Satellite Imagery

卫星图像
  • 文章类型: Journal Article
    营养状态指数(TSI)是量化和理解湖泊富营养化的关键指标,尚未充分探索长期水质监测,特别是内陆中小型水域。Landsat卫星为促进多尺度湖泊的时空监测提供了有效的补充。利用Landsat表面反射率产品检索了1984年至2023年中国1平方公里以上2693个湖泊的年平均TSI。我们的方法首先用决策树通过像素区分湖泊类型,然后得出营养状态与藻类生物量指数之间的关系。通过公开报告和现有数据集的验证证实了良好的一致性和可靠性。该数据集为不同面积尺度下的湖泊提供了可靠的年度TSI结果和可信的趋势,为进一步研究提供参考,为湖泊可持续管理提供便利。
    Trophic state index (TSI) serves as a key indicator for quantifying and understanding the lake eutrophication, which has not been fully explored for long-term water quality monitoring, especially for small and medium inland waters. Landsat satellites offer an effective complement to facilitate the temporal and spatial monitoring of multi-scale lakes. Landsat surface reflectance products were utilized to retrieve the annual average TSI for 2693 lakes over 1 km2 in China from 1984 to 2023. Our method first distinguishes lake types by pixels with a decision tree and then derives relationships between trophic state and algal biomass index. Validation with public reports and existing datasets confirmed the good consistency and reliability. The dataset provides reliable annual TSI results and credible trends for lakes under different area scales, which can serve as a reference for further research and provide convenience for lake sustainable management.
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  • 文章类型: Journal Article
    资源贫乏地区的社区面临健康,粮食生产,可持续性和整体生存挑战。因此,它们在围绕社会崩溃的全球辩论中很常见。拉帕努伊岛(复活岛)经常被用作一个例子,说明有限资源的过度开发如何导致灾难性的人口崩溃。这种叙述的一个重要组成部分是,接触前Rapanui人口增长率的快速上升和下降是由曾经广泛的岩石花园的建设和过度开发驱动的。然而,全岛岩石园艺的程度,虽然理解食物系统和人口的关键,必须更好地理解。这里,我们使用短波红外(SWIR)卫星图像和机器学习来生成全岛范围的岩石园艺估计,并重新评估RapaNui的先前种群规模模型。我们表明,这种农业基础设施的范围大大小于先前声称的范围,并且可能无法支持已经假设的庞大人口规模。
    Communities in resource-poor areas face health, food production, sustainability, and overall survival challenges. Consequently, they are commonly featured in global debates surrounding societal collapse. Rapa Nui (Easter Island) is often used as an example of how overexploitation of limited resources resulted in a catastrophic population collapse. A vital component of this narrative is that the rapid rise and fall of pre-contact Rapanui population growth rates was driven by the construction and overexploitation of once extensive rock gardens. However, the extent of island-wide rock gardening, while key for understanding food systems and demography, must be better understood. Here, we use shortwave infrared (SWIR) satellite imagery and machine learning to generate an island-wide estimate of rock gardening and reevaluate previous population size models for Rapa Nui. We show that the extent of this agricultural infrastructure is substantially less than previously claimed and likely could not have supported the large population sizes that have been assumed.
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  • 文章类型: Journal Article
    背景:非洲城市,特别是阿比让和约翰内斯堡,面对城市快速增长的挑战,非正式和紧张的卫生服务,气候变化导致温度升高。这项研究旨在了解这些城市与热相关的健康影响的复杂性。目标是:(1)使用健康绘制城市内热风险和暴露图,社会经济,气候和卫星图像数据;(2)建立分层热健康预测模型,以预测不良健康结果;(3)建立早期预警系统,以及时发出热浪警报。最终目标是培育具有气候适应性的非洲城市,保护不成比例的受影响人群免受热危害。
    方法:该研究将从2000年至2022年在约翰内斯堡和阿比让进行的合格成人临床试验或队列研究中获取健康相关数据集。将收集更多数据,包括社会经济,气候数据集和卫星图像。这些资源将有助于绘制热危害图并量化热健康暴露,风险和发病率升高的程度。结果将使用先进的数据分析方法来确定,包括统计评估,机器学习和深度学习技术。
    背景:该研究已获得Wits人类研究伦理委员会的批准(参考号:220606)。数据管理将遵循批准的程序。结果将通过讲习班传播,社区论坛,会议和出版物。将根据道德和安全考虑制定数据存储和管理计划。
    BACKGROUND: African cities, particularly Abidjan and Johannesburg, face challenges of rapid urban growth, informality and strained health services, compounded by increasing temperatures due to climate change. This study aims to understand the complexities of heat-related health impacts in these cities. The objectives are: (1) mapping intraurban heat risk and exposure using health, socioeconomic, climate and satellite imagery data; (2) creating a stratified heat-health forecast model to predict adverse health outcomes; and (3) establishing an early warning system for timely heatwave alerts. The ultimate goal is to foster climate-resilient African cities, protecting disproportionately affected populations from heat hazards.
