共查询到20条相似文献，搜索用时 15 毫秒
1.
Landscape patterns in a region have different sizes, shapes and spatial arrangements, which contribute to the spatial heterogeneity of the landscape and are linked to the distinct behavior of thermal environments. There is a lack of research generating landscape metrics from discretized percent impervious surface area data (ISA), which can be used as an indicator of urban spatial structure and level of development, and quantitatively characterizing the spatial patterns of landscapes and land surface temperatures (LST). In this study, linear spectral mixture analysis (LSMA) is used to derive sub-pixel ISA. Continuous fractional cover thresholds are used to discretize percent ISA into different categories related to urban land cover patterns. Landscape metrics are calculated based on different ISA categories and used to quantify urban landscape patterns and LST configurations. The characteristics of LST and percent ISA are quantified by landscape metrics such as indices of patch density, aggregation, connectedness, shape and shape complexity. The urban thermal intensity is also analyzed based on percent ISA. The results indicate that landscape metrics are sensitive to the variation of pixel values of fractional ISA, and the integration of LST, LSMA. Landscape metrics provide a quantitative method for describing the spatial distribution and seasonal variation in urban thermal patterns in response to associated urban land cover patterns. 相似文献
2.
This study proposes a landscape metrics-based method for model performance evaluation of land change simulation models. To quantify model performance at both landscape and class levels, a set of composition- and configuration-based metrics including number of patches, class area, landscape shape index, mean patch area and mean Euclidean nearest neighbour distance were employed. These landscape metrics provided detailed information on simulation success of a cellular automata-Markov chain (CA-Markov) model standpoint of spatial arrangement of the simulated map versus the corresponding reference layer. As a measure of model simulation success, mean relative error (MRE) of the metrics was calculated. At both landscape and class levels, the MRE values were accounted for 22.73 and 10.2%, respectively, which are further categorised into qualitative measurements of model simulation performance for simple and quick comparison of the results. Findings of the present study depict a hierarchical and multi spatial level assessment of model performance. 相似文献
3.
Spatio-temporal pattern analysis of land use/cover change trajectories in Xihe watershed 总被引：1，自引：0，他引：1
Dongchuan Wang Jianhua Gong Liding ChenLihui Zhang Yiquan SongYujuan Yue 《International Journal of Applied Earth Observation and Geoinformation》2012,14(1):12-21
Human-induced land use/cover change has been considered to be one of the most important parts of global environmental changes. In loess hilly and gully regions, to prevent soil loss and achieve better ecological environments, soil conservation measures have been taken during the past decades. The main objective of this study is to quantify the spatio-temporal variability of land use/cover change spatial patterns and make preliminary estimation of the role of human activity in the environmental change in Xihe watershed, Gansu Province, China. To achieve this objective, the methodology was developed in two different aspects, that is, (1) analysis of change patterns by binary image of change trajectories overlaid with different natural geographic factors, in which Relative Change Intensity (RCI) metric was established and used to make comparisons, and (2) analysis based on pattern metrics of main trajectories in the study area. Multi-source and multi-temporal Remote Sensing (RS) images (including Landsat ETM+ (30 June 2001), SPOT imagery (21 November 2003 and 5 May 2008) and CBERS02 CCD (5 June 2006)) were used due to the constraints of the availability of remotely sensed data. First, they were used to extract land use/cover types of each time node by object-oriented classification method. Classification results were then utilized in the trajectory analysis of land use/cover changes through the given four time nodes. Trajectories at every pixel were acquired to trace the history of land use/cover change for every location in the study area. Landscape metrics of trajectories were then analyzed to detect the change characteristics in time and space through the given time series. Analysis showed that most land use/cover changes were caused by human activities, most of which, under the direction of local government, had mainly led to virtuous change on the ecological environments. While, on the contrary, about one quarter of human-induced changes were vicious ones. Analysis through overlaying binary image of change trajectories with natural factors can efficiently show the spatio-temporal distribution characteristics of land use/cover change patterns. It is found that in the study area RCI of land use/cover changes is related to the distance to the river line. And there is a certain correlation between RCI and slope grades. However, no obvious correlation exists between RCI and aspect grades. 相似文献
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针对土地利用/覆盖（land-use and land-cover,LULC）方式是否影响城市空气污染空间分异特征形成的问题,利用遥感技术和景观生态学方法分别获取长株潭城市群核心城区LULC及其景观格局,绘制空气污染物浓度与气象影响因子空间分异图,引入地理探测器定量分析土地因子在融合气象要素前后对NO2、PM10、O3、PM2.5浓度空间分布差异的贡献强度。结果表明,建设用地面积比例越高,林地越低,NO2、PM2.5浓度越高,O3越低。非建设用地区域,污染物浓度随着土地景观格局破碎度、多样性指数值增大而升高,建设用地区域反之。LULC和土地景观格局的复合因子贡献力（P0.03~0.28）高于两者任意单独因子贡献力（P:0.01~0.11）,融合气象要素后,LULC对空气污染物空间分异特征形成的因子贡献力（P:0.18~0.53）显著增强。 相似文献
6.
