• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Effect of dike line adjustment on the tidal bore in the Qiantang Estuary, China*

    2017-06-07 08:22:46JianZeng曾劍GangChen陳剛CunhongPan潘存鴻ZhiyongZhang張芝永ZhejiangInstituteofHydraulicsandEstuaryHangzhou310020China
    關(guān)鍵詞:張芝陳剛

    Jian Zeng (曾劍), Gang Chen (陳剛), Cun-hong Pan (潘存鴻), Zhi-yong Zhang (張芝永) Zhejiang Institute of Hydraulics and Estuary, Hangzhou 310020, China

    Zhejiang Provincial Key Laboratory of Estuary and Coast, Hangzhou 310020, China,

    E-mail: zengjian@zjwater.gov.cn

    Effect of dike line adjustment on the tidal bore in the Qiantang Estuary, China*

    Jian Zeng (曾劍), Gang Chen (陳剛), Cun-hong Pan (潘存鴻), Zhi-yong Zhang (張芝永) Zhejiang Institute of Hydraulics and Estuary, Hangzhou 310020, China

    Zhejiang Provincial Key Laboratory of Estuary and Coast, Hangzhou 310020, China,

    E-mail: zengjian@zjwater.gov.cn

    2017,29(3):452-459

    In this paper, the effect of the dike line adjustment on the Qiantang Tidal Bore (QTB) is studied by physcial experiments. A lab-scale physical model of the Qiantang Estuary is built and the tidal bore is generated. With this model, the formation and pro-pagation processes of the tidal bore are simulated with or without the dike line adjustment. It is shown that the adjusted dike line changes the direction of the reflected tidal bore. The height of the tidal bore increases in the upstream region where the dike line is contracted. In the tested bent and forking regimes, the bore height at the upstream station is increased by 0.10 m and 0.04 m, respectively. Furthermore, the crossing bore still exists near the Daquekou station and the location slightly moves by about 3 km to the downstream region.

    Qiantang Estuary, tidal bore, physical model, dike line, land use

    Introduction

    A tidal bore, with the leading edge of the incoming tide forming water waves, is often generated by a rapid water level rise. It might occur when the tidal water flows into a funnel shape estuary in the opposite direction of the river current. For example, Chanson[1]pointed out that when a tide of a range over 4.5 m-6.0 m flows into a funnel shape estuary which narrows gradually, tidal bores are easy to occur. As many esturaies are trumpet-shaped, tidal bores are common[2,3]. However, the tidal bores in many estuaries are too small to be observed. And to our best knowledge, tidal bores can be observed in the Amazon River in Brazil, the Severn River in the UK[4], the Seine River in France, the Ganges River in India and the Qiantang Estuary in China. Among them, the Qiantang River, the Amazon and Ganges Rvers wit-ness the most famous tidal bores in the world. As a unique natural landscape, the tidal bore has its positive role. Tidal bores attract millions of tourists, which promotes significantly the development of local tourism and improves the local economy. On the other side, tidal bores also have negative effects, such as the brushing of riverbeds and damaging the buildings in and along the river. Therefore, the mechanisms of the occurrence and development of tidal bores are important issues not only for preventing damages caused by tidal bores, but also for protecting this natural landscape.

    Fig.1 Skecth of the Qiantang Estuary

    The Qiantang Estuary (Fig.1) in Zhejiang (China) is an ideal reference site for studying tidal bores asone sees there the largest tidal bore in the world. The Qiantang Tidal Bore (QTB) has a number of different shapes[5], such as the line tidal bore, the reflected tidal bore and the cross tidal bore. The tidal scene attracts millions of tourists each year, that promotes the local economic development and promotes the international reputation of the Hangzhou City in Zhejiang Province. Therefore, protecting the tidal bore is required and is one of the key indicators to evaluate the feasibility of projects along the Qiantang River. With the quick development of economy and the large population in China, the land is increasingly an important resource. In the seaboard near the Qiantang River, reclaiming land from sea is an efficient way to increase the land. However, this kind of projects will change the dike line of the Qiantang River and may influence the tidal bore. Therefore, it is important to study the effect of the dike line adjustment on the tidal bore.

    In recent years, various mathematical models were proposed to study the tidal bore[6-11]. However, these models are all based on two-dimensional depthaveraged shallow water equations and can not simulate the three-dimensional hydrodynamic characteristics of the tidal bore. Reichsterter and Chanson[12]and Xu et al.[13]established a three-dimensional numerical model to simulate the tidal bore. However it can only be used to simulate the motion of the tidal bore in a small region and can not be used to simulate the motion of the tidal bore in a field site. The physical model experiment is still an efficient way to study this complex hydraulic process. Chanson[3]conducted laboratory experiments in a water flume and examined the effect of the channel constriction and the bridge piers on the undular tidal bores. Based on the lab-scale results, he found that the bridges narrowed the channel, which caused a potential energy loss of the tidal bore and significantly affected the mixing properties of the tidal bore. Docherty and Chanson[14]used the same regular water flume to study the unsteady turbulence in breaking tidal bores. They found that the velocity fluctuates remarkably and there is an intense secondary motion behind the bore front. Huang et al.[15]developed a new method to generate tidal bores in the rectangular glass flume under various initial flow conditions with respect to the water depths and the ebb velocities before the tidal bore arrives. However, these experimental studies were all conducted using regular water flumes without considerations of the geometry of natural estuaries[16]. As for the practical projects on rivers or estuaries, entity physical model experiments are expected to be better because they are similar to real ones apart from a scale difference. The observed underlying mechanisms are expected in better agreement with reality. An entity physical model of the Qiantang Estuary[17]was established in Zhejiang Institute of Hydraulics and Estuary and was used to study the effect of practical projects on the QTB. In this paper, a dike line adjustment program in the segment from Daquekou to Jian Mountain in the Qiantang Estuary is studied and the effect of the dike line adjustment on the tidal bore is analyzed. Based on the analysis, some suggestions are made in view of practical projects.

