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。     

中国近海初级生产力的遥感研究及其时空演化

利用分级初级生产力模式反演估算了2003~2005年0^o~41^oN,105^o~130^oE海域的初级生产力,并分析了它们的时空演化。同时还计算了该时段内渤海、北黄海和南黄海、东海北部和南部以及南海的平均初级生产力状况,结果得出它们的年平均初级生产力 (2003~2005年) 分别为564.39、363.08、536.47、413.88、195.77和100.09 gCm^-2a^-1。北黄海、南黄海及东海南部的初级生产力分别在春季 (4~6月) 和秋季 (10、11月) 出现两次峰值,且春季的峰值高于秋季。然而,南海的两个峰值则分别出现在冬季 (1月)和夏季 (8月),且冬季的峰值高于夏季。渤海和东海北部则呈现单峰 (6月) 分布。渤海和南黄海的初级生产力几乎在整年内都高于其它海域,而东海南部和南海的初级生产力则在整年内都低于其他海域。其中,南海的初级生产力最低,月平均全都低于400 mgCm^-2d^-1。除南海以外的其它5个海域,在春季时期 (东海南部为3~6月,其他海域为4~7月) 的初级生产力最高,平均约占年平均值的41%,其年际变化也最大,平均标准偏差为6.68;而秋季时期 (东海南部为10~1月,其他海域为8~11月) 对年平均的贡献也很大,平均约33%;其他月份 (东海南部为2月和7-9月,其他海域为12~3月) 的贡献则最小。南海的初级生产力则在冬季时期 (12~3月) 最高,约占年平均的42%,夏末秋季 (8~11月) 次之,约30%,春季时期 (4~7月) 最低。叶绿素-a、海表温度、光合有效辐射、季风活动、河流排放、上升流、黑潮以及沿岸流等物理-化学环境因子是造成中国近海初级生产力时空演化的主要原因。     

北冰洋叶绿素a及初级生产力遥感反演研究进展

海洋表层叶绿素a浓度和浮游植物初级生产力是海洋生态系统的基础参数,可有效评估海洋生态系统的初级生物量及其变化.阐明北冰洋浮游植物生物量和初级生产力的时空变化,对预测北极环境快速变化背景下的海洋生态系统潜在变化、科学指导北冰洋的生态管理具有重要意义.本文总结了基于卫星数据的海表叶绿素a浓度和初级生产力的研究方法,整理归纳...     

海洋初级生产力遥感与GIS评估模型研究

本文探讨了利用遥感和地理信息系统技术获取海洋初级生产力的基本原理和方法。根据表层海水叶绿素遥感信息反演模型。介绍了三种基于表层海水中叶绿素浓度的海洋初级生产力算法。根据这三种算法,利用ＧＩＳ建模技术,推导了具有空间特征的海洋初级生产力的ＧＩＳ理论估算模型,以及这种模型的求解方法。     

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…     

青海省草地资源净初级生产力遥感监测

在研究特定区域的草地光能利用率和环境影响因素典型特点的基础上,建立基于光能利用率的草地NPP遥感估算模型,模拟并分析2006年青海省草地FPAR、光能利用率、NPP的空间分布和季相变化特征。研究结果表明,2006年青海省草地净初级生产力平均值为173.28 gC/(m2.a)。青海省东南部、南部和青海湖周围三个地区,是青海省草地NPP较高的区域。不同草地类型的NPP存在差异,高覆盖度草地的单位面积平均NPP为193.82 gC/(m2.a),中覆盖度草地NPP为157.14 gC/(m2.a),低覆盖度草地NPP为121.08 gC/(m2.a)。     

黑河流域植被净初级生产力的遥感估算

利用光能利用率模型C-FIX,高时空分辨率的SPOT/VEGETATION遥感数据,全球格网化气象再分析资料以及黑河流域土地利用图,估算了1998—2002年黑河流域不同生态系统净初级生产力(NPP)的年总量和平均生产力,输出了黑河流域NPP年累积量空间分布格局图、NPP季节动态图,分析了近5a来黑河流域NPP时空变化特征,评价了不同土地利用类型下的生态系统生产力水平差异。其结果表明,黑河流域陆地生态系统NPP空间分布及其季相变化特征是流域自然环境、地貌、气候以及人类生产活动长期共同作用和影响的结果,其中水分条件是控制黑河流域陆地生态系统NPP空间格局的决定因子。1998—2002年黑河流域山区高覆盖度草地和下游荒漠区净初级生产力持续下降,反映出这些地区生态环境恶化严重。这些研究结果可以为黑河流域的水-生态-经济系统的合理设计与有效实施提供科学数据集。     

云南省自然植被净初级生产力的时空分布特征

基于气候生产力模型,利用1960～2000年127个气象站气温、降水资料以及植被信息,对云南省自然植被净初级生产力的时空分布特征进行了分析。结果表明:41a云南自然植被年均NPP为4.23×108tDM/a,约占全国自然植被年均NPP总量的11.4%;单位面积的平均NPP为10.64tDM/(hm2·a),是全国平均水平的2.8倍。云南自然植被NPP随着纬度、经度和海拔高度的增加均呈现下降趋势,变化总趋势为北部<中部<南部,东部<中部<西部。云南自然植被NPP在干季(11～4月)和雨季(5～10月)差异显著,6～8月最大;41a来云南大部分地区自然植被NPP呈现上升趋势,20世纪70、80年代比60年代有所下降,90年代有所上升。气温增加,降水增加或不变的情况下,滇西北和滇东北NPP增加幅度大于其他地区,说明这些地区气温是制约自然植被NPP的主要因素;气温增加,降水减少的情况下,几个少雨区和多雨区NPP降低幅度大于其他地区,表明在上述地区限制NPP的主要因素是水分。     

陆地植被净初级生产力研究进展

 植被的净初级生产力(NPP)反映了植物每年通过光合作用所固定的碳总量，目前NPP研究是全球变化研究的重要内容之一。本文综述了近年来国内外在全球和区域陆地植被NPP的研究现状，对遥感(RS)和地理信息系统(GIS)在NPP研究中的应用作了分析，并对国内外NPP研究的不足和发展趋势作了讨论。     

澜沧江下游流域植被净初级生产力(NPP)时空变化及其驱动因素分析

利用遥感、地形、气候等数据,采用CASA模型对研究区2000年、2010年和2018年3月、7月、11月的NPP值进行估算,结果表明:(1)相对于2000年,2010年的NPP值呈下降趋势,2010年到2018年又向较好趋势发展,且NPP值在3个时期的年内变化均为7月＞3月＞11月;(2)NPP低值区主要分布在下游流域...     

Estimation of ocean primary productivity and its spatio-temporal variation mechanism for East China Sea based on VGPM model

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 CaseⅠand CaseⅡwater 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/m2/d, which is far higher than the average of subtropical ocean areas. The annual average of primary productivity is 236.95 g/m2/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.     

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.     

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.     

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.     

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。