基于知识与规则的红树林遥感信息提取     

张雪红 《南京气象学院学报》2011,(4):341-345

针对难以将红树林同陆地植被,尤其是同水体与陆地植被混合像元有效识别的现象,结合TM影像提取了能有效反映红树林湿地特征的绿度指数和湿度指数,同其他常用的NDVI、TM3/TM5、TM5/TM4等指数相比:绿度指数和湿度指数更能有效地提高红树林同陆地植被,尤其是同水体与植被混合像元的可分性.采用知识与规则方法提取红树林遥感信息,与其他学者常采用的分类特征及分类方法相比,识别精度有明显提高,Kappa系数提高0.10,错分率降低16.1个百分点.  相似文献   

Discrimination of coastal wetland environments in the Amazon region based on multi-polarized L-band airborne Synthetic Aperture Radar imagery     

Pedro Walfir M. Souza-Filho  Waldir R. Paradella  Suzan W.P. Rodrigues  Francisco R. Costa  José C. Mura  Fabrício D. Gonçalves 《Estuarine, Coastal and Shelf Science》2011

This study assessed the use of multi-polarized L-band images for the identification of coastal wetland environments in the Amazon coast region of northern Brazil. Data were acquired with a SAR R99B sensor from the Amazon Surveillance System (SIVAM) on board a Brazilian Air Force jet. Flights took place in the framework of the 2005 MAPSAR simulation campaign, a German-Brazilian feasibility study focusing on a L-band SAR satellite. Information retrieval was based on the recognition of the interaction between a radar signal and shallow-water morphology in intertidal areas, coastal dunes, mangroves, marshes and the coastal plateau. Regarding the performance of polarizations, VV was superior for recognizing intertidal area morphology under low spring tide conditions; HH for mapping coastal environments covered with forest and scrub vegetation such as mangrove and vegetated dunes, and HV was suitable for distinguishing transition zones between mangroves and coastal plateau. The statistical results for the classification maps expressed by kappa index and general accuracy were 83.3% and 0.734 for the multi-polarized color composition (R-HH, G-HV, B-VV), 80.7% and 0.694% for HH, 79.7% and 0.673% for VV, and 77.9% and 0.645% for HV amplitude image. The results indicate that use of multi-polarized L-band SAR is a valuable source of information aiming at the identification and discrimination of distinct geomorphic targets in tropical wetlands.  相似文献   

广东省红树林资源变化遥感监测   总被引：1，自引：0，他引：1  

吴培强  马毅  李晓敏  余国华 《海洋学研究》2011,29(4):16-24

利用1990年的Landsat-5TM、2000年的Landsat-7ETM+和2008年的CBERS-02BCCD 3期遥感影像对广东省近18a来的红树林湿地资源进行监测,并对其时空变化情况进行分析。结果表明:广东省红树林呈现不断增加的趋势,1990年、2000年和2008年的面积分别为7 733.2,8 722.0和9 593.3hm2;红树林由沿岸分散分布趋于集中分布;天然林减少,人工林增加。  相似文献   

海南八门湾红树林柱状沉积物中有机生物标志物的分布和降解   总被引：1，自引：0，他引：1  

孙蕴婕  吴莹  张经 《热带海洋学报》2011,30(2)

对海南岛红树林柱样中有机生物标志物等生物地球化学参数进行了初步研究.结果显示红树林中有机碳(OC)与总氮(TN)比值范围为5.35-7.47,碳稳定同位素(δ13C)值范围为-25‰--22.9‰.脂肪酸与正构烷烃浓度分布范围分别为7.8-21.8μg·g-1(干重)和3.2-25μg·g-1(干重).在表层沉积物中,红树林植物、细菌与浮游生物的脂肪酸生物标志物各占总脂肪酸的25.4%、12.9%和7.5%,结合较低的OC/TN比值和较高的δ13C值,表征了当地微生物和外源浮游植物的有机质贡献.各类脂肪酸在柱样中表现出不同的降解特征:多不饱和脂肪酸(PUFAs)优先被降解,而长链脂肪酸(LCFAs)则较为稳定,没有明显的降解.碳优势指数(CPI)和平均碳链长度(ACL)显示,埋藏深度越深,有机物的生物化学改造程度越大.  相似文献   

