Coastline and landscape changes in bay areas caused by human activities: A comparative analysis of Xiangshan Bay,China and Tampa Bay,USA     

Jialin Li  Yongchao Liu  Ruiliang Pu  Qixiang Yuan  Xiaoli Shi  Qiandong Guo  Xiayun Song 《地理学报(英文版)》2018,28(8):1127-1151

Using multitemporal Landsat TM/OLI images at a 10-year interval, in this study, we (1) extracted information of spatial location, length, and sinuosity of coastline and landscape configuration, diversity and fragmentation in the bay areas of Xiangshan Bay (XB), China and Tampa Bay (TB), USA from 1985 to 2015; (2) constructed indices of artificial coastlines and human disturbance on bay area landscapes; and (3) explored and discussed the impacts of human activities on changes of coastlines and landscape types in the two bay areas. Our analysis results demonstrate the following five points. (1) During the past 30 years, the lengths of natural coastline in XB and TB shrank, while the lengths of their artificial coastline increased first and then maintained stable. Since there were different influences of human activities on coastlines and landscape types between the two bay areas, XB experienced dramatic changes in parts of coastline geomorphologies and continuous decrease of coastline sinuosity, while, in TB, there was a little change in coastline geomorphologies and its coastline sinuosity was almost unchanged. (2) The intensity of human activities in XB was continuously enhanced from 1985 to 1995, and then the degree of enhancement had slowed down after 1995. However, in the time period, the impacted extent of human activities gradually increased and finally covered almost entire coastlines in XB. In TB area, although the intensity of human activities was enhanced, the degree of enhancement slowed down from 1985 to 2015 and the impacted areas of human activates were concentrated in several coastal city areas. (3) The average area of landscape patches strongly disturbed by human activities in both XB and TB generally showed a trend of decreasing from 1985 to 2005. However, during the period of 2005 to 2015, the average patch area of landscapes disturbed by different degrees of human activities in XB changed differently, while in TB it almost did not change. (4) From 1985 to 2005, the indices of landscape diversity in various areas of human disturbance in XB gradually increased, while in TB, changes in indices of the landscape diversity varied. From 2005 to 2015, the changes in the intensity of human disturbance in both bay areas were from weak to strong, whereas the indices of landscape diversity in XB and TB increased first and then decreased. (5) The landscape fragmentation index in different human disturbance areas in both XB and TB gradually increased from 1985 to 2005, while from 2005 to 2015, in both bay areas, the landscape fragmentation index presented a decreasing trend.  相似文献   

海湾健康的概念和评估:数值模型在乐清湾健康评估中的作用     

周大成  孙志林  黄煜  黄赛花  李莉 《海洋学报(英文版)》2016,35(8):3-15

本文引入数值化海湾健康理论,提出三维数值化海湾健康评估方法以评估和预测海湾健康动态。选用五个指标组用以构建数值化海湾健康指标体系,包括地理指标组、水动力和泥沙动态指标组、生态指标组、水质指标组和社会经济指标组,用以评估自然过程和社会经济对海湾健康的影响。每一指标组中包括不同数量的二级指标。根据二级指标的不同重要性,运用层次分析法对其赋予不同的权重。指标的数据来源于三维数值模型和观测数据。三维数值模型能够为海湾健康评估提供更加全面、完整和详细的数据,并且可以提供预测数据。以乐清湾为例,数值化海湾健康评估方法成功应用于其健康评估过程。基于评估结果,乐清湾口门处表层水体的地理环境是健康的,水动力过程和泥沙动态过程属于亚健康状态,水质和生态环境处于不健康状态。总体而言,乐清湾的海湾健康评估结果为亚健康状态。  相似文献   

人类活动对港湾岸线及景观变迁影响的比较研究————以中国象山港与美国坦帕湾为例   总被引：3，自引：0，他引：3  

刘永超  李加林  袁麒翔  史小丽  浦瑞良  杨磊  卢雪珠 《地理学报》2016,71(1):86-103

利用多时期遥感数据,以10年为时间步长,提取1985-2015年4个时期中国象山港和美国坦帕湾的岸线空间位置,长度和曲折度以及港湾地区景观构型,多样性和破碎度等信息,构建海岸人工化和港湾景观人工干扰指标,探讨人类活动对港湾岸线,景观演变的影响.结果表明:① 近30年来,象山港和坦帕湾自然岸线长度不断缩减,人工岸线长度呈先增后稳定的态势.由于两地人类活动方式的差异,象山港局部岸段形态发生剧烈变化,岸线曲折度不断变小;而坦帕湾岸线形态变化较小,岸线曲折度几乎保持不变.② 1985-1995年,象山港海岸人工化不断加强,1995年以后有所减弱,但人类活动的影响范围逐渐变大,几乎遍及整个港湾海岸.1985-2015年,坦帕湾海岸人工化强度虽有加强,但增幅缓慢,海岸人类活动也主要集中于各沿海城市区域.③ 1985-2005年,象山港和坦帕湾各人工化强度等级样区景观平均斑块面积总体呈减少趋势,但2005-2015年,象山港各强度样区景观平均斑块面积变化趋势不一,坦帕湾各强度样区变幅则较为平稳.④ 1985-2005年,象山港各强度样区景观多样性指数逐渐增大,而坦帕湾变化不一;2005-2015年,两港湾人工化强度由弱至强,景观多样性指数先增后减.⑤ 1985-2005年,象山港和坦帕湾不同人工化强度样区,景观破碎度指数逐渐增大;2005-2015年,两港湾景观破碎度指数呈减小趋势.  相似文献   

Macrobenthos of Kakinada Bay in the Godavari delta, East coast of India: comparing decadal changes   总被引：3，自引：0，他引：3  

