土地利用/覆被特征的碳汇生态价值时空演变研究——以江苏省滨海地区为例

土地覆被/覆被时空演变是陆地生态系统碳储量变化的重要影响因素。以土地利用/覆被变化为驱动,利用InVEST-Carbon模型估算江苏省2000-2015年的碳汇储量,分析了该地区碳汇储量的时空演变规律。研究表明,2000-2015年江苏省滨海地区林地、草地和耕地向城镇建设用地转换显著,显著区主要分布在研究区的北部和中部,草地减少明显,耕地和建设用地增加明显。2000-2015年江苏滨海地区碳汇量减少明显,中部和北部区域碳汇能力减弱显著。基于空间信息技术的碳汇时空演变研究,有效地完成了对陆地生态系统服务功能的评估,为区域生态环境保护、土地规划提供了重要的理论支撑。     

Landsat系列影像支持下的凤阳县石英砂矿区土地利用动态监测

利用1991—2015年间Landsat系列遥感影像,基于SVM方法获取凤阳县石英砂矿区土地利用信息,并通过GIS空间分析功能研究矿区土地利用类型的时空变化特征和规律。结果表明:(1)SVM方法对Landsat系列影像分类具有较高精度,且提取效率快,省时省力。(2)25年来,凤阳县石英砂矿区土地利用方式和空间格局发生了显著变化。工矿用地面积增加速度最快,主要由草地和林地转化而来;建筑用地面积持续增加,为侵占耕地、草地和水域所得;水域总面积变化量不大,呈现先减后增的趋势;草地面积急剧减少,净减量最大,主要转化为林地、耕地和工矿用地;耕地和林地面积先增后减,但林地净增加,而耕地被废弃、闲置或被建筑用地扩张占用,流失的耕地多分布在乡镇(村庄)、河流周边。(3)工矿用地和建筑用地面积变化呈正相关增加,对植被和水域的侵占逐年增加,矿区土地系统的质量朝着变差的方向发展。     

哈尔滨市土地利用变化及其对生态系统服务价值的影响

以哈尔滨市1996、2002和2008年的土地利用变化数据为基础,参照中国陆地生态系统单位服务价值系数,结合敏感度分析,探讨了哈尔滨市土地利用变化及其对生态系统服务价值的影响。结果表明,1996～2008年,哈尔滨市土地利用变化中,林地面积呈现出增加的趋势,而建设用地是增长最快的土地利用类型。这一期间,哈尔滨市总的生态系统服务价值从1996年的1123.63亿元,上升到2002年的1125.85亿元和2008年的1126.68亿元。生态系统服务价值的增加主要源于林地、建设用地、水域面积的扩大,其生态系统服务主要体现在水文调节、维持生物多样性和保持土壤上。因此,在制定土地利用规划时,应对林地、水域等生态服务价值系数较高的土地利用类型予以特别关注。     

青海省生态服务功能评价研究

采用定量指标法和模型法研究了青海省水源涵养、生物多样性、土壤保持、防风固沙生态服务功能。不同模型下的服务功能利用GIS进行空间叠加处理,得到青海省生态系统服务总值。对青海省净初级生产力(NPP)分析发现,水、光、热条件较好的区域植被覆盖较好,而定量指标法评价因子少、相关数据易获取,但是评价结果只是定性分析;模型法评价因子多、相关数据不易获取,但是评价结果为定量分析、极小区域评价与实际相符。基于两种模型的特点,本文采用"定量指标法"得出防风固沙功能评价数据与"模型法"得出的水源涵养、土壤保持功能评价数据进行叠加分析,即"综合法"。该方法较为客观地评价了青海省生态服务功能,也为下一步青海省生态保护红线的划定提供了有力的科学依据。     

基于多源遥感数据的物种多样性及陆表植被恢复力监测研究

生物多样性和生态系统恢复力是生态系统健康的关键因素和重要指标。物种多样性指一定区域内物种数量的总和,物种多样性监测是生物多样性监测与保护的核心部分。作为生态系统恢复力的重要组成部分,植被恢复力是陆表生态系统服务和生态系统功能的重要指标,直接决定了陆表植被变化、陆表生态系统稳定性等关键生态过程和生态参量。目前,受到观测手段的限制,物种多样性与陆表植被恢复力监测普遍空间范围小,时间范围不连续,其中热带地区植物物种多样性变化对植被影响效果争议较大。论文基于长时间序列高精度遥感数据,从动物物种多样性遥感监测、植物物种多样性变化对热带雨林影响的遥感评估、遥感植被恢复力监测三方面出发开展相关工作。主要工作和成果包括:     