    1. Overview of the study area

    The QTB usually initiates in the river segment of the Gaoyang Mountain, subsequently grows in the upstream and reaches its peak near Daquekou. The tidal bore gradually decays and finally disappears in Wenyan. The tidal bore propagation distance is about 90 km and the maximum tidal bore height is around 3.0 m. For relatively strong tidal bores, the water surface slope is in the range of 1:2.9-1:9.4. The propagation velocity of the leading edge is 4 m/s-7 m/s, and the maximum velocity at observation points is 12 m/s.

    Fig.2 Typical river regimes in the Jian Mountain reach

    The propagation of the tidal bore is significantly influenced by the river hydrodynamics in the JianMountain segment as shown in Fig.1. The seashore stretch from Ganpu to the Hangzhou Bay is 45.2 km. In this part, the cross section is relatively wide and the sediment transport of the ebb tide to deposit is easy and thus the river bed is considerably variable. Due to the strong reversing flow[5], the main channel swings sometimes and forms three river regimes: the bent, straight and forking regimes, as shown in Fig.2. After frequent flooding, the sediment deposits in the south branch and the water goes through the north branch, to form the straight regime (Fig.2(a)). However, because of the weak hydrodynamics of the backwater region and the sediment deposition in the middle position of the main channel, a forking regime (Fig.2(c)) is formed. During dry seasons, especially during continuous dry years, the tidal regime enhances relatively, so that the main channel swings towards the south direction, meanwhile the north region becomes a high beach to form a bent regime (Fig.2(b)). Over the past decade, under the influence of the reclamation in the north shore near the Jian Mountain and Haining, the main channel tends to move stably towards south instead of north. Even in rainy years, the existing period of the main channel in the north branch is becoming shorter more like a forking regime. With regard to the straight regime, the south branch is silted, and the tidal bore, known as the east tide, spreads towards the west direction along the Haining seawall in the north shore. In the case of the bent regime, the north branch is silted and the south branch stands alone. The tidal bore, known as the south tide, spreads upstream along the south bank of the Xiao Mountain, and the intersected angle between the spreading direction and the Haining seawall is small. As for the forking regime, the river shoal appears in the middle of the river and the main channel is divided into two branches with the tidal bores spreading upstream. When the two tidal bores from different branches meet in the river shoal upstream near Babao and Xincang, the tidal bores cross each other and spread individually, to form a crosstide in the cross-shape or the handstand Y shape. The tidal bore is uniform in the river segment from Babao to Yanguan due to the straight and regular river regime. During the flooding tide, when the tidal bore spreads to Yanguan, the forefront of the tidal bore is across the river, as known as the “l(fā)ine tidal bore”. In addition, the local tidal changes often occur in the reflection with the effect of the curve channel, the local shrinking, the spur dike, the seawall and so on.

    2. Experiment setup and verification

    2.1 Similarity condition

    In order to simulate the flow motion prototype accurately, the physical model should meet not only the geometrical similarity, but also the kinematic and dynamic similarity[18]. As for the dynamic similarity, there are many kinds of similarities, such as the Froude similarity, the Reynolds similarity[19], the resistance force similarity and so on. The Reynolds similarity is often used when the viscous force is the main factor while the Froude similarity[20]is used when the gravity and inertial forces are the main factors. In this study, the tidal bore is the focus and the characteristics of the tidal bore mainly depend on the Froude number, where c is the propagation velocity, v1is the flow velocity in front of the tidal bore,1h is the water depth in front of the tidal bore. According to the propagation velocity formula, the similarity of the propagation velocity is the same as that of the flow velocity. Consequently the Froude number should be the same between the prototype and the physical model to capture the accurate tidal bore variation. In addition , the resistance force is another main factor for the broad and shallow estuary. Therefore the Froude similarity and the Resistance Force similarity are selected in this study. Besides, due to the large horizontal scale and the small vertical scale, a distorted physical model is used. The physical quantities along the vertical direction do not satisfy the similarity condition in the distorted physical model, while the average values of the physical quantities along the vertical direction are still similar to the prototype. The similar scales of different physical quantities can be obtained by solving the unsteady twodimensional shallow water equations, which can be expressed as follows:

    where h is the water depth, u, v are the velocity components in x and y directions, respectively, g is the gravitational acceleration, b is the river bed elevation,fxS ,fyS are the friction gradients, respectively, in x and y directions, which can be expressed as follows:

    According to the kinematic similarity, the time scale can be expressed as

    According to the Froude number similarity, the vertical scale and the velocity scale are related as follows

    As for the roughness scale, according to the resistance force similarity and Eqs.(1) to (5), it can be expressed as

    Equations (6) to (8) are the similarity conditions for simulating the tidal flow in estuary based on the twodimensional shallow water equations.

    Fig.3 The layout of the lab-scale physical model

    Table 1 Similarities of scales used in the physical model

    2.2 Model setup of the Qiantang Estuary

    In view of the fact that the Qiantang Estuary is broad and shallow, the horizontal prototype-model scale is set as 1 000 and the vertical scale as 100. In the laboratory, a closed physical model is built (Fig.3). The upstream boundary of the lab-scale model is set at the Fuchunjiang hydropower station. The channel from the upstream boundary to the Laoyancang River section is simulated by an artificial meandering channel with a fixed flux. The downstream boundary is set at the Jin Mountain cross section. The total simulated prototype water area is about 2 200 km2. The key scales determined by the similarity condition are shown in Table 1.

