A Tracking Analyst for large 3D spatiotemporal data from multiple sources (case study: Tracking volcanic eruptions in the atmosphere)

Gad, Mohamed A.; Gračanin, Denis; Elmongui, Hicham G.

doi:10.1016/j.cageo.2017.10.003

Cited by 6 publications

(8 citation statements)

References 20 publications

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“…Through the analysis of the spatial-temporal trajectory data of algal blooms, we can extract the similarity features of these data and divide them into categories of similar behavior without prior knowledge [57]. A three-dimensional map was used to show the temporal-spatial synchronous variation characteristics [58] of algal blooms in Lake Dianchi. High-ABF areas were utilized as the hot zone to track the trajectory.…”

Section: Temporal-spatial Distributions Of Pixel-algae Frequencymentioning

confidence: 99%

MODIS-Satellite-Based Analysis of Long-Term Temporal-Spatial Dynamics and Drivers of Algal Blooms in a Plateau Lake Dianchi, China

Jing

Zhang

et al. 2019

Remote Sensing

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Algal blooms in eutrophic lakes have been a global issue to environmental ecology. Although great progress on prevention and control of algae have been made in many lakes, systematic research on long-term temporal-spatial dynamics and drivers of algal blooms in a plateau Lake Dianchi is so far insufficient. Therefore, the algae pixel-growing algorithm (APA) was used to accurately identify algal bloom areas at the sub-pixel level on the Moderate Resolution Imaging Spectroradiometer (MODIS) data from 2000 to 2018. The results showed that algal blooms were observed all year round, with a reduced frequency in winter–spring and an increased frequency in summer–autumn, which lasted a long time for about 310–350 days. The outbreak areas were concentrated in 20–80 km2 and the top three largest areas were observed in 2002, 2008, and 2017, reaching 168.80 km2, 126.51 km2, and 156.34 km2, respectively. After deriving the temporal-spatial distribution of algal blooms, principal component analysis (PCA) and redundancy analysis (RDA) were applied to explore the effects of meteorological, water quality and human activities. Of the variables analyzed, mean temperature (Tmean) and wind speed (WS) were the main drivers of daily algal bloom areas and spatial distribution. The precipitation (P), pH, and water temperature (WT) had a strong positive correlation, while WS and sunshine hours (SH) had a negative correlation with monthly maximum algal bloom areas and frequency. Total nitrogen (TN) and dissolved oxygen (DO) were the main influencing factors of annual frequency, initiation, and duration of algal blooms. Also, the discharge of wastewater and the southwest and southeast monsoons may contribute to the distribution of algal blooms mainly in the north of the lake. However, different regions of the lake show substantial variations, so further zoning and quantitative joint studies of influencing factors are required to more accurately understand the true mechanisms of algae in Lake Dianchi.

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Section: Temporal-spatial Distributions Of Pixel-algae Frequencymentioning

confidence: 99%

MODIS-Satellite-Based Analysis of Long-Term Temporal-Spatial Dynamics and Drivers of Algal Blooms in a Plateau Lake Dianchi, China

Jing

Zhang

et al. 2019

Remote Sensing

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“…While the investigation of NDVI can deliver observation of vegetation fluctuations in contrast to other vegetation indices by using Landsat imageries based on variations in absorption and reflectivity of energy resulting from vegetative cover in the red and near-infrared bands (Fung and Siu 2000). This technique hires the Multi-Spectral Remote Sensing data method to discover Vegetation Index, land cover organization, vegetation, water bodies, open area, undergrown area, mountainous areas, agrarian areas, and forests with limited band fusions of the remote sensed data, particularly to interpret exterior structures of the noticeable areas which are significant for policymakers while making strategies by using formula as (NIR-RED)/ ( NIR +RED) whereabouts NIR denotes reflectivity which discharges in the near-infrared frequency band of satellite (Gandhi et al 2015) to access the vegetative area in union councils.…”

