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首页> 外文期刊>Canadian Water Resources Journal >Development and Verification of Daily Gridded Climate Surfaces in the Okanagan Basin of British Columbia
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Development and Verification of Daily Gridded Climate Surfaces in the Okanagan Basin of British Columbia

机译：不列颠哥伦比亚省奥肯那根盆地日网格气候面的开发和验证

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摘要

Gridded estimates of daily minimum and maximum temperature and precipitation from 1960 to 2005 were prepared for the Okanagan Basin of British Columbia. The procedure utilized available daily climate data from 182 stations and employed a regression based interpolation scheme at 500 metre grid spacing. Spatial distribution of temperature took into account variations in temperature with elevation, an observed north-south temperature gradient, and proximity to several large lakes in the valley bottom. An inverse distance weighting scheme was used for the interpolation, and a constrained lapse rate approach was used to interpolate in areas that lie above the highest climate station. Temperature inversions were handled by fitting a second order polynomial and introducing a two-layer model. The precipitation routine differs from the temperature model in that the regressions were based on monthly precipitation totals, thus producing daily precipitation surfaces that incorporate an orographic component along with latitudinal trends. A "leave one out" cross-validation procedure was applied to 56 stations to test model performance. Cross-validation of the predicted surfaces indicated that, on average, the daily maximum temperature surfaces were more accurate than the daily minimum temperature surfaces. Mean Absolute Error (MAE) averaged 1.0℃ for maximum temperature while for minimum temperature MAE was in the range of 1.3℃ to 1.8℃ depending on the season. Errors in both temperature and precipitation surfaces are largest at higher elevations where station density is low. Over all stations, monthly MAE for precipitation averaged between 10% and 18%. A MAE calculated from differences between observed and predicted annual precipitation over all stations was 27 mm with a percent error of 6.2%. The model shows a positive bias (1.4) in the daily occurrence of precipitation resulting in an over-prediction of days with drizzle. Over 80% of incorrectly predicted wet days had less than 1 mm precipitation. These error statistics compare favourably to those from similar regression-based interpolation models.
机译：为不列颠哥伦比亚省的Okanagan盆地提供了1960年至2005年每日最低，最高温度和降水的网格估算。该程序利用了来自182个站点的每日气候数据，并采用了基于回归的插值方案（间距为500米）。温度的空间分布考虑了温度随海拔的变化，观察到的南北温度梯度以及靠近谷底的几个大湖泊的情况。插值使用反距离权重方案，而最高气候站以上的区域则采用约束失效率方法进行插值。通过拟合二阶多项式并引入两层模型来处理温度反演。降水例行程序与温度模型的不同之处在于，回归是基于月降水总量的，因此产生的日降水面包含地形成分和纬度趋势。对56个工作站应用了“留出一个”交叉验证程序，以测试模型的性能。对预测表面的交叉验证表明，平均而言，每日最高温度表面比每日最低温度表面更准确。根据季节，最高温度的平均绝对误差（MAE）平均为1.0℃，而最低温度的平均绝对误差（MAE）在1.3℃至1.8℃的范围内。温度和降水表面的误差在站密度较低的较高海拔地区最大。在所有气象站，平均每月降水量的MAE在10％至18％之间。根据所有观测站的年降水量与预测值之间的差异计算的MAE为27 mm，百分误差为6.2％。该模型在每天的降水中显示出正偏差（1.4），从而导致对小雨天的过度预测。超过80％的不正确预测的湿日降水少于1 mm。这些误差统计量比类似的基于回归的插值模型的误差统计量优越。

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  • 来源
    《Canadian Water Resources Journal》 |2010年第2期|P.131-154|共24页
  • 作者

    Denise Neilsen; Guy Duke; Bill Taylor; Jim Byrne; Stefan Kienzle; Ted Van der Gulik;

  • 作者单位

    Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, BC VOH 1Z0;

    rnDepartment of Geography, University of Lethbridge, Lethbridge, AB T1K 3M4;

    rnEnvironment Canada, Environment Canada, Vancouver, BC V6C 3S5;

    rnDepartment of Geography, University of Lethbridge, Lethbridge, AB T1K 3M4;

    rnDepartment of Geography, University of Lethbridge, Lethbridge, AB T1K 3M4;

    rnSustainable Agriculture Management Branch, BC Ministry of Agriculture and Land, Abbotsford, BC V3G 2M3;

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