冲积扇

Then it defines that thebackground value of soil erosion of the middle Yellow River is 650-1000 millon tons/year according to thetwo-way calculation results of aggradation volume of the river alluvial fan and sediment deposition volumeof the ancient river mouth, after comprehensive consideration and under the conditions of less...

然后根据由黄河冲积扇的堆积量和古黄河口泥沙淤积量两种途径的推估结果，经综合考虑后认为，在历史上人类活动较小情况下，黄河中游土壤侵蚀的自然背景值为每年6.5～10亿t。

These channels are most common near the apex of the alluvial fan body.

这些河道最常见于近冲积扇体的顶端。

Biyang fault-depression experience three evolutional phase: Mesozoic pull apart, Paleogene rift. Neogene downwarp basins. So it has in turn three basin-fill sequences and responding tectonic sequences, which were specified by regional unconformity; their general sedimentary style respectively is assemblage of fluvial fan～flood lake depositional system, fluvial fan ～ fan delta ～ lacustrine ～ delta depositional system. and fluvial plain ～ sand mudstone flat depositional system.

泌阳断陷历经中生代小型拉分盆地、早第三纪裂陷盆地和晚第三纪坳陷盆地等三个盆地原型的演化、叠合过程，形成了三个盆地充填序列及其所对应的三个构造层序，其界面皆为区域性构造不整合面；沉积总体样式分别为冲积扇～洪水-漫湖沉积体系组合、冲积扇～扇三角洲～湖泊～三角洲沉积体系组合、冲积平原～砂-泥坪～滨浅湖沉积体系组合。

In Luye River, the alluvial fans were incised by the main stream as terraces. The highest two levels of terraces in altitude have been deformed by active faults and folds. Field investigation shows the highest surface is covered by lateritic soils. In Beinan River, there are strath terraces developed.

鹿野溪的四阶河阶地，是河口冲积扇在河川下切后受切割形成的，卑南溪的四阶河阶地均分布於河川东岸，是鹿野溪冲积扇发育时，迫使卑南溪向东侧迁移，强烈的侧蚀作用形成的侵蚀面，在后期河川下切后形成的。

At the same time, the salt in the layer of soil has experienced from low to high then to low. In the alluviation fan and the top of alluvial plain, the soil salt form gathering is strong, that is to say, the content of salt relatively high in the layer of soil, but reduced in the bottom of soil. At the bottom of valley, the salt content increase from upper and bottom of soil, especially at the desert edge, this kind of trend is more obvious. Differentiation of soil characteristic was exited in mountain-basin system, and agriculture development should follow this rule.

土壤盐分空间变化规律明显：在前山区地带，土壤含盐量低；在冲积扇、冲积扇缘及冲积平原上部绿洲区，土壤耕层总盐高、表聚性强；从冲积平原中下部到亁三角洲绿洲，耕层盐分含量依次降低，但剖面盐分含量呈现依次增加趋势，形成盐分聚集的漏斗效应，尤其进入沙漠边缘区，这种趋势更加明显。

On the stage of Kongyi Member,the main sedimentary facies are the fluvial fan group and flooding plain,and going with the sedimentary surrounding of minitype limnological fluvial fan—gypsum saline.

研究区的沉积受喜山运动影响，在盆地南区产生拉张裂陷，形成孤立的沉积小盆地，并在这种沉积环境中沉积了孔店组地层，孔一段时期以盆缘冲积扇群、洪泛平原为主，局部伴有小型准盐化湖沼的冲积扇—膏盐湖沉积环境。

More and more research proves that alluvial fan is affected by many environmental factors such as tectonic activity, climatic conditions, base level change, drainage basin geology, geomorphology and plant covering of drainage basin, human activities; therefore, alluvial fan research bears great significance to theory of geomorphology and practicalities.

越来越多的研究表明，冲积扇的演化受构造、气候、基准面、流域地质地貌条件、植被覆盖程度以及人类活动等诸多环境因素的影响，因此，冲积扇研究具有十分重要的理论意义和现实意义。

The fault terrace zone controlled the occurrence and distribution of sand deposits, developing alluvial fan-fan delta system on the steep slope fault terrace and alluvial fan-fluvial-delta on the gentle slope fault terrace.

断阶带控制砂体的发育与展布，陡坡断阶带发育冲积扇-扇三角洲沉积体系，而缓坡断阶发育冲积扇-河流-三角洲沉积体系。

Lithological characterized by pyroclastic rocks interbedded with sedimentary rocks, with a few volcanic rocks.(2) The sedimentary facies: include normal fluvial, swamp, littoral and shallow lakes, as well as fallout facies of pyroclastic sediments, volcanic lahar facies, pyroclastic alluvial facies and pyroclastic fluvial facies (different from normal alluvial and fluvial facies).

1岩性——以火山碎屑岩、火山碎屑沉积岩和陆源碎屑沉积岩互层为特征，亦夹有少量火山岩；(2)沉积相类型——包括陆源碎屑沉积的河流相、沼泽相、滨浅湖相和火山碎屑沉积的空落相、火山泥石流相、火山碎屑冲积扇相和火山碎屑河流相(与陆源碎屑的冲积扇相和河流相不同)。

P in Shule River Alluvial Fan Oasis in Gansu subsidized by CNSF. Through field geological and environmental observations and sampling, quartz OSL dating, organic carbon ~(14)C dating, as well as analysis of TOC,grain size and Pollen assemblage of the samples from ten sediment profiles in front fine grain sediment zone of the Shule River Fan, the results obtained as follows:(1)The vegetation evolution history on Shule River Alluvial Fan and circumjacent since about 13 ka B.P. could be divided into 6 phases: about 12.1-13.1ka, a sparse coniferous and broadleaf trees - shrub grassland, cold and wet climate; 9.2-12.1ka, shrub grassland, temperature rising but precipitation and humidity getting down; 5.8-9.2ka, sparse forest with the most flourish shrub grassland under the optimal climate; 4.3-5.8ka, coniferous and broadleaf mixed forests -shrub grassland, temperature rising slightly and getting dry; 4.3-2.8ka, grass vegetation and climate became more dry; 2.8-2.3ka, coniferous forests -shrub grassland, precipitation and temperature getting down, but a higher relative humidity.

本文依托于&甘肃疏勒河冲积扇5万年来古天气环境与古水文演化&项目，以疏勒河冲积扇为研究对象，通过对疏勒河冲积扇扇缘细土带全新世古天气和古水文演变进行了20余个剖面的观测和取样、石英OSL和~(14)C测年、粒度组成和TOC分析以及孢粉鉴定，获得了以下成果和熟悉：(1)距今约13ka年来冲积扇和周边植被演化经历了6个阶段：约13.1～12.1ka，以针叶林为主的针阔混交林～灌丛草原，天气冷湿；12.1～9.2ka，灌丛草原，气温升高，降水量较低；9.2～5.8ka，疏林灌木草原，植被茂盛，温度和降水最佳；5.8～4.3ka，以针叶树为主的针阔混交林～灌丛草原，气温较高，降水减少；4.3～2.8ka，草原植被，天气变干；2.8～2.3ka，针叶林～灌木草原，降水减少，温度降低，相对湿度有所增加。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