京、津、冀土壤水分区划及其测站合理布局

THE DIVISION OF SOIL MOISTURE OF RATIONAL DISTRIBUTION OF STATIONS IN THE BEIJING-TIANJIN-HEBEI AREA

根据年降蒸差、年降水量和田间持水量等指标,运用类平均聚类分析方法,将京、津、冀地区划分出5个土壤水分区,并作了评价。用简单随机抽样方法,确定全区测站密度,在此基础上又依据各区田间持水量的变异程度,面积大小和农业指数,计算出各区的权重,以确定测站的布局和落点。分析了济南、密云等8个站的多年0～100cm 土层各层土壤湿度的极差和变异系数,对土壤湿度测定深度提出了探讨。

According to the indexes of difference between annual precipita- tion and potential evapotranspiration,annual precipitation and field capacity, using the method of average value cluster,the Beijing-Tianjin-Hebei area is divided into five soil moisture divisions.The description is made for each division. Using the method of simple random sampling,the station density in the whole eara is defined.Based on it,the weights of each division are calculated according to variation of field capacity,the area and agricultural indexes. Finally,distribution and locations of station are defined. The average difference between maximum and minimum of soil moisture in each layer(0～100cm)for many years and their variation coefficient are analy- sed(Dinan.Miyun etc.)The measuring depth of soil moisture is discussed.