东海初级生产力遥感反演及其时空演化机制

According to calculation results of ocean chlorophyll concentration based on SeaWiFS data by SeaBAM model and synchronous ship-measured data, this research set up an improved model for Case I and Case Ⅱ water bodies respectively. The monthly chlorophyll distribution in the East China Sea in 1998 was obtained from this improved model on calculation results of SeaBAM. The euphotic depth distribution in 1998 in the East China Sea is calculated by using remote sensing data of K490 from SeaWiFS according to the relation between the euphotic depth and the oceanic diffuse attenuation coefficient. With data of ocean chlorophyll concentration, euphotic depth, ocean surface photosynthetic available radiation (PAR), daily photoperiod and optimal rate of daily carbon fixation within a water column, the monthly and annual primary productivity spatio-temporal distributions in the East China Sea in 1998 were obtained based on VGPM model. Based on analysis of those distributions, the conclusion can be drawn that there is a clear bimodality character of primary productivity in the monthly distribution in the East China Sea. In detail, the monthly distribution of primary productivity stays the lowest level in winter and rises rapidly to the peak in spring. It gets down a little in summer, and gets up a little in autumn. The daily average of primary productivity in the whole East China Sea is 560.03 mg/m^2/d, which is far higher than the average of subtropical ocean areas. The annual average of primary productivity is 236.95 g/m^2/a. The research on the seasonal variety mechanism of primary productivity shows that several factors that affect the spatio-temporal distribution may include the chlorophyll concentration distribution, temperature condition, the Yangtze River diluted water variety, the euphotic depth, ocean current variety, etc. But the main influencing factors may be different in each local sea area.     

东海初级生产力遥感反演及其时空演化机制

针对基于SeaWiFS的海洋叶绿素浓度SeaBAM模型反演结果,在中国东海海域分别建立了Ⅰ、Ⅱ类水体的修订模式,反演计算获得了我国东海海域1998年各月叶绿素浓度的分布,并根据真光层深度与海水漫射衰减系数之间的关系,利用SeaWiFS的K490遥感资料反演获得的1998年各月真光层深度的分布,在VGPM模型支持下,反演计算获得了中国东海海域1998年的逐月初级生产力时空分布以及全年累积初级生产力分布状况。对东海海域海洋初级生产力逐月时空变化特征及其影响机制的初步研究结果表明,整个东海海域初级生产力的逐月变化具有明显的双峰特征,表现为冬季最低,春季迅速上升达到最高,夏季略有下降,秋季又略有回升。海域初级生产力日平均值为560.03 mg/m²/d,远高于世界亚热带海域平均状况。年平均值为236.95 g/m²/a。控制东海海洋初级生产力时空变化的主要因素可能包括叶绿素浓度分布、温度条件、长江冲淡水变化,以及真光层深度、海流锋面过程等,不同海区初级生产力时空变化的主要控制因素有所不同。     

Estimation of net primary productivity in China using remote sensing data

1 IntroductionAs a major part of terrestrial ecosystem, vegetation plays an important role in the energy, matter and momentum exchange between land surface and atmosphere. Through the process of photosynthesis, land plants assimilate carbon in atmosphere and incorporate into dry matter while part of carbon is emitted into atmosphere again through plant respiration. The remainder of photosynthesis and respiration is called net primary productivity (NPP), which is important in the global carbon…     

Feasibility study on the binary-parameter retrieval model of ocean suspended sediment concentration based on MODIS data

This paper brought out a new idea on the retrieval of suspended sediment concentration, which uses both the water-leaving radiance from remote sensing data and the grain size of the suspended sediment. A principal component model and a neural network model based on those two parameters were constructed. The analyzing results indicate that testing errors of the models using the two parameters are 0.256 and 0.244, while the errors using only water-leaving radiance are 0.384 and 0.390. The stability of the models with grain size parameter is also better than the one without grain size. This research proved that it is necessary to introduce the grain size parameter into suspended sediment concentration retrieval models in order to improve the retrieval precision of these models.     

渤海海洋悬浮泥沙二元特征参数MODIS遥感反演模型研究

This paper brought out a new idea on the retrieval of suspended sediment concentration, which uses both the water-leaving radiance from remote sensing data and the grain size of the suspended sediment. A principal component model and a neural network model based on those two parameters were constructed. The analyzing results indicate that testing errors of the models using the two parameters are 0.256 and 0.244, while the errors using only water-leaving radiance are 0,384 and 0.390. The stability of the models with grain size parameter is also better than the one without grain size. This research proved that it is necessary to introduce the grain size parameter into suspended sediment concentration retrieval models in order to improve the retrieval precision of these models.     