    METHODS: The research will acquire health-related datasets from eligible adult clinical trials or cohort studies conducted in Johannesburg and Abidjan between 2000 and 2022. Additional data will be collected, including socioeconomic, climate datasets and satellite imagery. These resources will aid in mapping heat hazards and quantifying heat-health exposure, the extent of elevated risk and morbidity. Outcomes will be determined using advanced data analysis methods, including statistical evaluation, machine learning and deep learning techniques.
    BACKGROUND: The study has been approved by the Wits Human Research Ethics Committee (reference no: 220606). Data management will follow approved procedures. The results will be disseminated through workshops, community forums, conferences and publications. Data deposition and curation plans will be established in line with ethical and safety considerations.
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  • 文章类型: Dataset
    在低收入和中等收入国家,与传统数据收集相关的巨大成本对促进公共卫生领域的决策构成了障碍。卫星图像提供了一个潜在的解决方案,但是图像提取和分析成本很高,需要专门的专业知识。我们介绍SatelliteBench,用于卫星图像提取和矢量嵌入生成的可扩展框架。我们还提出了一种新颖的多模态融合管道,该管道利用了一系列卫星图像和元数据。该框架进行了评估,生成了一个数据集,该数据集包含12,636张图像和嵌入,并附有全面的元数据,从2016年至2018年哥伦比亚的81个城市。然后在3个任务中评估数据集:包括登革热病例预测,贫困评估,和受教育的机会。性能展示了SatelliteBench的多功能性和实用性,提供可复制的,可访问和开放的工具,以加强公共卫生决策。
    In low- and middle-income countries, the substantial costs associated with traditional data collection pose an obstacle to facilitating decision-making in the field of public health. Satellite imagery offers a potential solution, but the image extraction and analysis can be costly and requires specialized expertise. We introduce SatelliteBench, a scalable framework for satellite image extraction and vector embeddings generation. We also propose a novel multimodal fusion pipeline that utilizes a series of satellite imagery and metadata. The framework was evaluated generating a dataset with a collection of 12,636 images and embeddings accompanied by comprehensive metadata, from 81 municipalities in Colombia between 2016 and 2018. The dataset was then evaluated in 3 tasks: including dengue case prediction, poverty assessment, and access to education. The performance showcases the versatility and practicality of SatelliteBench, offering a reproducible, accessible and open tool to enhance decision-making in public health.
