ABSTRACT Managed aquifer recharge (MAR) is an effective measure for integrated water resources in the North China Plain (NCP). During the recharging, the combined clogging in the aquifer caused by algae and suspended solid (SS) is a problem that was easily ignored by researchers. In this research, a sand column model was designed to investigate the SS-algae combined clogging mechanism in the porous medium during the Yellow River water recharge in the Yufuhe River channel of NCP. The SS-algae combined plugging of the medium appeared earlier and the plugging degree was more serious compared with the SS-only clogging and the algae-only clogging during the infiltration. Meanwhile, the surface clogging degree of the medium is more serious, and the interior is smaller in comparison to the SS-only group and the algae-only group. The filter cake and algae mat are the signs of SS clogging and algae clogging, and the algae mat structure in the SS-algae group is more dense compared to the algae-only group. In the combined clogging experiment, the outflow concentration of SS and algae in the medium is less than the SS-only group and the algae-only group. In addition, algae and SS can limit each other's migration in the medium.

黄河水在山前河道渗漏补给地下水过程中,水和悬浮泥沙的运动特征与在平原河道显著不同.以济南市黄河流域玉符河回灌补源工程为背景,设计二维砂槽试验模拟黄河水流经由砂卵砾石和灰岩组成的强渗漏带河床处时地表和地下径流的变化规律以及悬浮泥沙的迁移特征.结果表明:流经强渗漏带的黄河水转化为地表水、浅层孔隙水和深层岩溶水 3 部分;仅岩溶水是有效补给,转化效率为 60%～70%,悬浮颗粒物的存在使补给效率降低 21～37 个百分点;地表水和孔隙水受河床坡度和强渗漏带河床结构的影响流向下游;黄河水中 96%的悬浮泥沙被砂槽滤除,砂槽的表层和浅层泥沙沉积最严重;橡胶坝可促进高流速地表水向低流速孔隙水转化,但会加重泥沙在砂槽内沉积.

The Yellow River diversion project consists of three gates, two pumping stations, and one plain reservoir, with a total river length of 17.46 km in the Panzhuang Yellow River irrigation area, which provides the primary water source for the Dezhou central city, Shandong Province, China. The project is subject to the constraints of the Yellow River diversion sluice diverting water time, reservoir diverting water time, and combinations of pumping stations with self -flowing gates. The opening and closing forms of the gates and pumps are complicated and irregular, and the switching of the gates and pumps mainly depends on the experience of the staff, which makes the water transfer cost high and the water transfer time long. Based on engineering compositions in the study area, an optimal mathematical model is constructed by the dynamic programming method. By combining the flow and water level, the objectives of the minimum operation cost, the shortest water transfer time and the combination of the two are established. A new optimization scheme of the switch between gates and pumps combined with water level and flow is proposed, which reduces the operation cost by 20% and the water transfer time by 8%, providing an efficient operation mode.

Jinan, China, is famous for its springs. However, societal and economic development over the past decades has detrimentally altered the natural water cycle in the spring area. Managed aquifer recharge (MAR) is an effective measure to ensure the normal gushing of springs. Balancing water resource utilisation, ecological effects, and water quality risks is not always easy to implement. This study focused on the potential effects of MAR projects that divert water from multiple local surface water sites, e.g., the Yellow River and South-to-North Water Diversion (SNWD) Project. A numerical simulation model for the entire spring area was built using MODFLOW and MT3DMS. The SNWD Project diverts water with relatively high total dissolved solids (TDS) to the Yufu River, which consequently recharges groundwater and poses a potential risk to the downstream karst water in the Jinan Spring area. Different simulation scenarios were set, and the results showed that the 90% recovery ratio scheme yields the highest TDS reduction efficiency as well as the largest karst water extraction volume. In addition, the water table remains stable as a whole. The benefits of the designed scheme are multifold, including improving water quality up to Standard III groundwater quality and meeting the water needs of the economy. The study provides a novel method of addressing the groundwater quality risks posed by artificial recharge.