Dipti Raut  T. Ganesh  N.V.S.S. Murty  A.V. Raman   《Estuarine, Coastal and Shelf Science》2005,62(4):609-620

A one-year study (1995–1996) on the macrobenthos over a spread of (37) hydrographically differing GPS-fixed sites in Kakinada Bay (mean salinity 27.16±0.4) and adjacent mangrove channels (14.78±0.55) in the Godavari delta, one of India's largest estuarine systems, revealed a great preponderance of benthic life. There were 11 diverse taxa represented by 95 species collected through several (303) grab and dredge hauls. Based on Bray-Curtis similarity through hierarchical clustering implemented in PRIMER, it was possible to distinguish the benthos into four assemblages each of which represented sites in the Central and North bay (Paphia textrix – Typhlocarcinus sp. Assemblage), South-East bay (Protankyra similis – Paphia malabarica Assemblage), Mangrove Outlets (Cerithidea cingulata Assemblage) and Mangrove channels (Diopatra neapolitana Assemblage). Benthos densities (mean nos. dredge haul⁻¹) were highest (299 individuals) at sites close to mangrove outlets. Species diversity (Margalef, d; Shannon-Wiener, H′) was low in general (d 1.244 to 2.251 and H′ 0.038 to 1.502). Sediments were mostly clayey-silt in nature except in southeast bay where they are silt-sand. Organic matter (mean) was at or near 1.3%. The observations have revealed marked changes in benthic community structure relative to an earlier investigation held in 1958–1963 in this area. Over the years, species such as Turritella duplicata, Tonna dolium and Placuna placenta found in considerable numbers previously have dwindled. Anomia, Bursa and Atrina and echinoderms, Astropecten indica, Echinodiscus auritus and Temnopleurus toreumaticus and the brachiopod, Lingula sp. of common occurrence in early 60s are absent altogether attributable to long-term natural trends during the intervening years and/or events accompanying human impingement (e.g. industrial and urban growth, port expansion measures, aquaculture, mangrove denudation etc.). Despite such large-scale alterations in benthos community structure, there were no significant changes in “biodiversity” measured through Average Taxonomic Distinctness (AvTD) and Variation in Taxonomic Distinctness (VarTD). The investigation revealed that AvTD (Δ⁺) and VarTD (Λ⁺) for previous years and the present study remained well within the 95% confidence funnel implying taxonomic stability. It was found that species, which had replaced the earlier forms, were drawn from comparable (Linnean) hierarchy i.e. same phylum/class.  相似文献   

波浪对稳定海湾形成过程的实验   总被引：2，自引：0，他引：2  

常瑞芳 《中国海洋大学学报(自然科学版)》1994,(Z3)

通过一个稳定海湾形成过程的实验，研究了以波浪侵蚀为主的沙质海岸，在人工岬控制下海岸变形与波浪特性的关系。从而为海岸蚀退的预测提供了实验依据。  相似文献   

弧形海岸中间过渡带海滩剖面的地貌动态分析   总被引：1，自引：0，他引：1  

陈子燊  李春初 《海洋科学》1990,14(2):6-12

  相似文献   

大亚湾海水混合交换特征   总被引：5，自引：0，他引：5  

韩舞鹰  马克美 《海洋科学》1991,15(2):64-67

本文研究了大亚湾海水垂直与水平交换特征。结果表明:由于夏季表层水升温和粤东沿岸上升流高盐冷水入侵,大亚湾海水分层。大亚湾海水垂直循环属于单次混合型。高盐冷水入侵大亚湾的过程变异性很大,变化的时间尺度约15d,抬升速度为1.8×10~(-3)cm/s。  相似文献   

福建3个港湾和闽南—台湾浅滩海域光学参数的研究     

王宪  李文权 《台湾海峡》1993,12(2):124-129

本文根据现场浮游植物光合作用速率和叶缘素a 的测定值,以及海水光强度的衰减变化,计算了海水消光系数,推导了福建东山湾、罗源湾、厦门西港和闽南-台湾浅滩海域海水消光系数与透明度的经验关系式;讨论了悬浮颗粒对不同深度下浮游植物生长速率的影响。结果表明,福建近岸海域光学参数的差异主要在于悬浮物质的贡献;不同季节,生物活动对光学参数也有所影响。最大光合作用速率一般出现在光衰减为10%～30%,频率分布因子为70%～80%。  相似文献   

杭州湾的三维水流数值模拟   总被引：2，自引：1，他引：2  

马启南  陈永平等 《海洋工程》2001,19(4):58-66

建立了一个基于σ变换和内外模式分裂技术三维水流数学模型，采用有限节点法（平面）和变步长差分法（σ向）对方程进行了离散；通过风生流和环岛水流两个理论模式对所建模型进行了校验，并将该模型应用到杭州湾的三维水流数值模拟中，效果良好，所建模型垂向分辨率高，简单实用，可应用于河口，海岸，湖泊等大范围水域的水流数值计算。  相似文献   

海湾扇贝(Argopecten irradians)海上保苗技术的研究     

王远隆  杨晓岩  孙光  张德华 《海洋湖沼通报》1991,(4)

用网袋、塑料筒、网箱等不同器具对海湾扇贝进行海上保苗试验,保苗率分别可达到23.8％、28.3％和32.9％。网袋中贝苗的生长快于塑料筒快于网箱,在10～13.5℃条件下,平均日增长为20μm;13.5～17.5℃,平均日增长为30μm;17.5～19℃,平均日增长为140μm;19～22℃,平均日增长为80μm。作者认为,贝苗生长不仅与水温有关,而且与贝苗的不同生长阶段有关,在贝苗壳高为1.5～4.5mm这个阶段生长迅速。  相似文献