Research on Kunming Urban Riverbank Greening Construction

Urban riverbank has connected water and land eco-system in the city,not only playing a vital role in releasing flood and conserving water and soil,but also of significant landscape and ecological value.In view of riverbank greening construction in the comprehensive improvement of rivers in Kunming City in recent years,the paper has analyzed three common riverbank greening modes based on the field survey,that is,protective greening,landscape greening and ecological greening.Then,some suggestions and countermeasures have been proposed,including enhancing construction of ecological river,exploring historical and cultural connotation of rivers,and selecting reasonable plants' species and disposition mode.

Effects of climate factors on the height increment of poplar protec-tion forest in the riverbank field

Based on the data of stand investigation and stem analysis, the effects of climate factors on the poplar protection forest increment in the riverbank field of the Dalinghe and Xiaolinghe rivers of Liaoning Province, China were studied by step-wise regression procedure and grey system theories and methods. A regression model reflecting the correlation between the height increment of poplar protection forest and climatic factors was developed. The order of grey relevance for the effect of climatic factors on the height increment of poplar protection forest is: light>water>heat, and it could be interpreted that the poplar increment was mainly influenced by light factor, water factor, and heat factor. This result will provide scientific basis for the in-tensive cultivation and regeneration of the poplar protection forest in riverbank field in similar regions in China.

Soil-Column Test on Aniline Degradation in Riverbank Filtration under Denitrification Conditions

Drinking water is at risk from aniline pollution and thus aniline degradation and its mechanism have received much attention. In this paper, a soil column, including sediments and aquifer media, was collected from the Weihe riverbed and its bank, and used to research the characteristics of aniline degradation in the riverbank filtration process under denitrification conditions. The results indicate that all aniline could be degraded by the habituated indigenous microbes, and even mostly mineralized under denitrification conditions, but with a long lag phase. Some aniline degradation must involve deamination, while the majority undergoes covalent binding with humic substances to form complexes, and the complexes are easily degraded and even mineralized. During the degradation no intermediates were harmful to denitrifiers. Therefore, under denitrifaction conditions, aniline is degraded in RBF, and up to now aniline has not been monitored in the groundwater along the polluted river. During the 153 d testing process, the nitrate-nitrogen concentration was about 23.0 mg/L, and aniline concentrations were 40, 80 or 400 mg/L at 0-74 d, 75-105 d and 106-153 d respectively in infiltrating water. Indigenous microbes pass a lag period of 37 d, and grow on aniline as the source of carbon in the RBF under denitrification conditions. Aniline concentration in leachate was lower than the detected limits, so its removal rate was 100 %. Total organic carbon (TOC) removal rates were 97.99 %, 91.39 % and 75.30 % for 40, 80 and 400 mg/L aniline concentrations respectively, based on TOC monitored in infiltrating water and leachate.

Riverbank Erosional Features in the Stanley Pool of the Congo River and Some Geotechnical Classifications of the Sands

The Stanley Pool, an almost circular island about thirty kilometers in diameter, crossed by the Congo River, is subject to diversified erosion of its riverbanks. This study highlights description using geotechnical particle size distribution analysis of soils of the shoreline that make up the shoreline. Three critical areas of the island were examined to characterize the origins of these erosion phenomena. The results obtained show that the soil materials are mostly sands with very fine or fine grains characteristic of very unstable soils. The morpho-sedimentological characteristics of the areas studied show that these soils are plastic (with a Plasticity Index between 15 percent and 19 percent). The presence of water, action of currents or groundwater flow easily destabilize the materials that make up the riverbank and cause the fines to creep (Collapse of sandy riverbanks, Landslide of sandy riverbanks, …).