A two-dimensional sand tank model was designed to investigate the water distribution and sediment clogging of the Yellow River water during the seepage recharge process of the piedmont sand gravel channel in the North China Plain. Due to the high permeability of the sand gravel medium, only infiltration deep runoff (IDR) and surface runoff (SR) occurred in the sand tank experiment. The increase in water released did not improve the effective recharge. The IDR accounted for 65-85% of the water released. After clogging appeared, the value decreased to 15-30%. More than 96% of suspended solids were deposited in the surface and upper areas of the sand tank, among which the sand gravel surface covered by the thin clay layer formed by suspended particles was the main cause of the change in the distribution of IDR and SR. A rubber dam can promote the conversion of high velocity SR to low velocity lateral shallow runoff (LSR) by 25-30% while increasing the deposition mass of suspended particles in the sand tank. The rationality of the sand tank model was verified by the numerical model, and the fitting degree between the simulated and the measured results was greater than 0.9.

基于基坑降水问题的处理方式提出平原水库渗流大井法,并且借鉴了船闸工程中常用的渗流阻力系数法处理截渗帷幕的作用,提出了截渗帷幕影响下的水库渗漏量计算方程和壅水曲线方程.提出了一种新的解析法处理平原水库渗漏问题.应用该方法对北方某平原水库进行渗漏分析发现,渗漏与水库水位近似为线性关系;应用壅水曲线方程分析水库对库区周围地下水的抬升作用,得到了浸没范围与水库水位的关系曲线;对比无截渗帷幕下的计算结果发现,截渗帷幕设计不合理导致其截渗效果并不理想.

With the development of social economy, the contradiction between water supply and water demand is increasing. In order to alleviate this contradiction, an underground dam is proposed to be constructed in the downstream of one river for intercepting subsurface flow and increasing conjuctive utilization of surface water and groundwater. According to the hydrogeological condition of the downstream of one river, a groundwater flow numerical model through Visual Modflow was built to analyze the regulation and storage of groundwater for underground reservoir . The conclusions are as follows: the underground reservoir of a River has great potential for exploitation; the water regulation by storage of wet, normal, dry and special dry years is 23.928 million m(3), 20.565 million m(3), 17.43 million m(3) and 10.128 million m(3), respectively, and after the construction of underground reservoir, river has a great potential for development; the extraction scheme of 36 wells with a flow rate of 0.015 m(3)/s for the whole year is a more suitable scheme plan.

The basin of Nansihu lake is dominated by alluvial plain landform in Shandong Province, China. The region is rich in coal resources and coal mining has formed a large number of subsidence areas. In view of the difficulty of surface water regulation and storage in plain area and the fact that coal mining subsidence area can provide effective storage capacity. The mode of combination of flood, waterlogging control and water resources regulation by using coal mining subsidence area in the basin is put forward. The advantages and disadvantages compared constructing plain reservoirs with using coal mining subsidence area as reservoirs is recognized. The effects of flood control and waterlogging control in coal mining subsidence areas from the scale of watershed and specific cases are analysed. From the perspective of flood and waterlogging control effect, in 2025 and 2035, coal mining subsidence area can reduce the flood of 5% frequency by 12.43% and 34.22% respectively. By 2025, urban waterlogging at 20% frequency will be reduced by 56.19%. In 2035, the ability of coal mining subsidence area to resist urban waterlogging at the same frequency can reach 100%. The coal subsidence area in Longguhu can reduce the flooding at 10%, 5% and 2% frequencies by 15.8%, 12.1% and 9.2%, respectively. It can completely resist the one-day waterlogging in the city at 20% frequency and reduce the waterlogging in the city for three-days by 70.8%. The reconstruction of plain reservoir using the coal mining subsidence area is feasible in technology and engineering construction. But it is still faced with the problem to be solved of the guarantee rate of water supply, water quality etc…

Shouguang City is located in north-central of Shandong, distributing the piedmont plain and coastal plain from the south to north. This area, as a vegetable base in northern China, not only meets local needs but also has a large number of vegetables exported to domestic and foreign countries in the form of virtual water. The vegetable production in this area mainly depends on groundwater exploitation, which causes saltwater intrusion problems. This study establishes the linear model of virtual water and vegetable production, irrigation water consumption, total population, per capita vegetable sales volume, and the purchase amount of vegetable trade. The output of vegetable virtual water from 1980 to 2012 is calculated. 3.79 billion kg of vegetables were exported in the form of virtual water with a volume of 145 million m 3 in 2012, accounted for 78% of the average annual groundwater resources in the region. The vegetable trade development in Shouguang City from 1980 to 2002 can be divided into two stages: bare land vegetable cultivation in 1980–1990 and greenhouse vegetable cultivation in 1991–2002. The correlations among the annual virtual water output volume of vegetable trade, annual groundwater cumulative storage, groundwater depth at the center of depression area, and saltwater intrusion area are established and analyzed. In the first stage, for every 10 million m 3 of vegetable virtual water was transferred, the salt water intrusion area in this area increased by 13.8 km 2 ; in the second stage, the saltwater intrusion area increased correspondingly by 5 km 2 . The influence of saltwater intrusion on adjusting crop-planting structure is also analyzed to achieve the purpose of effectively alleviating the ecological and environmental problems in the area.