2000—2020年烟台市生境质量时空演变分析

文章以烟台市为研究区,基于土地利用类型,威胁元和威胁程度等数据,通过转移矩阵,运用InVEST模型获得2000、2010、2020年生境质量指数。结果表明：耕地和草地为研究区主要用地类型,建设用地和湿地面积逐年增加,以草地、耕地、林地流向建设用地和湿地为主。2000—2020年生境质量整体水平不高,呈现先下降后上升的趋势,不同区域生境质量差异较大。研究结果确定了烟台市生境质量时空状况,为维护烟台市生物多样性具有一定的参考价值。     

基于地理国情普查的生态环境分析

现选取四川天府新区作为研究区,基于四川省第一次全国地理国情普查成果,结合坡度和高程信息以及景观格局指数、水源涵养指数,对天府新区生态资源空间分布和生态环境状况进行了分析评价.结果表明:天府新区资源地带性分布特征明显,植被在各高程带上呈正态分布;新区东部龙泉山地区植被覆盖度高,水源涵养功能强,生态系统稳健;北部城区植被覆盖度低,水源涵养功能差,生态环境相对脆弱.     

贵州省赤水河流域生态系统水源涵养服务价值及其变化

生态系统的水源涵养服务价值评估是生态系统服务功能的重要评估方法之一,掌握水源涵养服务价值变化,能更好地对生态环境进行管控,也有利于对土地的利用进行调整,以此提高生态环境的利用价值。本文利用2010年Landsat 7、2015年资源三号卫星遥感数据以及发育系数、径流系数、年降水量等数据对贵州省赤水河流域进行分析,通过遥感解译、空间建模等方法计算出了研究区2010年、2015年的水源涵养量,采用替代工程法计算出了水源涵养价值量,结果对比分析表明：2015年较2010年,水源涵养量及价值量分别增加了5.76亿m³、35.19亿元。该评估为该区域水资源保护和利用以及生态环境建设提供了更有力的数据支撑,对下一步生态规划调整具有参考价值。     

2009—2017年北京市土地利用变化时空特征

对北京市土地利用类型、城市扩张程度和植被覆盖度进行时空特征分析,为合理制定城市空间规划和土地利用管理提供科学依据。以北京市全域为研究对象,基于2009、2013和2017年Landsat遥感影像基础,利用非监督分类方法得到土地类型图,计算城市扩张指数和植被覆盖度指数,并进行环路地类动态变化分析。结果表明：1)2009—2017年北京市绿地/耕地面积减少746.22 km²,建筑用地面积增加601.36 km²,两者面积变化表现出此消彼长的趋势;2)绿地/耕地及建筑用地的空间消长特点存在明显的环路差异;3)高植被覆盖度区域面积剧烈减少;4)土地利用类型和植被覆盖度变化在2009—2013年和2009—2017年两阶段内差异明显。可见北京市城市扩张速度有所减缓,绿地/耕地面积相对减少率高,城市土地利用变化存在明显的时空差异。     

梵净山长时序植被覆盖变化趋势与对比分析

梵净山具有独特的亚热带孤岛山岳生态系统和丰富的生物多样性,研究其植被覆盖长时序的时空演变和变化趋势,对于保护区的生态管理具有重要意义。本文基于GEE云平台,利用Landsat SR数据集进行去云和融合处理,使用最大值复合法合成年度NDVI数据集。通过像元二分模型法反演植被覆盖度,采用一元线性回归趋势分析法和Sen+Mann-Kendall趋势分析法对梵净山自然保护区的FVC进行逐像元的时空演变和趋势分析,并对比两种趋势分析的差异。结果表明：(1)近30年来,梵净山自然保护区的植被覆盖度呈先下降后上升的“U”形增长趋势,增长率为3.46%,植被覆盖情况得以明显改善。(2)在空间分布上,梵净山自然保护区的植被覆盖度呈现出中间高、四周低的特点。植被改善面积(占94.80%)远大于植被退化面积(占5.20%)。(3)两种趋势分析方法得出的梵净山自然保护区植被覆盖度变化趋势基本相似,但Sen+Mann-Kendall趋势分析法对显著变化结果的敏感程度高出2.18%。     

基于遥感生态指数的神府矿区生态环境评价

采用遥感技术对矿区生态环境进行监测与评价,对矿区生态环境的保护和可持续发展具有重要意义。本文首先提出了一种遥感生态指数（RSEI）改进方案,除了采用原模型的绿度指标、湿度指标、热度指标及干度指标4个生态指标外,引入植被净初级生产力（NPP）指标,并对矿区生态环境进行各单生态指标评价分析,然后采用改进后的遥感生态指数,对神府矿区2000—2016年的生态环境变化进行综合评价。评价结果表明,2000—2016年,神府矿区的遥感生态指数呈整体升高趋势,RSEI增幅约为0.1/10 a,大部分区域植被生产力逐渐增强,生态环境得到恢复,生态环境质量逐渐提升。     

