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181.
182.
海湾开发利用强度评估可反映海湾利用程度,是海湾开发潜力及其可持续开发研究的基础,对发展湾区经济意义重大.以1990—2015年每隔5 a共6期TM/ETM/OLI影像为数据源,提取宁波市杭州湾、象山港和宁波市三门湾各时期的岸线及土地利用数据,基于此从海湾岸线开发和土地利用两方面综合分析海湾开发利用强度及其变化特征.结果表明:1990—2015年间,宁波3湾岸线人工化程度不断加深,岸线人工化指数最高的海湾由象山港(0. 16)转变为宁波市三门湾(0. 61),部分淤泥岸段(尤其是宁波市杭州湾岸段)滩涂围垦强度弱于泥沙淤积强度,削弱了岸线人工化程度.整个研究期间,宁波市三门湾和宁波市杭州湾的岸线开发利用结构始终为单一主体结构,象山港则呈现出由单一主体依次向二元、多元结构演变的趋势. 1990—2015年间,宁波3湾的岸线和土地利用强度均有所增加,其中象山港岸线开发利用强度指数最大,达0. 42;宁波市杭州湾区域土地利用变动最为强烈,土地利用程度指数最大,达292. 300.区位和资源禀赋、社会经济水平及政策因素是造成宁波3湾区域开发利用程度差异的重要因素. 相似文献
183.
湖泊面积的变化能反映区域环境和气候的变化,对研究区域的气候和可持续发展意义重大。在RS、GIS技术的支撑下,以MSS、TM、ETM+、OLI遥感影像,彩红外航片,Quick Bird、World View-2数据为主要数据源,结合基础地理信息数据、专题资料和其他相关研究文献资料,利用膨胀型和腐蚀型算子的边缘检测算法提取抚仙湖1974、1977、1987、1993、1996、2000、2001、2002、2004、2005、2006、2009、2012、2014、2015年共15个时段的湖体边界,计算其面积,并分析抚仙湖岸线和面积的时空变化特征;最后,结合流域的气象、土地利用数据,采用灰色关联分析方法对岸线和面积变化的驱动力进行分析,得出其主要驱动因子并构建其多元线性回归模型。研究结果表明:(1)时间尺度上,1974年以来,抚仙湖岸线和面积的变化趋势都是增大-减小-再增大,2009年以后都在减小,且幅度较大,变化强度明显增强。(2)空间尺度上,40年来,抚仙湖在各个方向上都有萎缩和扩张,变化趋势复杂,总体重心往南偏移。(3)灰色关联分析显示人为和自然因素与岸线和面积变化的关联度都在0.6以上,表明抚仙湖湖面变化是耕地、建筑用地、植被覆盖以及气象因子共同作用的结果,而年平均气温与岸线和面积的关联度分别达到0.935和0.993,表明年平均气温是引起湖面变化的主要因子。 相似文献
184.
利用1975、1985、1995、2005和2015年5期Landsat影像对烟台芝罘湾海岸线40年的时空变化进行了分析,在此基础上,对围填海活动进行开发强度评价和潜力预测,结果表明,(1)40年间,芝罘湾岸线以向海方向运动为主,岸线长度增加13.09 km,湾顶部岸线变化强烈,海湾面积以大约0.19 km2/a的速度持续缩小;(2)岸线类型已由最初自然岸线为主转变为以人工岸线占绝对优势,其中,港口、码头类型岸线长度增速为0.52km/a,是引起岸线向海变化的主要岸线类型;(3)沿岸开发活动长期以围填海为主导,利用强度持续增强。至2015年,芝罘湾围填海可利用面积约为2.57 km2,照目前的开发速度,预计大约15~16 a后到达围填海潜力极限,节约、集约用海尤为重要。 相似文献
185.
Karim Nassar Wael Elham Mahmod Hassan Fath Ali Masria Kazuo Nadaoka Abdelazim Negm 《Marine Georesources & Geotechnology》2019,37(1):81-95
This study focuses on the shoreline change detection along the North Sinai coast in Egypt using geographic information system and digital shoreline analysis system (DSAS) during the elapsed period from 1989 to 2016. The measurement of shoreline variation is mainly described for three zones: zone I, El-Tinah plain bay; zone II, El-Bardawil Lake; zone III, El-Arish valley. The rates of shoreline changes in the form of erosion and accretion patterns are automatically quantified by four statistical parameters functioned in DSAS namely endpoint rate, net shoreline movement, linear regression rate (LRR), and least median of squares. LRR results elucidate that the western seaside of El-Tinah plain bay has experienced an extremely dynamic feature with an average erosion rate of ?8.17?m/year. The littoral drifts have been driven by eastward alongshore currents toward the east side of the bay to be accreted with an average rate of +4.28?m/year. Moreover, the shoreline has progressed west of El-Bardawil inlet (1), El-Bardawil inlet (2), and El-Arish harbor. Subsequently, the corresponding average beach growth rates are found to be +2.7, +8.5, and +6.5?m/year, respectively. In contrast, the shoreline on the down-drift side to the east has negatively retreated, and the corresponding beaches have regressed at rates of ?4.5, ?8.65, and ?2.9?m/year, respectively. 相似文献
186.