Transport of nutrients and organic matter in a mangrove swamp     

Y. Akamatsu  S. Ikeda  Y. Toda 《Estuarine, Coastal and Shelf Science》2009

Field observations of the tidal transport of nutrients and organic matter in a mangrove swamp on Ishigaki Island, Okinawa, Japan revealed that groundwater flow from the swamp plays a significant role in increasing concentration of dissolved inorganic phosphorous and organic matter in a major channel. In contrast, dissolved inorganic nitrogen is transported from the mangrove swamps via surface water flow in the small channels of the swamp.  相似文献   

Recent effects of tidal and hydro‐meteorological changes on coastal plains near the mouth of the Amazon River     

José Tasso Felix Guimarães  Marcelo Cancela Lisboa Cohen  Marlon Carlos França  Luiz Carlos Ruiz Pessenda  Eduardo de Jesus Souza  Afonso César Rodrigues Nogueira  Ronnie Alves 《地球表面变化过程与地形》2013,38(13):1535-1549

The goal of this work was to understand the main hydrodynamic processes acting on tidal flats of the coast of Amapá near the mouth of the Amazon River, and how they change over the short term (~ 20 years). The analysis of morphological and geobotanical units was carried out by applying processing and interpretation methods to optical and synthetic aperture radar (SAR) images, combined with data on water salinity, maximum flood height, sedimentary facies data, rainfall and river discharge. The temporal analysis of morphological and geobotanical units suggests the relative stabilization of savannah, ‘várzea’ and mangrove areas during the drier period and increasing tidal amplitude between 1987 to 1997. The wetter period and decreasing tidal amplitude between 1997 to 2008 led to an increase in the area of ‘várzea’ and lakes over savannah, and the expansion of mangroves mainly over the inundated field and tidal mud/mixed flats. Therefore, the decrease in rainfall index during the drier period is well‐correlated with the reduction of the Calçoene River discharge and jointly with increasing tidal amplitude favored the increase of migration rate of the mud bank and erosion profile along the littoral. It was followed by the increase of the Calçoene River discharge and jointly with decreasing tidal amplitude during the wetter period, favoring the development of mangroves on muddy substrates near the coastline. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

粤港澳大湾区红树林长时间序列遥感监测     

贾凯  陈水森  蒋卫国 《遥感学报》2022,26(6):1096-1111

随着遥感数据量的爆发式增长,对变化过程分析的精细化要求与本地算力不足之间的矛盾日益突出。GEE（Google Earth Engine）地理云平台的出现,解决了用户算力紧张的行业痛点。本文以粤港澳大湾区为研究区,在GEE的支持下,构建1987年—2020年年度湿地分类数据集,分析大湾区红树林的时间阶段性特征和空间扩张过程,结合连续长历时分析对变化时间点的准确识别,揭示了保护区设立与滩涂造林等工程在红树林保护与修复中的积极成效。主要结论有：（1）截止到2020年,大湾区共有红树林2174 ha,81%的红树林集中在深圳湾、淇澳岛和镇海湾;（2）大湾区的红树林经历了由平稳发展（1987年—2003年）到快速增长（2003年—2020年）的变化过程,其主要增量来源于镇海湾（40%）和淇澳岛（28%）;（3）淇澳岛和镇海湾的红树林仍处于快速增长期,但淇澳岛增速最快,从2002年至今面积翻了30倍,深圳湾则在早期的快速增长（1987年—2009年）后进入平稳期（2009年—2020年）;（4）由于保护区设立时间较早,深圳湾成为大湾区唯一一个形成稳定核心区的红树林分布区,镇海湾虽然拥有最大的红树林面积,但林道狭窄,景观破碎,生态系统反而更加脆弱;（5）设立自然保护区和滩涂造林都对红树林面积增长起到了积极作用。本研究为大湾区海岸带湿地生态系统保护与修复提供科学的证据支持,对沿海生态屏障建设具有一定的指导作用。  相似文献   

八门湾红树林土壤放线菌多样性及抗病原菌活性分析     

刘敏  车文学  边伟杰  甘禧霖  赵怀宝 《海洋与湖沼》2022,53(2):352-363

红树林土壤中蕴藏着丰富的放线菌资源,是新菌种的重要来源。为获得更多新的放线菌资源以用于开发新的生物活性化合物,了解放线菌的多样性是非常重要和必要的。研究采用扩增子高通量测序和传统培养法对八门湾红树林土壤放线菌进行了非培养和培养水平多样性研究,同时对其抗病原菌活性进行了分析。对于非培养水平多样性研究,与细菌通用引物相比,利用放线菌相关引物可以提高放线菌丰度的检测水平,其百分比含量提高2.47倍;可以检测到放线菌门更多的目、科和属;对于在目水平上的放线菌类群组成来说,Acidimicrobiales、Corynebacteriales、Gaiellales、Kineosporiales、Solirubrobacterales是优势类群,但是在用两对不同引物得到的结果中,其百分含量差异较大。放线菌相关引物更适合环境样品中放线菌多样性的分析。对于培养水平多样性研究,分离到256株放线菌,属于7个目、9个科、14个属, Shannon-Wiener多样性指数为1.32, Streptomyces(42.58%)和Micromonospora(42.19%)是优势属;与模式菌株的相似性小于98.5...  相似文献   

