共查询到20条相似文献，搜索用时 62 毫秒
1.
2.
3.
4.
钱彤 《水土保持应用技术》2017,(4):26-27
大凌河哨口桥节点位于大凌河干流重点河段上,是连接朝阳市和外界的重要道路。传统的河道治理导致河流被完全人工化、渠道化,改变了河流蜿蜒型的基本形态,急流、缓流、弯道及浅滩相间的格局消失,观赏性差。同时,许多水生生物种群的生存环境遭到破坏,生态系统退化,河道水污染严重。通过系统地规划,确定了"一坎、一潜、三湿地"的治理方案,对河道节点进行了生态治理与修复。达到了改善水质、美化环境、修复和维护河道生态的目的,同时,为人们提供一个水清、滩绿、景美的亲水休闲娱乐场所。为辽西地区同类河道治理提供了参考。 相似文献
5.
当前传统城市河流与城市周边用地之间缺少河漫滩作为过渡,河道多被束缚在堤防之内,这种堤防不允许周期性洪泛跃堤的单一结构往往令城市河流进入快排模式,河流只是消化洪水的通道。而在非洪泛期,这种快排通道式的河道也随之失去了应有的生态功能。以平顶山湛河支流香山沟治理工程的生态修复方案设计为例,提出了在城市近郊恢复河流生态栖息地的可行性及必要性。通过宏观层次上对河流生态系统的恢复,中观层次上对河流物理结构的修复,微观层次上具体栖息地设施的构建,阐述了河漫滩生态修复是保证河流生态系统完整的重要途径。 相似文献
6.
[目的]对太湖流域河网水体生态修复工程及其效果进行对比分析,为该流域环境管理及水质改善提供基础。[方法]以太湖流域的夏庄浜、洛西河、凤沟河三条河流为例,通过在河道中分别实施复合塔式生物滤池处理工艺、五级负荷削减治理工艺、生态景观修复工艺,对3个工程的运行效果进行比较,研究出适用于流域河网地区的生态修复技术。[结果]三条河流生态修复工程的处理效果由强到弱依次为:夏庄浜洛西河凤沟河,由此可得3种生态修复工艺的去除污染物能力顺序为:复合塔式生物滤池处理工艺五级负荷削减治理工艺生态景观修复工艺。[结论]污染物去除效果表明,3种工艺对河道中氮、磷等污染物质的去除效果均较好,并具有良好的生态景观效果,通过进一步优化,可形成适用于河网地区的水质改善关键技术。 相似文献
7.
北京市中小河流治理技术探讨 总被引：2，自引：0，他引：2
借鉴国外河流生态治理方面的先进经验,结合北京市中小河流现状及治理中存在的问题,提出了中小河流治理原则,对中小河流治理的平面形态修复、断面形态修复及岸坡防护等关键技术进行了探讨。结合北京的典型实例,阐述了中小河流生态治理技术的应用及效果,对保障河流防洪安全和水资源利用,促进人水和谐,推进北京市经济社会健康、快速发展意义重大。 相似文献
8.
崔国强 《水土保持应用技术》2014,(4):48-48
辽宁省境内河流众多,受地理位置、地形地貌和气候等因素的影响,辽宁省洪水灾害频繁,给人民生命财产安全和经济社会发展带来严重威胁。近年来为防治水患灾害,全省各级政府都高度重视河道治理工作,转变思路,改变模式,融入生态治河的理念,提升规划设计、建设管理的水平。结合辽宁省河道治理实践,对河道生态治理的常用模式进行了探讨,以期为辽宁省河道生态治理提供参考模式。 相似文献
9.
生态河流构建原理与技术 总被引：11，自引：0，他引：11
传统的河流整治技术，如裁弯取直、疏开挖河道、浆砌石或混凝土加固河岸、高筑河堤等，忽略了河流的生态特性，结果导致河流水文发生改变，生态系统受到严重创伤。分析了河流治理技术的发展现状及遇到的问题，提出生态河流的概念，并探讨了生态河流的基本特征和构建原理，然后分别从河道景观设计、河道平面形态设计、河道断面设计和岸堤设计几个方面论述了生态河流构建的技术体系。最后，以镇江古运河生态岸堤构建为例，介绍了生态岸堤构建的实施办法，旨在探讨河流的生态治理的方法，实现人与自然和谐发展。 相似文献
10.
黄杖子河作为北票市城区内重要河流,也是辽西地区城市河流的典型,其河道的整治关系着北票地区的经济发展和生态规划布局的实施。因此,以黄杖子河为例,对辽西地区城市河道存在的问题进行了分析,明确河道治理的必要性,并拟定具体的河道整治规划方案。针对河道整治规划内容对生态护坡工程、河道悬浮物沉淀池处理和溢流坝改造工程进行了具体的设计。 相似文献
11.