Time series evaluation of landscape dynamics using annual Landsat imagery and spatial statistical modeling: Evidence from the Phoenix metropolitan region

Urbanization is a natural and social process involving simultaneous changes to the Earth’s land systems, energy flow, demographics, and the economy. Understanding the spatiotemporal pattern of urbanization is increasingly important for policy formulation, decision making, and natural resource management. A combination of satellite remote sensing and patch-based models has been widely adopted to characterize landscape changes at various spatial and temporal scales. Nevertheless, the validity of this type of framework in identifying long-term changes, especially subtle or gradual land modifications is seriously challenged. In this paper, we integrate annual image time series, continuous spatial indices, and non-parametric trend analysis into a spatiotemporal study of landscape dynamics over the Phoenix metropolitan area from 1991 to 2010. We harness local indicators of spatial dependence and modified Mann-Kendall test to describe the monotonic trends in the quantity and spatial arrangement of two important land use land cover types: vegetation and built-up areas. Results suggest that declines in vegetation and increases in built-up areas are the two prevalent types of changes across the region. Vegetation increases mostly occur at the outskirts where new residential areas are developed from natural desert. A sizable proportion of vegetation declines and built-up increases are seen in the central and southeast part. Extensive land conversion from agricultural fields into urban land use is one important driver of vegetation declines. The xeriscaping practice also contributes to part of vegetation loss and an increasingly heterogeneous landscape. The quantitative framework proposed in this study provides a pathway to effective landscape mapping and change monitoring from a spatial statistical perspective.     

皖江城市带植被NPP时空变化及其气候响应

针对现有植被净初级生产力研究对城市圈、城市带尺度缺乏关注的问题,基于MODIS遥感数据、地面气象资料等,利用改进的CASA模型,结合回归分析、相关分析等方法探究了2000—2013年皖江城市带植被NPP的时空变化及其对气候因子的响应,为区域生态环境质量评价提供参考。结果表明:近14年来,皖江城市带植被NPP总体呈增加趋势;不同土地利用类型NPP差异显著,林地草地耕地建设用地未利用土地水体;年NPP均值呈现由南部向西北部减少的空间分布特征;植被NPP年际变化率较小,介于±10gC·m-2·a-1范围内;温度是影响研究区植被NPP时空变化的主要气候因子。     

Land use change analysis for agricultural management — A case study of Tehsil Talwandi Sabo,Punjab

Remote sensing applications have been operationalised in most of the natural resources management themes and at present the trend is on integrated surveys to arrive at sustainable developmental packages. In accordance with the IMSD project, the Tehsil Talwandi Sabo in district Bathinda has been selected for integrated survey and resource management analysis. In the present study multidate remote sensing data has been analysed to map existing land use and temporal changes. The study in Talwandi Sabo suggests that land use pattern in the tehsil is not similar to that of general land use pattern prevailing in the State. The area under settlements show many fold increase while there is no increase in forest land. Sandy areas comprising sand dunes (levelled and unlevelled) require suitable management for proper ecosystem balance.     

Monitoring of forest fires in Bhadra wildlife sanctuary

The Western Ghats constitute one of the three biodiversity hot spots in India, which is under constant threat from various quarters. Among the several anthropogenic causes, fire is one of the important anthropogenic factor, which plays a pivotal role in vegetation succession and ecosystem processes. It is very important to understand the ecological changes due to fire and other anthropogenic factors for conservation and management of biodiversity. Because of its synoptic, multi-spectral and multi-temporal nature remote sensing data can be a good source for forest fire monitoring. In the present study, an effort has been made to monitor the burnt areas using March 2000 and 2004 IRS LISS — III data. The study revealed that an area of 2.15 km² and 4.46 km² was affected by fire in 2000 and 2004 respectively. Repeated drought, followed by mass flowering and dying of bamboo accelerated the spread of fire from ground to canopy in areas with high bamboo density.     

