江苏中部海岸潮沟形态对滩涂围垦的响应

发布时间：2018-06-28 06:57

本文选题：潮沟 + 滩涂围垦　；参考：《海洋学报》2016年01期

【摘要】：根据2001-2013年江苏中部海岸的遥感影像和野外观测数据,对滩涂围垦影响下潮沟的形态演变过程进行分析。结果显示,研究区潮沟在大规模滩涂围垦影响下整体有明显的退化和消亡趋势,潮沟集水面积由2001年的293.94km2逐渐降低到2013年的103.40km2,潮沟长度随着其集水面积的缩减呈幂函数减小(R~2=0.98),而潮沟宽度随着潮沟长度和集水面积的变小呈指数方式变窄(R~2分别为0.87、0.93),总体上研究区每围垦1km2滩涂,潮沟长度和宽度分别减小约2.60km和0.67m,在整个滩涂围垦过程中,落潮后期潮滩的主要排水方式逐渐由潮沟排水向滩面排水方式转变。江苏中部海岸潮沟形态在统计上具有多尺度分形结构,总体上研究区分纬值从大到小依次为潮沟分维值、各潮沟系统分维值、单支潮沟分维值。研究区潮沟的分维值(无标度区间25~210内)在滩涂围垦影响下呈波动性降低,由2001年的1.26逐渐降低到2013年的1.13,各潮沟系统的分维值随着其分汊个数减少呈线性降低(R~2=0.89),各单支潮沟的分维值随着其蜿蜒性减小呈线性降低(R~2=0.86)。根据潮沟的退化和消亡过程反推潮沟的起源和发育过程,本研究认为研究区最早出现的一类潮沟可能是陆源水流侵蚀型潮沟,而滩面水流冲刷型和潮流辐聚侵蚀型潮沟是随着潮滩淤积变宽过程逐渐发育的,其最初的发育形态可能是潮滩下部的冲刷凹地。
[Abstract]:Based on the remote sensing images and field observation data of the central coast of Jiangsu Province from 2001 to 2013, the morphological evolution process of tidal trenches under the influence of tidal flat reclamation was analyzed. The results show that the tidal trench in the study area has a distinct trend of degradation and extinction under the influence of large scale tidal flat reclamation. The catchment area of tidal trench gradually decreased from 2001 293.94km2 to 103.40 km ~ 2 in 2013. The length of tidal ditch decreased by power function with the reduction of catchment area (R ~ (2 +) ~ 0. 98), while the width of tide ditch narrowed exponentially with the length of tide ditch and the area of catchment (R ~ (2). For each reclamation of 1km2 beach in the study area, The length and width of tidal trench decreased by about 2.60km and 0.67m, respectively. During the whole process of tidal flat reclamation, the main drainage mode of tidal flat gradually changed from trench drainage to beach surface drainage. The morphology of tidal trenches in central Jiangsu Province has a multiscale fractal structure. In general, the fractal dimension of tidal trench, the fractal dimension of each tidal channel system and the fractal dimension of single tidal channel are studied in order of distinguishing latitude value from large to small. In the study area, the fractal dimension of tidal trench (within the scale free range of 25 ~ 210) is reduced under the influence of tidal flat reclamation. From 1.26 in 2001 to 1.13 in 2013, the fractal dimension of each tidal channel system decreases linearly with the decrease of its branch number (R ~ (2 +) ~ (2 +) ~ (0.89), and the fractal dimension value of each single tidal channel decreases linearly with the decrease of its sinkiness (R ~ (2 +) ~ (2) ~ (0.86). According to the origin and development of the tidal trench in the process of degeneracy and extinction, this study suggests that the earliest type of tidal trench in the study area may be the erosion trench of continental water flow. However, the tidal trenches are gradually developed along with the tidal flat siltation widening process, and the initial development form may be the erosion concave in the lower part of the tidal flat.
【作者单位】：南京师范大学地理科学学院江苏省地理信息资源开发与利用协同创新中心;
【基金】：气候变化重大基础研究项目 ( 2013CB956503 ) 国家自然科学基金( 40973053 , U1405234 ) 江苏高校优势学科建设工程项目( 164320 H116 )。
【分类号】：P748

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