洪湖湿地大气调节价值评价研究

以洪湖湿地为研究对象,基于现有研究资料对其大气调节服务价值进行了定量评价。结果表明:洪湖湿地大气调节服务总价值为254.52×106元/a,是过去研究结果的11.6倍,其中湿地植物净固定的温室气体价值(包含甲烷折算的排放价值)为58.50×106元/a,表现为较强的碳汇;湿地释放氧气价值为176.51×106元/a,增湿调温价值为19.51×106元/a。洪湖湿地植被净固定温室气体价值、释放氧气价值和增湿调温价值分别占大气调节服务总价值的22.98%、69.35%和7.7%。     

辽宁双台河口芦苇湿地固碳价值评价研究

基于野外监测数据和碳税法对辽宁双台河口芦苇湿地的固碳价值进行了定量评价。结果表明:辽宁双台河口芦苇湿地总面积为30 815 hm~2,大约占到了自然保护区总面积的20%,其年均净固定二氧化碳(CO_2)量为13 320 kg/hm~2,年甲烷(CH_4)排放的CO_2当量为3 330.3kg/hm~2。将芦苇湿地固定CO_2的正效应减去CH_4排放的负效应,得到辽宁双台河口芦苇湿地的年固碳量为9 989.7 kg CO_2/hm~2,具有较强的碳汇,其总固碳价值为2.37亿元,其中净吸收CO_2的价值为3.16亿元(正效应价值),净排放CH_4的价值为0.79亿元(负效应价值)。     

海平面上升对长江口三岛影响的预测研究

根据国际权威机构ＩＰＣＣ １９９０年对２１世纪全球海平面上升的最佳估计值和本区地壳沉降速率以及地面沉降趋势,确定下一世纪长江口相对海平面上升１．０ｍ左右。在此基础上,预测了相对海面上升对海岸工程,交通水利设施湿地损失,洪涝灾害及盐水入侵的影响。     

一种湿地河流叶绿素a遥感反演方法

叶绿素a作为一项重要的水质安全评价指标,其浓度的准确监测对水产行业发展、水生态系统平衡和人类饮水安全等有着重要意义。随着对地观测卫星传感器空间和光谱分辨率的提高,遥感技术在河流水质时空变化监测中发挥着越来越重要的作用。本文以新疆巴音布鲁克湿地河流水体为研究对象,同步采集了水体反射光谱和水样,并在实验室对叶绿素a、浊度等水质参数进行测定。首先,基于光谱波段对叶绿素a浓度的敏感性分析,构建了多种光谱指数模型;然后,提出以4.50 mg/m³作为水体叶绿素a浓度分级阈值,利用三波段半分析模型因子D3B与叶绿素a的线性关系建立水体叶绿素a浓度分级标准,进而对比评估了11种经验、半分析模型分别在全部样本数据集和两级叶绿素a浓度数据集中的精度表现;其次,根据各模型精度结果选用三波段半分析模型D3B和蓝绿波段比模型OC₂V4,组成叶绿素a分级反演算法OC₂-D3B,其精度（R²=0.96,RMSE=0.32 mg/m³,MAE=0.24 mg/m³,MRE=5.71%）相比以上2种单一算法提高了50%以上;最后,本文利用Sentinel-2影像,对湿地河流水体叶绿素a浓度的空间分布特征和季节时序模式进行了分析,得到该水域夏季叶绿素a含量最高,春秋季次之,冬季最低的结论。此外,本研究还发现气温相比其他环境因子对水体Chl-a浓度的控制作用更加明显。     

洪泛区湿地生态环境功能及管理对策

洪泛区湿地是一种重要的湿地类型,是水陆自然景观的重要组成部分,为流域中水陆相互作用的交错带,具有独特的生态环境功能。对洪泛区湿地的生态环境功能进行了科学表述,针对我国洪泛区湿地目前面临的主要生态环境问题提出了合理的管理对策。     

龙感湖小流域元素时空分布及湿地拦截功能探讨

众所周知,湖滨湿地是湖泊环境的屏障,它对流域入湖物质具有吸收与拦截作用。通过长江中游龙感湖湖滨湿地和湖泊沉积物中元素含量在时间序列上的对比研究,发现湖滨湿地对入湖主要重金属元素确有明显拦截作用;但对于化学性质活跃,易以溶液态迁移的元素如Fe、Mn等不具备明显的拦截功能。人类活动对湿地的破坏,减弱了湿地对流域入湖物质的拦截功能,加速了湖泊生态环境的恶化。     