Martin Yemefack Wietske Bijker Steven M. De Jong 《International Journal of Applied Earth Observation and Geoinformation》2006
This paper investigates statistical relationships between land use/land cover (LULC), Landsat-7 ETM+ imagery and landscape mosaic structure in southern Cameroon where the conversion of tropical rain forest to shifting cultivation leads to dynamic processes, acting on the spatial aggregation of various LULC types. A Global Positioning System (GPS) was used in the field to identify a total of 171 shifting cultivation patches representing eight LULC types in two sub-areas. Because of the lack of a cloud-free image for the date of field sampling, the ETM+ imagery was acquired 2 months after field survey, during which it was assumed that no significant changes in LULC occurred (all dry season). Per pixel correlations were developed between spectral reflectance data, vegetation indices and LULC. As an exploratory study, several statistical methods (analysis of variance, means separations (Tukey HSD), principal component analysis (PCA), geo-statistical analysis, image classification and landscape metrics) were applied on point data and sensor images for evaluating the spatial variability within the landscape. Most variables explained 30–72% of LULC variation in the whole dataset. Those variables with high information content of LULC (infrared bands 4, 5, 7 and derived indices and PC1) also showed long ranges (6 km) spatial dependence as compared to those varying only within 1 km range. The results of these statistical analyses suggested the need to group some LULC types and the application of the Maximum Likelihood Classifier (MLC) for supervised classification provided a LULC map with the highest accuracy (81%) after consolidation of perennial LULC types, such as bush fallow, forest fallow and cocoa plantations. Landscape metrics computed from this map showed a high level of patch diversity and connectivity within the landscape and provided input data that can further be used to simulate predictive maps as substitute to cloud-covered sensor imageries. Landsat-7 ETM+ imagery proved to be useful in discriminating (with about 80% accuracy) the most dynamic LULC types such cropped plots and young fallow patches (shifting every season) and the extension front of the agricultural landscape. 相似文献
7.
Diwakar Paudel Jay Krishna Thakur Sudhir Kumar Singh Prashant K. Srivastava 《国际地球制图》2015,30(2):218-241
Soil is a vital part of the natural environment and is always responding to changes in environmental factors, along with the influences of anthropogenic factors and land use changes. The long-term change in soil properties will result in change in soil health and fertility, and hence the soil productivity. Hence, the main aim of this paper focuses on the analysis of land use/land cover (LULC) change pattern in spatial and temporal perspective and to present its impact on soil properties in the Merawu catchment over the period of 18?years. Post classification change detection was performed to quantify the decadal changes in historical LULC over the periods of 1991, 2001 and 2009. The pixel to pixel comparison method was used to detect the LULC of the area. The key LULC types were selected for investigation of soil properties. Soil samples were analysed in situ to measure the physicochemical soil properties. The results of this study show remarkable changes in LULC in the period of 18?years. The effect of land cover change on soil properties, soil compaction and soil strength was found to be significant at a level of <0.05. 相似文献
8.
