共查询到19条相似文献，搜索用时 234 毫秒
1.
《国土资源遥感》2017,(3)
以2000年、2008年和2013年获取的TM和ETM遥感图像、地理国情普查数据、水利普查数据和多年统计数据为主要数据源,采用遥感和GIS技术,结合实地调查,对黑河流域甘肃段湿地资源的类型、面积、组成和分布等情况进行了系统研究。结果表明:研究区湿地面积整体呈减少趋势,且2008年前减速较快,2008年后减速明显变缓。湿地资源变化是自然因素和人类活动共同作用的结果。其中,影响该区湿地资源变化的主要自然因素有降水量、气温、上游来水量、下泄量和冻土等;人类因素作为一种外在力量在湿地资源变化中的作用越来越明显,人口数量的变化与人们对土地改造与利用的强度是逐渐改变湿地景观最活跃、最直接的影响因素;政府决策与湿地保护恢复工程则对湿地资源保护起了推动作用。 相似文献
2.
市域尺度货物运输碳排放时空变化及因素分析 总被引：1，自引：0，他引：1
针对货物运输导致碳排放成为温室气体主要来源之一的问题,该文综合货物运输车辆的微观温室气体排放及时空变化,从市域尺度分析货物运输碳排放的时空变化规律。利用微观排放模型计算了2000年、2005年、2010年和2015年全国286个城市货物运输碳排放的空间分布及其变化,并应用地理加权回归模型探究城市化不同层面因素对碳排放时空分布变化的影响。结果表明:货物运输碳排放具有显著的空间集聚特征,且高排放地区的集聚规律更加显著;地理加权回归模型精度明显高于普通线性回归模型,经济变量、人口变量、货运强度变量与货物运输碳排放存在显著正相关关系。该研究可为中国各市级区域制订节能减排政策提供量化的科学依据。 相似文献
3.
环渤海滨海湿地时空格局变化遥感监测与分析 总被引：10，自引：2，他引：8
基于多期Landsat TM 等遥感数据, 采用目视解译和实地样点采集相互支撑的方法, 完成了环渤海
地区2000 年、2005 年及2008 年湿地提取和分类; 运用单一类型变化率模型、区域动态度模型和动态转移矩
阵, 揭示了环渤海湿地的时空格局、变化特点和驱动机制。研究显示环渤海地区的8 类湿地中, 属于人工湿
地类型的盐场和水库坑塘面积比例大且近8 年增长速度也最快, 年均分别增加205.52 km2 和146.10 km2, 滩
地和海涂减少最明显; 环渤海地区的三大流域中, 黄河流域湿地变化最显 相似文献
4.
以1990 年、1994 年、2000 年和2009 年4 期遥感影像数据为数据源,基于CA-Markov 模型,利用4 种不同的时间策略模拟了若尔盖国家级自然保护区和10 km 缓冲区范围内湿地变化.以1994 年保护区建立为时间节点,研究了政策干预前后保护区里外湿地类型的变化情况,从而评估若尔盖保护区的建立对湿地保护的意义.研究结果表明,若尔盖保护区湿地退化严重,湿地保护的效果并不显著. 相似文献
5.
以1990年、1994年、2000年和2009年4期遥感影像数据为数据源,基于CA-Markov模型,利用4种不同的时间策略模拟了若尔盖国家级自然保护区和10 km缓冲区范围内湿地变化。以1994年保护区建立为时间节点,研究了政策干预前后保护区里外湿地类型的变化情况,从而评估若尔盖保护区的建立对湿地保护的意义。研究结果表明,若尔盖保护区湿地退化严重,湿地保护的效果并不显著。 相似文献
6.
