Development of Rural Banks in Yellow River Delta

The status quo of new-type rural financial institutions in the Yellow River delta is summarized.It is pointed out that these financial institutions have improved the development of economy concerning agriculture,rural areas and peasants,but due to the shortage of capital,deficit and many other reasons,the outlets is fewer,which can not serve the agriculture,rural areas and peasants well.The necessity of developing rural banks in the Yellow River delta is introduced:firstly,rural banks can serve the agriculture,rural areas and peasants well with flexible system and management methods.Secondly,rural banks can serve and support the vulnerable groups of the three rural issues concerning agriculture,countryside and famers well.Thirdly,rural banks provide strong support for the all around development of rural business concerning the agriculture,rural areas and peasants.Fourthly,rural banks have significant advantages in serving the agriculture,rural areas and peasants.The probability of developing rural banks in the Yellow River delta is analyzed from the three advantages of policy,environment and economy.The challenges faced by the development of rural banks are studied as follows:firstly,the short-term profits are hard to take effect.Secondly,the capital quantity of rural banks is large.Thirdly,the pressure of competition and operation is great.Thus the countermeasures of developing rural banks in the Yellow River delta are put forward:for instance,clarifying the service object in a certain area;using the minority to bring along the majority;reducing the risk of asymmetric information by information technology.

Iron Oxen on the Banks of the Yelow River

The twelfth year of the Kaiyuan Reign during the Tang Dynasty （725 A. D.）Each iron ox is about 3.3 m long and 2.5 m high, weighs about 30 t, and is mounted on a square ron base which is 2.3 m wide and 0.5 m thick. Behind the rear legs of each iron ox, there is a large horizontal iron bar which is about 2.33 m long, 0.4 m in diameter, and was used to support the iron chain bridge across over the roaring Yellow River. Under the square iron base, there are 6 slant iron columns buried in the ground, each of which is about 3 m long and 0.4 m in diameter. The iron base and columns weigh about 40 t. The total weight of each whole iron ox sculpture is approximately 70 t

Strategic Planning of "Yellow River Golden Bank" of Yinchuan Section

Through the analysis on location condition,industrial development situation of "Yellow River Golden Bank" of Yinchuan section,strategic idea for this section has been proposed,providing theoretical basis for Yinchuan City to build a distinctive city along Yellow River.

Healthy Yellow River’s essence and indicators

River＇s healthy life is a description of their living conditions, and it is also a comprehensive assessment of river＇s functions and relations with the human society. Through analyzing the demands of human being and river ecosystem, the continuous flow, safe river channel for water and sediment transportation, good water quality, sustainable river ecosystem and water supply capacity are regarded as symbols of the healthy Yellow River. Minimum flow, maximum flood discharging capacity, bank-full discharge, transverse slope of floodplain, water quality degree, wetlands area, aquatic ecosystem, and water supply capacity, altogether eight quantitative indicators are set as symbols of healthy Yellow River, and their corresponding standards are determined based on the analysis with historical hydrological data and observed data of 1956-2004.

Variations of bank shift rates along the Yinchuan Plain reach of the Yellow River and their influencing factors

It is important to examine the lateral shift rate variation of river banks in different periods. One of the challenges in this regard is how to obtain the shift rate of river banks, as gauging stations are deficient for the study of river reaches. The present study selected the Yinchuan Plain reach of the Yellow River with a length of 196 km as a case study, and searched each point of intersection of 153 cross-sections （interval between two adjacent cross-sections was 1.3 km） and river banks in 1975, 1990, 2010 and 2011, which were plotted according to remote sensing images in those years. Then the shift rates for the points of intersection during 1975-1990, 1990-2010 and 2010-2011 were calculated, as well as the average shift rates for different sections and different periods. The results show that the left bank of the river reach shifts mostly to the right, with the average shift rates being 36.5 m/a, 27.8 m/a and 61.5 m/a in the three periods, respectively. Contemporarily, the right bank shifts mostly to the right in the first period, while it shifts to the left in the second and third periods, with the average shift rates being 31.7 m/a, 23.1 m/a and 50.8 m/a in the three periods, respectively. The average shift rates for the left and right banks during the period 1975-2011 are 22.3 m/a and 14.8 m/a, respectively. The bank shift rates for sections A, B and C are different. The shift rate ratio of the left bank in the three sections is 1：7.6：4.6 for shift to the left and 1：1.7：3.8 for shift to the right, while that of the right bank is 1：1.8：1.2 for shift to the left and 1：5.6：17.7 for shift to the right during the period 1975-2011. Obviously, the average shift rate is the least in section A, while it is maximum in section B for shift to the left and in section C for shift to the right. The temporal variation of the shift rate is influenced by human activities while the spatial variation is controlled by the local difference in bank materials.