中国近海初级生产力的遥感研究及其时空演化

1 Introduction Ocean primary productivity controls the exchange of carbon dioxide at the air-sea interface and plays an important role in the global carbon cycle and climate change. Most oceanographic research on primary productivity has focused on the ma…     

Satellite-derived primary productivity and its spatial and temporal variability in the China seas

The spatial and temporal variability of primary productivity in the China seas from 2003 to 2005 was estimated using a size-fractionated primary productivity model. Primary productivity estimated from satellite-derived data showed spatial and temporal variability. Annual averaged primary productivity levels were 564.39, 363.08, 536.47, 413.88, 195.77, and 100.09 gCm-2a-1 in the Bohai Sea, northern Yellow Sea (YS), southern YS, northern East China Sea (ECS), southern ECS, and South China Sea (SCS), respectively. Peaks of primary productivity appeared in spring (April–June) and fall (October and November) in the northern YS, southern YS, and southern ECS, while a single peak (June) appeared in the Bohai Sea and northern ECS. The SCS had two peaks in primary productivity, but these peaks occurred in winter (January) and summer (August), with the winter peak far higher than the summer peak. Monthly averaged primary productivity values from 2003 to 2005 in the Bohai Sea and southern YS were higher than those in the other four seas during most months, while those in the southern ECS and SCS were the lowest. Primary productivity in spring (March–June in the southern ECS and April–July in the other five areas) contributed approximately 41% on average to the annual primary productivity in all the study seas except the SCS. The largest interannual variability also occurred in spring (average standard deviation = 6.68), according to the satellite-derived estimates. The contribution during fall (October–January in the southern ECS and August–November in the other five areas) was approximately 33% on average; the primary productivity during this period also showed interannual variability. However, in the SCS, the winter (December–March) contribution was the highest (about 42%), while the spring (April–July) contribution was the lowest (28%). The SCS did share a feature with the other five areas: the larger the contribution, the larger the interannual variability. Spatial and temporal variability of satellite-derived ocean primary productivity may be influenced by physicochemical environmental conditions, such as the chlorophyll-a concentration, sea surface temperature, photosynthetically available radiation, the seasonally reversed monsoon, river discharge, upwelling, and the Kuroshio and coastal currents.     

Phosphorus forms in sediments of the East China Sea and its environmental significance

By means of SEDEX, ASPILA and XRF, depth-dependent changes of different phosphorus forms in sediment cores from specific areas of the offshore Changjiang Estuary (Yangtze Estuary) in 1998 were analyzed. Results show that contents of total phosphorus (TP), organic-phosphorus (OP) and iron-phosphorus (Fe-P) decreased down-core, while those of absorbed-phosphorus (Ad-P) and calcium-phosphorus (Ca-P) increased. The distribution tendency of detritus-phosphorus (De-P) is not obvious. Results also show that TP, Fe-P and OP contents at Meso station of the Changjiang Estuary and Hangzhou Bay are higher than that of the other stations. This suggests that the pollutants carried by the Changjiang and the Qiantang rivers from inland have affected the natural environment in offshore area. TP, Fe-P and OP contents of each station become higher from bottom to top, indicating the amount of the terrestrial pollutants carried by the two rivers has been enhanced since the last 30-50 years. Ad-P, Ca-P, Fe-P and OP are all active phosphorus in sediments, and their re-cycling in sediment is closely related to each other.     

东海沉积物中磷的存在形态及其环境意义

By means of SEDEX, ASPILA and XRF, depth-dependent changes of different phosphorus forms in sediment cores from specific areas of the offshore Changjiang Estuary (Yangtze Estuary) in 1998 were analyzed. Results show that contents of total phosphorus (TP), organic-phosphorus (OP) and iron-phosphorus (Fe-P) decreased down-core, while those of absorbed-phosphorus (Ad-P) andcalcium-phosphorus (Ca-P) increased. The distribution tendency of detritus-phosphorus (De-P) is not obvious. Results also show that TP, Fe-P and OP contents at Meso station of the Changjiang Estuary and Hangzhou Bay are higher than that of the other stations. This suggests that the pollutants carried by the Changjiang and the Qiantang rivers from inland have affected the natural environment inoffshore area. TP, Fe-P and OP contents of each station become higher from bottom to top, indicating the amount of the terrestrial pollutants carried by the two rivers has been enhanced since the last 30-50 years. Ad-P, Ca-P, Fe-P and OP are all active phosphorus in sediments, and their re-cycling in sediment is closely related to each other.     