耕地景观破碎化成因及对农村收入影响分析 总被引：2，自引：0，他引：2
《测绘科学》2020,(4)
为了定量分析耕地破碎化的驱动因素,评价其对农村收入水平的影响,该文基于景观指数分析法选取景观指标计算景观指数,使用熵权法计算贵州省遵义市播州区21个乡镇的耕地破碎化综合指数;利用地理加权回归模型,计算耕地破碎化综合指数与各环境因子间的相关性,同时分析耕地破碎化综合指数对农村年人均可支配收入的影响。实验结果显示,该区域耕地破碎化是各类环境因素综合作用的结果,农村收入水平与耕地破碎度呈负相关。由此可见,景观指数分析与地理加权回归分析相结合既能够较好地反映耕地破碎化程度,同时也能清晰地揭示耕地破碎化的驱动因素及其对农村收入水平的影响,有助于我们进一步理解耕地破碎化的内涵,为提升农村收入水平提供理论参考。 相似文献
7.
针对传统地理加权回归方法无法解决时空非平稳性的问题,该文提出了一种路网距离约束的时空地理加权回归方法。引入时间特性,进一步把握了不同因子在时空维度影响的分异性;以路网距离度量约束,提高模型解释力。以北京市城6区1980—2015年的1 632个住宅小区特征价格数据为例,通过与直线距离约束的常规地理加权回归方法等进行比较,采用各模型的AIC与拟合优度等指标对模型置信水平高低进行评价。实验结果表明,路网距离约束的地理加权回归模型不仅能够提高模型的拟合精度,还能更好地揭示房价在时间与空间方面的变化规律。 相似文献
8.
生态系统服务权衡协同关系是掌握区域生态演化机理的重要指标。大量研究以行政区作为整体，对区域内的生态系统服务权衡协同关系进行描述，但是有关区域内生态系统服务空间异质性及多种生态系统服务间影响差异性的研究尚缺乏。本文以汾河流域作为研究区，基于1986年、1995年、2005年、2015年4期影像解译得到的土地利用分类结果，以及统计和生态数据，利用多尺度地理加权回归模型（MGWR）对生态系统服务权衡协同关系进行分析，并通过与土地利用数据相结合，定量分析土地转移对生态系统服务权衡协同关系的影响，探究生态系统服务的演化机理。研究表明：多尺度地理加权回归模型能解决生态系统服务权衡协同关系存在的空间异质性，从而准确揭示多种生态系统服务之间的内在关系；利用多尺度地理加权回归模型获得最佳生态系统服务组合的方式能有效降低数据冗余，提高工作效率；土地利用类型的变化是生态系统服务权衡协同关系演化的主要驱动因素；流域内植被退化会使粮食生产和产水量之间的权衡关系下降，使生物多样性和产水量等其他生态服务之间的协同关系下降；1986年—2015年间流域内单项生态系统服务间以协同关系为主导，且水源涵养与产水量间的协同关... 相似文献
9.
针对地理加权回归参数估计采用最小二乘方法,最小二乘估计易受离群值影响,导致地理加权回归模型并不稳健的问题,该文提出基于稳健度量选权迭代的地理加权回归分析方法,核心思想是通过标准化残差构造权重函数,通过迭代加权降低离群值对回归模型参数估计的影响。利用模拟数据与真实数据进行试验,分别与GWR、RGWR进行对比分析,以MSE、MAE为指标进行性能评价。模拟数据试验中,RMIWGWR模型比RGWR模型的MSE、MAE指标分别提升9.29%和8.34%;真实数据试验中,RMIWGWR模型比RGWR模型的MSE、MAE指标分别提升63.88%和38.45%。试验表明:该方法可改善粗差存在环境下地理加权回归模型参数估计精度,提升模型拟合效果。 相似文献
10.
