江苏中部海岸潮沟的形态特征与演变过程研究
发布时间：2018-11-05 11:55
【摘要】：潮沟作为一种典型的沉积地貌单元,在世界各地海岸潮间带广泛分布,对潮沟地貌和潮沟演变过程进行研究具有重要的理论和实践意义。本文根据1981-2013年江苏中部海岸的遥感影像和野外观测数据,对潮沟的平面形态与演变过程进行分析。结果显示,江苏中部海岸潮沟(根据其长度差异)一般分为4级,1至3级潮沟的个数分别为21、97和688(1：5：33),其平均长度分别为7587±1544、1921±916和327±200m;潮沟在中潮带比较发育,其密度Dd和分汊率Y明显大于高潮带和低潮带；主潮沟曲率r从高潮带向低潮带呈减小趋势。潮沟的摆动性具有明显的区域和级别差异,与北部的潮滩区域相比,海岸潮差较大的南部潮滩区潮沟的摆动性较大：同一个潮沟系统,其1级潮沟的摆动性2级潮沟3级潮沟；同一条潮沟,其下段的摆动性中段上段；同一区段,弯曲岸段的摆动性顺直岸段；1级潮沟上段、2级潮沟中上段、3级潮沟或位于盐沼内的潮沟其摆动性不明显。 外来引种互花米草和大规模滩涂围垦活动对潮沟产生了较大影响,尤其是后者明显地抑制了潮沟的发育。在大规模滩涂围垦影响下,研究区潮沟集水面积A由2001年的293.94km2逐渐降低到2013年的103.40km2；潮沟长度ΣL随着其集水面积A的缩减呈幂函数减小(R2=0.98),潮沟宽度ΣW随着潮沟长度ΣL和集水面积A的变小呈指数方式变窄(R2=0.87,R2=0.93),总体上,每围垦1km2滩涂,潮沟长度ΣL和宽度ΣW分别减小约2.60km和15.5m；研究区潮沟形态在统计上存在多尺度的分形结构,在围垦活动影响下,其分维值D由2001年的1.26快速降低到2013年的1.13,其中,各潮沟系统的分维值D随着其交汇点个数ΣN的减少而快速降低(R2=0.93),各单支潮沟的分维值D随着其蜿蜒性w的减小而快速降低(R2=0.92)；在整个滩涂围垦过程中,落潮后期潮滩的主要排水方式由潮沟排水逐渐向滩面排水方式转变。 根据野外观测资料和潮沟形态相关性分析,研究区潮沟最初发育的时间可以追溯到潮滩的形成和发育时期,潮沟最初的形态是低潮带下部的冲刷洼地或切口,切口或洼地在水流作用下快速演变为沟槽；并随着潮滩变宽和集水面积增大而快速发育,形成树枝状的潮沟系统。根据随机概率模型模拟,潮沟的发育过程大致经历四个重要时期：低潮带发育时期、中潮带发育时期、高潮带发育时期和细潮沟填充发育时期。
[Abstract]:Tidal trench, as a typical sedimentary geomorphological unit, is widely distributed in the intertidal zone of the world's coasts. It is of great theoretical and practical significance to study the tidal trench landform and the evolution of tidal trench. Based on the remote sensing images and field observation data of the central coast of Jiangsu Province from 1981 to 2013, the plane morphology and evolution process of tidal trenches are analyzed in this paper. The results show that the tidal trenches along the central coast of Jiangsu Province are generally divided into 4 grades according to their length differences. The number of tidal trenches of grade 1 to 3 is 21 97 and 688 (1:5:33) respectively, the average length is 7587 卤154 4U 1921 卤916 and 327 卤200 m, respectively. The density Dd and branching rate Y of the trench are higher than those of the high tide zone and the low tide zone. The curvature of the main tide trench r decreases from the high tide zone to the low tide zone. Compared with the tidal flat area in the north, the swinging characteristic of the tidal trench in the southern coastal tidal beach area is greater than that in the northern tidal flat area: the swinging tidal trench of the first grade trench is of grade 2 tidal trench of the same tidal trench system, and that of the tidal trench of grade 1 is higher than that of the tidal flat area in the north. The swinging upper segment of the lower segment of the same tidal trench, the swinging straight shore segment of the curved bank section, the upper segment of the 1st grade trench, the middle segment of the 2nd grade trench, the 3rd grade trench or the tidal ditch located in the salt marsh have not obvious swinging characteristics. The introduction of exotic Spartina alterniflora and the large scale tidal flat reclamation have a great influence on the tidal trench, especially the latter obviously inhibits the development of the tidal trench. Under the influence of large scale tidal flat reclamation, the area A of tidal gullies in the study area gradually decreased from 2001 293.94km2 to 103.40 km ~ 2 in 2013. The length of tidal trench 危 L decreases by power function with the reduction of its catchment area A (R _ 2N _ (0.98), and the width of tide ditch 危 _ W narrows exponentially with the length of tide trench 危 _ L and the decrease of catchment area A (R _ (2) 0.87 ~ (?) R _ (2) ~ (0. 93). In general, every reclamation of 1km2 beach is carried out. The length 危 L and width 危 W of the trench decreased by about 2.60km and 15.5mrespectively. Under the influence of reclamation activities, the fractal dimension D decreased rapidly from 1.26 in 2001 to 1.13 in 2013. The fractal dimension D of each tidal channel system decreases rapidly with the decrease of the number of the intersection point 危 N (R2N 0.93), and the fractal dimension value of each single tidal channel decreases rapidly with the decrease of its meandering w (R2N 0.92). During the process of tidal flat reclamation, the main drainage mode of tidal flat changed from trench drainage to beach surface drainage. Based on field observation data and correlation analysis of tidal channel morphology, the initial development time of tidal trench in the study area can be traced back to the formation and development period of tidal flat. The initial form of tidal trench is scour depression or notch in the lower part of low tide zone. Notches or depressions rapidly evolved into grooves under the action of water flow; As the tidal flat widens and the catchment area increases rapidly, a dendritic tidal trench system is formed. According to the stochastic probability model, the development process of tidal trench has four important periods: low tide zone development period, middle tide zone development period, high tide zone development period and fine tide trench filling development period.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P737.1
