1) large backwater zone
大回水区
1.
This paper studies the causes of its extinction of Meta population from the perspective of biology,analyses the problems of present protective measures and gives the suggestion to set up a natural protected area network in large backwater zones of middle and lower reaches of the Changjiang River.
本文试从生物学的角度,探讨其Meta种群灭绝的原因和现有保护措施存在的问题,并提出了在长江中、下游大回水区建立自然保护区网的设想。
2) the Backwater Reach
回水区
1.
Eutrophication Investigation on the Backwater Reach of the Branch River of the Three Gorges Reservoir;
重庆三峡库区支流河口回水区富营养化研究
2.
The contents of different nitrogen forms and phosphorus forms in surface sediments and the soils of water-level-fluctuating zone of the backwater reach from input river of Three Gorges Reservoir were measured,and their distribution character were studied,Major conclusions were described as follows:1.
主要研究了三峡入库河流大宁河回水区沉积物及消落区土壤氮磷营养盐的赋存形态及其分布特征,并对消落带土壤进行氮磷释放动力学特征研究,以掌握三峡水库秋季蓄水运行(156m)条件下大宁河流域回水区沉积物分布特征,以期为分析水库运行对大宁河沉积物变化的影响、探讨水体中营养负荷的迁移变化规律提供基础数据,结果表明:1。
3) backwater area
回水区
1.
Characteristics of soil seed banks in backwater area of Three Gorges Reservoir water-level-fluctuating zone at initial stage of river-flooding
三峡库区消落带回水区水淹初期土壤种子库特征
4) backwater reach
回水区
1.
The contents of different phosphorus forms in surface sediments and the soils of water-level-fluctuating zone of the backwater reach from input river of Three Gorges Reservoir were measured,using the standard measurement and test(SMT) procedure of phosphorus forms in freshwater sediments.
应用淡水沉积物中磷形态的标准测试程序(SMT)对三峡入库河流大宁河回水区表层沉积物、消落带土壤不同形态P进行了分级测定,分析了各形态磷之间以及各形态磷与样品理化性质如有机质、主要氧化物组成之间的相关性。
5) backwater region
回水区
1.
Application of the neural network in prediction for chlorophyll-a in branch backwater region
神经网络在次级河流回水区叶绿素a浓度预测中的应用
6) the area of fluctuant backwater
回水变动区
1.
Study of the model of water quality for the period of time of backwater in the area of fluctuant backwater of Three Gorges Reservoir anabranch-embouchure;
三峡库区次级河流河口回水变动区回水时段水质模型
补充资料:水库变动回水区
水库变动回水区
region of reservoir
shu一ku匕一。门do}191飞L{lshLJ}日一水库变动回水区(fluetuating baCkwaterregion of reservoir)水库最高水位[u1水末端和最低水位回水末端之间的河段。水库变动回水区具有水库和河道的双重特性。在水库蓄水期中.变动回水区受塑水影响,水流流速降低,泥沙迅速落淤。当水库水位消落时,变动回水区自上而下逐渐脱离雍水影响,恢复天然河道状态,水流流速提高、蓄水期落淤的泥沙将被水流冲刷起动,搬运至下游深水区内。因此.在水库变动回水区内,水位变化频繁,泥沙冲淤交替.其变化幅度均远大于天然河流。 变动回水区的泥沙冲淤数量和冲淤过程主要取决于水库的运行方式。由于河流的绝大部分泥沙来rl汛期,如果水库在汛期蓄水运用,大t泥沙将淤积在变动回水区内,汛期水库水位越高,淤积的泥沙量就越大。当枯水期水库因供水而水位下降时,变动回水区内会发生强烈的冲刷现象。对于沙质河床,在宽浅的过渡段,河道中将产生强烈的沙波运动,导致航道迁徙不定和水深变化无常。对于卵石河床在浅滩部位.枯水期的小流t可能难以冲走汛期搬运来的大量卵石,从而使水深不足和碍航.因此,当在航运发达的河流上修建水库时,为了减少水库消落期间的冲刷沙量,需要适当地降低汛期水库水位和抬高枯水期水位。 水库变动回水区大致可分为上段和下段两部分.变动回水区上段,水库塞水影晌的持续时间较短,水位立高值也较小,因此建库后除泥沙淤积t将较天然情况有所增多外,河流的形式不至产生重大的变化。变动回水区的下段,由于塑水作用增大,建库后往往会产生河型的变化。通常,河流平面形态的变化趋势是分岔河道向单一河道发展,弯曲河道向徽弯河道发展.在横向的形态方面,由于水位变幅增加.河道向高滩深槽发展,断面较天然情况下窄深。这些变化都有利于改善航运的条件。河型的转化会导致河流的主格易位,当新的航摘中存在礁石等碍航因家时,需要进行一定的整治。
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