Suyundukov Ya. T. Suyundukova M. B. Bezuglova O. S. Khabirov I. K. Khasanova R. F. Semenova I. N. Rafikova Yu. S. Ilbulova G. R. 《Eurasian Soil Science》2022,55(1):27-35
Eurasian Soil Science - The results of the study of the properties of urban soils of the city of Sibay located in the mining region of the Republic of Bashkortostan are presented. A specific... 相似文献
12.
13.
Kholodov V. A. Farkhodov Y. R. Yaroslavtseva N. V. Ziganshina A. R. Maksimovich S. V. 《Eurasian Soil Science》2022,55(7):998-1004
Eurasian Soil Science - Layers were step-by-step removed from macroaggregates (2–1 mm in diameter) of Protocalcic Chernozems via successive abrasion in a revolving rotator during 5, 10, 15,... 相似文献
14.
15.
《Communications in Soil Science and Plant Analysis》2012,43(15-16):1631-1646
Abstract Brazil has approximately 30 million hectares of lowland areas, known locally as “Varzea,”; distributed throughout the country. Soils in these areas have the potential to support agricultural production, but very little is known about their fertility. The current experiment was undertaken to characterize the chemical and physical properties of representative “Varzea”; soils collected at 0–20, 20–40, 40–60, and 60–80 cm depth intervals from 23 sites in Goias State of Brazil. Organic matter contents averaged 42 g/kg in the surface 20 cm of soil and should make a significant contribution to overall nutrient availability. Soil pH increased slightly with depth from a mean value of 5.2 in the surface 20 cm of soil to a mean value of 5.4 in the 60–80 cm depth interval. Several soils had exchangeable Al values ≥ 1.0 cmol Al/kg, but soil Al saturation was generally less than the 60% level frequently associated with Al toxicity. However, cereal and legume production could benefit from lime addition in many of these soils. Although base saturation was fairly low in some soils, exchangeable Ca and Mg levels were, in general, adequate throughout the profile. Extractable P levels were adequate in most surface soil samples. Extractable K levels in these soils were generally low, and the application of K fertilizers should be beneficial, especially in conjunction with lime addition. The high clay content “Varzea”; soils of the Brazilian lowlands have some drainage problems but generally exhibit favorable chemical properties for crop production when compared to soils of the well‐drained Cerrados. 相似文献
16.
Ye. V. Rogozhina N. V. Kostina L. S. Malyukova 《Moscow University Soil Science Bulletin》2011,66(1):32-35
An estimation of potential nitrogen-fixing activity of various soil types under agrophytocenoses of tea, filbert, peach, and
pawpaw which grow in the area of Greater Sochi is given. High indicators of nitrogen fixation activity in the soil in the
course of vegetation were characteristic of agrocenoses of pawpaw, peach, and filbert. The lowest level of nitrogen fixation
was noted in the soil of a tea plantation. A negative correlation dependence of potential nitrogen-fixing activity on the
acidity of the soil solution was established. A study of the seasonal dynamics of the activity of nitrogen fixation of soils
of agrocenoses of the subtropical zone of Russia made it possible to distinguish a less active winter and more active spring-summer-autumn
periods. 相似文献
17.
物联网是一个集信息通信、数据交换、传感器技术与软件工程于一体的综合性产业,探讨和分析了物联网的结构体系与发展中遇到的安全问题。 相似文献
18.
荔枝种子从果实中剥离出来后, 即使在室内条件下, 也极易失水干缩, 潮湿环境中又易发霉而腐烂。扫描电镜观察表明: 种皮上布满纹孔, 水分散失面积很大; 种脐部为疏松的海绵组织, 且营养丰富。据此, 生产上应对种子彻底清洗, 并保存于适当湿度的环境中, 以提高其发芽率。 相似文献
19.
The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180–250°C) and also in an air‐popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first‐order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kernels in the sample with critical pressures equal to or less than the internal aqueous vapor pressure. Minimum popping temperatures predicted by the model are 181 ± 2°C (oil) and 187 ± 2°C (air), in good agreement with previously reported direct measurements. 相似文献
20.
三门峡水库库岸坍塌成因分析与防治措施研究 总被引：10，自引：0，他引：10
三门峡水库自1960年9月蓄水运行以来,库岸坍塌现象频繁发生,平均每年塌岸0.5～0.7亿m3.指出了造成库岸坍塌的原因主要是地质环境的影响以及水力条件的变化;不同的地形、地貌、地质结构和岩性特征,表现了不同的塌岸强度,其中黄土塬区为极强塌岸段,黄河Ⅱ级阶地为强烈塌岸段,黄河Ⅰ级阶地为中等强烈塌岸段;分析了引起库岸坍塌的主要水力条件有大气降水、地表水和地下水,并且不同水力条件及其变化特征,对库岸坍塌影响的方式和程度也不同;最后给出了防治库岸坍塌应采用标本兼治的原则,治标是指对塌岸进行必要的加固、支挡、衬砌等;治本就是根据引起塌岸的原因以及不同地质环境条件下的塌岸特征和水力条件,因地制宜,因害设防,从根本上进行综合治理. 相似文献