Research and Experimental Application of Empirical Formulas to Calculate Riverbank Erosion in Tien River in the Mekong Delta

In recent years,the problem of riverbank and coastal erosion in the MD(Mekong Delta)is very complicated;landslides occur in most of the inland and coastal provinces.Most riverbank landslides occur gradually,but in contrast to sudden landslides that cause great damage,occur with increasing frequency.This shows that the trend of riverbank erosion will be more complicated and more frequent,especially in the context of extreme weather changes and changes in hydrological regime in the next time.Statistics from the authorities show that,if in 2010 the whole region had nearly 100 landslide points;by 2020 it had increased to more than 680 points;in which Dong Thap in the Tien River is one of the two localities with the most serious riverbank erosion.Currently,there are many methods used to assess and forecast the level of riverbank erosion in specific areas,such as:method of document analysis,measurement data;physical model;mathematical models and empirical formulas.In this study,the empirical formula is used to calculate the landslide level for the Tien River section in Cao Lanh,Dong Thap province.The calculation results according to the empirical formula have a certain agreement with the actual data,the correlation coefficient is 0.90 and the Nash coefficient is 0.78,the relative error of less than 15%is 80%of the cross-section.Such results have shown the possibility of applying empirical formulas to establish and calculate for other landslide areas along the banks of Hau River and MD.

On the Embodiment of Chinese Classical Thought in Whitman's Urban Ecological Poetics——Taking the Riverbank of the Ferry Crossing Last Winter as an Example

Whitman believes that people in cities should establish a harmonious relationship between humans and nature.In his urban imagination,humans are a common link in the entire ecosystem.As a part of heaven and earth,everything is one.Through dialogue with nature,Whitman explored that man and nature should be equal and harmonious.Whitman embodies the unique urban ecological poetics in his essay the Riverbank of the Ferry Crossing Last Winter,which contains Chinese classical thought of harmony between man and nature.

长江中下游崩岸险情智能感知预警与防治关键技术研究构想及成果展望

崩岸是长江中下游河道自然演变的常见形式,严重威胁防洪安全、航道畅通及沿江经济基础设施正常运行甚至是人民生命财产安全。三峡工程等水利水电工程建成运行引起长江中下游水沙情势显著改变,近年来,中下游河道持续冲刷、局部河势调整、崩岸频发,造成多方面不利影响。尽管以往已开展了相关研究并进行了治理,但由于影响因素众多,崩岸机理复杂,隐蔽性、突发性和随机性强,预警及治理难度依然很大。本文以“崩岸机理揭示—大范围筛查—介入式监测—多尺度预警—系统化防治”为总体思路开展研究,围绕流-固耦合作用下的崩岸机理与险情智能筛查、河道岸坡土体全要素实时感知及崩岸模拟预警技术、耦合河势控制措施的崩岸系统防治技术等关键科学技术问题,重点研究持续冲刷下河势变化与崩岸动态响应关系,研发多源信息融合的崩岸险情智能筛查技术、河道岸坡全要素一体化智能感知技术、多尺度河道崩岸预测与预警技术,以及耦合河势控制措施的崩岸系统防治技术,旨在揭示持续冲刷条件下长江中下游崩岸发生的驱动因素及内在机理,研发崩岸险情智能感知预警及防治关键技术,实现崩岸险情智能筛查、多要素监测、动态预警与系统防治。研究有望显著提高长江中下游河道崩岸发生的预见性和治理技术水平,促进崩岸从灾后抢护向灾前预防转变,为河道系统治理和水安全保障能力提升提供科技支撑。

