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91.
92.
Nianzhi Jiao Yantao Liang Yongyu Zhang Jihua Liu Yao Zhang Rui Zhang Meixun Zhao Minhan Dai Weidong Zhai Kunshan Gao Jinming Song Dongliang Yuan Chao Li Guanghui Lin Xiaoping Huang Hongqiang Yan Limin Hu Zenghu Zhang Long Wang Chunjie Cao Yawei Luo Tingwei Luo Nannan Wang Hongyue Dang Dongxiao Wang Si Zhang 《中国科学:地球科学(英文版)》2018,61(11):1535-1563
The China Seas include the South China Sea, East China Sea, Yellow Sea, and Bohai Sea. Located off the Northwestern Pacific margin, covering 4700000 km~2 from tropical to northern temperate zones, and including a variety of continental margins/basins and depths, the China Seas provide typical cases for carbon budget studies. The South China Sea being a deep basin and part of the Western Pacific Warm Pool is characterized by oceanic features; the East China Sea with a wide continental shelf, enormous terrestrial discharges and open margins to the West Pacific, is featured by strong cross-shelf materials transport; the Yellow Sea is featured by the confluence of cold and warm waters; and the Bohai Sea is a shallow semiclosed gulf with strong impacts of human activities. Three large rivers, the Yangtze River, Yellow River, and Pearl River, flow into the East China Sea, the Bohai Sea, and the South China Sea, respectively. The Kuroshio Current at the outer margin of the Chinese continental shelf is one of the two major western boundary currents of the world oceans and its strength and position directly affect the regional climate of China. These characteristics make the China Seas a typical case of marginal seas to study carbon storage and fluxes. This paper systematically analyzes the literature data on the carbon pools and fluxes of the Bohai Sea,Yellow Sea, East China Sea, and South China Sea, including different interfaces(land-sea, sea-air, sediment-water, and marginal sea-open ocean) and different ecosystems(mangroves, wetland, seagrass beds, macroalgae mariculture, coral reefs, euphotic zones, and water column). Among the four seas, the Bohai Sea and South China Sea are acting as CO_2 sources, releasing about0.22 and 13.86–33.60 Tg C yr~(-1) into the atmosphere, respectively, whereas the Yellow Sea and East China Sea are acting as carbon sinks, absorbing about 1.15 and 6.92–23.30 Tg C yr~(-1) of atmospheric CO_2, respectively. Overall, if only the CO_2 exchange at the sea-air interface is considered, the Chinese marginal seas appear to be a source of atmospheric CO_2, with a net release of 6.01–9.33 Tg C yr~(-1), mainly from the inputs of rivers and adjacent oceans. The riverine dissolved inorganic carbon (DIC) input into the Bohai Sea and Yellow Sea, East China Sea, and South China Sea are 5.04, 14.60, and 40.14 Tg C yr~(-1),respectively. The DIC input from adjacent oceans is as high as 144.81 Tg C yr~(-1), significantly exceeding the carbon released from the seas to the atmosphere. In terms of output, the depositional fluxes of organic carbon in the Bohai Sea, Yellow Sea, East China Sea, and South China Sea are 2.00, 3.60, 7.40, and 5.92 Tg C yr~(-1), respectively. The fluxes of organic carbon from the East China Sea and South China Sea to the adjacent oceans are 15.25–36.70 and 43.93 Tg C yr~(-1), respectively. The annual carbon storage of mangroves, wetlands, and seagrass in Chinese coastal waters is 0.36–1.75 Tg C yr~(-1), with a dissolved organic carbon(DOC) output from seagrass beds of up to 0.59 Tg C yr~(-1). Removable organic carbon flux by Chinese macroalgae mariculture account for 0.68 Tg C yr~(-1) and the associated POC depositional and DOC releasing fluxes are 0.14 and 0.82 Tg C yr~(-1), respectively. Thus, in total, the annual output of organic carbon, which is mainly DOC, in the China Seas is 81.72–104.56 Tg C yr~(-1). The DOC efflux from the East China Sea to the adjacent oceans is 15.00–35.00 Tg C yr~(-1). The DOC efflux from the South China Sea is 31.39 Tg C yr~(-1). Although the marginal China Seas seem to be a source of atmospheric CO_2 based on the CO_2 flux at the sea-air interface, the combined effects of the riverine input in the area, oceanic input, depositional export,and microbial carbon pump(DOC conversion and output) indicate that the China Seas represent an important carbon storage area. 相似文献
93.
岷江上游毛榛、辽东栎灌丛及3种人工幼林土壤种子库的比较 总被引:7,自引:0,他引:7
本文采用野外调查与萌发实验相结合的方法对岷江上游地区自然恢复的灌丛以及 3种人工林的土壤种子库状况进行了比较研究。结果显示 ,各样地土壤种子库的储量为 192 5 0~ 3 13 60粒 /(m2 × 10cm)之间 ,人工林的土壤种子库储量和物种数量都大于自然恢复的灌丛 ,其顺序为连香树Cercidiphyllum japonicum、油松Pinustabulaeformis混交林 >连香树林 >油松林 >毛榛Corylusmandshurica、辽东栎Quercusliaotungensis灌丛 ,各样地土壤种子库密度的垂直分布均为上层 >中层 >下层。在各样地土壤种子库的生活型组成中 ,乔木种类所占比例极少 ,而草本种类的数量较多。在灌丛的土壤种子库中 ,灌木的物种数量及其在种子库中所占的比例均大于人工林。大序醉鱼草Buddlejamacrostachya、喜阴悬钩子Rubusmesogaeus、华西绣线菊Spiraealaeta在种子库中的大量存在明显提高了灌木在各样地土壤种子库中所占的比例 相似文献
94.
