平水年

冬小麦水分满足系数Wdm在平水年及干旱年型下分别为0.91和0.74。

The water meeting index , Wdm was 0.91 and 0.74 in normal and dry years , respectively .

1996年属平水年，生长季末土壤水盈余18mm；

The year 1996 was a normal flow year , and soilwater had a surplus of 18 mm at the end of the growing season .

对净灌溉供水量NIR进行频率分析，确定了平水年（50%）、中等干旱年（75%）以及干旱年（95%）的烟草生育期的需水量和有效降雨量。

By analyzing frequency of net irrigation water supply , water requirement and effect rainfall of tobacco growth stage in moderate year ( 50 % ) , medium dry year ( 75 % ) and dry year ( 95 % ) were confirmed .

结果表明，极旱年地下生物量的峰值达到1249g·m-2，比平水年峰值586g·m-2高1倍多。

The results indicated that the peak value of underground biomass reached 1249 g · m - 2 in extremely arid year , higher than that in normal year ( 586 g · m - 2 ) .

平水年，深根系区与浅根系区土壤水分变化差异表现在30cm深度以下，而丰水年其差异主要表现在土壤表层（0~30cm）；

The large differences on soil water between deep-root and shallow-root plant plots could be seen in the surface layer ( 0 ~ 30 cm ) in rainy year , but under 30 cm depth in average year .

无论平水年还是丰水年，深根系区土壤水分变幅均比浅根系区大。

The variation ranges of soil water in the deep-root plant plots were wider than those of shallow-root plant plots .

在平水年，降水可满足幼树生长需要，补充灌水虽可促进春梢生长，但对提早开花结实有负作用；

In normal year , the precipitation could meet the water needs of young trees , while supplemental irrigation could increase spring shoot growth but was unfavorable to blossoming .

不同水文年的丰水期硝氮浓度以丰水年最高，平水年次之，枯水年最低。

The concentration of nitrate in high water season in wet years is highest , in mean year take the second place , and in dry year is lowest .

地表水的污染风险大于地下水，稻季的污染风险大于麦季，丰水年的污染风险大于平水年。

The risk is higher to surface water than to groundwater , in the rice season than in the wheat season , and in years with excessive rainfall than in those with normal rainfall .

平水期个人年总风险约是丰水期的6倍。

The health risk of PAHs in the level period was six times than abundant water period .

并研究了仅由均值变化引起的这两个流域丰水、平水及枯水年出现的概率变化。

The probability of annual runoff for high , normal , and low flow years due to the change of mean annual runoff was studied .