Spatial distribution characteristics of sea-ice-hazard risk in Bohai, China

Abstract

Sea-ice hazard causes serious harm to aquaculture, marine navigation, offshore oil production and other activities in the Bohai Sea, China. To study the spatial distribution characteristics of sea-ice-hazard risk in Bohai is therefore desirable. The thickness and area of sea ice in the Bohai Sea during the winters (December–March) of 1987–2011 were estimated using data from the NOAA (US National Oceanic and Atmospheric Administration) satellite. The sea-ice thickness was converted into a sea-ice-hazard index after defining this index, and the different sea-ice-hazard risk grades were classified. The occurrence probability of sea-ice hazard was also calculated using fuzzy risk theory, and the spatial distribution characteristics of sea-ice-hazard risk in the Bohai Sea were studied. The results show that the sea-ice-hazard risk for offshore aquaculture decreased as the offshore distance increased. All the oilfields in Liaodong Bay are influenced by sea-ice hazard, two of the fields in Bohai Bay are slightly affected and the remaining fields are not influenced. The risk for marine navigation is related to the location of the port and the distance from the port. The risk in the port area is the highest; it is reduced by more than 30% at distances 10 km away from the port.

黄渤海海冰分布特征及其影响因子

“…黄渤海位于 41°N 以南的亚欧大陆东侧， 作为北 半球最南端的季节性海冰区， 黄渤海每年冬半年 (11 月至翌年 3 月) 都会出现结冰现象 [1] 。海冰的存 在能够减轻冬季风暴对黄渤海海岸的破坏， 保护当 地生态环境 [2] ； 海冰作为淡水资源加以开发利用， 可 以部分解决沿岸地区淡水缺乏问题 [3][4][5] ； 同时海冰一 直是冬季影响中国渤海和黄海的最主要的海洋灾害 之一 [6] ， 对渤海与黄海北部的水产养殖、 海洋导航、 海上石油生产和其他海事活动造成了严重危害 [7] 。 为更加有效地利用海冰资源， 减小海冰灾害造成的 影响， 众多学者对黄渤海海冰时空分布特征、 冰情 影响因子和海冰灾害进行了卓有成效的研究。黄 渤海海冰分布特征和冰情影响因子方面， 如王萌等 [8] 利用卫星资料分析了 1996-2011 年冬季渤海海冰 的时空分布， 从多年平均状况来看， 渤海海冰主要 集中在辽东湾， 且年际变化较大， 单日海冰面积最 大年份的日最大冰面积均超过 3 万 km 2 ， 单日海冰面 积最小年份的日最大冰面积均不超过 1 万 km 2 ， 且海 冰面积与营口站气温积温及气温之间均呈负相关关 系； 王相玉等 [9] 利用冬季大连和丹东气温， 研究了黄渤 海冰情的时空分布和年代际变化特征， 指出受冬季 气温升高的影响， 20 世纪 80 年代中期至 21 世纪初黄 渤海冰情较轻； 郑冬梅等 [10] 根据年尺度渤海冰情等 级资料， 探讨了 ENSO 和 PSO 对海冰的影响， 指出春 季 ENSO 和 PSO 是渤海冰情年代际变化的影响因 素； 刘钦政等 [11]…”

Quantifying the spatial ripple effect of the Bohai Sea ice disaster in the winter of 2009/2010 in 31 provinces of China

“…Bohai Sea ice usually appears in late November, reaches its maximum extent in February of the following year, and gradually melts in March (Wang et al 2011). Marine fisheries, ocean transportation and ocean engineering are usually affected by sea ice (Gu et al 2013). For marine fisheries, floating ice may damage offshore aquaculture equipment, resulting in fish and shrimp die-offs due to lack of dissolved oxygen; and fishing activities are restricted by sea ice, which leads to direct economic losses to the fishery (Song et al 2010).…”

“…Sea ice is one of special hazard types threating offshore aquaculture, marine navigation and ocean engineering (Ogilvie and J onsd ottir 2000;Song et al 2010;Chen et al 2011;Liu et al 2012), and sea ice disasters mainly occur within 10 km of the coastline in northern China (Gu et al 2013). The loss statistics associated with sea ice disasters improved after the large-scale sea ice event that occurred in the winter of 2009/2010 (Sun et al 2011).…”

Risk assessment of sea ice disasters on fixed jacket platforms in Liaodong Bay

“…Guo et al (2008) proposed three sea ice parameters, i.e., thickness, strength, and period, as the influencing factors of sea ice disasters and established three sea ice disaster risk levels, i.e., as zero risk, low risk, and high risk. Gu et al (2013) converted sea ice thickness into a sea ice hazard index and determined sea ice hazard risk levels. However, due to the differences in the classification results of sea ice disasters on different offshore engineering structures and sea ice factors, the sea ice data required in the assessment of structural ice disaster are different.…”