塔里木盆地奥陶系古潜山碳酸盐岩岩溶储层具有埋藏深、非均质性强的特点。岩溶储集空间主要为后期溶蚀孔、溶洞和溶缝为主。通过古地貌恢复及岩溶垂向分带研究,结合油藏开采动态,对轮古7井区以东地区奥陶系碳酸盐岩岩溶储层评价与预测。研究认为:高产高效井主要位于岩溶缓坡地的峰丘洼地、丘峰洼地及岩溶峰丛谷地的溶丘、溶峰及其边坡部位。垂向上表层岩溶带和垂向渗滤带的上部,开发效果较好,多发育裂缝-孔洞型、洞穴型储层;径流溶蚀带、潜流溶蚀带岩溶发育相对较弱,局部发育小规模溶洞或岩溶管道,岩溶储层以裂缝型或孔洞型为主。在此基础上预测出五个高产高效油气储层岩溶区,为油气勘探与开发提供依据。 相似文献
95.
Wenchuan Earthquake: Way of thinking is changed 总被引:9,自引:0,他引:9
Yong Chen Li Li Juan Li Gang Li 《《幕》》2008,31(4):374-377
On 12 May, 2008, at 14:28:04 local time, an Ms 8.0 earthquake struck the Wenchuan County, Sichuan Province, in southwest China (Figure 1). This quake left about 70,000 people dead, 18,000 missing and over 370,000 injured. In the 75 days after the main shock, 20,000 aftershocks were recorded, which included 241 with Ms≥4.0, 205 with 4.0≤M≤4.9, 30 with 5.0≤Ms≤5.9, and 6 with Ms≥6.0. The largest aftershock took place 13 days after the main shock, in Qingchuan County, 110 km northeast of the epicenter of the quake (Chen, 2008). The losses from the quaketriggered geological disasters accounted for over a third of the total quake losses, which is extremely rare in the history of earthquake disasters. Secondary disasters, such as landslides, rockslides, landfalls, debris flows, etc., were widely distributed. Large numbers of buildings collapsed, including ones with steel reinforcing in the area of the epicenter. Infrastructure was badly damaged. In many areas, communications, and power and water supplies were cut off. The earthquake left over 35 large quake-dammed lakes, which threatened further disasters in the catchment areas. 相似文献
96.
97.
Distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments from Zhanjiang Bay and Leizhou Bay, South China 总被引:4,自引:0,他引:4
The concentrations and spatial distribution of polycyclic aromatic hydrocarbons have been investigated in two adjacent bays of Zhanjiang and Leizhou, China. The total concentrations of the 16 USEPA priority PAHs were ranged from 41.96 to 933.90ng/g dry weight with an average concentration of 315.98ng/g and ranged from 21.72 to 319.61ng/g with an average concentration of 103.91ng/g in Zhanjiang and Leizhou Bays, respectively. The spatial distribution of PAHs was site-specific and appeared to be somewhat positively correlated with TOC and negatively correlated with sediment grain size in the two bays. The values of Phe/Ant, BaA/228 and InP/276 were higher than 10, less than 0.2, and from 0.2 to 0.5, respectively, indicating that the sources of PAHs in the two bays were mainly from petroleum and its combustion, which predominantly originated from those ships and boats coming and going in the two bays. 相似文献
98.
99.
梅冥相 《沉积与特提斯地质》1993,13(6):34-43
在前人研究及自己野外观察的基础上,本文把碳酸盐岩米级旋回层序归为四大类:深水非对称米级旋回层序、L-M米级旋回层序、潮下碳酸盐米级旋回层序、潮坪碳酸盐米级旋回层序。米级旋回层序的形成机制是与米兰柯维奇旋回有关的高频率海平面振荡变化旋回所形成的间断-加积旋回沉积作用,它们的识别标志主要是岩石类型、界面特征、产出环境等。碳酸盐岩米级旋回层序的规则的垂直叠加形式是识别三级旋回层序的基础。 相似文献
100.
GPCP与中国台站观测降水的气候特征比较 总被引:4,自引:0,他引:4
文中利用GPCP降水资料和中国大陆740个台站雨量计降水观测结果,分析研究了1980-2000年中国大陆范围内两者的异同.平均降水率分布结果表明:在中国台站雨量计分布密集地区(100°E以东)两者的多年年平均、季平均和月平均降水率分布具有很好的一致性,即均能表现自春季至冬季中国大陆降水分布自东南向西北伸展,然后向东南后退的气候变化特点.对长江中下游、华北、东北、西南的降水距平随时间的变化分析表明,两者的月距平随时间变化也具有很好的相似性,相关系数均超过0.8.差异分析还表明,由于中国降水季节性变化和台站雨量计密度不均匀,造成春秋冬三季节GPCP和台站雨量计之间的差异较小,而夏季差异较大.总体上GPCP有过高估计降水率的趋势.在GPCP逐月降水资料既能很好地反映出100°E以东中国大陆降水的气候分布,又能很好地表示出上述地区降水量异常变化的基础上,我们利用GPCP降水资料对青藏高原和中国大陆西北地区西部降水分布及变化进行了分析.结果表明20世纪80年代前期青藏高原西部降水偏多,而90年代后降水量减少;中国西北地区降水总体偏少,但没有明显的变化趋势. 相似文献