不同距离气象数据对细小可燃物含水率预测模型精度的影响

Distance of meteorological data from test site and fine fule forecast model accuracy

为研究不同距离气象数据对细小可燃物含水率预测模型精度的影响,对2010年春、秋季防火期大兴安岭地区塔河县盘古林场的樟子松Pinus sylvestris var.mongolica林、兴安落叶松Larix gmelinii林和白桦Betula platyphylla林等3种林分下细小可燃物含水率进行连续的观测,同时采集试验期内的气象数据构建细小可燃物含水率预测模型。结果表明:利用盘古气象站数据构建的气象因子中,日降水量(R)和前n d降水量之和(Ran),以及前n d平均相对湿度(Han)(n=1~2)显著正相关,春季和秋季分别与日最高气温(Tmax)和连旱天数(d)显著负相关;利用距离实验地较近的盘古气象站的气象数据所建模型精度优于距离较远的塔河模型,模型的平均绝对误差(EMA)和平均相对误差(EMR)分别降低了2.7%和22.6%(P<0.01)。从细小可燃物的异质性和模型的精度来看,在建模气象数据的采集中,应重视气象因子时间和空间尺度的选取,以确保模型精度。

To determine the influence of meteorological data at different distances from a research site on the accuracy of a prediction model for water content of fine fuels, a model was established and tested in the spring and autumn of 2010. Continuous observations were conducted on the moisture content of fine fuels in Pinus sylvestris var. mougolica, Larix gmelinii, and Betula platyphylla stands in the Pangu Forest Farm of Tahe Coun-ty, Da Xingan Ling Prefecture and compared to meteorological data such as precipitation （R）, total precipitation for u d （Ran）, average relative humidity （Han）, daily maximum temperature （Tmax）, and drought days （d）. Results indicated that for meteorological factors in spring and autumn, R was positively correlated with Ran and Han （n = 1-2） , but negatively correlated with Tmax and d. The model using the meteorological data of the Pangu Meteorological Station was more accurate than the Tahe Model which was further away having a significantly lower mean absolute error （EMA） of 2.7% and mean relative error （EMR） of 22.6% （P〈0.01）. From the hetero- geneity of the fuels and the accuracy of the model, attention should be paid to the selection of time and the spatial scale of the meteorological factors when modeling meteorological data collection so as to ensure model accuracy.