Knowledge Resource Center for Ecological Environment in Arid Area
| 华南热带湿润海岸风沙运动规律和防沙工程研究 | |
| 其他题名 | The research on the characteristics of aeolian sand transport and sand prevention engineering in tropical humid coastal southern China |
| 韩庆杰 | |
| 出版年 | 2009 |
| 学位类型 | 博士 |
| 导师 | 屈建军 |
| 学位授予单位 | 中国科学院寒区旱区环境与工程研究所 |
| 中文摘要 | 海岸风沙运动观测与模拟研究的区域主要集中于欧洲与北美的温带湿润海岸，而全球其它广大地区海岸风沙运动观测与模拟的研究相对较少，例如热带的湿润海岸。华南海岸风沙活动强烈，海岸沙丘地面积有2.378×105ha，不仅在中国海岸沙丘中，而且在世界热带湿润海岸沙丘中均占有重要地位。然而，对于该区域，在海岸风沙运动观测与模拟研究方面相对极为薄弱。\n风沙传输主要影响海岸沙丘的增长，沙漠化和危害沿岸建筑。表面湿度被认为是一个影响风沙传输的非常重要的因素, 尤其是在海滩和前丘的交互带。因此，本文基于华南热带湿润海岸风沙运动规律的研究，在学习和总结沙坡头铁路防沙体系经验的基础上，对海岸国防设施风沙危害进行了工程防治。最终，成功建立了海岸风沙防护体系，研究了其防护效益，并在开放式沙滩成功引种了红树林。初步结论如下：\n1．建立了一个新的预测热带湿润海滩湿沙起动摩阻速度的方程，结果指出对于给定粒径，湿沙的起动摩阻速度随ln100M线性增加。当我们评价一些被广泛使用的模型时，预测结果的巨大差异被表现出来。在湿度低于0.0062（=0.5M1.5A）时，Chepil（1956）和Selah and Fryrear（1995）的理论模型和试验数据有较好的一致性。在湿度高于0.0062时，Belly（1964）的经验模型和试验数据更具有可比性。模型中被广泛使用的参数M1.5可能界定了水分存在形式的过渡点。在所有测试湿度下，随着有效风速的增加，侵蚀模数的增加呈现指数为正值的幂函数关系。随着湿度的增加，侵蚀模数的降低呈现指数为负值的幂函数关系。当湿度和风速同步变化时，风蚀模数同有效风速的0.73次方成正比，但同湿度的1.48次方成反比。当M≥0.83%（= M1.5B），仅由颗粒间水膜所产生的粘滞力就足以抑制大风情况下的绝大部分侵蚀的发生。\n2．海滩湿润床面，不同高度跃移沙粒的水平和垂直速度符合Gaussian 分布，平均水平颗粒速度随高度和风速增加。在所有测试风速下，伴随湿度为0.591%和1.464%的两个转折点，湿沙表面跃移云颗粒速度随湿度呈现波动或阶梯式变化格局，湿度的累计数量变化引起了沉积物中水分粘滞力和床面硬度的基本变化。这种累计效应同土壤的持水力相关，湿度0.591%和1.464%（接近于M1.5= 1.591%）相应的可能代表了由颗粒表面水膜产生的分子吸附力（M＜0.591%）和颗粒间水桥产生的毛细作用力（M＞1.464%），当0.591%＜M＜1.464%时，颗粒间的力正由分子吸附力向毛细作用力过渡。湿润床面上流沙云平均顺风向速度随高度的变化能够被表达为一个幂函数方程。整体上，平均颗粒垂直速度随着湿度而增加，颗粒的垂直运动逐渐由向下过渡为向上，过渡点湿度与水平颗粒速度的一致。\n3．如果近表层输沙廓线的反向弯曲被忽略，一个湿沙表面的输沙廓线能够被表达为一个指数方程。一般，湿度增大，整体输沙率降低，高湿度床面的沙粒有相对更大的比例被传输到更高的位置。当湿度和风速增加，蠕移比例和相对衰减率降低，更多地颗粒会在更高处传输。蠕移比例的变化范围很广，从0.12到0.33，平均为0.22，依耐于湿度和风速。目前的研究中，湿度达到0.587%和1.448%（接近于1.591% = M1.5）之间时，蠕移比例、相对衰减率和输沙廓线的特征高度强烈降低，而这一湿度区间可能代表了沉积物中的力正由颗粒表面水膜中的分子吸附力向颗粒间水桥产生的毛细作用力过渡。整体输沙率的结果显示，只要湿度能够达到M1.5，颗粒间的液体桥便基本形成，由湿度产生的粘滞力就足以抑制大风情况下大部分输沙的发生。\n4．根据海岸风沙活动规律及潮汐作用特点，借鉴包兰铁路沙坡头段风沙危害防治体系的经验，提出了以拦为主，拦固结合，以工程措施为先导，最终以生物措施替代工程措施的综合防治思路。在海岸潮间带设置防浪拦沙堤，拦截沙源，防止海浪对防护区固沙设施的冲击破坏；在流沙区设置蜂巢式固沙障稳定沙面；在防护区两侧布设阻沙栅栏，阻隔侧向来沙；在设施区辅以红粘土掺合、化学固沙剂和覆网措施，固定就地起沙并对过境风沙流加以输导。防护体系的建立有效抑制了风沙对国防设施的危害，促进了植被的恢复和土壤的改良，在学科上拓宽了风沙防治的研究领域，为海岸风沙危害防治提供了理论依据和技术储备。\n5. 开放式沙滩红树林的成功引种为海岸红树林生态系统恢复提供了可行的方案，并对促进沙质海岸生态系统的可持续发展具有重要现实意义。 |
| 英文摘要 | The study areas have mostly focused on aeolian sand transport on temperate wet coasts in Europe and North America. Studies of aeolian sand transport in other coastal areas around the world such as tropical wet coasts are relatively rare. The movement of blowing sand is quite intense in tropical wet coastal areas such as those of southern China, which cover an estimated 2.38×103 km2 around the world, and demonstrates the significance of these areas. However, observations and simulations of coastal aeolian sand transport for such areas are relatively rare. \nWind erosion has major impacts on dune growth, desertification, and architecture on sea coasts. surface moisture has often been cited as a particularly important regulator of aeolian sand transport, especially in beach–dune interactions in the coastal zone. Therefore, Lessened from the Shapotou railway sand-protecting system, this thesis discusses engineering prevention of sand drift disaster based on research about the characteristics of aeolian sand transport in tropical humid coastal southern China. Finally, a successful sand prevention system is establishment, the benefits of sand prevention relatively are discussed and the mangrove is introduced successfully in a open sand beach, Some of primary conclusions in this paper were given as follows: \n1．