    2.3 Model verification

    The physical model of the Qiantang Estuary is verified against the observed hydrological data in May 2003, August 2005, and April 2006. Due to the limited space here, only the validation results of the tidal bore in the flooding season May 19th, 2003 are included. The water level processes are listed in Table 2 (pxrefers to the observed value,mx the experimental value). The lab-scale model accurately reproduces the propagation process of the tidal bores in these days. The water level and the flow velocity obtained by the experiment agree well with the measured values.

    Table 2 Comparisons of experimental and observed bore heights

    Fig.4 Comparison of the leading edge of the observed and experimental tidal bores

    Fig.5 Comparisons of tidal heights during the tidal bore

    The observed data show a bent regime in May 2003. Under the influence of the river curve of the Jian Mountain, the tidal bore reaches the Caoe River after it is initiated in the river segment of the Gaoyang Mountain. And then under the influence of the embankment line in the southern shore, the leading edge of the tidal bore gradually turns to north. After passing through the 22nd work section, the direction of the tidal bore becomes almost perpendicular to the north shoreline and directly beats against the right side of the seawall near Daquekou. After passing Daquekou, the tidal bore turns to west and forms a line tidal bore in the straight river way. The modeled and observed tracks of the leading edge of the tidal bore are largely consistent (Fig.4). Figure 5 shows the verification results of the tidal height at different survey stations. It can be seen that the experimental tidal level values are in agreement with the observed values, and the maximum error is generally less than 0.15 m.

    2.4 Boundary conditions

    The terrain condition significantly influences the propagation characteristics of the tidal bores. In view of the tendency that the main channel is relatively stable in moving towards south in the river segment of the Jian Mountain in the recent decade, the river bathymetries in July 2005 and July 2006 are selected to represent the bent and forking regimes, respectively. The tidal prisms below the annual average of the high tidal level in the river segment from Daquekou to the Caoe River are 4.24×108m3and 4.06×108m3in cases of the bent and forking regimes, respectively, which are close to the average prism, 4.35×108m3.

    For the downstream boundary, the measured tidal range of the typical spring tides is around 8.06 m. With a safety factor of 1%, the design tidal type is taken as a spring tide with a range of 8.15 m. This characteristic value is equivalent to the tidal range of safety factor of 1%. At the upstream boundary, the design flow condition is the annual average discharge (952 m3/s) of the Fuchunjiang hydropower station.

    Fig.6 Adjustment scheme of the Haining dike line and the locations of the survey points

    3. Results and discussions

    3.1 Dike line adjustment scheme

    Under the natural conditions, the river width and the discharge area are determined by the combined effects of the riverbed, the water discharge and the sediment transport. Consequently, in the dike line adjustment of the estuary, the morphological relationship should be considered and the water depth or the discharge area should keep invariable during the adjustment activity. For the specific situation of the riversegment of the Jian Mountain, the proposed reclamation area is 10 600 acres, spanning from Daquekou to the Jin Mountain. The embankment is about 9 610 m long and the maximum reclamation width is 2.5 km, as shown in Fig.6.

    Fig.7 Changes of tidal height during the tidal bore near Daquekou

    3.2 Effect of dike line adjustment on tidal bore

    In the case of the bent regime, the tidal bore propagates upstream along the deep groove of the south shore. Subsequently, the tidal bore almost directly meets the seawall from Daquekou to Xincang to form a strong reflected tide. As the seawall is convex towards the river, the reflection separates the tidal bore into two parts, which propagate, respectively, upstream and downstream. From the water level monitored at the 11# station (Fig.7(a)), one sees a spreading tidal bore head and a reflected tidal head near Daquekou. Table 3 lists the variations of the tidal height at different stations under the condition of the bent regime. The experimental results show that the adjusted dike line has little influence on the spreading tidal height at 1#-11# stations and the variations are within 0.03 m. However, the influence of the dike line adjustment on the height of the reflected tidal bore in the river segment from Daquekou to Xincang is more significant, and the tidal heights of the reflected tide at 9# and 11# stations are elevated up 0.09 m and 0.39 m, respectively. In the upstream region of Daquekou, due to the dike line adjustments, which cause changes of the layout and the trend of Daquekou to the Xincang segment, the direction and the strength of the reflected tide are also changed, as a result, the spreading tidal bore heights near Babao and Yanguan are lifted up 0.13 m and 0.10 m, respectively. The direction of the reflected tidal bore is shown in Fig.8(a). The adjusted dike line induces the oblique reflection and the direction of the reflected tide turns towards the upstream region, which enhances the momentum of the tide.

    Fig.8 Distributions of tidal height and tidal direction in different regimes

    Under the condition of the forking regime, the tidal bore near the Caoe River is divided into the south tide and the east tide. The two tides propagate in the directions upstream along the south and north deep troughs, respectively. The experiment shows that, although the adjusted dike line occupies a part of the north deep trough, the forking regime does not change remarkably. The east tide still exists in the front of the new dike line and it is crossed with the reflected tide of the south tide. However the momentum of the east tide is weakened and the crossing location moves downstream slightly. As shown in Table 4 and Fig.7(b), due to the redistribution of the discharge of the north and south deep troughs caused by the Haining dike line scheme, the tide height in front of the southern shore (1#-4#) is slightly elevated, and the increased range is generally within 0.03 m. As for the frontiers of the north shore (8#-13#), due to the existence of the spreading tide, the reflected tide and the crossed tide, the bore variation caused by the dike line scheme is irregular and the variation values are larger than those in front of the south shore, which causes the adjustment scheme change the dike line profile betweenDaquekou to Xincang and makes the reflected direction of the tide turn upstream and enhances the momentum of the tide (Fig.8(b)). Due to the characteristics of the location near Daquekou, three tidal bores appear in this position: the south spreading tide, the south reflected tide, and the east spreading tide. The influences of the adjustment dike line on these three tides are different. The south spreading tide and the south reflected tide are elevated by 0.05 m and 0.08 m, respectively. However, the east spreading tide is lowe-

    red by 0.06 m under the influence of the dike line adjustmen.