崩塌滑坡-堰塞湖-溃决洪水-泥石流灾害链演化特征分析及防治对策研究

某沟谷两岸坡面陡峻,沟谷狭窄,纵坡降较大,在地震、降雨等不利因素影响下,其左岸堆积体上方的崩滑堵沟隐患点可能出现失稳,并发展为崩塌滑坡-堰塞湖-溃决洪水-泥石流灾害链。针对此灾害链不同阶段的演化特征,采用相应的数值模拟模型和数值计算方法进行模拟分析和计算,评价其对沟口桥梁工程的影响,并采取相应的防治对策。经分析计算,崩塌滑坡隐患点距沟底高程落差约1 km,岩体体积约8×10^(6)m^(3),平均厚度约26 m,崩塌滑坡堵河可形成最大水深为14.4 m、面积约为7.19×10^(4)m^(2)、方量约为2.74×10^(5)m^(3)的堰塞湖;堰塞湖溃决形成洪水过程中,桥梁处最大水深为4.43 m(不含原始水位),最大流速为7.54 m/s,峰值流量为807 m^(3)/s;在溃决洪水强烈揭底冲刷和侵蚀的条件下,溃决洪水引发的泥石流在桥梁处的最大水深为7.1 m、最大流速为8 m/s、峰值流量为1685.5 m^(3)/s、最大冲刷深度为16.58 m。为减少该灾害链对桥梁工程的影响,采取河道疏通、岸坡防护和监测预警等防治措施。

黄河下游典型河段滩岸崩退特性研究

黄河下游局部河段滩岸崩退频繁,严重危害堤防及滩区安全。通过对黄河下游开展现场观测,结合已有断面地形实测数据,描绘滩岸崩退全过程及特点,评估土体特性及近岸水沙条件对崩岸的影响。研究表明:滩岸崩退引起黄河下游河道展宽,且崩岸规模具有时空差异性,2006年和2018年汛期重点河段平滩河宽分别增加了57.03 m和7.83 m,代表性横断面单侧滩岸最大崩退宽度高达207.20 m。黄河下游土体压实程度低,抗冲能力差,加之土体抗剪强度随含水量增大呈反向变化,致使在汛期崩岸频发。“大流量-小含沙量”的水沙组合易于造成崩岸,而在大含沙量下因泥沙在近岸河床淤积而降低了崩岸发生规模。建议对重点区域滩岸进行长期监测,并加强生态友好型护岸系统建设。

NUMERICAL STUDY ON THE PURIFICATION PERFORMANCE OF RIVERBANK

During the rain time, the runoff infiltrates into the riverbank through the collecting gutter and slope surface. The city runoff is generally polluted by organic, oil, heavy metal particulates, etc. The pollutants moving with the water through the riverbank experience advection, dispersion, diffusion, adsorption, biochemical reaction and plant uptaking processes. In this article, a mathematical model was developed to simulate the performance of pollutant removal of the riverbank. The model took those main mechanisms into account. The modified Richards equation was used in simulating flow field. The mass balance law was employed in deriving the equation for pollutant transport, where the diffusion and dispersion were described with the Fick-type law, the adsorption was macroscopically expressed as form isotherm, and the bio-chemical degradation process was assumed to follow the Monod kinetics. The NH3-N and TP were considered in the present model. The mathematical model was descritized with a finite element numerical model, which was applied to two types of model riverbanks. In the model test, the hydraulic loading was assumed to have the intermittent pattern simulating the storm runoff of certain return period, and the values of the rainfall runoff and concentrations of the NH3-N and TP were taken from the model test. The computed overall removal rates for the NH3-N and TP in 6 cases are in the range of 88%-98%, 87%-97%, respectively. The differences between the computed and tested overall removal rates for the NH3-N and TP are less than 5%. The time-varying oscillation pattern of the concentrations of the NH3-N and TP were rationally simulated, which shows that the model presented in this article can be used to assess the purification performance of the riverbank constructed with sand or soil.

河岸边坡对抛投沙袋落点规律影响的试验研究

通过概化水槽试验,分析了有河岸边坡情况下开底驳船和翻板船抛投沙袋的漂移、偏移落距和落点范围规律,并研究了不同抛投方式的影响。试验结果表明:河岸边坡的存在会导致沙袋发生滑动或滚动,增加沙袋的漂移和偏移落距,且坡度越大,沙袋在顺水流方向的落点越分散;沙袋平均漂移落距随流速的增大而增大,流速较大时,边坡坡度变化对沙袋漂移落距影响较小,流速较小时,开底驳船抛投时沙袋平均漂移落距随边坡坡度的增大而增大,翻板船抛投沙袋在顺水流方向的落点越集中;开底驳船抛投方式比翻板船抛投方式的沙袋落点更分散,但落点范围相差不大。

