The earliest clepsydra was a copper pot holding water with a small opening at the bottom and a pole with scales standing in the center. When the water dropped through the small hole, people determined time by the scale on the pole as the water level decreased.

最早的漏壺用一只銅壺盛水色情日韩在线成人网站视频，壺底有一個小洞，壺中插一根刻有刻度的標桿，水從小洞滴出后，人們根據(jù)水位降低后標桿上的刻度來判斷時間美女汚汚无遮挡免费视频。

When it rains in the Petén, mosquitoes swarm in such clouds that today's Maya have to drive them away with greasy smoke from torches burning cohune palm nuts. In the dry season, the heat bakes the swampy bajos , or bottomlands, the rivers fall, and drought threatens.

佩滕地區(qū)一旦下雨，蚊子便如鳥云般成群涌現(xiàn)，現(xiàn)在的瑪雅人就必須以火炬燃燒羽葉棕櫚果實日本超碰97人人爽人人爱，用帶油脂的煙驅(qū)趕它們免费强奸网，到了干季，熱氣炙烤著遍布沼澤的洼地igao.com视频在线；河川水位降低一级毛在线，干旱隨時會降臨。

There will be 54×10^8 m^3 of saline groundwater can be used if the water level declines to 10m depth in the Hebei Plain in avoiding the seawater infall.

經(jīng)計算日韩欧美亚洲中文字幕看，若將地下咸水水位降低到10m色色色。com，在避免海水人侵的情況下，河北平原將有54×10^8立方公尺的咸水可以利用农村女人一级毛片20岁的毛片。

Because of the high water level and large permeability in sand, the cement mixing pile was also used as the anti-seepage pensile curtain, and deep-well system was set up at the same time to depress the water line.

場地水位高且與閩江有直接水力聯(lián)系老王黄色网站中文字幕，砂層滲透系數(shù)大，設(shè)計最大坑內(nèi)水位降深為11m午夜性爱熟妇青青乐园，通過設(shè)置水泥攪拌樁懸掛止水帷幕国产激情无码一区二区app，采用深井降水系統(tǒng)成功地降低了坑內(nèi)水位无码精品视频。

The water often becomes saltier because of the concentration of minerals.

這是因為桉樹蒸騰率非常高igao视频在线观看，這水渠從導致地下水位降低土壤水分。

By comparing the landslide displacement and the shearing strain increment under different water level condition, discovered that along with the rising water level, the displacement and the shearing strain increment of Taping landslide are obviously increased, it is show that the landslide has the obvious response to the storage, the water rise cause the stability of landslide present the reduction tendency.

通過不同水位狀態(tài)下滑坡位移和剪應變增量的分析中文字幕第一区你懂的，發(fā)現(xiàn)女人帮男人橹的视频网站，隨著水位的上升，塔坪滑坡的位移及剪應變增量都明顯增大性欧美lx╳lx╳，說明滑坡對蓄水有明顯的響應一级婬片A片免费播放视频，水位上升使滑坡的穩(wěn)定性有降低的趨勢。

A relative low lake level between 8660～6010 cal.yr BPwas reflected by the clayey silt sediment with the median size less than 25μam and the sandcontent less than 4%,and the Pediastrum concentration was normally low.Between 6010 and2250 cal.yr BP,the median size and sand content increased greatly,and the Pediastrumconcentration raised sharply,suggesting a relative low lake level.After 2250 cal.yr BP,boththe median size and the Pediastrum abundance abruptly declined,suggesting the lake returnedto high level and the climate changed to humid.

UG04孔硅藻記錄重建的湖泊水位變化基本上支持孢粉重建的古植被和古氣候：8660～7230 cal.yr BP硅藻組合以浮游類主導www.欧洲视频在线，浮游／底棲比達40以上欧美性爱片网站，指示水位較高，氣候略濕潤国产羞羞涩涩午夜视频；7230～2330 cal.yr BP浮游類硅藻豐度和浮游／底棲比降低亚洲性爱区第一页，湖泊處于低水位，氣候干旱人看看人人摸人人操；2330～930 cal.yr BP浮游類硅藻豐度和浮游／底棲比增加人人看人人看，湖泊水位升高，氣候濕潤99久久国产一级特片无码。

A mass of experiments validated that exploitation and rational utilization of saline shallow groundwater, declining the water level to an optimal depth to reducing water invalid evaporation can increase amount of water resources and storage capacity of aquifer, prevent waterlogging or drought, improve groundwater salinity and control the process of soil salination, improve the eco-environment, alleviate the threat for the resource of fresh water.

大量的實驗證明在线观看免费黄色网站，合理開發(fā)利用淺層咸水，使咸水水位降低到合理水平起碰在线免费视频，可以：避免地下水的無效蒸發(fā)黄色网站免费看a片，增加水資源量；增強調(diào)蓄能力和抗早防澇能力；促進淺層咸水淡化欧美性爱αV在线视频，改造鹽堿地久久亚洲精品少妇毛片无码，改善生態(tài)環(huán)境；減輕對淡水資源的威脅国产综合在线观看视频。

Trashrack plugged into the lower pool water level.

攔污柵堵塞a黄色网址，進水池水位降低。

In operation, the alignment and the magnetic reed switch with the position of the float should be to reduce the water level, whichever is automatically cut off power supply to achieve the purpose of automatic water level should be repeated reed switch off electrical calibration sensitivity.

在操作過程中高潮流水抽搐免费视频在线，調(diào)準干簧管和磁性浮子的配合位置應以水位降低能自動切斷電源為準下载日韩精品视频在线观看免费，從而達到自動控制水位的目的，應反復校準干簧斷電器的靈敏度亚洲观看一区二区三区。