本文编号：2312007
[Abstract]:Tidal trench, as a typical sedimentary geomorphological unit, is widely distributed in the intertidal zone of the world's coasts. It is of great theoretical and practical significance to study the tidal trench landform and the evolution of tidal trench. Based on the remote sensing images and field observation data of the central coast of Jiangsu Province from 1981 to 2013, the plane morphology and evolution process of tidal trenches are analyzed in this paper. The results show that the tidal trenches along the central coast of Jiangsu Province are generally divided into 4 grades according to their length differences. The number of tidal trenches of grade 1 to 3 is 21 97 and 688 (1:5:33) respectively, the average length is 7587 卤154 4U 1921 卤916 and 327 卤200 m, respectively. The density Dd and branching rate Y of the trench are higher than those of the high tide zone and the low tide zone. The curvature of the main tide trench r decreases from the high tide zone to the low tide zone. Compared with the tidal flat area in the north, the swinging characteristic of the tidal trench in the southern coastal tidal beach area is greater than that in the northern tidal flat area: the swinging tidal trench of the first grade trench is of grade 2 tidal trench of the same tidal trench system, and that of the tidal trench of grade 1 is higher than that of the tidal flat area in the north. The swinging upper segment of the lower segment of the same tidal trench, the swinging straight shore segment of the curved bank section, the upper segment of the 1st grade trench, the middle segment of the 2nd grade trench, the 3rd grade trench or the tidal ditch located in the salt marsh have not obvious swinging characteristics. The introduction of exotic Spartina alterniflora and the large scale tidal flat reclamation have a great influence on the tidal trench, especially the latter obviously inhibits the development of the tidal trench. Under the influence of large scale tidal flat reclamation, the area A of tidal gullies in the study area gradually decreased from 2001 293.94km2 to 103.40 km ~ 2 in 2013. The length of tidal trench 危 L decreases by power function with the reduction of its catchment area A (R _ 2N _ (0.98), and the width of tide ditch 危 _ W narrows exponentially with the length of tide trench 危 _ L and the decrease of catchment area A (R _ (2) 0.87 ~ (?) R _ (2) ~ (0. 93). In general, every reclamation of 1km2 beach is carried out. The length 危 L and width 危 W of the trench decreased by about 2.60km and 15.5mrespectively. Under the influence of reclamation activities, the fractal dimension D decreased rapidly from 1.26 in 2001 to 1.13 in 2013. The fractal dimension D of each tidal channel system decreases rapidly with the decrease of the number of the intersection point 危 N (R2N 0.93), and the fractal dimension value of each single tidal channel decreases rapidly with the decrease of its meandering w (R2N 0.92). During the process of tidal flat reclamation, the main drainage mode of tidal flat changed from trench drainage to beach surface drainage. Based on field observation data and correlation analysis of tidal channel morphology, the initial development time of tidal trench in the study area can be traced back to the formation and development period of tidal flat. The initial form of tidal trench is scour depression or notch in the lower part of low tide zone. Notches or depressions rapidly evolved into grooves under the action of water flow; As the tidal flat widens and the catchment area increases rapidly, a dendritic tidal trench system is formed. According to the stochastic probability model, the development process of tidal trench has four important periods: low tide zone development period, middle tide zone development period, high tide zone development period and fine tide trench filling development period.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P737.1
【参考文献】
相关期刊论文 前10条
1 谢东风;高抒;;淤泥质潮流深槽最大冲刷深度的一个概念模型[J];海洋学研究;2006年03期
2 陈君,冯卫兵,张忍顺;苏北岸外条子泥沙洲潮沟系统的稳定性研究[J];地理科学;2004年01期
3 邵虚生;潮沟成因类型及其影响因素的探讨[J];地理学报;1988年01期
4 张忍顺,王雪瑜;江苏省淤泥质海岸潮沟系统[J];地理学报;1991年02期
5 黄海军,樊辉;黄河三角洲潮滩潮沟近期变化遥感监测[J];地理学报;2004年05期
6 张忍顺;渤海湾淤泥质海岸潮汐汊道的发育过程[J];地理学报;1995年06期
7 沈永明,张忍顺,王艳红;互花米草盐沼潮沟地貌特征[J];地理研究;2003年04期
8 王颖;朱大奎;;中国的潮滩[J];第四纪研究;1990年04期
9 刘建华;杨世伦;史本伟;罗向欣;付信坤;;长江口崇明东滩潮沟地貌形态和演变[J];海洋学研究;2012年02期
10 陈勇;何中发;黎兵;赵宝成;;崇明东滩潮沟发育特征及其影响因素定量分析[J];吉林大学学报(地球科学版);2013年01期
，本文编号：2312007
本文链接：https://www.wllwen.com/kejilunwen/haiyang/2312007.html