安吉县生物多样性保护优先区域森林生态系统服务价值核算

森林生态系统为人类提供了生态系统服务,生物多样性是制约森林生态系统服务发挥的关键因素之一。本文以安吉县生物多样性保护优先区为试点区域,分析了现有国内外生态系统服务价值的内涵及核算体系,针对核算的关键难点和问题,以核算体系合理、模型可操作、数据可获取及参数设置科学为原则,构建适用于安吉县的森林生态系统服务价值核算理论技术方法,实现对安吉县生物多样性优先保护区域的生态系统服务价值的空间量化核算。结果显示,2018年安吉县生物多样性优先保护区域森林生态系统服务总价值为65.37亿元,每公顷森林生态系统服务价值在80 000元以上。     

利用地学信息图谱的江西省生态服务价值结构研究

提出了生态服务价值结构的概念,并引入地学信息图谱,以江西省为研究区,利用HJ卫星数据,获得了江西省各县的土地利用类型面积;以修正的生态服务价值估算方法,计算得到了各县6种不同土地利用类型的生态服务价值;利用Weaver组合指数,对江西省县域生态服务价值进行类型划分;将生态服务价值类型与地学信息图谱相结合,使江西省生态服务价值谱系化,依此分析了江西省生态服务价值图谱结构类型特征与组合类型特征,为区域生态环境的可持续发展和构建低碳江西提供了参考建议,为生态经济研究提供了参考。     

Spatiotemporal analysis of vegetation variability and its relationship with climate change in China

This paper investigated spatiotemporal dynamic pattern of vegetation, climate factor, and their complex relationships from seasonal to inter-annual scale in China during the period 1982–1998 through wavelet transform method based on GIMMS data-sets. First, most vegetation canopies demonstrated obvious seasonality, increasing with latitudinal gradient. Second, obvious dynamic trends were observed in both vegetation and climate change, especially the positive trends. Over 70% areas were observed with obvious vegetation greening up, with vegetation degradation principally in the Pearl River Delta, Yangtze River Delta, and desert. Overall warming trend was observed across the whole country (>98% area), stronger in Northern China. Although over half of area (58.2%) obtained increasing rainfall trend, around a quarter of area (24.5%), especially the Central China and most northern portion of China, exhibited significantly negative rainfall trend. Third, significantly positive normalized difference vegetation index (NDVI)–climate relationship was generally observed on the de-noised time series in most vegetated regions, corresponding to their synchronous stronger seasonal pattern. Finally, at inter-annual level, the NDVI–climate relationship differed with climatic regions and their long-term trends: in humid regions, positive coefficients were observed except in regions with vegetation degradation; in arid, semiarid, and semihumid regions, positive relationships would be examined on the condition that increasing rainfall could compensate the increasing water requirement along with increasing temperature. This study provided valuable insights into the long-term vegetation–climate relationship in China with consideration of their spatiotemporal variability and overall trend in the global change process.     

Application of Remote Sensing in Monitoring Unsustainable Wetlands: Case Study Hamun Wetland

Monitoring wetland as one of the important parts of the global ecosystem is necessary for conservational programs. But, usually, collecting in situ data is restricted in these areas because of their remote locations, vast area and dynamic conditions. Remote sensing provides a cost effective tool to investigate hydrological patterns and the seasonal trend of changes in wetlands. In this paper, Land-use/land-cover change during water inundation period of Hamun wetland was investigated in order to determine change trend during this period. Hamun wetland is an unsustainable ecosystem, and monitoring this wetland is essential for conservation goals. This trend is critical for decision makers in order to plan the conservational scheme in all unsustainable ecosystems. To reach this objective, the land-use/land-cover maps during inundation period of Hamun were produced using Landsat 8 time series images. The results of accuracy assessment showed the classification of water and vegetation have the highest accuracy (94% and 93%, respectively). And the accuracy of plants in the water classes was the lowest (water–veg?=?89.9%, veg–water 1?=?88.8%, veg–water 2?=?87.6%). This means the higher misclassification is in determining the vegetation in the water. Then, the changes in the land-cover classes in relation to wetland inundation were investigated. Results of land-use/land-cover change illustrate the regions that were suitable for water birds but lost their suitability when the wetland dried out. These areas are crucial for water bird’s conservation. Satellite data determined these areas with acceptable accuracy.     

光谱指数趋势面的城市地表温度降尺度转换

针对城市及周边区域建造区和自然地表交织分布的特点,探讨了利用归一化植被指数(NDVI)和归一化建造指数(NDBI)构造趋势面的地表温度(LST)降尺度方法,以北京市市区及周边较平坦区域为例实现了LST自960 m向120 m的降尺度转换。分析了LST空间分布特征及NDVI、NDBI对地物的指示性特征;以北京市四至六环为界分析NDVI、NDBI趋势面对地表温度的拟合程度及各自的适用区域;在120 m、240 m、480 m和960 m 4个尺度上评价了NDVI、NDBI和NDVI+NDBI趋势面对LST的拟合程度和趋势面转换函数的尺度效应;对NDVI、NDBI和NDVI NDBI等3种方法的降尺度结果分覆盖类型、分区域对比评价。实验结果表明结合两种光谱指数的NDVI NDBI方法降尺度转换精度有所改善,改善程度取决于地表覆盖类型组合。