Particle size shapes the prokaryotic microbial communities in mangrove sediments: A case study of Sanya,China     

Wu Qu  Michael Vicent Shija  Jie Wu  Min Jin  Jianxin Wang  Runying Zeng  Zhuhua Chan 《海洋学报(英文版)》2022,41(8):120-128

The prokaryotic microbial communities in the sediments play crucial roles in the ecological functions of mangrove ecosystems. Therefore, the environmental factors that affect the structures of these prokaryotic microbial communities could indirectly participate in the regulation of mangrove functions, which is of great value for mangrove studies. The particle size (PS) of soils is recently demonstrated as a key environmental factor for shaping the microbial communities; however, this hypothesis has rarely been tested for mangrove environments. A case study of three tropical mangroves from Sanya, China was performed in this work to assess the influence of PS on the prokaryotic microbial community structures of bacteria, archaea, diazotrophs, and denitrifiers in the sediments. Results showed the variability in the spatial scale and the stability in the temporal scale for the prokaryotic communities, indicating that the tropical mangrove sediments could be a versatile but stable environment. Among the collected environmental factors, PS, salinity, and humidity had the greatest impacts, and PS mostly affected the structures of these prokaryotic communities based on its highest R2 values of canonical correspondence analysis, Mental test, and linear fitting (p≤0.05). Furthermore, PS was positively correlated with the diversity and abundance of diazotrophic communities and negatively correlated with the abundances of methanogenic communities including Methanobacteriaceae, Methanospirillaceae, Methanoregulaceae, and Methanosaetaceae. Former studies show the increasing trend of PS caused by the rise of sea level and the intensification of human activities. Therefore, our findings indicate that PS could be a potential intermediate that links climate change and human activities with the possible ecological function migration of mangroves; meanwhile, the increase of PS could in turn release the stress of these environmental changes by increasing the abundance and diversity of the diazotrophic community and decreasing the abundances of methanogens.  相似文献   

中国典型红树林沉积物中多溴联苯醚和替代型溴系阻燃剂污染特征     

李华薇  徐向荣 《热带海洋学报》2022,41(1):117-130

本文研究了中国四省区(福建、广东、广西和海南)共16处红树林湿地表层沉积物中多溴联苯醚(polybrominated diphenyl ethers, PBDEs)和5种替代型溴系阻燃剂(alternative brominated flame retardants, ABFRs)的污染特征, 包括十溴二苯乙烷(decabromodiphenyl ethane, DBDPE)、1, 2-双(2, 4, 6-三溴苯氧基)乙烷[1, 2-bis (2, 4, 6-tribromophenoxy) ethane, BTBPE]、六溴苯(hexabromobenzene, HBB)、五溴甲苯(pentabromotoluene, PBT)和五溴乙苯(pentabromoethylbenzene, PBEB)。结果表明, PBDEs、DBDPE和BTBPE在我国红树林湿地沉积物中广泛存在, 而HBB、PBT和PBEB仅在部分红树林湿地检出。PBDEs总含量的均值范围为1.39~293ng·g^-1(干重), 其污染程度具有明显的空间差异性(p=0.016), 并且与当地人口和经济水平显著正相关(p<0.01)。在红树林沉积物样品中, BDE 209是最主要的同系物, 占PBDEs总含量的72%~96%; DBDPE和BTBPE是最主要的ABFRs, 浓度的均值范围分别为0.489~29.4ng·g^-1(干重)和0.0127~1.11ng·g^-1(干重)。BDE 209与其替代品DBDPE的含量显著正相关(p<0.01), 反映出二者在红树林湿地沉积物中空间分布的相似性, 这说明BDE 209和DBDPE可能具有相似的污染源和/或环境行为。DBDPE与BDE 209的浓度比值范围为0.0839~0.925, 表明我国红树林湿地沉积物中DBDPE的污染水平还未超过BDE 209, 但ABFRs逐渐替代使用而带来的环境问题不容忽视。  相似文献