Under the background of network teaching during the epidemic period, the advantages of network teaching are analyzed, and ways of improvement of online learning efficiency are reflected on firstly. Then the online teaching experiences of specialized English courses are summarized taking the major of water conservancy engineering as an example, which is set up by the University of Jinan. In addition, the interview method is used to explore the students' feelings about online learning and their evaluations as well as suggestions of the course. Finally, the shortcomings of postgraduate network teaching are pointed out. It is supposed to provide references for the future network teaching, and promote the cultivation of postgraduates.

To study the influences of sand and gravel layer and groundwater velocity of Yufuhe River on atrazine migration, adsorption-desorption and sand column experiments were carried out. Results show that the adsorption capacity of montmorillonite, raw sand and washed sand to atrazine sequentially weakens. In different media, the time for atrazine concentrations to peak in washed sand with montmorillonite (WSM), raw sand and washed sand is 60, 135 and 105 minutes respectively, and the peak concentration accounts for 84, 90 and 95% of the initial concentrations. Under different flow rates, the peak time in washed sand at flow rates of 100, 150 and 200 mL/min is 135, 105 and 75 minutes, and the peak time in WSM is 90, 60 and 45 minutes, respectively. Results from this study indicate that increasing flow velocity and suspended colloids concentrations can promote the migration of atrazine in aquifers, while the presence of clay minerals in sand and gravel layers can reduce atrazine migration. Thus, during Yellow River water recharging, the sand and gravel layer of Yufuhe River is helpful to protect the aquifer, but the colloids-associated migration of atrazine can contaminate groundwater in underlying karst aquifer.

基于山东省1997、2002、2007、2012年可比价投入产出表估算三大产业的用水效率、用水效益及虚拟水净输出量变化情况,采用灰色关联分析法分析用水效率与产业结构合理化程度、用水效率与社会技术之间的关系.结果表明:15 a来山东省的用水效率和用水效益不断提高;第一产业虚拟水由净输出变为净输入,第二产业虚拟水净输出量先增加、后减小,第三产业虚拟水净输出量一直在增加;产业结构趋于合理化,间接消耗意义上的社会技术表现为退步;产业结构合理化及社会技术进步都有利于用水效率的提高,应进一步研究社会技术评价指标的选取.

A two-dimensional sand tank experiment was designed to explore the mechanism of water distribution and silt clogging of Yellow River water whilst replenishing groundwater in ‘open window’ reach of the piedmont river and strong seepage area consisting of a gravel and karst layer from top to bottom. Water released through the reach was divided into surface, pore and fracture karst water, of which karst water was an effective recharge from the surface water. A reasonable released water plan is necessary in recharging to avoid invalid recharge. The karst water accounted for 60–70% of the amount of water released before clogging, and this value was reduced to approximately 10–20% whilst a thin clay layer formed from suspended particles on the surface layer of the medium after clogging. The removal rate of suspended solids along vertical and lateral directions in the medium can reach over 96%. The retained amount of suspended particles was mainly distributed on the surface and upper layer region of the medium. A rubber dam can improve effective infiltration whilst promoting suspended solid deposition in the medium. The fitting degree of the numerical simulation and measured results was above 0.9, which proves the reliability of the sand tank model results.

Virtual water trade in a region is affected by both nature and humans. To study the contributions of human activities to virtual water trade quantitatively, an innovative method of quantitative comparison and analysis is put forward. At first, the climates are adjusted into a unified standard. Then the impacts of increment and reduction of foreign water are studied. Additionally, the impacts of water management policy are studied according to the comparable water quotas. Results show that with the development of economy, an N-shaped trend and inverted U-shaped trend exist with regard to the net exports of agricultural and industrial virtual water, respectively. The net imports of virtual water have beneficial effects to the water environments of water deficient areas, while the net exports have negative effects. In 1997, the net exports of agricultural and industrial virtual water reduced by 20.13% and 49.67% respectively due to the cut-off of Yellow River channel compared with that under the average Yellow River water diversion. In 2017, they increased by 1.32% and 41.99% respectively because of the South-to-North Water Transfer project and reduced by 10.01% and 20.39% respectively under the effects of the most stringent water management policy.