    Table 3 Changes of the bore height under the condition of bent regime

    Table 4 Changes of the bore height under the condition of forking regime

    To sum up, the implementation of the dike line adjustment from Daquekou to the Jian Mountain does not weaken the intensity of the QTB. In contrast, the dike line adjustment shrinks the river and occupies the energy dissipation zone, which reduces the energy loss of the tidal bore and propagates upstream with a stronger energy. It is beneficial for the protection of the QTB. Consequently, this study provides a new method to protect the QTB by adjusting the dike line and shrinking the river. However, the size of the dike line adjustment should be carefully determined, because with a larger dike line adjustment, the tidal prism from the East Sea will be less, which will weaken the QTB.

    4. Conclusion

    Based on an entity physical model of the Qiantang Estuary in laboratory, the effect of the dike line adjustment from Daquekou to the Jian Mountain on the tidal bore is investigated. It is concluded that the adjusted dike line changes the intersection angle between the tidal bore spreading direction and the seawall, which affects the strength and the spreading direction of the tidal bore. The strength of the tidal bore is enhanced in the upstream region of the dike line adjustment, and is reduced in the downstream region. Due to the different spreading characteristics of the tidal bore caused by factors such as the river bathymetry and the boundary conditions, the influences of the dike line adjustment schemes in different river segments on the tidal bore are different. Therefore, the influences of the tidal bore on the future dike line adjustment in the Qiantang Estuary should be specially considered in a location-specific manner.

    [1] Chanson H. Current knowledge in tidal bores andtheir environmental, ecological and cultural impacts [J]. Environmental Fluid Mechanics, 2011, 11(1): 77-98.

    [2] Bonneton P., Bonneton N., Parisot J. P. et al. Tidal bore dynamics in funnel-shaped estuaries [J]. Journal of Geophysical Research: Oceans, 2015, 120(2): 923-941.

    [3] Chanson H. Undular tidal bores: Effect of channel constriction and bridge piers [J]. Environmental Fluid Mechanics, 2011, 11(4): 385-404.

    [4] Fairley I., Ahmadian R., Falconer R. A. et al. The effects of a Severn Barrage on wave conditions in the Bristol Channel [J]. Renewable Energy, 2014, 68: 428-442.

    [5] Lin B. Y., Huang S. C., Mao X. Z. Deformation process of tidal waves in Qiantang Estuary [J]. Journal of Hydrodynamics, Ser. A, 2002, 17(6): 665-675(in Chinese).

    [6] Madsen P. A., Simonsen H. J., Pan C. H. Numerical simulation of tidal bores and hydraulic jumps [J]. Coastal Engineering, 2005, 52(5): 409-433.

    [7] Pan C. H., Dai S. Q., Chen S. M. Numerical simulation for 2D shallow water equations by using Godunov-type scheme with unstructured mesh [J]. Journal of Hydrodynamics, Ser. B, 2006, 18(4): 475-480.

    [8] Pan C. H., Lin B. Y., Mao X. Z. Case study: Numerical modeling of the tidal bore on the Qiantang River, China [J]. Journal of Hydraulic Engineering, ASCE, 2007, 133(2): 130-138.

    [9] Lu H. Y., Pan C. H., Lu X. X. et al. Numerical simulations of the third Hainng reclamation project effect on the tidal bore in the Qiantang River [J]. Chinese Journal of Hydrodynamics, 2008, 23(4): 484-491(in Chinese).

    [10] Pan C. H., Lu H. Y., Zeng J. Characteristic and numerical simulation of tidal bore in Qiantang Rive [J]. Hydro-Science and Engineering, 2008, 30(2): 1-9(in Chinese).

    [11] Shi J., Tong C., Yan Y. et al. Influence of varying shape and depth on the generation of tidal bores [J]. Environmental Earth Sciences, 2014, 72(7): 2489-2496.

    [12] Reichstetter M., Chanson H. Negative surges in open channels: Physical and numerical modeling [J]. Journal of Hydraulic Engineering, ASCE, 2013, 139(3): 341-346.

    [13] Xu Z. Y., Xu C. J., Chen R. et al. Three-dimensional numerical simulation of bore against sheet-pile groin [J]. Journal of Zhejiang University (Engineering Science), 2014, 48(3): 504-513(in Chinese).

    [14] Docherty N., Chanson H. Physical modeling of unsteady turbulence in breaking tidal bores [J]. Journal of Hydraulic Engineering, ASCE, 2012, 138(5): 412-419.

    [15] Huang J., Pan C. H., Kuang C. P. et al. Experimental hydrodynamic study of the Qiantang River tidal bore[J]. Journal of Hydrodynamics, 2013, 25(3): 481-490.

    [16] Chanson H., Toi Y. Physical modelling of breaking tidal bores: Comparison with prototype data [J]. Journal of Hydraulic Research, 2015, 53(2): 264-273.

    [17] Zeng J., Sun Z. L., Xiong S. L. Effect of bridge engineering on tidal bore in Qiantang Estuary [J]. Journal of Zhejiang University (Engineering Scicence), 2006, 40(9): 1574-1577(in Chinese).

    [18] Wang Q. S., Kang H. G., Wang K. Three-dimensional unstructured modelling of wave-induced circulation over a plane and irregular beach [J]. Journal of Hydrodynamics, 2016, 28(2): 219-226.