We developed a new formula to predict the threshold friction velocity of the wetted sand, which indicated that the threshold shear velocity increased linearly with increasing ln100M for a given particle diameter. When we evaluated several widely used predictive models, we found considerable variation in their predictive ability. The theoretical models proposed by Chepil (1956) and Selah and Fryrear (1995) predicted the observed datawell at moisture contents below 0.0062 (=0.5M1.5A), whereas the empirical model of Belly (1964) fits the data better for M＞0.0062. The M1.5A parameter that is used in many models could thus represent a transition point at which the water forms will change. The wind erosion modulus is related to the effective wind velocity by a power functionwith a positive exponent at all test moisture contents, whereas the erosion modulus decreased with increasing surface moisture content following a power function with a negative exponent. When both wind speed and sand moisture varied simultaneously, thewind erosion moduluswas proportional to the 0.73 power of the effective wind velocity, but inversely proportional to the 1.48 power of the moisture content. the cohesion force created by water films surrounding the sand particles could provide sufficient resistance to protect a soil against erosion even under gale conditions at M≥0.83% (=M1.5B).\n2．The horizontal and vertical velocity distribution of saltating sand grains at different heights accords with a Gaussian distribution pattern in a moisture beach. Horizontal particle velocity is increases with height and wind velocity. The velocity of saltating sand grains in a moisture surface show a fluctuation or step-like variation with two transition point of 0.591% and 1.464% in all test wind. Accumulation of the quantitative change in moisture content would cause a basic change of sand water cohesion capacity and bed rigidity. This cumulative effect relates to water-holding capacity of sand . Moisture contents of 0.591% and 1.464%(close to M1.5=1.591%) might represent molecular adsorption capacity of film water (M＜0.591%) and capillarity from water bridge (M＞1.464%), for 0.591%＜M＜1.464%, the force between grains is occur a transition from molecular adsorption to capillarity. The change with height of the mean horizontal velocity of a saltating sand cloud can be expressed by a power function. As a whole, the mean vertical particle velocity is increases with moisture contents, vertical movement of particle show a transition from downwards to upwards and moisture contents of transition point consistent with those of horizontal particle velocity.\n3．