Urban heat islands (UHIs) have attracted attention around the world because they profoundly affect biological diversity and human life. Assessing the effects of the spatial structure of land use on UHIs is essential to better understanding and improving the ecological consequences of urbanization. This paper presents the radius fractal dimension to quantify the spatial variation of different land use types around the hot centers. By integrating remote sensing images from the newly launched HJ-1B satellite system, vegetation indexes, landscape metrics and fractal dimension, the effects of land use patterns on the urban thermal environment in Wuhan were comprehensively explored. The vegetation indexes and landscape metrics of the HJ-1B and other remote sensing satellites were compared and analyzed to validate the performance of the HJ-1B. The results have showed that land surface temperature (LST) is negatively related to only positive normalized difference vegetation index (NDVI) but to Fv across the entire range of values, which indicates that fractional vegetation (Fv) is an appropriate predictor of LST more than NDVI in forest areas. Furthermore, the mean LST is highly correlated with four class-based metrics and three landscape-based metrics, which suggests that the landscape composition and the spatial configuration both influence UHIs. All of them demonstrate that the HJ-1B satellite has a comparable capacity for UHI studies as other commonly used remote sensing satellites. The results of the fractal analysis show that the density of built-up areas sharply decreases from the hot centers to the edges of these areas, while the densities of water, forest and cropland increase. These relationships reveal that water, like forest and cropland, has a significant effect in mitigating UHIs in Wuhan due to its large spatial extent and homogeneous spatial distribution. These findings not only confirm the applicability and effectiveness of the HJ-1B satellite system for studying UHIs but also reveal the impacts of the spatial structure of land use on UHIs, which is helpful for improving the planning and management of the urban environment. 相似文献
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景观格局是研究景观功能和动态的基础。景观指数分析在土地利用/土地覆盖、生态系统服务、森林监控、城市蔓生以及生物多样性等方面应用广泛。现有许多景观指数之间存在不同程度的相关性,不仅导致信息冗余,还将影响结果解译的清晰性和准确性。同时,已有研究主要针对栅格数据,针对矢量数据的景观指数分析研究较少。为解决上述问题,以广州市土地利用景观格局为例,在矢量数据格式下计算了44个常用的景观指数,并运用相关分析和因子分析相结合的多元统计分析法,提取了6个核心景观指数,这些指数描述了广州市土地利用景观格局的6个维度:景观破碎度、平均斑块面积、平均形状复杂度、空间分散度、形状复杂度差异和土地类型的相似性。 相似文献
11.
Stylized environments and ABMs: educational tools for examining the causes and consequences of land use/land cover change 总被引：1，自引：0，他引：1
A challenge in land change science is to assess the causes and consequences of LULC change and associated pattern–process relations. Increasingly, land change organizations are examining land use at local to global scales for historical, contemporary and future periods through scenarios that assess population–environment interactions. Spatial analytical tools in GIScience are being used to link people and environment and to search for the distal and proximate factors that affect local to global land use patterns. Spatial simulation models that rely upon complexity theory as the framework and agent-based models as the analytical approach offer the capability to inform through experimentation about land issues important to science and society. Using a stylized landscape where a selected set of key social, geographical and ecological elements are spatially organized, we describe how land dynamics can be examined through agent-based models as educational tools that are useful in the classroom, boardroom and public forums. 相似文献
12.
Modelling coastal land use change by incorporating spatial autocorrelation into cellular automata models 总被引：1，自引：0，他引：1
This paper presents a spatial autoregressive (SAR) method-based cellular automata (termed SAR-CA) model to simulate coastal land use change, by incorporating spatial autocorrelation into transition rules. The model captures the spatial relationships between explained and explanatory variables and then integrates them into CA transition rules. A conventional CA model (LogCA) based on logistic regression (LR) was studied as a comparison. These two CA models were applied to simulate urban land use change of coastal regions in Ningbo of China from 2000 to 2015. Compared to the LR method, the SAR model yielded smaller accumulated residuals that showed a random distribution in fitting the CA transition rules. The better-fitting SAR model performed well in simulating urban land use change and scored an overall accuracy of 85.3%, improving on the LogCA model by 3.6%. Landscape metrics showed that the pattern generated by the SAR-CA model has less difference with the observed pattern. 相似文献
13.
