查询词典 alluvial fan

In view of Helan Mountain-Yinchuan basin is a ecological Continuum, it's innovative to put forward the holistic system of Helan Mountain-Yinchuan Basin as suitable scale for landscape management. Based on the fact that Helan Mountain-Yinchuan Basin in a circle composed by deserts and Loess Plateau,and seven vegetation ( the mountain forest belt,mountain shrub-grass belt,mountain foot desert grassland belt,oasis belt in diluvial fan plain,oasis belt in alluvial plain,wetland belt near the Yellow river, desert grassland belt in Obrdos platform) belong to the system, a"mountain-plain oasis-river-platform eco-productive paradigm"is proposed.

基于贺兰山——银川盆地是一个生态连续的复合系统，创新性地提出以整个山盆系统做为景观整体管理的尺度；基于贺兰山——银川盆地处于生态脆弱圈内山地森林带、山地灌草带、山麓荒漠草原带、洪积平原带、黄河冲积平原带、黄河滩涂湿地带、鄂尔多斯台地荒漠草原带等7个植被带的水平和垂直地带性特点，提出了贺兰山——银川盆地系统山地-平原绿洲—黄河—台地的生产生态范式。

Yangtze River Delta Metropolitan Area, which is formed in the Yangtze River into the sea fan alluvial plain, with Shanghai as the leading Soviet Union and Yugoslavia. Zhejiang northeast industrial belt.

长江三角洲都市圈，是指在长江入海而形成的扇形冲积平原上，以上海为龙头的苏中南、浙东北工业经济带。

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。

In piedmont alluvial-proluvial fan, phreatic water closely connects with confined water, they are fresh water and the good watershed for centrally municipal water supply.

2山前冲洪积扇区，潜水和承压水联系密切，水质好，是城市集中供水水源地的良好选择。

For each strategy, a corresponding exploitation plan of groundwater was designed. Then each designed exploitation plan (except scheme 3) was put into the model for calculation and simulation. The analysis on the forecasting results every plan indicates that:(1) Shuting down the self-provided wells is the most direct and effective method, playing an important role in the land subsidence prevention.(2) The resumption of compressed soil by groundwater artificial recharge is limited. So the artificial recharge can\'t provide essential effect for the resumption of land subsidence, unless the artificial recharge is much more than the groundwater withdrawal.(3) The method of "adjusting the exploitation stratum of groundwater to the shallow" has an obvious effect on the land subsidence prevention.(4)"Sand wells" can increase the leakage recharge for confined aquifer, and thus can slow and prevent the development of the land subsidence.(5) For the groundwater exploitation in Xi\'an, emergency self-provided wells should be managed according to the well spacing of 1600m, 2000m and 1600m, respectively, in the river terrace area, alluvial-proluvial fan area and loess tableland area to exploit the first confined groundwater. Corresponding individual well yield can be set as 2500m~3/d, 1500 m~3/d and 200 m~3/d. Make emergency self-provided wells pump in the dry year and stop pumping groundwater to restore and conserve underground water sources in average years and wet years. In this way, groundwater withdrawal of 162000m~3/d can be obtained to provide for the supplement of water supply in Xi\'an. As a result, the water supply stress can be released in dry years. The groundwater depression formed in the exploiting year can resume in 3-4 years. At the same time, this exploitation manner will not lead to obvious land subsidence.

本文利用所建的模型预测了现状开采条件下未来20年的地下水位和地面沉降的变化，在此基础上，提出了防治西安市地面沉降的五个地下水开采方案，利用所建的地面沉降模型对各个设计方案其进行了模拟和预报，对预测结果的分析表明：①封停自备井是防治地面沉降最为直接和最有效的对策，对防治地面沉降起着最为积极的作用；②采用人工回灌方法使被压缩的土层得到的恢复是非常有限的，对地面沉降不能起到根治作用，只有回灌量明显大于开采量时才能有一定的效果；③&调整开采层次，在浅层取水&对防治地面沉降的效果十分明显；④布设&砂井&可以增加对承压含水层的越流补给量，从而可以有效地缓解和控制地面沉降的发生和发展；⑤对西安市的地下水开采，可在河流阶地区、冲洪积扇区和黄土塬区分别采用1600m、2000m、1600m的井间距布置应急自备井，分别采用2500m~3/d、1500 m~3/d和200 m~3/d的单井开采量，开采第一承压水，在平水年或者丰水年不开采，涵养地下水源，在枯水年启动这些应急自备井开采，在输出分析范围内共可获得162000 m~3/d(5913万m~3/a)开采量，可以有效地补充西安市的供水水源，缓解供水紧张局面，开采年开采导致的下降的水位可在停采3～4年后得到基本恢复，同时，这种开采方式不会造成大的地面沉降量。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。