Jinan, Shandong Province, China frequently faces challenges related to spring protection and water supply security, and managed aquifer recharge (MAR) presents an effective solution to these challenges. Three MAR projects with multiple sources in Yufuhe River in Western Jinan City are conductive to increasing groundwater supply and maintaining groundwater levels. In order to determine the reasonable recharge flows and time, the hydrogeological conditions of the study area were described, the river infiltration recharge processes were simulated by Hydrus-2D software, and the recharge schemes for different groundwater depths were put forward. The results show that the model can achieve the better fitting effect. When the releasing flow is small, the optimal scheme is to continuously discharge water by 286800, 282500 and 282000 m 3 /d for 19.5, 12.7 and 10.5 days when the groundwater depth is 42, 30, 23 m at Cuima Village respectively. This study has certain significance for the efficient water lease of the Yufuhe River recharge project in Jinan City.

The Yellow River flood plain in northern of China, affected by the low precipitation and the large amount of well irrigation, is facing the ecological problems of serious groundwater overdraft and expansion of drawdown cone area. Taking Linqing city of Shandong Province as an experimental area, the technical scheme and parameters of Open channel-Underground perforated pipe-Shaft groundwater recharge system were designed by combining theoretical calculation and field test, and the effect of recharge was observed and analyzed. The results show that this project has increased groundwater amount of 52310.82m 3 by water diversion for 7 days compaired with existing canal system, accounting for 60.7% of the total groundwater recharge. This recharge technology can effectively increase the amount of groundwater replenishment and raise the groundwater table as well as scope of groundwater recharge. It has the advantages of no energy consumption, no land occupation, rechargeability, and drainage. Thus, it is of great significance to the recovery of groundwater drawdown cone area and the comprehensive treatment of drought and waterlogging.

The North China Plain is the main grain production district in China, with a large area of well irrigation resulting in a large groundwater depression cone. In the 1970s and 1980s, small-scale managed aquifer recharge (MAR) projects were developed to recharge shallow groundwater, which played an important role in ensuring stable and high crop yields. MAR projects are divided into 10 types based on local water conservancy characteristics. The combined use of well–canal irrigation has been widespread in the Yellow River Irrigation District of Shandong Province for nearly 40 years, where canals play multiple roles of transporting and storing Yellow River water or local surface water, recharging groundwater and providing canal irrigation. Moreover, the newly developed open channel–underground perforated pipe–shaft–water saving irrigation system can further expand the scope and amount of groundwater recharge and prevent system clogging through three measures. Finally, an adaptability zoning evaluation system of water spreading has been established in Liaocheng City of Shandong Province based on the following five factors: groundwater depth, thickness of fine sand, specific yield, irrigation return flow, and groundwater extraction intensity. The results show that MAR is more adaptable to the western region than to the eastern and central regions.

Managed aquifer recharge (MAR) is an important approach to address water security, water quality decline, ground subsidence, and aquifer degradation. In this study, the large-scale recharge experiments were conducted in a natural river with multiple water sources. The MAR with multi-source water was investigated by developing an improved matter-element model under a limited recharged quantity and period in Jinan, China. Results showed that the background levels (BL) of groundwater quality before recharge was relatively good. However, the use of different water sources would cause a significant increase in the content of some groundwater quality indexes, which might further induce deterioration of regional groundwater quality. And the water quality in porous and karst aquifer displayed deteriorating trends during different water source recharge. Additionally, the adverse effects of recharge water sources on regional groundwater quality in turn was South-to-North Water Diversion Project (SN) > Yellow River (YR) > Wohushan Reservoir (WR). Meanwhile, the high-risk indexes in groundwater quality were presented during different water source recharge. Accordingly, relevant suggestions and measures were then put forward to optimize the MAR with multi-source water and explore the high-efficiency and low-risk recharge mode.

A Correction to this paper has been published: https://doi.org/10.1007/s11356-020-11965-9

针对山东省济南市、潍坊市、临沂市和济宁市城市景观水面的分布状况,选取合适的空间分布指标,综合分析4个城市景观水空间分布的优劣.同时以济南城区黄台桥以上流域面积为研究区域,分别从全年蒸发量和夏季蒸发量两个方面,对比分析景观水面和城市陆面对于调节区域温度的影响程度,从而更加合理地规划城市景观水的空间格局,充分发挥景观水的生态效应.