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  • 文章类型: Journal Article
    芒果果实在为人体提供必需营养方面起着至关重要的作用,巴基斯坦芒果在全球范围内备受追捧。对农产品不断增长的需求要求加强监测和管理农业资源的方法。传统的实地调查是劳动密集型和耗时的,而遥感提供了一个全面和有效的替代方案。随着时间的推移,遥感领域取得了长足的发展,卫星技术被证明有助于在整个生长阶段对作物进行大规模监测。在这项研究中,我们利用从使用Landsat-8卫星图像和机器学习的芒果农场收集的新数据来检测芒果园。我们在旁遮普省六个月的时间里从一个农场收集了总共2150棵芒果树样本,巴基斯坦。然后,我们使用七个多光谱波段分析了每个样本。Landsat-8框架提供了高分辨率的地表图像,用于检测芒果园。这项研究依赖于独立的数据,为训练更高级的机器学习模型提供优势,并以高精度产生可靠的发现。我们提出的优化CART方法优于现有方法,取得了显著的99%的准确性得分,而k-Fold验证得分也达到了99%。这项研究为农业遥感的发展铺平了道路,为作物管理产量估算和更广泛的精准农业领域提供潜在的好处。
    The mango fruit plays a crucial role in providing essential nutrients to the human body and Pakistani mangoes are highly coveted worldwide. The escalating demand for agricultural products necessitates enhanced methods for monitoring and managing agricultural resources. Traditional field surveys are labour-intensive and time-consuming whereas remote sensing offers a comprehensive and efficient alternative. The field of remote sensing has witnessed substantial growth over time with satellite technology proving instrumental in monitoring crops on a large scale throughout their growth stages. In this study, we utilize novel data collected from a mango farm employing Landsat-8 satellite imagery and machine learning to detect mango orchards. We collected a total of 2,150 mango tree samples from a farm over six months in the province of Punjab, Pakistan. Then, we analyzed each sample using seven multispectral bands. The Landsat-8 framework provides high-resolution land surface imagery for detecting mango orchards. This research relies on independent data, offering an advantage for training more advanced machine learning models and yielding reliable findings with high accuracy. Our proposed optimized CART approach outperformed existing methods, achieving a remarkable 99% accuracy score while the k-Fold validation score also reached 99%. This research paves the way for advancements in agricultural remote sensing, offering potential benefits for crop management yield estimation and the broader field of precision agriculture.
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  • 文章类型: Dataset
    需要在精细的空间和时间尺度上了解直接的森林砍伐驱动因素,以设计适当的森林管理和监测措施。为了实现这一点,参考数据集,用于设计人工智能(AI)方法,对经历森林损失的地区内的直接森林砍伐驱动因素进行详细分类,需要全面和适应当地的方式。喀麦隆就是这样,在刚果盆地,近年来森林砍伐率不断上升。这里,我们创建了一个带有相关标签的地球观测数据集,以对喀麦隆的详细直接森林砍伐驱动因素进行分类,其中包括卫星图像(Landsat和PlanetScope)以及有关基础设施和生物物理特性的辅助数据。该数据集提供了以下十五个标签:油棕,木材,水果,橡胶和其他大型种植园;草地/灌木丛;小规模油棕或玉米种植园和其他小规模农业;采矿;选择性伐木;基础设施;野火;狩猎;和其他。
    Understanding direct deforestation drivers at a fine spatial and temporal scale is needed to design appropriate measures for forest management and monitoring. To achieve this, reference datasets with which to design Artificial Intelligence (AI) approaches to classify direct deforestation drivers within areas experiencing forest loss in a detailed, comprehensive and locally-adapted way are needed. This is the case for Cameroon, in the Congo Basin, which has known increasing deforestation rates in recent years. Here, we created an Earth Observation dataset with associated labels to classify detailed direct deforestation drivers in Cameroon, which includes satellite imagery (Landsat and PlanetScope) and auxiliary data on infrastructure and biophysical properties. The dataset provides the following fifteen labels: oil palm, timber, fruit, rubber and other-large scale plantations; grassland/shrubland; small-scale oil palm or maize plantations and other small-scale agriculture; mining; selective logging; infrastructure; wildfires; hunting; and other.