The paper demonstrates two issues; (i) how a ‘moving window approach’, that translates pixel level detected changes to landscape level, can be implemented; (ii) how the approach can overcome the limitations of pixel level change information to characterize change over large areas. First we detected changes from two periods (1986 and 2010) of LULC maps. On the pixel-based changes, we ran focal statistics summation operator separately for selected window sizes (1–10 km). Further, we assessed effect of scale in depicting the pattern and amount of change. The approach is found useful to overcome major shortfalls of pixel-based change characterization. However, varying scale of analysis provide varying amount of change and differently represent change patterns. Thus, implementing the approach over complex and large areas requires multi-scale approach. Subdividing complex and large areas into homogeneous zones can help to implement the multi-scale approach and facilitate the selection of appropriate scale of analysis. 相似文献
14.
关键陆表参数遥感产品真实性检验方法研究进展 总被引：1，自引：0，他引：1
遥感产品真实性检验是定量遥感基础研究的重要环节,是客观评价遥感产品精度、稳定性和一致性的重要手段,对于提高遥感定量化水平、推动和扩展遥感产品的深化应用具有重要的意义。本文基于当前陆表参数遥感产品真实性检验研究的相关成果,归纳总结了陆表参数遥感产品真实性检验方法,并就其中的5种真实性检验方法,即基于地面单点测量检验、基于地面多点采样检验、基于高分辨率数据的检验、交叉检验和间接检验,阐述了各方法的特点、局限性、适用条件。文章在最后探讨了陆表关键参数遥感产品真实性检验评价指标和验证中影响精度评价的关键因素。本文对于遥感产品真实性检验工作的开展和真实性检验系统研发具有重要的指导意义。 相似文献
15.
Sigismond A. Wilson 《国际地球制图》2013,28(6):476-501
Capturing the scope and trajectory of changes in land use and land cover (LULC) is critical to urban and regional planning, natural resource sustainability and the overall information needs of policy makers. Studies on LULC change are generally conducted within peaceful environments and seldom incorporate areas that are politically volatile. Consequently, the role of civil conflict on LULC change remains elusive. Using a dense time stack of Landsat Thematic Mapper images and a hybrid classification approach, this study analysed LULC changes in Kono District between 1986–1991, 1991–2002 and 2002–2007 with the overarching goal of elucidating deviations from typical changes in LULC caused by Sierra Leone's civil war (1991–2002). Informed by social survey and secondary data, this study engaged the drivers that facilitated LULC changes during war and non-war periods in a series of spatial regression models in exploring the interface between civil conflict and LULC change. 相似文献
16.
遥感估算地表蒸散发真实性检验研究进展 总被引：3，自引：1，他引：2
地表蒸散发是连接土壤—植被—大气连续体的纽带,结合遥感技术估算地表蒸散发已成为获取区域乃至全球尺度时空连续地表蒸散发量的有效手段。由于遥感估算地表蒸散发容易受到地表空间异质性和近地层气象条件复杂性的影响,在模型机理与变量参数化方案、输入数据和时间尺度扩展等方面存在不确定性,影响了其准确度的提高和应用范围的拓展,因此需要开展真实性检验。本文综述了当前遥感估算地表蒸散发(包括植被蒸腾和土壤蒸发)真实性检验研究的相关成果,重点归纳并总结了应用于遥感估算地表蒸散发真实性检验的直接检验法和间接检法的主要原理、适用性和优缺点,在此基础上阐述了当前遥感估算地表蒸散发真实性检验研究所面临的挑战。分析表明：由于地表空间异质性的普遍存在,遥感估算地表蒸散发真实性检验研究在理论和方法方面还受到诸多挑战,今后应打破地表蒸散发遥感产品真实性检验局限在均匀地表的传统思路,发展非均匀地表遥感估算地表蒸散发真实性检验的理论框架,包括地表水热状况空间异质性的度量、非均匀地表验证场的优化布设、非均匀下垫面地表蒸散发的多尺度观测试验、卫星像元/区域尺度地表蒸散发相对真值的获取、验证过程中的不确定性分析以及遥感估算地表蒸散发的实证研究等,并构建一个多源、多尺度、多方法、多层次的真实性检验技术流程,以期把遥感估算地表蒸散发真实性检验作为突破口,提升相应遥感产品的应用水平,推动定量遥感科学的发展。 相似文献
17.