The spatial-temporal dynamic characteristics of the marsh in the Sanjiang Plain

Using the methods of combining landscape ecology with GIS spatial analysis, this paper analyses the dynamics of the marsh landscape structure of the Sanjiang Plain in the past 20 years, furthermore, taking Fujin County, located in the north of the plain, as an example, analyzes the conversion between marsh and other land use types. It is shown that the marsh in the Sanjiang Plain decreased greatly in the past 20 years, but the trend has begun to reverse. The marsh area decreased by 51.33% from 1980 to 1996, whereas it decreased by 4.19% from 1996 to 2000. The fragmentation of the marsh increased; the number of the patches increased by 326 from 1986 to 1996, whereas it only increased by 18 patches from 1996 to 2000. It is obvious that the speed of patches number diminished and the marsh fragmentation decreased, which shows that the reclamation of the marsh converted from the fragmentation to the brim in a large area of the marsh. The reclaimed marsh has mainly converted to paddy field and dry land. Large-scale reclamation in the Sanjiang Plain influences its natural environment directly: the climate of the region turns from cold and wet to warm and dry, which makes the marsh both in the low-temperature northern part and in the deeply stagnant eastern part suitable for further agricultural development.     

Channels,wetlands and islands in the Okavango Delta,Botswana, and their relation to hydrological and sedimentological processes

The Okavango wetland in northern Botswana is one of the world's largest inland deltas. The delta is a dynamic environment with shifting channel routes, causing growth and decay of ?anking wetlands, and giving birth to islands. Primary island nuclei are formed by ?uvial processes and bioengineering, and subsequently grow into secondary larger islands of irregular shape by clastic and chemical sedimentation, and later by coalescence. This article presents classi?cations and quantitative estimations of channels, wetlands and islands of the Okavango Delta. Islands were classi?ed dependent on composition, pattern of composition, shape and juxtaposition. 90 per cent of all islands in the entire wetland were identi?ed, with a classi?cation accuracy of 60 to 85 per cent. Smaller islands of the nucleus types dominate the upper parts of the delta, whereas larger secondary islands are more common in the distal part, a re?ection of the age of the islands. Islands in the entry valley of the delta, the Panhandle, are larger in the top end – the primary region of recent clastic sedimentation. The overall size distribution of islands in the delta, however, shows no clumps, indicating that island growth is a uniform process over time and space. The total area ?ooded at least every decade is approximately 14 000 km², of which 9000 km² is classi?ed as actual wetland. Channel meandering decreases from the Panhandle to the distal part of the delta, with the abandoned Thaoge channel as an exception. Occurrence of ?uvially formed islands in the distal delta indicates that the water ?ow and area of inundation must once have been much larger. Copyright © 2004 John Wiley & Sons, Ltd.     

兼容多源数据的森林湿地信息提取和比较分析

针对以光谱特征差异为依据,提取森林湿地信息精度低的问题,该文采用兼容多源数据的分类回归树(CART)提取方法,并以大沾河国家森林湿地进行实证研究。基于Landsat8遥感数据、Radarsat-2极化雷达数据和地形辅助数据,采用SPM软件分别构建3种特征变量组合的CART决策树模型,并获取分类规则,最后根据规则对研究区的森林湿地信息进行提取。结果表明:3种特征变量组合中,兼容光谱、纹理、雷达与地形辅助数据的CART决策树的森林湿地信息提取精度最高,用户精度和制图精度分别达到了88.46%和82.14%。研究结果体现了雷达数据与地形辅助数据有助于提取森林湿地信息。     

辽宁盘锦湿地监测数据分析

利用2013、2008、2003年的高分辨率航空影像、地理国情普查数据以及其他专业资料,对盘锦湿地10年来的地表覆盖实施了监测,分析了湿地周边水田面积、人类活动区域和南部海水养殖区的变化情况以及保护区内部地表覆盖现状和10年来的变化。结果显示,随着盘锦市经济的发展,对保护区的人为干扰逐年增强,湿地保护力度亟需加强。