黄河上游宁蒙河段平滩流量变化与水沙过程的响应关系

平滩流量是表征河道排洪输沙能力的重要指标,开展宁蒙河段平滩流量变化机理的研究对于治理黄河意义重大,本文采用实测资料分析的方法,研究了黄河上游宁蒙河段平滩流量变化特征及其与汛期水沙过程的定量关系。研究结果表明:黄河上游宁蒙河段沿程六站平滩流量由1960年代中期的3600~5800 m^(3)/s减小到目前的1900~4000 m^(3)/s。2000年前宁蒙河段三湖河口平滩流量与汛期水沙过程关系点群与2000年后两者关系点群存在明显分区,说明2000年后宁蒙河段河床演变机理发生了变化,遵循不同规律。建立的宁蒙河段三湖河口平滩流量与汛期水沙过程的定量关系式表明,宁蒙河段平滩流量随着汛期平均水量的减小(增大)而减小(增大),随着汛期平均来沙系数的减小(增大)而增大(减小),随着汛期水流过程参数的增大(减小)而增大(减小)。

不同水分调控对沿黄灌区向日葵水分利用影响研究

为探究达拉特旗黄河南岸灌区向日葵根系吸水来源及其利用策略,通过测定达拉特旗黄河南岸灌区向日葵木质部水及其各种潜在水源(降水、土壤水和地下水)的氢氧同位素组成(δD和δ18O),利用直接对比法和MixSIAR模型研究对比不同灌溉制度下向日葵不同生育期水分来源及各水源利用差异。结果表明,向日葵在苗期、拔节期、灌浆期和成熟期的吸水深度分别在0~30、0~50、0~70和30~90 cm土层。不同灌溉量下,向日葵的主要吸水层具有一定的差异。0~10、10~30、30~50、50~70、70~90 cm深度土壤水和地下水对向日葵平均贡献比例分别为22.17%、17.99%、18.74%、14.68%、15.97%和10.45%。通过相关性分析,50 cm以下土层水分贡献对产量提高有利,0~10 cm土壤水、30~50 cm土壤水和地下水利用对灌溉水利用效率具有正相关关系。设置灌溉定额为187.5 mm时能显著提高产量,灌溉定额为100 mm时,能显著提升灌溉水利用效率。

黄河邻岸异形超深基坑支护结构变形研究

根据济南穿黄济洛路隧道合建段深基坑项目,针对黄河邻岸异形深基坑施工支护结构变形开展了研究工作,主要研究成果为:(1)基坑开挖地下连续墙整体变形呈现“中间大、两端小”的形态,变形趋势呈现出先缓后快再趋于平稳的过程;阳角部位变形较大,深度为22 m时的偏移量有增大趋势,ZQL 24偏移值最大为33.1 mm;(2)基坑开挖地下连续墙顶竖向位移在深度为16~22 m时,沉降速度较大,整体为下降的趋势;地下连续墙顶水平位移偏移方向偏向远离基坑一侧,偏移量呈增大趋势,阳角部位的偏移量相对较大;(3)首道支撑处于逐渐受拉状态,其他支撑轴力值基本呈增加趋势,与深层水平位移监测数据吻合,同时混凝土支撑承受荷载远大于钢支撑。

Lateral erosion/accretion area and shrinkage rate of the Linhe reach braided channel of the Yellow River between 1977 and 2014