    [19] Zhang Z., Shi B., Guo Y. et al. Improving the prediction of scour around submarine pipelines [J]. Proceedings of the Institution of Civil Engineers-Maritime Engineering, 2016, 169(4): 163-173.

    [20] Leng X., Chanson H. Unsteady turbulence, dynamic similarity and scale effects in bores and positive surges [J]. European Journal of Mechanics-B/Fluids, 2017, 61(1): 125-134.

    10.1016/S1001-6058(16)60756-4

    February 25, 2015, Revised April 5, 2016)

    * Project supported by the National Nature Science Foundation of China (Grant Nos. 41376099, 51609214 and 41676085), the Public Sector of the Ministry of Water Resources Research (Grant No. 201401010).

    Biography:Jian Zeng (1974-), Male, Ph. D., Professor

    Zhi-yong Zhang,

    E-mail: zhangzy@zjwater.gov.cn

    猜你喜歡
    張芝陳剛
    Hard-core Hall tube in superconducting circuits
    Characterization of topological phase of superlattices in superconducting circuits
    Theoretical design of thermal spin molecular logic gates by using a combinational molecular junction
    SU(3)spin–orbit coupled fermions in an optical lattice
    Comprehensive Evaluation Method for Safety Performance of Automobile Textiles
    “草圣”張芝:不愛權(quán)貴愛布衣
    HIV-1 Env三聚體抗原改造研究進展
    張芝臨池洗墨
    專心成就書法大師
    “三數(shù)”求解大揭秘
    国产精品 国内视频| 欧美 亚洲 国产 日韩一| 亚洲av中文av极速乱| 另类精品久久| 波多野结衣一区麻豆| 99热全是精品| 视频区图区小说| 精品视频人人做人人爽| 久久久久精品性色| 久久久久久伊人网av| 1024视频免费在线观看| 国产欧美日韩一区二区三区在线| 一级毛片黄色毛片免费观看视频| av女优亚洲男人天堂| 在线观看三级黄色| 性色av一级| 综合色丁香网| 国产精品偷伦视频观看了| 18禁裸乳无遮挡动漫免费视频| 亚洲精品在线美女| 免费播放大片免费观看视频在线观看| 熟妇人妻不卡中文字幕| 久久久久久伊人网av| 亚洲中文av在线| 久久国产亚洲av麻豆专区| 99久久中文字幕三级久久日本| 蜜桃在线观看..| 在线观看国产h片| 久久国产精品大桥未久av| 五月天丁香电影| 国产激情久久老熟女| 啦啦啦视频在线资源免费观看| 亚洲经典国产精华液单| 亚洲伊人色综图| 国产黄色免费在线视频| 午夜激情av网站| 精品久久蜜臀av无| 精品国产乱码久久久久久男人| 国产亚洲精品第一综合不卡| 一区二区三区乱码不卡18| 一级,二级,三级黄色视频| 国产欧美日韩一区二区三区在线| www.熟女人妻精品国产| 在线天堂最新版资源| 人妻少妇偷人精品九色| 菩萨蛮人人尽说江南好唐韦庄| 男的添女的下面高潮视频| 国产精品麻豆人妻色哟哟久久| 日韩一区二区三区影片| 又黄又粗又硬又大视频| 国产97色在线日韩免费| 美女高潮到喷水免费观看| 精品亚洲乱码少妇综合久久| 国产1区2区3区精品| 久久精品国产自在天天线| 国产精品二区激情视频| 青春草国产在线视频| 久久午夜综合久久蜜桃| 岛国毛片在线播放| 国产老妇伦熟女老妇高清| 久久精品国产自在天天线| 精品一区二区三卡| 热99国产精品久久久久久7| 97在线视频观看| 亚洲成人av在线免费| 国产欧美日韩一区二区三区在线| 成人漫画全彩无遮挡| 视频区图区小说| 成人毛片60女人毛片免费| 如何舔出高潮| 高清欧美精品videossex| 国产成人av激情在线播放| 成人毛片a级毛片在线播放| 久久久久久人人人人人| 