Section: Image Preprocessingmentioning

confidence: 99%

“…The geospatial analysis includes various Geographic Information System tools and techniques. Keeping in view the objectives of this study, the Tracking Analyst tool (Data Clock Manager) in ArcGIS was used to monitor and associate spatiotemporal variable data from several sources which use path evidence to access the positions of time-enabled and spatially variable scatter data via an amalgamation of trajectory alteration and spatial interpolation (Gad et al 2018). Hotspot statistical analysis in ArcGIS was used as recognition of present hotspots is considered as one of the primary steps for developing policy to alleviate urban flooding which uses Getis-Ord Gi statistic to discover spatial variations (Zia and Shirazi 2019;Zia et al 2021).…”

Section: Geospatial Analysismentioning

confidence: 99%

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The Effect Of Urban Green Spaces In Reducing Urban Flooding In Lahore, Pakistan, Using Geospatial Techniques

Zia

Nasar-u-Minallah

Zahra

et al. 2022

GES

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Urban Green Spaces (UGS) curtails all environmental issues and ensure an eco-friendly locale. Similarly, the emergence of UGS is very helpful to cope with emerging urban flooding in cities by setting up the world standard of green space ratio (20 to 25 percent of the area) and green per capita (9m2 ) in a geographical area. Therefore, the present study is conducted to evaluate the causal effect relation of UGS with the frequency of urban flooding. For this purpose, 69 selected union councils are taken as a study area in District Lahore, Pakistan. The relation between UGS and the occurrence of floods is evaluated using geo-statistical and geospatial analysis techniques during the monsoon rainfalls from 2013 to 2019. Furthermore, the data sets of sore points (inundated areas), occurrences of urban flooding (number of event occurrences), green per capita, and green ratio are used. Results revealed that selected union councils in Lahore don’t have enough urban green spaces. There is only a 51 sq km area with adequate UGS that accounts for only 18 percent of the study area. The rest of the area does not meet the world standards of green area. There are some areas including Ravi town, Gulberg town, and Samanabad town with green per capita more than 4 green per capita. On the other hand, there are only 02 union councils including Race Course and Model Town that are comprised of a 20 percent green area. The findings of the study will be helpful for proper urban planning and strategies i.e. with greener structures.

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“…Asencio-Cortés et al., 2018; Yin et al., 2018); and to track volcanic eruptions (e.g. Gad et al., 2018).…”

Section: Lessons For Global Development Policymentioning

confidence: 99%

Data deprivations, data gaps and digital divides: Lessons from the COVID-19 pandemic

Naudé

Vinuesa

2021

Big Data & Society

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This paper draws lessons from the COVID-19 pandemic for the relationship between data-driven decision making and global development. The lessons are that (i) users should keep in mind the shifting value of data during a crisis, and the pitfalls its use can create; (ii) predictions carry costs in terms of inertia, overreaction and herding behaviour; (iii) data can be devalued by digital and data deluges; (iv) lack of interoperability and difficulty reusing data will limit value from data; (v) data deprivation, digital gaps and digital divides are not just a by-product of unequal global development, but will magnify the unequal impacts of a global crisis, and will be magnified in turn by global crises; (vi) having more data and even better data analytical techniques, such as artificial intelligence, does not guarantee that development outcomes will improve; (vii) decentralised data gathering and use can help to build trust – particularly important for coordination of behaviour.

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A Tracking Analyst for large 3D spatiotemporal data from multiple sources (case study: Tracking volcanic eruptions in the atmosphere)

Cited by 6 publications

References 20 publications

MODIS-Satellite-Based Analysis of Long-Term Temporal-Spatial Dynamics and Drivers of Algal Blooms in a Plateau Lake Dianchi, China

MODIS-Satellite-Based Analysis of Long-Term Temporal-Spatial Dynamics and Drivers of Algal Blooms in a Plateau Lake Dianchi, China

The Effect Of Urban Green Spaces In Reducing Urban Flooding In Lahore, Pakistan, Using Geospatial Techniques

Data deprivations, data gaps and digital divides: Lessons from the COVID-19 pandemic

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