用微气象方法估算淮河流域能量平衡(HUBEX/IOP 1998/99)的统计分析和比较研究

摘要

利用1998和1999年HUBEX强化观测期在安徽寿县用微气象方法(波文比-能量平衡法和涡度相关法)观测的资料,分析了该地区的能量平衡特征,同时与其他地区的结果进行了初步比较,结果表明:(1)用涡度相关方法测定的感热和潜热之和(H+E)ec与下垫面有效能量(Rn-G)的一致性比较好,但用波文比方法估算的潜热通量Ebr比用涡度相关法测定的潜热通量Eec略高(约10%).(2)大部分净辐射能用于了地表蒸发,1998和1999年,净辐射通量的平均日总量分别是13.89 MJ m-2 d-1和11.83 MJ m-2 d-1;两年的平均波文比分别是0.14 (杂草)和0.06(稻田).(3)波文比在日出和日落时数值大且不稳定,白天比较小且比较稳定,另外,1999年在稻田上观测到明显的局地平流现象.(4)通过与我国其他地区的观测资料比较,淮河流域稻田的波文比最小(0.06),在内蒙古草原观测的波文比值最大(0.57).波文比值的大小主要与土壤水分有关.%In order to study energy and water cycles in the Huaihe River Basin, micrometeorological measurements were carried out in Shouxian County, Anhui Province, during HUBEX/IOP (May to August 1998 and June to July 1999). The employed techniques included Bowen Ratio-Energy Balance (BREB) and Eddy Covariance (EC) methods. In this paper, the basic characteristics of the energy balance components in the district are analyzed. Furthermore, the results are compared with those from other regions of China.The main results are as follows: (1) There was a consistency between the available energy (Rn-G) and the sum of sensible (H) and latent (E) heat fluxes measured by the EC method (H+E)ec, but Ebr was slightly larger (about 10%) than Eec; (2) Most of the net radiation (Rn) was used to evaporate water from the surface. During HUBEX/IOP in 1998 and 1999, the mean daily amounts of Rn were 13.89 MJ m-2 d-1 and 11.83 MJ m-2 d-1, and the mean Bowen Ratios (β) were 0.14 (over ruderal) and 0.06 (over paddy) respectively; (3) The diurnal variation characteristic of β was larger and unsteady at sunrise and sunset, and smaller and steady during the rest of the daytime. Local advection appeared in the afternoon over paddy areas in 1999; (4) In comparison with the results from other regions of China, the nean β was the lowest (0.06) over paddy areas in the Huaihe River Basin and the highest (0.57) during June-August 1998 in Inner Mongolia grassland. The Bowen Ratio β is mainly related to the soil humidity.