国产1区2区3区精品| 色吧在线观看| 老鸭窝网址在线观看| 中文字幕亚洲精品专区| 91久久精品国产一区二区三区| 免费观看av网站的网址| 80岁老熟妇乱子伦牲交| 九九爱精品视频在线观看| 男男h啪啪无遮挡| 久久精品国产自在天天线| 看十八女毛片水多多多| 久久久国产欧美日韩av| 曰老女人黄片| 观看美女的网站| 国产免费福利视频在线观看| 蜜桃国产av成人99| 中文字幕av电影在线播放| 丝袜美腿诱惑在线| 伦精品一区二区三区| 一区二区av电影网| 欧美xxⅹ黑人| 国产成人精品福利久久| 久久精品国产亚洲av天美| 狂野欧美激情性bbbbbb| 一本大道久久a久久精品| 日日摸夜夜添夜夜爱| 欧美中文综合在线视频| 日韩不卡一区二区三区视频在线| 超色免费av| 亚洲一码二码三码区别大吗| 久久国产精品大桥未久av| 亚洲在久久综合| 久久精品aⅴ一区二区三区四区 | 国产精品熟女久久久久浪| 最近手机中文字幕大全| 天美传媒精品一区二区| av又黄又爽大尺度在线免费看| 国产精品亚洲av一区麻豆 | 精品酒店卫生间| 国产精品不卡视频一区二区| 在线观看免费视频网站a站| 一区二区日韩欧美中文字幕| 一区福利在线观看| 国产色婷婷99| 亚洲少妇的诱惑av| 九九爱精品视频在线观看| 久久久久久人人人人人| 精品少妇内射三级| 国产精品偷伦视频观看了| 久久人妻熟女aⅴ| 欧美激情 高清一区二区三区| 精品一区二区三卡| 韩国av在线不卡| 午夜老司机福利剧场| 欧美少妇被猛烈插入视频| 欧美另类一区| 夫妻午夜视频| 国产精品免费大片| 男女边吃奶边做爰视频| 国产日韩一区二区三区精品不卡| 成人影院久久| www.熟女人妻精品国产| 97在线视频观看| www.熟女人妻精品国产| 人人澡人人妻人| 久久韩国三级中文字幕| 久久国内精品自在自线图片| 热99国产精品久久久久久7| 亚洲欧美清纯卡通| av卡一久久| 观看美女的网站| 黄色毛片三级朝国网站| 国产精品久久久久久av不卡| 日日爽夜夜爽网站| 黄色怎么调成土黄色| 亚洲国产精品一区三区| 国产片内射在线| 国产人伦9x9x在线观看 | 亚洲国产欧美日韩在线播放| 国产精品蜜桃在线观看| 亚洲国产成人一精品久久久| 曰老女人黄片| 秋霞在线观看毛片| 国产成人a∨麻豆精品| 两个人看的免费小视频| 午夜久久久在线观看| 欧美精品国产亚洲| 久久久久视频综合| 久久精品久久久久久噜噜老黄| 最黄视频免费看| 99香蕉大伊视频| 日韩伦理黄色片| 观看av在线不卡| 国产熟女午夜一区二区三区| 五月伊人婷婷丁香| 久久久久精品久久久久真实原创| 亚洲激情五月婷婷啪啪| 国产黄色免费在线视频| 视频在线观看一区二区三区| 丝袜人妻中文字幕| 最新的欧美精品一区二区| 最新的欧美精品一区二区| 黑丝袜美女国产一区| 欧美在线黄色| 欧美+日韩+精品| videosex国产| 大香蕉久久网| 美女高潮到喷水免费观看| 国产欧美亚洲国产| 精品国产一区二区三区久久久樱花| 永久免费av网站大全| 亚洲激情五月婷婷啪啪| 麻豆av在线久日| 午夜福利网站1000一区二区三区| 国产黄色免费在线视频| 欧美亚洲 丝袜 人妻 在线| 亚洲激情五月婷婷啪啪| 久久久久久久久久久久大奶| 电影成人av| 国产麻豆69| 国产男人的电影天堂91| 亚洲国产精品一区三区| 亚洲综合色网址| 多毛熟女@视频| 日本爱情动作片www.在线观看| 日韩中文字幕视频在线看片| 少妇的丰满在线观看| 精品第一国产精品| 午夜日韩欧美国产| 欧美人与性动交α欧美软件| 亚洲国产色片| 在线观看www视频免费| 久久精品国产亚洲av天美| 在线观看人妻少妇| 久久亚洲国产成人精品v| 亚洲av电影在线进入| 你懂的网址亚洲精品在线观看| 亚洲精品美女久久久久99蜜臀 | 久久精品国产自在天天线| 免费观看在线日韩| 天天躁夜夜躁狠狠久久av| 日韩av不卡免费在线播放| 午夜av观看不卡| 亚洲欧美成人综合另类久久久| 亚洲欧美成人综合另类久久久| 国产麻豆69| 欧美另类一区| 天堂8中文在线网| 国产日韩一区二区三区精品不卡| 亚洲精品国产av成人精品| 99久久综合免费| 国产欧美亚洲国产| a级片在线免费高清观看视频| 黄片小视频在线播放| 国产又色又爽无遮挡免| 1024香蕉在线观看| 国产毛片在线视频| 宅男免费午夜| 国产午夜精品一二区理论片| 中文字幕人妻丝袜一区二区 | 日韩欧美一区视频在线观看| 亚洲精品一二三| videosex国产| 国产成人精品无人区| 国产黄频视频在线观看| 精品国产一区二区久久| 可以免费在线观看a视频的电影网站 | 新久久久久国产一级毛片| 午夜福利乱码中文字幕| 国产在线视频一区二区| 母亲3免费完整高清在线观看 | 熟女少妇亚洲综合色aaa.