If the back-turn in the flux profile very near the surface are neglected, the flux profiles of a moisture surface can be expressed as exponential-decay functions. In general, total transport rate is decreases with moisture contents, whereas a relatively larger proportion is transported at greater heights for the higher moisture content sand. Creep proportion and relative decay rate generally decreased with the increasing moisture contents and wind velocity, and more grains are transported at higher levels. Creep proportion varies widely, ranging from about 0.12 to 0.33, depending on moisture contents and wind speed. In present study, creep proportion, relative decay rate and characteristics of flux profile are decrease significantly within moisture range from 0.587% to 1.448%(close to 1.591%= M1.5)，which range might represent a transition from molecular adsorption to capillarity. The results of total transport rate indicate that the water bridge between particles are essence established, cohesion capacity could provide sufficient resistance to occur of most sand transport even under gale conditions as long as M≥M1.5.\n4．Based on the characteristics of aeolian sand transport and tide activities on the coast, and lesson from the railway sand controlling system in the Shapotou region, we put forward to sand prevention pattern which gives priority to sand-blocking measure, assisted by sand-fixing measure and piloted with engineering measures and biological measures substituted for it step by step, Sand-block dam is established on inter-tidal region to block sand and prevent the wave destroy the sand-fixing facilities. Honeycombing sand-fixing net is set on the mobile sand, two sand-block barriers are built at the two sides of it to isolate from sand resource. Clay mix, chemical measures and overlaying net were used to prevent the sand entrainment on local site and sand transport from other sites. The establishment of sand prevention systems are restrain disaster of the national defense implement caused by aeolian sand transport, and facilitate soil amelioration and plant restoration. It not only extends the research field for sand disaster controlling, but also provides the theory and technique for coastal sand disaster controlling. \n5. The successful introduction of mangrove is provide a feasible measure to restoration of the mangrove ecology system in a open sand beach, and has a significance to sustainable development of coastal ecology system. |
| 中文关键词 | 风沙运动 ; 湿度 ; 起动 ; 侵蚀 ; 颗粒速度 ; 输沙 ; 防沙工程 ; 效益 ; 热带湿润海岸 |
| 英文关键词 | aeolian sand transport moisture content entrainment erosion particle velocity sand transport sand pr |
| 语种 | 中文 |
| 国家 | 中国 |
| 来源学科分类 | 自然地理学 |
| 来源机构 | 中国科学院西北生态环境资源研究院 |
| 资源类型 | 学位论文 |
| 条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/286750 |
| 推荐引用方式 GB/T 7714 | 韩庆杰. 华南热带湿润海岸风沙运动规律和防沙工程研究[D]. 中国科学院寒区旱区环境与工程研究所,2009. |
| 条目包含的文件 | 条目无相关文件。 | |||||
| 个性服务 |
| 推荐该条目 |
| 保存到收藏夹 |
| 导出为Endnote文件 |
| 谷歌学术 |
| 谷歌学术中相似的文章 |
| [韩庆杰]的文章 |
| 百度学术 |
| 百度学术中相似的文章 |
| [韩庆杰]的文章 |
| 必应学术 |
| 必应学术中相似的文章 |
| [韩庆杰]的文章 |
| 相关权益政策 |
| 暂无数据 |
| 收藏/分享 |
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
