Study on the Countermeasures to Improve the Public Outdoor Leisure and Fitness Function on the Two Rivers and Four Banks in the Main Urban Area of Chongqing

The main urban area of Chongqing is surrounded by two rivers and set against each other.With its unique waterfront landscape,it has the resource conditions to become a leisure tourism destination.Intending to enhance people’s happiness,improve city quality,and promote Chongqing’s main urban area to become a tourist destination,this paper finds out the existing problems in the construction of public outdoor leisure and fitness facilities on the two rivers and four banks of Chongqing’s main urban area through investigation and analysis based on relevant experiences at home and abroad,takes the value chain theory as the guidance,and to find solutions to the problem.On this basis,combined with the law of economic operation,this paper puts forward the guiding ideology,principles,development goals,functional orientation,and development path for the improvement of public outdoor leisure and fitness on two rivers and four banks in the main city of Chongqing,and accordingly puts forward the policy system and guarantee measures for its improvement.

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

One-Step Reverse Osmosis Based on Riverbank Filtration for Future Drinking Water Purification

The presence of newly emerging pollutants in the aquatic environment poses great challenges for drink-ing water treatment plants.Due to their low concentrations and unknown characteristics,emerging pol-lutants cannot be efficiently removed by conventional water treatment processes,making technically,economically,and environmentally friendly water purification technologies increasingly important.This article introduces a one-step reverse osmosis(OSRO)concept consisting of riverbank filtration(RBF)and reverse osmosis(RO)for drinking water treatment.The OSRO concept combines the relatively low-cost natural pretreatment of river water with an advanced engineered purification system.RBF pro-vides a continuous natural source of water with stable water quality and a robust barrier for contami-nants.With the pre-removal of particles,organic matter,organic micro-pollutants(OMPs),and microbes,RBF becomes an ideal source for a purification system based on RO membranes,in comparison with the direct intake of surface water.OSRO treatment removes almost 99.9%of the particles,pathogens,viruses,and OMPs,as well as the vast majority of nutrients,and thus meets the requirements for the chlorine-free delivery of drinking water with high biostability.The OSRO treatment is cost effective com-pared with the standard conventional series of purification steps involving sprinkling filters,softening,and activated carbon.Artificial bank filtration(ABF),which functions as an artificial recharge in combi-nation with a sand filtration system,is proposed as an alternative for RBF in the OSRO concept to supply drinking water from locally available resources.It is also suggested that the OSRO concept be imple-mented with wind power as an alternative energy source in order to be more sustainable and renewable.An OSRO-based decentralized water system is proposed for water reclaiming and reuse.It is suggested that future water treatment focus on the combination of natural and engineered systems to provide drinking water through technically efficient,financially feasible,resource reusable,and environmentally relevant means.

Heritage Corridor Construction:New Idea for Protection of Heritage along the Right Bank of the Yalu River

This paper analyzed feasibility,mode,and significance of heritage corridor construction along the right bank of the Yalu River.It stated that the region along the right bank of the Yalu River conforms to characteristics of heritage corridor and is suitable for heritage corridor theory.For Liaoning and Jilin provinces integrating their tourism into the One Belt and One Road strategy,and promoting harmonious use of regional tourist resources,vigorous development of tourism,and targeted poverty alleviation through tourism,the heritage corridor construction is of profound significance.

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.

Erosion risk assessment:A case study of the Langat River bank in Malaysia

River bank erosion is one of the major and unpredictable hazards worldwide including in Malaysia.Soil detachment at river banks is due to two processes:1)hydraulic erosion imposed by channel flow and 2)sub aerial erosion due to the weakening and weathering of bank materials.This paper is focused on the second aspect of the erosion process which mainly depends on the combination of rainfall intensity and the ability of the soil to withstand the raindrop effects.The relative combination of sand,silt and clay in a soil is argued to have an impact on erosion resistance.In cohesive soil composition,sand forms the largest size ranging from 0.05 to 2 mm whereas silt is adequately moderate(ranging from 0.002 to 0.05 mm)and clay is the smallest of all three(less than 0.002 mm).With the knowledge that soil composition does indeed have an effect on erosion resistance,this paper will attempt to relate risk assessment index of river bank erosion specifically to soil composition.Thus,the objectives of this document are as follows;1)to produce risk assessment index for river bank erosion and 2)to carry out a case study for selected rivers in Malaysia pertaining to river bank assessment.The index is produced by inferring the previously developed scale on soil erodibility.Past researchers created the“ROM”scale(named after the researchers,Rolan and Mazidah)to assess degree of soil erodibility into five classes namely“critical”,“very high”,“high”,“medium”and“low”.Instead of using semi empirical formula from the“ROM”scale,a percentage of soil composition was inferred to produce risk assessment index.It was found that as the percentage of clay decreased,susceptibility index became higher and approached a critical level.Application of the newly developed index is verified by conducting a case study at the Langat River,Kajang,Malaysia.The soil composition was classified and form fitted into the index.It was found that the middle reach of the Langat river is susceptible to severe erosion due to low percentage of clay.This finding agreed well with the visual observation of these reaches as a large portion of gully type of erosion had been observed throughout the study.The establishment of risk assessment index which firmly indicates the relationship between soil composition and river bank erosion can be used as a tool in forecasting the risk levels.This formulation is well proven to assess river bank conditions and the associated critical shear stress is very much close with the previously published shear stress.

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.

Hydraulics of crest spillway with large unit discharge and low Froude number

With respect to the crest spillway with large unit discharge and low Froude number, the hydraulics of the slit-type energy dissipater at the outlet should be noticed due to the complicated flow regimes. In the present paper, some issues about hydraulic characteristics were experimentally investigated by means of five slit-type outlets and four tetrahedrons, including the flow choking, impact to river banks and jet trajectory. The main findings are as follows. The critical Froude number for the flow choking decreases with increasing outlet width of the slit-type energy dissipater. If the flow Froude number is expressed by the parameters just before this energy dissipater, the tetrahedron placed inside the side wall of the outlet could efficiently avoid the flow impact to the river bank of same side, and compared with the jet trajectory of the slit-type energy dissipater, the outlet with tetrahedron has different trajectory trend, i.e., the distance of the jet trajectory decreases with the increase of the water head due to special form of the outlet tetrahedron.