丘陵山地人工林显热通量的参数敏感性分析

Sensitivity Analysis for Sensible Heat Flux from a Mixed Plantation Using LAS Measurements in Hilly Zone of North China

采用2009年5月至9月期间大孔径闪烁仪(LAS)每日连续观测数据,并基于Monin-Obukhov近地层大气相似理论,测算了地处河南省济源市的华北丘陵山地30年生栓皮栎-侧柏-刺槐人工混交林的显热通量(H),分析了H对波文比(β)、零平面位移(d)、LAS光线路径有效高度(ZLAS)与风速(v)、空气温度(Ta)等关键参数的敏感性。结果表明:在本研究区域,β值在0.4 4.0范围内浮动变化时,LAS法测算得到的H值影响不大;ZLAS值大小浮动±20%时,H的测算值与参考值相差达35%;d数值大小浮动±50%时,H的测算值与参考值相差仅为1%;Ta值大小浮动±10%时,H的测算值与参考值仅为0.2%左右,v值大小浮动±20%时,H的测算值与参考值相差达到了10%左右。

Based on the LAS data from May to September and MOST in the BLS, the sensible heat flux （H） of a 30-year-old mixed plantation in the hilly zone of the North China in 2009 was calculated. The sensitivity effects of Bowen ratio （β）, zero-plane displacement height （d）, beam height （ZLAS）, wind speed （v） and air temperature （Ta） were analyzed. The results showed that under arid and semi-arid atmosphere conditions in the study area, was a less sensitive factor in the rang 0. 4 -4. 0; when ZLAS fluctuated by 20%, the difference between estimated value and reference value of H was 35% ; when d fluctuated by 50%, the difference was 1% ; when Ta fluctuated by 10%, the difference was 0. 2% ; when v fluctuated by 20%, the difference was 10%.