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  • 文章类型: Journal Article
    武装冲突导致的国内人口流离失所可能会对该地区的土地利用和土地覆盖(LULC)以及实现可持续发展目标(SDGs)的努力产生重大影响。这项研究的目的是确定冲突驱动的国内流离失所者(IDPs)对达尔富尔卡斯地区植被覆盖和环境可持续性的影响,苏丹。使用QGIS软件对2016年和2022年的Sentinel-2卫星图像进行监督分类和变化分析。使用随机森林(RF)机器学习(ML)分类器分析前哨2级2A数据。成功分类了五种土地覆盖类型(农业用地,植被覆盖,建成区,沙子,和bareland),总体准确度超过86%,Kappa系数大于0.74。结果表明,在六年的研究期间,植被覆盖面积下降了35.33%(-10.20km2),相当于植被覆盖率的年平均损失率为-5.89%(-1.70km2)。相比之下,在两个研究年度之间,农业用地和建成区分别增加了17.53%(98.12km2)和60.53%(5.29km2)。不同LULC类别之间的变化趋势表明人类活动尤其是国内流离失所者的潜在影响,自然过程,以及两者在研究区域的结合。这项研究强调了国内流离失所者对受冲突影响地区自然资源和土地覆盖模式的影响。它还提供了相关数据,可以支持决策者恢复受影响地区并防止进一步的环境退化以实现可持续性。
    Internal displacement of populations due to armed conflicts can substantially impact a region\'s Land Use and Land Cover (LULC) and the efforts towards the achievement of Sustainable Development Goals (SDGs). The objective of this study was to determine the effects of conflict-driven Internally Displaced Persons (IDPs) on vegetation cover and environmental sustainability in the Kas locality of Darfur, Sudan. Supervised classification and change analysis were performed on Sentinel-2 satellite images for the years 2016 and 2022 using QGIS software. The Sentinel-2 Level 2A data were analysed using the Random Forest (RF) Machine Learning (ML) classifier. Five land cover types were successfully classified (agricultural land, vegetation cover, built-up area, sand, and bareland) with overall accuracies of more than 86% and Kappa coefficients greater than 0.74. The results revealed a 35.33% (-10.20 km2) decline in vegetation cover area over the six-year study period, equivalent to an average annual loss rate of -5.89% (-1.70 km2) of vegetation cover. In contrast, agricultural land and built-up areas increased by 17.53% (98.12 km2) and 60.53% (5.29 km2) respectively between the two study years. The trends of the changes among different LULC classes suggest potential influences of human activities especially the IDPs, natural processes, and a combination of both in the study area. This study highlights the impacts of IDPs on natural resources and land cover patterns in a conflict-affected region. It also offers pertinent data that can support decision-makers in restoring the affected areas and preventing further environmental degradation for sustainability.
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  • 文章类型: Journal Article
    如果城市社区的绿地不足以营造舒适的环境,就会出现城市热岛,居民的健康将受到不利影响。当前的卫星图像只能有效地识别大规模的绿色空间,无法捕获三维建筑空间内的行道树或盆栽植物。在这项研究中,我们使用Google街景上的深度卷积神经网络语义分割模型来提取台北市邻里级的环境特征,台湾,包括绿色植被指数(GVI),建筑视图因子,和天空景观因素。使用空间分辨率为0.01°的2018年至2021年的每月温度数据。我们应用了线性混合效应模型和地理加权回归来探索行人绿色空间与环境温度之间的关联,控制季节,土地利用信息,和交通量。他们的结果表明,较高的GVI与较低的环境温度和温差显着相关。交通流量或特定土地用途较高的地点,如宗教或政府,与更高的环境温度有关。总之,社区一级街景图像的GVI可以提高对城市绿地的理解,并与其他社会和环境指标一起评估其影响。
    Urban heat islands will occur if city neighborhoods contain insufficient green spaces to create a comfortable environment, and residents\' health will be adversely affected. Current satellite imagery can only effectively identify large-scale green spaces and cannot capture street trees or potted plants within three-dimensional building spaces. In this study, we used a deep convolutional neural network semantic segmentation model on Google Street View to extract environmental features at the neighborhood level in Taipei City, Taiwan, including the green vegetation index (GVI), building view factor, and sky view factor. Monthly temperature data from 2018 to 2021 with a 0.01° spatial resolution were used. We applied a linear mixed-effects model and geographically weighted regression to explore the association between pedestrian-level green spaces and ambient temperature, controlling for seasons, land use information, and traffic volume. Their results indicated that a higher GVI was significantly associated with lower ambient temperatures and temperature differences. Locations with higher traffic flows or specific land uses, such as religious or governmental, are associated with higher ambient temperatures. In conclusion, the GVI from street-view imagery at the community level can improve the understanding of urban green spaces and evaluate their effects in association with other social and environmental indicators.
