水文特征年内分配的优势期和优势值

THE DOMINATING DATE AND DOMINATING VALUE OF THE HYDROLOGIC CHARACTERISTIC ALLOTMENT IN A YEAR

用圆周方位来表示水文特征年内出现的日期,而用径向距离来表示相应的特征值,计算部分圆环面积内的密度值,绘制等密线,即得水文特征等密图。该图直观地反映了水文特征年内出现的优势中心及其相应的优势期和优势值,优势度则是它们出现的可能性大小。优势期和优势值是水文特征年内分配的一个重要特点,本文利用等密图的表示方法,揭示和分析了这一客观存在的水文现象。

The circular locality is used to express the date that the hydrologic characteristics occur in a year, the radial distance to express the correspondent characteristic value, and the density value in the partial ring area is calculated,the isodense is drawn, therefore the isogram of the hygrologic characteristics is got. The isogram reflects the dominating centre that the hydrologic characteristics occur in a year and the corresppondent dominating date and dominating value. The dominance is used to express the probability that they occur. The dominating date and dominating value are important features that the hydrologic characteristics allot in a year. The paper uses the representation of isogram to enunciate and analyze the hydrologic phenomenon in objective existence.