以京津冀地区为研究对象,结合地理国情数据开展PM_(2.5)浓度估算方法的研究,在相关因素分析的基础上,运用土地利用回归方法与地理加权回归方法建立PM_(2.5)浓度空间分布回归模型,采用十折交叉验证对比模型稳定性与拟合精度,探索研究区最优建模方法及PM_(2.5)重要影响因子。结果表明:从模型稳定性及拟合精度来看,地理加权回归模型优于土地利用回归模型,模型调整后的R2分别为0.85、0.832,平均相对误差为12.4%、13.8%,均方根误差为10.61μg/m3、11.94μg/m3。相关分析判定结果表明,京津冀地区PM_(2.5)浓度的影响因子主要为气温、气压、房屋建筑、林地、耕地、降水、污染企业等。 相似文献
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Nidhi Nagabhatla Sonali S. Sellamuttu A. Ghosh Bobba Max Finlayson Rohan Wickramasuriya Martin Van Brakel S. Narendra Prasad Chiranjibi Pattanaik 《Journal of the Indian Society of Remote Sensing》2012,40(1):47-64
Ecosystem based approach (EBA) for resource management is a concerted, environmentally tuned and an integrated framework that
holistically addresses the ecological character of the natural resource, its societal benefit spectrum and its environmental
functions. In this paper, the EBA concept is closely linked with the emerging concept of multiple use systems (MUS) while
taking account of environmental, economic, and social factors that govern the ecosystems services and benefits. We elucidate
a multi-scalar approach and multiple case studies to understand EBA particularly in context of a wetlandscape. At the global
scale, Ramsar sites of international importance are geospatially analyzed with reference to their agro-ecology and biodiversity.
At regional scale, the agrarian use of inland wetlands in India was re-evaluated taking account of database from a recent
inland wetland inventory. At the local scale, drawing on the landscape characterization and the ecological economics for fresh
water Lake Kolleru in India and the Muthurajawela Marsh-Negombo Lagoon coastal marsh in Sri Lanka, we illustrate some of the
practical challenges in balancing wetland conservation, development needs and the overall well-being of local people. We also
discuss how variability in the scale, geophysical characteristics of the site and the data availability confines the ability
to simplify a single complete approach to address issues in complex ecosystem such as wetlands. All levels of the study are
supported by a variety of earth observation data and the geographical information system (GIS) tools. The site level analysis
also draws on socio-economic assessment tools. 相似文献
13.
采用TM、SPOT-5卫星遥感数据,通过建立杭州湾滨海湿地分类体系和解译标志并进行人机交互解译,完成了杭州湾1987、1995、2003和2009年滨海湿地提取和分类。研究了4期杭州湾滨海湿地的利用状况、面积,以及时空格局变化情况,研究显示:1987~2009年期间,杭州湾滨海湿地主要表现为滩涂湿地的逐年减少和库塘湿地的逐年增加;1995年之前湿地变化以自然驱动力为主,之后人类活动影响明显,对近海域、滩涂不断开发,尤以南岸为主;以杭州湾湿地公园为典型的沼泽草甸湿地得到了较好的保护。 相似文献
14.
Nidhi Nagabhatla R. Wickramasuriya S. N. Prasad 《Journal of the Indian Society of Remote Sensing》2009,37(3):443-455
The present study investigates the potential of readily available and easily accessible global data sets to understand regional/local
level interactions in wetland systems. The biogeographical zones of India were used a base-frame to select three sites. The
study well fits the interests of National Wetland Committee of India to investigate and document fundamental information on
wetland extent/distribution. The national partnership with SACON represents this interest. SACON commenced the inland wetland
inventory module at national scale using geospatial data, although the provincial scale analysis is underway. In addition,
the global irrigated area mapping (GIAM-IWMI) project generated multi-scalar spatial outputs for irrigated/rain-fed areas.
With the existing information base, a multi-level geospatial analysis using Arc GIS algorithmic modelling was used to derive
comprehensive appraisal of wetland systems complementing the data from GIAM and SACON. It was observed that the overlap between
the two layers was 58 percent for Gujarat and 10 percent in Tamil Nadu. In Krishna basin the wetland’s cover 1.04 million
hectare excluding the rice agro-ecosystem. The difference in the biogeography of the case sites governs the gradient of information
derived from both data layers. Additionally, the global lakes and wetlands database (GLWD) database added thematic information
on coastal wetlands. In summary we describe the cross-scaling the global data layers to compliment the regional/national level
monitoring assignments. 相似文献
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Ninglei Ouyang Guosheng Li Linlin Cui Huajun Liao 《Journal of the Indian Society of Remote Sensing》2018,46(4):655-666
Based on field monitoring and remote sensing extraction, this paper analyzed the landscape evolution, reclamation process and transformation characteristics in north Jiangsu coastal region since 1980 through landscape transfer analysis, landscape spatial conversion model, and landscape dynamicity model. Results indicated that natural wetland decreased while in contrast the artificial wetland increased. Natural wetland was mostly converted into mudflats, and large proportion of mudflats were subsequently exploited into aquaculture waters, and other man-made construction projects. Significant transformation ranking ahead were mudflat to aquaculture waters, Suaeda glauca to dry land, Suaeda glauca to aquaculture waters, Couch grass to aquaculture waters, respectively. The proportion of transformation caused by anthropogenic activities was up to 82%, much higher than natural succession. Coastal ecological systems were severely disturbed and destroyed largely due to wetland reclamation and resources exploitation. The results suggest that the impact of human activity on wetland ecology needs more attention. 相似文献
17.