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  • 文章类型: Journal Article
    萨赫勒地区和撒哈拉以南非洲大部分地区的农业在很大程度上仍在下雨。同时,气候变化已经导致该地区降雨模式难以预测,即使气温上升也会增加农业生产所需的水量。我们评估灌溉在多大程度上可以加强农业社区的气候适应能力。我们的研究样本包括马里近1000个不同的地点,在过去的二十年中引入了基于河流的灌溉,随着天气条件恶化和政治动荡爆发。使用交错展开的灌溉和20年的重复观察,使我们能够比较位置的灌溉前和灌溉后的结果,同时调整混杂因素。我们在地理上将灌溉干预措施的数据与使用卫星图像和调查测量的农业条件联系起来,以及儿童营养和健康结果和冲突事件数据。使用双向固定效应模型准实验估计反事实结果,我们发现,灌溉的引入导致了支持田地上农业产量的大幅增加,这些成就甚至在十年后仍然存在。由于灌溉,附近社区的儿童不太可能发育迟缓或浪费,和冲突风险在最近的社区减少。其中一些收益被远离新安装的灌溉的条件恶化所抵消。这些发现表明,即使半干旱地区的政治冲突已经增加,可持续灌溉可能为改善社区的长期福祉和社会凝聚力提供有价值的工具。
    Agriculture in the Sahel and much of sub-Saharan Africa remains to a large extent rainfed. At the same time, climate change is already causing less predictable rainfall patterns in the region, even as rising temperatures increase the amount of water needed for agricultural production. We assess to what extent irrigation can strengthen the climate resilience of farming communities. Our study sample consists of nearly 1,000 distinct locations in Mali in which small-scale, river-based irrigation was introduced over the past two decades, as weather conditions worsened and political upheaval erupted. Using the staggered roll-out of the irrigation and repeated observations over 20 years allows us to compare the pre- and postirrigation outcomes of locations while adjusting for confounding factors. We geospatially link data on irrigation interventions with agricultural conditions measured using satellite imagery and surveys, as well as child nutrition and health outcomes and conflict event data. Using a two-way fixed effects model to quasi-experimentally estimate counterfactual outcomes, we find that the introduction of irrigation led to substantial increases in agricultural production on supported fields, with these gains persisting even a decade later. Children in nearby communities are less likely to be stunted or wasted due to the irrigation, and conflict risks decrease in the closest communities. Some of these gains are offset by worsening conditions farther away from the newly installed irrigation. These findings suggest that, even with political conflicts in semi-arid areas already increasing, sustainable irrigation may offer a valuable tool to improve communities\' long-term well-being and social cohesion.
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  • 文章类型: Dataset
    由于全球变化,东非山区生态系统面临越来越大的威胁,把他们独特的社会生态系统置于危险之中。为了监测和了解这些变化,研究人员和利益相关者需要可访问的分析准备遥感数据。尽管卫星数据可用于许多应用,它通常缺乏准确的几何方向,并且具有广泛的云层覆盖。这可能会产生误导性的结果,并使其不可靠的时间序列分析。因此,使用前需要综合处理,包括多步骤操作,需要大的计算和存储容量,以及专业知识。这里,我们提供高质量,大气校正,以及贝尔山脉(埃塞俄比亚)的无云分析Sentinel-2图像,乞力马扎罗山和梅鲁(坦桑尼亚)生态系统在东非。我们的数据集范围从2017年到2021年,以月度和年度汇总产品以及24个光谱指数提供。我们的数据集使研究人员和利益相关者能够立即进行有影响力的分析。这些应用可以包括植被测绘,野生动物栖息地评估,土地覆盖变化检测,生态系统监测,和气候变化研究。
    The East African mountain ecosystems are facing increasing threats due to global change, putting their unique socio-ecological systems at risk. To monitor and understand these changes, researchers and stakeholders require accessible analysis-ready remote sensing data. Although satellite data is available for many applications, it often lacks accurate geometric orientation and has extensive cloud cover. This can generate misleading results and make it unreliable for time-series analysis. Therefore, it needs comprehensive processing before usage, which encompasses multi-step operations, requiring large computational and storage capacities, as well as expert knowledge. Here, we provide high-quality, atmospherically corrected, and cloud-free analysis-ready Sentinel-2 imagery for the Bale Mountains (Ethiopia), Mounts Kilimanjaro and Meru (Tanzania) ecosystems in East Africa. Our dataset ranges from 2017 to 2021 and is provided as monthly and annual aggregated products together with 24 spectral indices. Our dataset enables researchers and stakeholders to conduct immediate and impactful analyses. These applications can include vegetation mapping, wildlife habitat assessment, land cover change detection, ecosystem monitoring, and climate change research.
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