基于贴现率的东黄海鲐鱼动态生物经济模型分析

渔业资源是一种可再生资源,其资源的可持续利用不仅与其种群大小有关,而且还与作业规模、单位作业的经济成本和贴现率等有关。传统生物经济模型通常忽视了贴现率对渔业资源配置的影响。本文根据1999年-2009年中、日、韩三国在东黄海捕捞的鲐鱼渔获量以及生产成本数据,结合贴现率和渔获价格等数据,构建基于贴现率的东黄海鲐鱼动态生物经济模型。结果表明,贴现率为10％,30％时,短期利益占长期利益的10％～20％．渔获价格在（2327—4654）元／t时,可保证鲐鱼渔获量低于最大可持续产量,从而有效地控制捕捞强度,确保鲐鱼资源的可持续利用。     

东海区大陆海岸带高强度开发的时空特征及驱动机制

东海区大陆海岸带作为中国海洋经济发展的前沿阵地,具有重要的战略地位。探究海岸带高强度开发的时空变化特征及驱动因素有助于揭示海岸带开发强度演变过程与规律,推动海岸带资源环境与社会经济可持续和高质量发展。故文章以东海区大陆海岸带为研究对象,利用1990—2020年7期海岸线与土地利用数据,揭示东海区大陆海岸线、海岸带土地利用的开发利用强度特征,通过地理探测器方法探究海岸带高强度开发的驱动因素。结果表明：(1)东海区大陆海岸带岸线平均移动速率为32.34 m/a,北部区域海岸线平均移动速率（43.54 m/a）大于南部（20.23 m/a）。杭州湾南岸区域在多个时期内海岸线平均移动速率最快,厦门-漳州区域的海岸线平均移动速率较慢。在空间分布上,海岸线变迁较为剧烈的区域主要集中在河口、海湾以及城市等级较高的沿海区域。(2)耕地、林地、草地、水域、海域等面积不断减少,城镇建设及工矿用地面积不断增加。海岸带南部与北部的土地开发强度整体较高,中部区域土地开发强度较弱。(3)自然因素奠定了东海区大陆海岸带土地利用开发强度的宏观格局,社会经济要素起着重要推动作用。     

Ecosystem service valuation of bays in East China Sea and its response to sea reclamation activities

Journal of Geographical Sciences - Ecosystem service values (ESVs) of bays and their response to sea reclamation are of great practical importance for forming bay eco-compensation policy and...     

中日东海问题实质及海域划界问题研究

中日两国在东海问题上有诸多争端,主要包括东海油气田资源、钓鱼岛归属以及东海海域的大陆架与专属经济区划界之争。两国间就此争端已举行多轮双边磋商,均无实质性进展。本文从两国历史、国际海洋法、地缘政治、军事战略的角度分析中日产生争端的根源,揭示问题的实质,拟定出一套合情的解决方案,并对未来的东海局势发展与我国的应对策略进行研究。     

Flux and fate of Yangtze River sediment delivered to the East China Sea

Numerous cores and dating show the Yangtze River has accumulated about 1.16 × 10¹² t sediment in its delta plain and proximal subaqueous delta during Holocene. High-resolution seismic profiling and coring in the southern East China Sea during 2003 and 2004 cruises has revealed an elongated ( 800 km) distal subaqueous mud wedge extending from the Yangtze River mouth southward off the Zhejiang and Fujian coasts into the Taiwan Strait. Overlying what appears to be a transgressive sand layer, this distal clinoform thins offshore, from  40 m thickness between the 20 and 30 m water depth to < 1–2 m between 60 and 90 m water depth, corresponding to an across shelf distance of less than 100 km. Total volume of this distal mud wedge is about 4.5 × 10¹¹ m³, equivalent to  5.4 × 10¹¹ t of sediment. Most of the sediment in this mud wedge comes from the Yangtze River, with some input presumably coming from local smaller rivers. Thus, the total Yangtze-derived sediments accumulated in its deltaic system and East China Sea inner shelf have amounted to about 1.7 × 10¹² t. Preliminary analyses suggest this longshore and across-shelf transported clinoform mainly formed in the past 7000 yrs after postglacial sea level reached its mid-Holocene highstand, and after re-intensification of the Chinese longshore current system. Sedimentation accumulation apparently increased around 2000 yrs BP, reflecting the evolution of the Yangtze estuary and increased land erosion due to human activities, such as farming and deforestation. The southward-flowing China Coastal Current, the northward-flowing Taiwan Warm Current, and the Kuroshio Current appear to have played critical roles in transporting and trapping most of Yangtze-derived materials in the inner shelf, and hence preventing the sediment escape into the deep ocean.     

