That the black mudstone deposited in deep water interbedded with salt and gypsum deposited in shallow water shows that during the sedimentation of 3 ( superscript rd ) and 4 ( superscript th ) sub - member , the lake level changes frequently 也正是由于湖平面变化频繁，在沉积中心的周围主要物源方向上形成一系列低水位期的砂体。
One of the main contents of continental sequence stratigraphy is dividing the three - order sequence into " lst , tst and hst " , representing three stages of a lake basin deposition 摘要陆相层序地层学的一个主要内容是将三级层序划分为“低水位体系域、湖进体系域和高水位体系域”等三个水位域沉积体系，分别代表着一个湖盆沉积的三个阶段。
The batch of eggs from which the juvenile green turtles were hatched was rescued from a beach on september 29 last year because the nesting site was located below the high tide mark and would be submerged under high tides 渔护署于去年九月二十九日在一个泳滩发现一窝海龟蛋，由于产卵地当时处于低水位，海龟蛋极可能在潮涨时被水淹没。
Lowstand system tract , transgressive system tract and highstand system tract are all have characteristic of changing gradually in tune and space . it ' s the new theory of sequence stratigraphy applying on the continental sedimentary basin 低水位、水进及高水位体系域都具有时间、空间渐变的特征，这是层序地层学理论应用于陆相沉积盆地的新认识。
( 4 ) this paper shows that the urassic badaowan formation in north part of the hami depression possesses a depositumal system of fan and fan delta and shallow lake fades with the analysis of seismic stratigraphy 通过地震地层学分析和储层横向预测研究，首次提出四道沟地区侏罗系八道湾组早期低水位时期沉积了由北向南的冲积扇?扇三角洲?湖泊沉积体系。
The result of data analysis and studying shows that the low stand system of down - sha - 3 formation , the high stand system of mid - sha - 3 formation and the low stand system of up - sha - 3 formation are important to form subtal trap 从分析资料和研究的结果发现，沙三下段低水位体系域、沙三中段高水位体系域、沙三上段低水位体系域对于隐蔽圈闭的形成有着非常重要的贡献。
During the time of maxi - pumping , it is in circular form to make use of the structural advantages of the circular shape , and during the time of low - water , the cofferdam is in special form to meet the requirements for the construction of the lower pylon - columns 最大抽水状态时为圆形结构，充分发挥了圆形结构受力好的特点；低水位时由圆形变成异形，以适应下塔柱施工的需要。
From the beginning of sq9 ' s development , the sedimentary environment turn to be lake basin bog . with water becoming shallow , coal seam appeared in lowstand system tract , delta plain and delta front are the main sedimentary bodies in highstand system tract 从层序9开始，水体开始变浅，向湖沼环境过渡，低水位体系域和水进体系域出现了煤线，高水位体系域以三角洲平原及三角洲前缘沉积为主。
In hst beneath the boundary have good interconnecting sand body , poor lateral sealing , and no oil shows ; in lst and tst above it have delta distributary channel sand reservoir with serious heterogeneity and good lateral sealing , being oil layer 界面之下的高水位体系域砂体连通性好、侧向封堵不好、不含油，层序界面之上的低水位体系域及水进体系域三角洲分流河道砂体储集层非均质性强、侧向封堵条件好、含油。
Regarding the reinforcement as a engineering anti - seismic measure in the real dam , a numerical model is set up to simulate the reinforcement and the effects on the dam seismic resistance at two water levels are evaluated 讨论并建立了坝体伸缩横缝在地震荷载作用下穿越缝间抗震钢筋的数学模型，给出了动力非线性子结构法考虑缝间抗震钢筋影响的求解公式；并就正常高水位常与低水位两种水位工况，对坝体的抗震性能进行了计算分析。
