华北平原1981～2001年作物蒸散量的时空分异特征

Spatio-temporal Distribution of Crop Evapotranspiration from 1981-2001 over the North China Plain

利用土壤—植被—大气传输机理模型(VIP模型),以GIS背景数据库(土地利用图、土壤质地图和数字高程图)为支撑,在NOAA-AVHRRNDVI数据和气象信息的驱动下,连续模拟了1981～2001年华北平原冬小麦和夏玉米生育期的蒸散过程。结果表明:模拟的作物蒸散量与Lysimeter观测值和其他学者的田间试验研究结果具有较好的一致性。华北平原冬小麦多年平均蒸散量空间上呈现南高北低的趋势,其中黄河以北地区和山东半岛的蒸散量在200～400mm之间,南部地区在400～466mm之间。对玉米而言,北部的海河低地平原以及津、冀、鲁的沿海地区多年平均蒸散量变化在230～380mm,其余大部分地区蒸散量在380～470mm。除本区最南端的极少部分地区外,华北平原大部分地区冬小麦生育期内的自然降水都小于蒸散量,水分亏缺量大于200mm,而夏玉米生育期内大部分地区的降水大于蒸散量。

With the aid of Geographic Information System,a Soil-Vegetation-Atmosphere Transfer model (VIP model)was used to simulate crop evapotranspiration in the North China Plain(NCP) from 1981 to 2001 based on GIS,RS and meteorology information.The simulated evapotrans-piration is comparable with the observation of Lysimeter and data from the literature.The results show that cumulative evapotranspiration of winter wheat is higher in the southern part than that in the northern part of the NCP,about 200～400 mm in the northern and 400～466 mm in the southern.For summer corn,the cumulative evapotranspiration is 230～380 mm in the northern part and 380～470 mm in the southern.During most of the years of the simulated period,precipitation amount was less than actual evapotranspiration of winter wheat,whereas the situation is quite different for summer corn in the NCP.