黄河流域蒸散量分布式模拟

针对传统区域蒸散计算模型中净辐射及其各组成要素的计算直接采用国外经验公式或点上观测资料空间内插的不足，利用基于中国气象站观测资料建立的净辐射及其各组成要素的计算公式和遥感反演的地表反照率，以黄河流域作为研究区域，在考虑地形起伏和下垫面多样性等地表非均匀性因素的基础上，实现了黄河流域净辐射及其各组成要素的分布式模拟；在印证流域尺度存在蒸散互补相关关系的基础上，将净辐射、气温、水汽压等系列要素分布式拟合结果与基于区域蒸散互补理论的AA（Advection-Aridity model）模型耦合，实现了黄河流域蒸散量的分布式模拟。与基于水量平衡的黄河流域多年平均蒸散量空间分布图对照表明，二者趋势分布吻合很好，分区验证的最小相对偏差为1.14%，最大为26.80%，全流域平均相对偏差为1.50%，且分布式蒸散拟合结果更加细致地体现了蒸散量的空间变化情况。集成的区域蒸散分布式模型，以蒸散互补理论为基础，考虑了区域蒸散对近地层大气的反馈作用，仅以数字高程模型和常规气象站观测数据为输入项，应用方便。

Distributed modeling of evapotranspiration in the Yellow River basin

In the traditional models for areal evapotranspiration estimation, net radiation and its composition elements were generated by simulation of foreign empirical formulas or by interpolation of site observation data, which was one of the key reasons influencing the simulation accuracy of areal evapotranspiration. Using the developed models fitted by the meteorological observation data and the land surface albedo derived by remote sensing data, we achieved distributed modeling results of meteorological elements such as net radiation, air temperature, vapor pressure etc in the Yellow River basin. The heterogeneity of land surface such as topography and land cover diversity was considered in these simulations. With confirmation that the complementary relationship between actual evapotranspiration and potential evapotranspiration is available on a basin-wide scale, distributed simulation of evapotranspiration in the Yellow River basin was generated by coupling the distributed modeling results of the above elements with the advection-aridity model which was founded on the complementary relationship theory. Comparison shows that the spatial distribution of the simulated annual evapotranspiration has a good consistency with the isograms which was derived by water balance and sub-region tests showed that the minimum relative error is 1.14%, the maximum is 26.80% and the whole river basin average is 1.50%. Furthermore, the simulated evapotranspiration indicts the details more fine. The integrated distributed model for areal evapotranspiration simulation was founded on the complementary relationship theory, which takes into account the feedback of regional evapotranspiration upon the near-surface layer atmosphere, and it is easy to use for only taking DEM data and conventional meteorological data as input.