摘要
通过对胶州湾1936～2002年4期海图的地形对比和1986年、2007年2期Landsat-5TM影像的对比，分析了近70多年来胶州湾的冲淤灾害地质形势。根据胶卅I湾近百年来的沉积速率特征将其冲淤灾害形势划分为9类，结果表明：胶州湾在1936～1963年间总体呈现轻微淤积态势，但显浪-红岛连线以东区域（含沧口水道）以轻微侵蚀为主。与前期相比，胶州湾在1963-1982年间的淤积强度明显减弱，基本由轻微淤积转为冲淤平衡状态。该时期内沧口水道转为以较强淤积为主，大沽河水道和岛耳河水道处于大面积轻微侵蚀状态。胶州湾在1986～2007年间多数岸段向海显著淤长，岸线的平均淤进速率为10^1～10^2m／a；海床总体上呈轻微侵蚀状态。此外，根据对均衡态下潮汐汉道P—A关系的分析，胶州湾近70年来口门的潮流振幅和相应的等效摩阻系数都呈减小趋势，这表明胶州湾口门的不稳定性逐渐增加。
Based upon the comparisons between underwater bathymetries digitized from nautical charts （1936--2002） and between coastlines derived from two landsat--5 TM images （1986--2007）, the hazardous geology associated with erosion and deposition was ana- lyzed for the past 70 years. During the last century, the sedimentary pattern was divided into nine types according to the depositional rates. The results show that the slight sedi- mentation happened as a whole in Jiaozhou bay from 1936 to 1963, while the slight erosion appeared in the eastern embayment （including Cangkou channel）. Unlike before, the dep- osition obviously decreased from 1963 to 1982 and then the sedimentary environment transferred into the equilibrium. Besides, the strong sedimentation was dominant in Cangkou channel during this period. However, the Daguhe and Daoerhe channels were slightly eroded. Subsequently, most of coasts extended obviously towards the sea between 1986 and 2007; the average coastline extending rate was 10^1-10^2 m yr^-1 and the slight erosion was observed on the seabed. Moreover, the analysis of tidal prism and cross-sectional area of tidal inlets shows that the current velocity amplitude and the corresponding equ-coefficient of friction had decreased over the past 70 years in Jiaozhou bay. This indicates that the entrance of Jiaozhou bay tended to be relatively instable.
出处
《地理研究》
CSCD
北大核心
2011年第7期1169-1177,共9页
Geographical Research
基金
国家"九2八"(908-02-03-08)
浙江省自然科学基金重点项目(ZS080241)
国家自然科学基金项目(40776049)
关键词
灾害地质
冲淤强度
潮流振幅
等效摩阻系数
胶州湾
hazardous geology
intensity of erosion and siltation
current velocity amplitude
equ-coefficient of friction
Jiaozhou bay