S. Mukherjee S. Shashtri C. K. Singh P. K. Srivastava M. Gupta 《Journal of the Indian Society of Remote Sensing》2009,37(3):527-537
The monitoring of land use/land covers (LULCs) is an indispensable exercise for all those involved in executing policies to
optimize the use of natural resources and minimize the ill impacts on the environment. The study here aims at analyzing the
changes that occurred in LULC over a time span from 1990 to 2005 using multi date data of a part of Punjab. The digital data
consisted of two sets of Landsat Thematic Mapper (TM) data and one set of IRS-1C data. Utilizing hybrid classification technique
for interpretation and on field validation, it has been found that canal irrigation leads to changes in LULC as there is a
change in cropping pattern as well as increase in water logged area. 相似文献
18.
Changes in landscape composition and configuration patterns of Sancaktepe Municipal District in the Asian side of Istanbul Metropolitan City of Turkey were analysed using landscape metrics. Class-level and landscape-level metrics were calculated from the land cover/land use data using Patch Analyst, an extension in the Arc View GIS. The land cover/land use data were derived from classified satellite images of Landsat Thematic Mapper of 2002 and 2009 for Sancaktepe District. There was evidence of increase in agglomeration process of built-up patches as indicated by the increases in mean patch size, decrease in total edge and number of patches between 2002 and 2009. The urban expansion pattern experienced overall was not fragmented but concentrated due to infilling around existing patches. Changes in Area-Weighted Mean Shape Index and Area-Weighted Patch Fractal Dimension Index indicated that the physical shapes within built-up, forest and bareland areas were relatively complex and irregular. A conclusion is made in this study that spatial metrics are useful tools to describe the urban landscape composition and configuration in its various aspects and certain decisions whether to approve a specific development in urban planning could, for example, be based on some measures of urban growth form or pattern in terms of uniformity and irregularity, attributable to the dynamic processes of agglomeration and fragmentation of land cover/land use patches caused by urban expansion. 相似文献
19.
Sudhir Kumar Singh Szilárd Szabó George P. Petropoulos Manika Gupta Tanvir Islam 《国际地球制图》2017,32(2):113-127
Analysis of Earth observation (EO) data, often combined with geographical information systems (GIS), allows monitoring of land cover dynamics over different ecosystems, including protected or conservation sites. The aim of this study is to use contemporary technologies such as EO and GIS in synergy with fragmentation analysis, to quantify the changes in the landscape of the Rajaji National Park (RNP) during the period of 19 years (1990–2009). Several statistics such as principal component analysis (PCA) and spatial metrics are used to understand the results. PCA analysis has produced two principal components (PC) and explained 84.1% of the total variance, first component (PC1) accounted for the 57.8% of the total variance while the second component (PC2) has accounted for the 26.3% of the total variance calculated from the core area metrics, distance metrics and shape metrics. Our results suggested that notable changes happened in the RNP landscape, evidencing the requirement of taking appropriate measures to conserve this natural ecosystem. 相似文献
20.
This paper presents a land use and land cover (LULC) classification approach that accounts landscape heterogeneity. We addressed this challenge by subdividing the study area into more homogeneous segments using several biophysical and socio-economic factors as well as spectral information. This was followed by unsupervised clustering within each homogeneous segment and supervised class assignment. Two classification schemes differing in their level of detail were successfully applied to four landscape types of distinct LULC composition. The resulting LULC map fulfills two major requirements: (1) differentiation and identification of several LULC classes that are of interest at the local, regional, and national scales, and (2) high accuracy of classification. The approach overcomes commonly encountered difficulties of classifying second-level classes in large and heterogeneous landscapes. The output of the study responds to the need for comprehensive LULC data to support ecosystem assessment, policy formulation, and decision-making towards sustainable land resources management. 相似文献