Quantitative studies on river channel lateral erosion/accretion area changes over time can reveal the characteristics of channel evolution. Taking the 213-km-long Linhe reach braided channel of the Yellow River as an example, area changes in channel bank ero- sion/accretion in four sub-reaches （S1, S2, S3 and S4） over 19 different periods were evalu- ated on the basis of remote sensing images captured since 1977. Mean channel shrinkage rate for the whole river reach was also obtained. Results show that the left and right banks of the Linhe reach were dominated by lateral net accretion between 1977 and 2014. The channel area of this section of the Yellow River was characterized by reduction between 1977 and 2001, while periods of alternate erosion and accretion occurred subsequent to 2001. Mean channel shrinkage rate in the Linhe reach braided channel was 6.15 km2/yr between 1977 and 2014, while the most remarkable changes in channel planform occurred in the 1990s. Compared to 1995, channel length and sinuosity increased by 5.8% and 6.6% by 2000, while channel area and mean width decreased by 39.4% and 42.8%, respectively. Significant changes in channel planform and shrinkage of the Linhe reach occurred in the 1990s, mainly as a result of the joint-operation of the Longyangxia and Liujiaxia reservoirs since 1986, which caused substantial reductions in runoff and sediment flux during the annual flooding season. In addition, bank erosion/accretion in the four sub-reaches was affected by the physical properties of local banks, engineering emplaced to protect channel banks, and hydrodynamic differences. However, since the implementation of integrated river manage- ment measures from 2000 onwards, these changes have been significantly mitigated and the health of the Linhe reach braided channel of the Yellow River has been restored.

黄河下游游荡段河势演变及模拟技术

黄河下游滩岸易崩退,主流易摆动,尤以游荡段最为显著,危及防洪安全。当前定量模拟河势变化过程仍是河流动力学领域一大难题。从滩岸变形、深泓摆动等方面研究了小浪底水库运行后游荡段河势的变化特点,揭示了影响河势演变的主要因素,并提出了滩岸变形及深泓摆动的定量模拟技术,可为黄河下游河道治理提供科学依据。

黄河上游沙漠小流域粗沙岸坡重力侵蚀滑塌过程及型态的数值模拟

采用黄河上游“十大孔兑”典型沙漠小流域“苏达尔沟”的数字高程数据,以黄土岸坡的滑塌过程和型态作为参照组,基于强度折减理论,通过数值模拟和野外实测资料对比验证,概化模拟降雨均匀入渗条件下沙漠粗沙岸坡的滑塌过程及型态.结果表明:受土体颗粒之间黏聚力的影响,粗沙岸坡主要表现为分层、片状滑塌,而黄土岸坡多表现为块状或团状滑塌;较之黄土岸坡的弧型滑动,粗沙岸坡为折线型滑动,滑塌型态直立,模拟与实测结果定性吻合.

黄河下游河道滩岸崩退与淤长过程的耦合模拟

黄河下游滩岸变形时常发生,对河床稳定、防洪安全、滩区耕地保护等方面产生诸多不利影响,因此有必要在河道水沙数学模型中考虑滩岸变形计算。以1维水沙输移及床面冲淤计算模型为基础,结合滩岸崩退与淤长计算模块,建立了能同时模拟河床纵向冲淤与滩岸横向变形的耦合模型。采用该模型计算了黄河全下游(755 km长河道)的河床纵向与横向变形过程,选取2018年及2020年作为率定及验证年份对该模型进行测试。计算结果表明:该模型可以很好地模拟黄河下游滩岸崩退及淤长过程,黄河下游游荡段、过渡段、弯曲段河段平滩宽度的计算误差在2018年分别为4、5、1 m, 2020年分别为12、14、4 m;选取典型断面进行分析,发现该模型可以精细地模拟黄河下游不同河型河段的断面形态变化过程、滩岸崩退及淤长宽度的变化过程,以及大致准确地模拟河床冲淤厚度变化过程。黄河下游3个河段滩岸变形程度差异较大,游荡段滩岸变形幅度远大于过渡段与弯曲段,过渡段与弯曲段变形幅度相差不大;3个河段滩岸崩退幅度均大于淤长幅度,体现出下游河床呈现展宽的趋势;黄河下游滩岸崩退与淤长会对河床冲淤产生重要影响,其中游荡段滩岸变形对于河床冲淤影响较大,而过渡段及弯曲段的河床变形主要表现为水沙不平衡输移引起的床面冲淤。