近年来随着三门湾内围垦工程规模的不断扩大,三门湾的岸线及水深地形发生了显著变化,有必要重新评估三门湾内的潮汐振幅特征。本研究基于ADCIRC二维潮汐模型,开展了三门湾围垦工程实施前后潮汐振幅变化规律的研究。结果表明:三门湾内以半日潮为主,湾口和湾顶处振幅相差较大。单纯考虑围垦工程引起的岸线变化时,半日潮振幅受到的影响较为明显,振幅以减小为主,M2分潮减小幅度为0. 08~0. 10 m。采用经验公式预测了围垦工程造成的最终回淤量,围垦工程附近平均淤积为1. 5~2. 5 m,深水区附近淤积更加严重。当考虑了回淤导致的地形变化后,围垦工程区附近的潮汐振幅会有显著的减小,半日分潮减小幅度要远大于全日分潮,在围垦区域前沿,M2分潮振幅减小幅度较为明显,然后向外侧逐步减小。与单纯岸线变化相比,水深地形改变导致的潮汐振幅变化幅度要远大于前者。 相似文献
187.
Nusret Demir Bülent Bayram Dursun Zafer Şeker Selen Oy Abdülkadir İnce Salih Bozkurt 《Marine Geodesy》2019,42(2):166-185
Noise and an abnormal distributed-image histogram is the main challenge of using SAR data. From this point of view, this study’s authors motivated the non-use of user-defined input parameters. To achieve this purpose, a fuzzy approach was proposed to extract shoreline from SENTINEL-1A data. The parameters in the processing of the SENTINEL-1A image were generated automatically with LIDAR-intensity-derived object-based segmentation results. The LIDAR-intensity image was segmented with the Mean-shift method. The corresponding result was used to estimate the input parameters for fuzzy clustering of the SENTINEL-1A image. Fuzzy segmentation was proposed, due to the expected large number of values regarding water and land classes except for the pixels along the shoreline. The memberships for land and water classes were separately computed. In the proposed approach, the results from LIDAR and SENTINEL-1A dataset are promising, with differences below 1 pixel (10?m) by evaluation with the used reference vector data. 相似文献
188.
Maurizio D'Anna Déborah Idier Bruno Castelle Gonéri Le Cozannet Jeremy Rohmer Arthur Robinet 《地球表面变化过程与地形》2020,45(8):1895-1907
Shoreline change is driven by various complex processes interacting at a large range of temporal and spatial scales, making shoreline reconstructions and predictions challenging and uncertain. Despite recent progress in addressing uncertainties related to the physics of sea-level rise, very little effort is made towards understanding and reducing the uncertainties related to wave-driven shoreline response. To fill this gap, the uncertainties associated with the long-term modelling of shoreline change are analysed at a high-energy cross-shore transport dominated site. Using the state-of-the-art LX-Shore shoreline change model, we produce a probabilistic shoreline reconstruction, based on 3000 simulations over the past 20 years at Truc Vert beach, southwest France, whereby sea-level rise rate, depth of closure and three model free parameters are considered uncertain variables. We further address the relative impact of each source of uncertainty on the model results performing a Global Sensitivity Analysis. This analysis shows that the shoreline changes are mainly sensitive to the three parameters of the wave-driven model, but also that the sensitivity to each of these parameters is strongly modulated seasonally and interannually, in relation with wave energy variability, and depends on the time scale of interest. These results have strong implications on the model skill sensitivity to the calibration period as well as for the predictive skill of the model in a context of future climate change affecting wave climate and extremes. © 2020 John Wiley & Sons, Ltd. 相似文献
189.
Shoreline Change Modeling on Emergency Beach Nourishment Project on West Beach of Beidaihe, China 总被引:3,自引:0,他引:3
By use of a shoreline-change numerical model (GENESIS) based on one-line theory, a preliminary modeling study on shoreline changes caused by a beach nourishment project in Beidaihe, China, is presented in this paper. Firstly, the GENESIS model is verified and model sensitivity to the major parameter changes is discussed by simulating a hydraulic model test. The beach nourishment project, after that the shoreline change is kept being monitored, is a small-scale emergency one carried out to use two bathing places on the west beach in the summer, 2008. In this paper the shoreline changes caused by the beach nourishment project are modeled by the GENESIS model, and the computed results fit well with the measured shorelines. With the same model and parameters, a long-term performance of the project is predicted, and the result shows that the bathing places only can be suitable for bathing in 2 to 3 years without subsequence nourishment project. Therefore, it is proposed to nourish the beaches in time to keep the service life of the beach in recent years and carry out the beach nourishment project for the whole west beach as soon as possible. 相似文献
190.
Impact of Brunswick River Mouth Training Walls on Adjacent Beaches, Brunswick Heads, New South Wales, Australia 总被引:1,自引:0,他引:1
1 .IntroductionTheBrunswickbeach barrierbegantodeveloparound 6 50 0yearsagoattheendofthepostglacialmarinetransgression .Onshoreandalongshoretransportofmarinesandsoccurredfollowingthestabi lizationofsealevelresultinginbeachandduneextensionwhichoccurredonmanyNSWbeachesuntilabout30 0 0to 1 0 0 0yearsBP (Roy ,1 980 ) ,followedbyperiodsofstabilitytorecession .TherecessionalongthenorthernNSWandsouthernQLDcoastisattributedtocontinuingnorthwardlongshoresandtransportestimatedatbetween 2 0 0 0 0 0m… 相似文献