Change Detection of Land Use and Riverbank in Mekong Delta, Vietnam Using Time Series Remotely Sensed Data

By taking the advantages of remote sensing technology, changes of land cover in Ca Mau Peninsular （the Southern part of the Mekong delta） and erosion of riverbank of the Mekong River have been defined. Change detection using time-series optical and radar satellite images （Landsat, SPOT and Radarsat） is the main approach in this study. Typical land cover in Ca Mau Peninsular is mangrove; its changes are observable by analysing imageries from 1973 to 2008. The results showed that more than half of the mangrove area was converted into shrimp farms. This made forest cover severely declined. Riverbank of the Mekong River also was detected to be eroded and accreted in a complicated form. Locations along the left and right banks of Tien and Hau river are defined as hot spots that are seriously suffered erosions. Topographic maps in 1966-1968 were taken into account as base line data, which was analyzed along with satellite images from 1989 to 2009. In addition, the Digital Shoreline Analysis System （DSAS） package was taken to analyze trend of changes in terms of changing prediction.

岸坡淤积对高桩码头结构受力的影响及清淤防治措施

利用有限元方法分析了岸坡淤积对高桩码头结构受力的影响,提出了码头下方局部清淤联合码头后方开挖以减小淤积影响的防治措施。通过构建高桩码头排架结构的实体单元模型,探讨了岸坡淤积和使用荷载的耦合作用对码头结构内力及水平位移的影响;通过比较岸坡淤积过程中的桩基受力及变形,揭示了桩基损伤机理,即岸坡淤积使桩土相互作用面积增大,桩基受到的附加淤积土压力作用增大,导致受横梁约束桩基的桩顶弯矩增大。岸坡淤积对码头结构存在显著影响,随着淤积高度的增加,桩基的内力及水平位移、横梁的水平位移显著增大;码头岸坡淤积、码头后方超淤及船舶撞击力的联合作用,对淤积岸坡的坡顶处和后侧的向岸斜桩的内力影响最大,桩基最易受损;对码头下方的淤积坡肩进行局部清淤,联合在码头后方挖槽的清淤措施,可有效降低危险桩基的桩顶弯矩,减小淤积对码头结构的影响。

水沙变化条件下不同边界弯曲河道演变特征研究

弯曲河道具有迂回曲折的外形和蜿蜒蠕动的动态特征,其形成、发展和演变是受多种因素综合影响的复杂过程。为研究水沙变化条件下弯曲河流的河道演变特征,采用自然模型法在室内水槽中塑造出相对自然的弯曲河道,设置有、无护岸措施两种工况进行模型试验。结果表明:在有护岸措施条件下,河道纵剖面上游段冲刷下切、下游段变化不大,河道整体比降呈减小趋势,河道深泓弯曲度减小,其演变响应特性对含沙量的变化更敏感;在无护岸措施条件下,河道滩槽演变调整作用较强,纵剖面呈整体式下切,且下游段纵剖面下切幅度较上游段大,河道深泓弯曲度逐渐增大,其演变响应特性对流量的变化更敏感。弯曲河道发生演变的实质是变化的水沙条件与河道形态调整之间相互适应的过程,演变的最终趋势是河道的形态结构与水沙条件达到相互协调的平衡状态。

中小河道生态护岸工程再生透水混凝土试验研究

为了研究再生透水混凝土在中小河道生态护岸工程应用中的性能表现,通过煅烧与助磨剂助磨改善再生微粉的活性,并利用煅烧再生微粉、再生粗骨料等制备中小河道护岸用植生透水混凝土进行试验研究。结果表明:煅烧后的再生微粉粒径、需水量比、浆体粘度、减水剂饱和掺量和浆体强度均有所提高,其中400℃煅烧的再生微粉需水量比和粘度最大,600℃煅烧的再生微粉浆体强度最高,煅烧温度超过800℃时,再生微粉生成β-C_(2)S和钙铝黄长石,浆体强度有所降低。煅烧后的再生微粉颗粒变粗,掺加0.8%丙二醇助磨60 min后煅烧再生微粉D_(50)粒径由137μm降到20.85μm,以煅烧再生微粉25.0%取代水泥制备再生骨料透水混凝土,各项性能满足植生混凝土规范要求。

