The Abandoned Yellow River Delta of northern Jiangsu faces serious erosion hazard due to global climate change, sea-level rise, human activities and shortage of sediments. In this present work, coastal erosion hazard and vulnerability level along the Abandoned Yellow River Delta have been assessed with the aid of RS and GIS. The coastal vulnerability index (CVI) is used to map the relative vulnerability in the study area. Shoreline change rate, depth contours change rate, coastal slope, subaqueous slope, sedimentary dynamic environment, suspended sediment concentration, mean high tidal height, utilization of coastal types and coastal development suitability are used as the evaluation indexes to assess the coastal erosion hazard and vulnerability level. Analytic hierarchy process (AHP) is used to calculate the weights of each evaluation index. The results show that the Abandoned Yellow River Delta presents a high coastal erosion vulnerability level. The vulnerability level indicates that over 50% of the study area presents a high and very high vulnerable level, and over 75% of coastal area presents above the moderate vulnerable level. The coastal erosion vulnerability map prepared from this study can provide reference for the coastal zone protection, disaster prevention and mitigation, proper planning and management of this coastal region.

在全球气候变化、海平面上升背景下,全球许多海岸已经成为承受巨大压力的生态系统。应用海岸敏感性指数(Coastal Sensitivity Index, CSI)对中国环渤海海岸进行敏感性分析,采用岩性、海岸坡度、地貌、岸线变化速率、相对海平面上升水平、平均波高以及平均潮差多种变量的不同组合计算环渤海海岸479个单元格的敏感性数值。结果表明,增加变量数目或以岩性代替岸线变化能有效提高敏感性指数的区分能力,但不同组合下环渤海海岸敏感性宏观空间格局无较大差异。总体上,胶辽隆起带与大兴安岭-太行隆起带的山地丘陵基岩海岸敏感性相对较低,而以辽东湾辽河口附近沿岸平原海岸和渤海湾-黄河三角洲-莱州湾南岸平原海岸为代表的渤海、华北沉降带表现的敏感性相对较高。研究结果有助于海岸管理与规划人员在全球变化背景下识别海岸敏感区域,从而有选择性地采取应对措施缓解海岸带压力,并且为开展河口海岸生态系统脆弱性研究奠定科学基础。从长远来看,海岸敏感性分析如果与社会因子相结合更能有效提升海岸带系统整体的脆弱性研究水平。

历史时期的黄河以善决善徙闻名于世。其尾闾入海路线大致可归结为三条。或北道由天津附近入渤海,历时二千四百余年;或中路趋山东利津入海,历时一千四百余年;或南线出云梯关入黄海,历七百余年。

The coast of Jiangsu is famous for its dynamic singularity of both serious eroded coast reach and rapid progradingone. The erosional coast of Jiangsu is 301.7km long or 31.6% of the province total shoreline. Of them muddy coast is 271.6km and sandy coast, 30.1km, which is the only segment of sandy coast in Jiangsu. This singularity is relevant to the following three features. The first one is the effect by great changes of the two big river mouths. The lower reaches of the Huanghe River began to enter the Yellow Sea by north of Jiangsu in 1128 after capturing the Huaihe River and was back to the Bohai Sea by Shandong Province in 1855. This evolution of the Huanghe River, which famous for carrying plenty of sediments, caused great hydrodynamic change, especially the sedimentation conditions of the Jiangsu coast. The second one is the long muddy coast.During the 700 years that the Huanghe River entered the Yellow Sea by Jiangsu, the coast was transformed from sandy coast to muddy, and 92% of the shoreline of Jiangsu is muddy coast now. The third one is the diversity of the openness of the several coast reaches. With the substantial change of the large-scale submarine sand ridge fields on the inner continental shelf, the screening state of the coast reaches changes accordingly. There are four segments of the erosional coast reaches in Jiangsu. The first one is the abandoned Huanghe River Delta coast. The delta shoreline and the subaquatic delta have been heavily eroded because of the losing of sediments supply. Meantime, the coast reach of the abandoned river mouth retreated rapidly and has not been controled until the 1970s when the seawall and the bank protection were built. But this promotes the vertical erosion on the intertidal flat.The average rate of vertical erosion from 1980 to 1992 is 13.5 cm/a. The isobath of 15 m is only 4.65 km away from the bank, and the isobath of 10 m moved 0.37 km every year toward the bank from 1937 to 1994. The second isLusi coast, the southern part of the coast of Jiangsu. The erosion of this segment is mainly because of large-scale tidal channel movement toward the bank and development of winding. The shoreline retreated more than 1 km from 1916 to 1969. The super tidal flat in front of the seawall was wholly eroded, and the rate of vertical erosion on the intertidal flat is 3.6 cm/a. The third segment is the Jianggang coast. Some tidal creeks on the tidal flat moving toward the bank caused heavy erosion, and some erosional mud cliffs are as high as 5 m. The cliffs can retreat 20-30 m within one spring tide cycle. The fourth is the sandy coast in the northern part of Jiangsu coast. Some dams were built on some rivers flowing into the sea and break off the sediment source supplying the coast. Meanwhile, digging of coastal sands helped the erosion.

空间分异是自然和社会经济过程的空间表现,也是自亚里士多德以来人类认识自然的重要途径。地理探测器是探测空间分异性,以及揭示其背后驱动因子的一种新的统计学方法,此方法无线性假设,具有优雅的形式和明确的物理含义。基本思想是：假设研究区分为若干子区域,如果子区域的方差之和小于区域总方差,则存在空间分异性;如果两变量的空间分布趋于一致,则两者存在统计关联性。地理探测器q统计量,可用以度量空间分异性、探测解释因子、分析变量之间交互关系,已经在自然和社会科学多领域应用。本文阐述地理探测器的原理,并对其特点及应用进行了归纳总结,以利于读者方便灵活地使用地理探测器来认识、挖掘和利用空间分异性。

Spatial stratified heterogeneity is the spatial expression of natural and socio-economic process, which is an important approach for human to recognize nature since Aristotle. Geodetector is a new statistical method to detect spatial stratified heterogeneity and reveal the driving factors behind it. This method with no linear hypothesis has elegant form and definite physical meaning. Here is the basic idea behind Geodetector: assuming that the study area is divided into several subareas. The study area is characterized by spatial stratified heterogeneity if the sum of the variance of subareas is less than the regional total variance; and if the spatial distribution of the two variables tends to be consistent, there is statistical correlation between them. Q-statistic in Geodetector has already been applied in many fields of natural and social sciences which can be used to measure spatial stratified heterogeneity, detect explanatory factors and analyze the interactive relationship between variables. In this paper, the authors will illustrate the principle of Geodetector and summarize the characteristics and applications in order to facilitate the using of Geodetector and help readers to recognize, mine and utilize spatial stratified heterogeneity.