冻融作用对岸坡土体宏微观特性及岸坡稳定性影响研究

冻融作用是季冻区岸坡失稳破坏的主要原因。以黄河内蒙古什四份子弯道岸坡土体为对象,通过三轴剪切和扫描电镜试验,研究了冻融作用下岸坡土体的宏观和微观特性,并基于强度折减法,对冻融前后岸坡稳定性进行了分析。结果表明:随冻融循环次数增加,土体弹性模量、黏聚力和抗剪强度均呈减小趋势,其中弹性模量大小与含水率成反比,黏聚力在15次冻融后降幅达43.6%~60.04%,内摩擦角无明显变化规律;冻融后土体颗粒真圆度和孔隙概率熵随冻融次数增加先下降后上升,颗粒分形维度变化趋势与之相反,土体定向性和孔隙率呈增大趋势;黏聚力与土体孔隙率和颗粒真圆度相关,特别是与孔隙率呈高度负相关性,且土体微观参数间有明显的自相关性;冻融后岸坡稳定安全系数降幅达41.8%,说明冻融作用会显著降低岸坡稳定性,冻融后岸坡易发生失稳破坏。

基于DPSIR的黄河口及毗邻海域生态系统健康评价

为综合评价黄河口及毗邻海域的生态系统健康状况,借鉴驱动力-压力-状态-影响-响应(DPSIR)模型,选取人口增长率、年径流量、富营养化指数、浮游植物多样性指数、生态环境治理投资等28个反映生态系统健康状况的因子建立评价指标体系。基于实测和统计数据等基础资料,采用层次分析法和综合指数法对2011—2020年黄河口及毗邻海域生态系统健康状况和变化趋势进行评价。结果表明:2011—2020年黄河口及毗邻海域生态系统基本处于亚健康与健康状态,2018年以来,随着黄河口生态水量调度力度加大,生态系统健康状况显著向好。

黄河内蒙古段造床流量变化及其影响因素

造床流量是反映河床冲淤的表征指标,也是河道整治的主要参数。基于1960—2019年实测数据,运用改进马卡维耶夫法、平滩水位法、地貌功法,计算并分析了石嘴山、巴彦高勒、三湖河口、头道拐水文站造床流量。结果表明:时间上,1960—1989年、2010—2019年造床流量为2100~3540 m^(3)/s,中水河槽冲刷,1990—2009年造床流量为740~1300 m^(3)/s,河槽淤积萎缩严重;空间上,造床流量呈现上站大于下站的特点;造床流量受来水量影响较大,在汛期水量低于105亿m 3的情况下,可以通过刘家峡、龙羊峡、海勃湾水库三库联调适当增大汛期来水量,强化黄河内蒙古段造床作用。研究结果显示改进马卡维耶夫法物理意义明确,计算结果相对合理,可为冲积性河流造床流量确定及黄河内蒙古段河道治理提供参考。

黄河源水生态产品“水银行”交易定价研究——基于水生态产品价值实现角度

基于水生态产品价值实现角度探讨“水银行”交易模式下水生态产品交易定价。采用鲁宾斯坦议价模型对黄河源的水生态产品通过“水银行”交易模式进行定价。结果表明:2005—2012年单位水生态产品定价均值比2003—2004年高416.94%,建议完善黄河源生态环境保护相关的政策,促进当地居民保护生态环境的积极性从而改善黄河源的讨价还价能力,提升“水银行”交易价格,提高黄河源水生态产品价值的实现程度。

黄河源区高寒草甸型二元结构河岸抗冲特性

针对高寒草甸型二元结构河岸抗冲特性,采用自主设计的原位冲刷装置在黄河源区弯曲河流典型二元结构河岸,开展0.4 m/s、1.0 m/s和1.6 m/s三种流速条件的上部根土层和下部砂土层的原位冲刷试验,分析冲刷后的剖面轮廓三维曲面特征。试验结果显示,当冲刷流速由0.4 m/s增加至1.6 m/s时,根土层、级配不良砂和级配良好砂河岸的淘刷深度增加幅度分别为19.9%、17.6%和27.2%。二元结构河岸的土体抗冲系数随冲刷时间增大呈指数函数增长,河岸抗冲能力依次为根土层>级配不良砂>级配良好砂。河岸上部的根土层,由于根系的缠绕和网结作用显著增强了土体抗冲能力,其平均抗冲系数分别是级配不良砂和级配良好砂的2.5倍和4.1倍。

黄河两岸深基坑安全监测技术分析

基坑安全监测是地下工程建设运行的重要技术保障。基坑监测手段有传统人工配合仪器监测和自动化监测等方式,文章以黄河两岸深基坑工程监测为例,在预算可控的前提下,通过基坑监测项目实际经验,从监测内容、监测方法、数据处理和信息反馈等方面,比对分析两种监测手段的差异之处,讨论基坑监测项目实施操作的最优方案,为同类型项目提供新思路。