| 精品少妇久久久久久888优播| 人妻人人澡人人爽人人| 看免费av毛片| av电影中文网址| 蜜桃国产av成人99| 久久人人97超碰香蕉20202| 天天影视国产精品| 在线天堂中文资源库| 日本黄色日本黄色录像| 交换朋友夫妻互换小说| 国产欧美日韩综合在线一区二区| 亚洲欧洲精品一区二区精品久久久 | 超碰97精品在线观看| 一区二区三区激情视频| 在线免费观看不下载黄p国产| 成人二区视频| 巨乳人妻的诱惑在线观看| 国产一区二区激情短视频 | 97在线人人人人妻| 午夜福利乱码中文字幕| 美女脱内裤让男人舔精品视频| 91国产中文字幕| 自拍欧美九色日韩亚洲蝌蚪91| 国产精品女同一区二区软件| 五月天丁香电影| 女人高潮潮喷娇喘18禁视频| 久久鲁丝午夜福利片| 黑丝袜美女国产一区| 一区在线观看完整版| 国产人伦9x9x在线观看 | 久久鲁丝午夜福利片| 伊人亚洲综合成人网| 最近最新中文字幕大全免费视频 | 又黄又粗又硬又大视频| 国产精品99久久99久久久不卡 | 在线免费观看不下载黄p国产| 狠狠精品人妻久久久久久综合| 天天躁夜夜躁狠狠躁躁| 天天影视国产精品| 五月开心婷婷网| 男女啪啪激烈高潮av片| 精品久久久久久电影网| 丝瓜视频免费看黄片| 亚洲美女搞黄在线观看| 国产又色又爽无遮挡免| 一级毛片黄色毛片免费观看视频| 久久精品亚洲av国产电影网| 中国三级夫妇交换| 亚洲 欧美一区二区三区| 狂野欧美激情性bbbbbb| 丁香六月天网| 九草在线视频观看| 日韩一本色道免费dvd| 国产97色在线日韩免费| 国精品久久久久久国模美| 777久久人妻少妇嫩草av网站| 伊人久久大香线蕉亚洲五| 宅男免费午夜| 99re6热这里在线精品视频| 久久精品人人爽人人爽视色| 国产av码专区亚洲av| 在线看a的网站| 少妇被粗大猛烈的视频| 亚洲欧美成人综合另类久久久| 日韩一卡2卡3卡4卡2021年| 日日摸夜夜添夜夜爱| 亚洲精品第二区| 搡老乐熟女国产| 一二三四在线观看免费中文在| 999久久久国产精品视频| 国产日韩欧美在线精品| 夫妻性生交免费视频一级片| 久久免费观看电影| 极品人妻少妇av视频| 丰满乱子伦码专区| 一区二区三区四区激情视频| 校园人妻丝袜中文字幕| 观看美女的网站| 人妻人人澡人人爽人人| 黄网站色视频无遮挡免费观看| 日日啪夜夜爽| 久久久久国产网址| 日本-黄色视频高清免费观看| 亚洲一区二区三区欧美精品| 午夜激情久久久久久久| 97在线视频观看| 王馨瑶露胸无遮挡在线观看| 999久久久国产精品视频| 国产淫语在线视频| 在线天堂中文资源库| 成人黄色视频免费在线看| 免费久久久久久久精品成人欧美视频| 欧美人与性动交α欧美软件| 欧美精品亚洲一区二区| 熟妇人妻不卡中文字幕| 伦理电影大哥的女人| 久久99一区二区三区| 美女主播在线视频| 日日爽夜夜爽网站| a级毛片黄视频| 三上悠亚av全集在线观看| 国产精品.久久久| 午夜日本视频在线| 七月丁香在线播放| 男男h啪啪无遮挡| 老司机亚洲免费影院| 国产乱来视频区| 青春草视频在线免费观看| 黄色一级大片看看| 免费女性裸体啪啪无遮挡网站| 日日撸夜夜添| 久久热在线av| 一区二区三区乱码不卡18| 丝袜在线中文字幕| 久久毛片免费看一区二区三区| 国产一区二区激情短视频 | 午夜免费鲁丝| 超碰成人久久| 精品亚洲成a人片在线观看| 国产不卡av网站在线观看| 久久久久久久久久人人人人人人| 哪个播放器可以免费观看大片| 国产精品人妻久久久影院| 人人澡人人妻人| 91精品伊人久久大香线蕉| 亚洲精品日本国产第一区| 丰满饥渴人妻一区二区三| 国产在线一区二区三区精| 丝袜美腿诱惑在线| 制服丝袜香蕉在线| 亚洲精品日韩在线中文字幕| 国产欧美日韩综合在线一区二区| 97在线视频观看| 少妇人妻 视频| 国产精品免费大片| 午夜免费鲁丝| 亚洲欧美日韩另类电影网站| 亚洲精华国产精华液的使用体验| 中文字幕人妻丝袜制服| 日日撸夜夜添| 国产综合精华液| 秋霞在线观看毛片| 少妇的逼水好多| 美女高潮到喷水免费观看| 99国产精品免费福利视频| 国产成人精品久久二区二区91 | 高清欧美精品videossex| 婷婷色av中文字幕| 老汉色av国产亚洲站长工具| 国产熟女欧美一区二区| 一级片免费观看大全| 久久午夜综合久久蜜桃| 夜夜骑夜夜射夜夜干| 狠狠精品人妻久久久久久综合| 国产av一区二区精品久久| 成人毛片60女人毛片免费| √禁漫天堂资源中文www| 又黄又粗又硬又大视频| 亚洲av免费高清在线观看| 一个人免费看片子| av有码第一页| 成人国语在线视频| 亚洲成人手机| 性色av一级| 巨乳人妻的诱惑在线观看| 国产高清不卡午夜福利| 美女国产视频在线观看| 青春草亚洲视频在线观看| 欧美日韩精品网址| 人妻一区二区av| 亚洲人成电影观看| 啦啦啦在线免费观看视频4| 亚洲一区中文字幕在线| 美女视频免费永久观看网站| 欧美+日韩+精品| a级毛片在线看网站| 日韩av免费高清视频| 欧美成人午夜精品| 国产精品不卡视频一区二区| 欧美人与性动交α欧美精品济南到 | 国产成人一区二区在线| 亚洲欧美一区二区三区黑人 | 五月天丁香电影| 久久精品久久久久久久性| 日本-黄色视频高清免费观看| 最新中文字幕久久久久| 亚洲国产最新在线播放| 999精品在线视频| 欧美日韩视频精品一区| 自拍欧美九色日韩亚洲蝌蚪91| 亚洲国产精品成人久久小说| 