Dynamic change of net primary productivity and fractional vegetation cover in the yellow river Basin using multi-temporal AVHRR NDVI Data

An exponential relationship between net primary productivity (NPP) and integrated NDVI has been found in this paper. Based on the relationship and using multi-temporal 8 km resolution NOAA AVHRR-NDVI data, the spatial distribution and dynamic change of NPP and fractional vegetation cover in the Yellow River Basin from 1982 to 1999 are analyzed. Finally, the effect of rainfall on NDVI is examined. Results show that mean NPP and fractional vegetation cover have an inclining trend for the whole basin, and rainfall in flood season influences vegetation cover most.     

Dynamic change of net primary productivity and fractional vegetation cover in the Yellow River Basin using multi-temporal AVHRR NDVI Data

An exponential relationship between net primary productivity (NPP) and integrated NDVI has been found in this paper. Based on the relationship and using multi-temporal 8 km resolution NOAA AVHRR-NDVI data, the spatial distribution and dynamic change of NPP and fractional vegetation cover in the Yellow River Basin from 1982 to 1999 are analyzed. Finally, the effect of rainfall on NDVI is examined. Results show that mean NPP and fractional vegetation cover have an inclining trend for the whole basin, and rainfall in flood season influences vegetation cover most.     

中国东海区海洋倾废管理现状与对策

实现对海洋倾废科学有效管理是保护海洋环境及海洋资源的一项重要内容和主要任务.东海作为我国海洋生产力最大的海区,近年来,随着海洋事业和沿海区域经济的发展,向海上倾倒废弃物的数量和规模都在不断增加.在实际海洋倾倒过程中存在着倾倒区选划利用不合理、违法违规倾倒和执法监管不力等问题,直接影响着东海海洋生态环境平衡与可持续发展.因此,在对1999-2010年东海区海洋倾废活动现状进行全面客观梳理的基础上,就倾倒行为存在的主要问题进行实证分析,并结合东海区沿岸省市海洋发展的情况与对海洋倾倒的实际需求,为实现对海洋倾废合理有效的管理,保护海洋生态环境提出切实可行的对策.     

黄东海表层海水溶解氧时空变化规律研究

海水中的溶解氧(DO)是影响海洋渔业经济、反映海洋物理化学过程的重要因素。该文依据20世纪90年代末期我国在黄东海海域完成的162个表层海水DO监测数据,利用GIS技术对其进行平面插值拟合,生成该海域DO的四季分布等值线图,据此分析黄东海海域的DO分布和季节变化规律。结果表明：基于太阳辐射导致的海水温度时空差异,影响黄东海DO分布及其季节变化的主要因素是黄海暖流和大陆入海径流。     

海洋悬浮泥沙二元特征参数MODIS遥感反演模型研究

本文提出了一种采用海面离水辐射率和泥沙粒径二元特征参数来反演研究海区(渤海)海洋表层悬浮泥沙浓度的新的遥感反演算法,以此为基础分别建立了基于MODIS遥感数据和泥沙粒径二元特征参数的主成分和神经网络两种泥沙浓度反演模型,并对比分析了两类模型的反演精度以及泥沙粒径因子对模型的影响。分析结果表明,新建立的二元特征参数反演算法在采用主成分模型和神经网络模型时的检验误差分别为0.256和0.244,而忽略泥沙粒径因子贡献的主成分模型和神经网络模型的检验误差分别为0.384和0.390,因此可以认为,在泥沙浓度反演模型中加入粒径因子时,模型的预测精度和模型稳定性均比只考虑浓度对反射率贡献的模型有显著改善。