长寿湖国家湿地公园河滩草甸类型及其物种多样性

以长寿湖国家湿地公园保护区中河滩草甸为研究对象,通过实地研究和查阅相关资料,对长寿湖国家湿地公园河滩草甸植被类型及物种多样性进行调查分析。结果表明:该湿地公园内河滩草甸共有3种群落类型,分别为灰脉苔草沼泽草甸群落、乌拉草沼泽草甸群落、东方羊胡子草沼泽草甸群落;其中灰脉苔草沼泽草甸群落(俗称塔头沼泽)作为水陆过渡带最具代表性的沼泽群落,受气候和光照、温度等影响具有差异性。

许昌市城区河流滨岸植物多样性评价

为了解许昌市河流滨岸植物多样性现状,通过Shannon-weiner指数、Pielou指数和频度综合分析许昌市9条河流12个断面滨岸植物多样性.结果表明,样地含属3种以上的科有2个,芦苇、牛筋草、酸模、狗尾草、艾的频度较高,在群落中有代表性.河流滨岸植物的Shannon-Wiener指数在0~1.876波动,Pielou均匀度指数在0~1波动,植被多样性状况较好.

倒h形抗滑桩在沿河道路岸坡加固过程中的应用研究

以环环湖公路建设项目为依托工程,分析了以数值模拟的方法对比分析了锚索抗滑桩和倒h形抗滑桩在加固沿湖岸坡的效果。研究分析发现,采用倒h形抗滑桩对河湖岸坡边坡进行加固时,坡体滑动范围、位移量、桩身位移与桩身弯矩均处于较低水平,且支挡效果较好,由此可知,倒h形抗滑桩在加固沿湖岸坡方面具有一定的优越性。

High-solids anaerobic mono-digestion of riverbank grass under thermophilic conditions

The purpose of this study was to investigate the potential of high-solids anaerobic mono-digestion of riverbank grass under thermophilic conditions, focusing on the effects of the strength and the amount of inoculum. Ensiled grass was inoculated with three different inocula; inoculum from liquid anaerobic digester（LI）, inoculum from dry anaerobic digester（DI）, and mixture of LI and DI（MI）, at feedstock-to-inoculum ratio（FIR） of 1, 2 and 4. The ensiling process of riverbank grass reduced moisture content（p 〉 0.05）, while the hemicellulose content was significantly increased from 30.88% to 35.15%（p 〈 0.05）, on dry matter basis. The highest methane production was at an FIR of 2 with MI（167 L/kg VSadded）,which was significantly higher（p 〈 0.05） than with DI, but not significant compared to LI（p 〉 0.05）. At an FIR of 4, digesters inoculated with LI and DI failed to produce methane,whereas 135 LCH4/kg VSaddedwas obtained with MI. The kinetic studies showed that at an FIR of 1 with LI and MI, the inoculum had less of effects on the hydrolysis rate constant（0.269 day-1and 0.245 day-1） and methane production（135 versus 149 L/kg VSadded）; rather,it affected the lag phase. In a thermophilic HS-AD of riverbank grass, the mixture of inoculum with low and high total solids content（TS） helps increase the TS of inoculum and digestion process. An FIR of 2 was deducted to be the limit for a better startup time and higher volumetric productivity of methane.

资江大新段河岸边坡稳定性的定量评价

基于资江大新段河岸基础地质资料,运用遥感影像、实地勘测和评价指标赋分相结合的方法,开展了资江大新段河岸边坡稳定性的定量评价。通过10个典型断面岸坡植被覆盖率、基岩类别、倾角、高度和岸坡冲刷状况等五个要素的赋分分析,得到资江大新段河岸处于基本稳定状态,尚属于健康状况。