欧美av亚洲av综合av国产av | 久久青草综合色| 伊人久久大香线蕉亚洲五| 日韩,欧美,国产一区二区三区| 亚洲精品自拍成人| xxx大片免费视频| 高清欧美精品videossex| 久久精品aⅴ一区二区三区四区 | 亚洲成av片中文字幕在线观看 | 视频区图区小说| 高清不卡的av网站| 国产亚洲av片在线观看秒播厂| 人人妻人人澡人人爽人人夜夜| 26uuu在线亚洲综合色| 日韩欧美精品免费久久| 黑人巨大精品欧美一区二区蜜桃| 国产在线视频一区二区| 色婷婷av一区二区三区视频| 午夜老司机福利剧场| 精品国产一区二区三区四区第35| 黄频高清免费视频| 成人国语在线视频| 三级国产精品片| 秋霞伦理黄片| 人人妻人人澡人人看| 午夜日韩欧美国产| 亚洲内射少妇av| 在线免费观看不下载黄p国产| 人妻 亚洲 视频| 欧美精品一区二区免费开放| 国产精品免费大片| 飞空精品影院首页| 国产熟女欧美一区二区| 99热网站在线观看| 少妇熟女欧美另类| 波野结衣二区三区在线| 亚洲国产av新网站| 亚洲精品成人av观看孕妇| 久久国产精品大桥未久av| 少妇人妻久久综合中文| 欧美精品亚洲一区二区| www.av在线官网国产| 亚洲综合色网址| 蜜桃国产av成人99| 欧美精品人与动牲交sv欧美| 久久精品久久精品一区二区三区| 在线观看一区二区三区激情| 日韩av不卡免费在线播放| 咕卡用的链子| 精品亚洲成国产av| 国产精品 国内视频| 午夜激情久久久久久久| 精品少妇一区二区三区视频日本电影 | 亚洲精品在线美女| 欧美激情 高清一区二区三区| 女人精品久久久久毛片| 一本大道久久a久久精品| 美女中出高潮动态图| 久久久久精品久久久久真实原创| 国产精品久久久久久av不卡| 亚洲人成网站在线观看播放| 只有这里有精品99| 人人妻人人添人人爽欧美一区卜| 亚洲国产毛片av蜜桃av| 欧美精品人与动牲交sv欧美| 日本爱情动作片www.在线观看| 久久久久久人人人人人| 久久精品熟女亚洲av麻豆精品| 成人毛片60女人毛片免费| 亚洲国产欧美在线一区| 超碰97精品在线观看| 岛国毛片在线播放| 欧美少妇被猛烈插入视频| 国产日韩欧美视频二区| 中文字幕人妻丝袜一区二区 | 成年女人在线观看亚洲视频| 亚洲av欧美aⅴ国产| √禁漫天堂资源中文www| 亚洲国产精品国产精品| 美女脱内裤让男人舔精品视频| 国产高清国产精品国产三级| 亚洲国产欧美日韩在线播放| 成人毛片a级毛片在线播放| 精品一区在线观看国产| 一边摸一边做爽爽视频免费| 中文字幕人妻丝袜制服| 亚洲精品国产色婷婷电影| 在线观看人妻少妇| 国产精品 国内视频| 精品久久久精品久久久| 午夜影院在线不卡| 天天操日日干夜夜撸| 精品卡一卡二卡四卡免费| 国产淫语在线视频| 国产成人91sexporn| 欧美日韩精品网址| 欧美日韩一区二区视频在线观看视频在线| av一本久久久久| 在线免费观看不下载黄p国产| 不卡视频在线观看欧美| 最黄视频免费看| a级毛片黄视频| 国产在线视频一区二区| 亚洲精品国产色婷婷电影| 狠狠精品人妻久久久久久综合| 亚洲第一av免费看| 国产麻豆69| 欧美日韩av久久| 一级毛片黄色毛片免费观看视频| 91在线精品国自产拍蜜月| 国产欧美亚洲国产| 另类亚洲欧美激情| 免费高清在线观看视频在线观看| 亚洲欧美一区二区三区久久| 亚洲三级黄色毛片| 亚洲美女视频黄频| 少妇 在线观看| 成人毛片60女人毛片免费| 久久热在线av| 黄片小视频在线播放| 日韩大片免费观看网站| 男人舔女人的私密视频| 99国产综合亚洲精品| av又黄又爽大尺度在线免费看| 免费黄网站久久成人精品| 美女大奶头黄色视频| 久久国内精品自在自线图片| 黄片小视频在线播放| 男女高潮啪啪啪动态图| 18禁观看日本| 在线观看免费日韩欧美大片| 最近手机中文字幕大全| 精品酒店卫生间| 国产激情久久老熟女| 国产精品国产三级国产专区5o| 欧美亚洲 丝袜 人妻 在线| 99久久综合免费| 女性生殖器流出的白浆| 91久久精品国产一区二区三区| 在线观看免费视频网站a站| 一区二区av电影网| 亚洲精品国产av蜜桃| 久久久亚洲精品成人影院| a 毛片基地| 国产在线免费精品| 亚洲 欧美一区二区三区| 精品视频人人做人人爽| 欧美精品国产亚洲| 飞空精品影院首页| 成人黄色视频免费在线看| 国产精品熟女久久久久浪| 免费观看在线日韩| 啦啦啦视频在线资源免费观看| 亚洲男人天堂网一区| 国产精品亚洲av一区麻豆 | 七月丁香在线播放| 久久精品国产鲁丝片午夜精品| 国产精品 国内视频| 狂野欧美激情性bbbbbb| 叶爱在线成人免费视频播放| 婷婷色综合www| 国产毛片在线视频| 日本av手机在线免费观看| 免费在线观看完整版高清| 爱豆传媒免费全集在线观看| 一个人免费看片子| av福利片在线| 韩国精品一区二区三区| 中文欧美无线码| 晚上一个人看的免费电影| 男的添女的下面高潮视频| a级毛片黄视频| 黑丝袜美女国产一区| 美国免费a级毛片| 国产成人精品福利久久| 国产免费视频播放在线视频| 少妇的逼水好多| 伦理电影免费视频|