G. Manju V. M. Chowdary Y. K. Srivastava S. Selvamani A. Jeyaram S. Adiga 《Journal of the Indian Society of Remote Sensing》2005,33(1):51-61
Sustainable management of wetland ecosystem is necessary as it serves the important functions such as food storage, water
quality maintenance and providing habitat for different species of wildlife. Hence, an inventory of wetlands in any given
area is a pre-requisite for their conservation and management. A study has been carried out to delineate the wetlands of east
Champaran district of Bihar, India, using IRS ID LISS III data. The data for the pre and post monsoon seasons have been analysed
and the wetlands have been qualitatively characterized based on the turbidity and aquatic vegetation status. The extent of
water logging problem in the study area was inferred from the seasonal variation of waterspread during both the seasons. The
three categories of wetlands (ponds/lakes, water logged areas and oxbow lakes) have been identified. From the analysis, it
has been observed that the inland wetlands constitute 2.7% of the study area, of which 1.8% is subjected to water logging.
Thus, this study highlights the usefulness of remotely sensed data for wetland mapping, seasonal monitoring and characterization. 相似文献
18.
Wetlands play irreplaceable key roles in ecological and environmental procedures. To make effective conservation and management, it is essential to understand the wetlands’ distribution and changes. In this study, an approach based on decision rules algorithm in conjunction with maximum likelihood classification is proposed for coastal wetland mapping using multi-temporal remotely sensed imagery and ancillary geospatial data. As a case study, Multi-temporal Advanced Visible and Near Infrared Radiometer type 2 images acquired by Japanese Advanced Land Observation Satellite are analysed to investigate the seasonal change pattern of coastal wetlands in Washington State, USA. Geospatial data, including Digital Elevation Model and spatial neighbourhood knowledge, are further integrated to characterize wetland features and discriminate classes within a certain elevation ranges. The final result is a refined coastal wetland map with 15 land cover categories. Preliminary evaluation of the final result shows that the proposed approach is effective in coastal wetland mapping. 相似文献
19.
Accurate wetland maps are a fundamental requirement for land use management and for wetland restoration planning. Several wetland map products are available today; most of them based on remote sensing images, but their different data sources and mapping methods lead to substantially different estimations of wetland location and extent. We used two very high-resolution (2 m) WorldView-2 satellite images and one (30 m) Landsat 8 Operational Land Imager (OLI) image to assess wetland coverage in two coastal areas of Tampa Bay (Florida): Fort De Soto State Park and Weedon Island Preserve. An initial unsupervised classification derived from WorldView-2 was more accurate at identifying wetlands based on ground truth data collected in the field than the classification derived from Landsat 8 OLI (82% vs. 46% accuracy). The WorldView-2 data was then used to define the parameters of a simple and efficient decision tree with four nodes for a more exacting classification. The criteria for the decision tree were derived by extracting radiance spectra at 1500 separate pixels from the WorldView-2 data within field-validated regions. Results for both study areas showed high accuracy in both wetland (82% at Fort De Soto State Park, and 94% at Weedon Island Preserve) and non-wetland vegetation classes (90% and 83%, respectively). Historical, published land-use maps overestimate wetland surface cover by factors of 2–10 in the study areas. The proposed methods improve speed and efficiency of wetland map production, allow semi-annual monitoring through repeat satellite passes, and improve the accuracy and precision with which wetlands are identified. 相似文献