不透水层

随着种子的发育成熟，栅栏细胞长度逐渐增加，由松散排列变为整齐致密，形成不透水层；

With the maturity of seeds , the palisade cells became longer , from loosely arranged turned into neatly and tightly , formed water impermeable layer ;

城市化把地面大面积变成不透水层，使径流系数增大，汇流时间缩短，洪水总量与洪峰流量增大，城市河流洪水灾害的发生频率增大。

The urbanization has turned the ground surface into an impermeable layer in a large area , increased runoff coefficient , shortened the concentration time , increased the total volume of flood water and peak discharge of floods and increased the frequency of floods of city rivers .

大沽河下游平原区沉积了丰富的砂层，平面上呈串珠状分布，厚38m，下伏白垩纪红砂岩不透水层。

There are abundant sand layers in the Dagu River plain , which are 3 ~ 8 m thick and like a string of beads in the plane distribution .

若已知存在不透水层，不透水层内的水压力分布规律如何。

If the water-tight stratum had already existed , what the groundwater pressure distribution regular in it .

城市土地利用的特殊性、不透水层面积的增加，使城市非点源污染不同于农业非点源污染，而控制难度更大。

The particularity of urban land use and the increase of impervious surface area make urban non-point source pollution differ from agricultural non-point source pollution , and more difficult to control .

东天山达坂城地区大规模层间水压碎屑岩发育于晚古生代裂谷沉积盆地中，受不透水层与富水层岩石组成的流体压力仓控制。

A large-size interlayer hydrofracturing clastic rocks , which were found in late-Paleozoic rift-sedimentary basin in Dabancheng region of East Tianshan Mountain , are controlled by the fluid compartments consisting of impermeable stratum and water-rich stratum .

本文针对无径流深观测资料地区的实际情况，考虑了水田、旱地、水面积和不透水层地面面积比重，建立了相关计算公式推求陆地蒸发量。

In view of the fact about observation data lack of runoff depth , the article considers the area proportion of the paddy field , the dry land , the water and no water seepage layer and establishes the relevant calculation formula for ascertaining evaporation volume of the land .