scholarly journals An Assessment of Spatio-Temporal Characteristics of Lightning Occurrence with Elevation, a Case of Uganda

2021 ◽  
Author(s):  
Peter Wasswa ◽  
Geoffrey Sabiiti ◽  
Harriette Okal ◽  
Paul Kato ◽  
Joyce Lunyolo ◽  
...  
Keyword(s):  
Recent Decade ◽  
Shuttle Radar Topography Mission ◽  
Lightning Flash ◽  
Lightning Strikes ◽  
Temporal Characteristics ◽  
Elevation Data ◽  
Electric Power Networks ◽  
Spatio Temporal ◽  
Elevation Model ◽  
Imaging Sensor

Lightning has received a lot of attention in scientific literature during the recent decade, not only because it is an impressive atmospheric phenomenon but also its associations with severe storms that cause unprecedented damages to agriculture, electric power networks, property, and life. This study assessed the Spatio-temporal characteristics of lightning occurrence with elevation in Uganda using lightning flash and elevation datasets for a period of fifteen years (1998-2013). Datasets used in this study included daily lightning flashes as captured by Lightning Imaging Sensor (LIS) aboard on Tropical Rainfall Measurement Mission (TRMM) satellite and elevation data in form of Digital Elevation Model (DEM) obtained from the Shuttle Radar Topography Mission (SRTM). Spatio-temporal results indicated that ~80% of areas with an elevation that ranges from 800-1200 m above mean sea level (masl) in Uganda had severe lightning occurrences and ~20% of areas with an elevation greater than 1200 m (masl) had severe lightning occurrences. The country received an enhanced number of lighting events with the highest number in 1999. Subsequently, a reduced trend was observed from 2002 to 2007 followed by an increment in the number of lightning events in (2010, 2011, 2012, and 2013). The intensity of the events decreased gradually though two peaks were observed, (1998-2001) and (2010-2013). Furthermore, results indicate escalations in the frequency and duration of lightning events from 60 times in 1998 to approximately 200 times in 2013 and from 1000 microseconds in 1998 to more than 2000 microseconds in 2013. Generally, the country experienced an enhanced increase in lighting occurrences over the study period which therefore calls for urgent actions to combat the root cause and also provide effective measures to reduce the impacts of lightning strikes.

scholarly journals SRTM DEM levels over papyrus swamp vegetation – a correction approach

2009 ◽  
Vol 21 ◽  
pp. 81-84 ◽  
Author(s):  
G. Petersen ◽  
I. Lebed ◽  
N. Fohrer
Keyword(s):  
Correction Factor ◽  
Ground Level ◽  
Shuttle Radar Topography Mission ◽  
Radar Signal ◽  
Real Surface ◽  
Srtm Dem ◽  
Ground Control Points ◽  
Digital Elevation ◽  
Elevation Data ◽  
Elevation Model

Abstract. The SRTM DEM, a digital elevation model based on the Shuttle Radar Topography Mission of February 2000 is a source of elevation data with nearly worldwide coverage. It has proven its usefulness in various regions but problems persist for densely vegetated areas where, caused by the organic matter and water content of the vegetation, the radar signal is reflected at some level between the vegetation canopy and the ground level. This level varies with different types and densities of vegetation cover and has so far not been assessed for papyrus areas. The paper describes the approach and establishment of a correction factor for a pilot area in the Sudd swamps of southern Sudan based on comparison of SRTM reference levels and ground control points collected during field surveys between 2004 and 2006. Results show a correction factor between the sensed and the real surface of 4.66 m and a average penetration depth of the radar signal into the dense papyrus vegetation of 0.34 m.

scholarly journals An Analysis of the Flood-Prone Areas in Birnin Kebbi, Using Remote Sensing and GIS

2020 ◽  
pp. 77-85
Author(s):  
Abdullahi Muktar ◽  
Sadiq A. Yelwa
Keyword(s):  
Local Government ◽  
Shuttle Radar Topography Mission ◽  
Local Government Area ◽  
Geographical Information ◽  
Lower Altitude ◽  
Digital Elevation ◽  
Elevation Data ◽  
Point Data ◽  
Elevation Model ◽  
Flooding Events

Aim: To identify settlements that are vulnerable to flooding within River Rima floodplain in Birnin Kebbi Local Government Area of Kebbi State, Nigeria. Study Design: A flood vulnerability test was conducted by observing the relationship between the locations of settlements on the floodplain and elevation data, considering previous flooding events. Place and Duration of Study: The study covers Birnin Kebbi Local Government Area of Kebbi State, Nigeria. Methodology: This study uses Digital Elevation Model DEM obtained by The Shuttle Radar Topography Mission (SRTM). The Geographical Information System (GIS) technique (Map Overlay) was used where DEM was overplayed by settlement location (point data). Similarly, 3D view was used to confirm the result. Conclusion: The result shows that 12 settlements in Birnin Kebbi LGA were located at the lower altitude (<207m) with close proximity from the river channel. Therefore, the settlements and the surrounding farmlands become vulnerable to flooding. Recommendations: It was recommended that the settlements should be relocated to higher ground for safety. Local farmers should use species of rice that can survive longer time when submerged by water. The Environmental Monitoring Agencies should include detailed images showing affected areas in their publications.

scholarly journals Spatio-temporal Variability of Lightning Climatology and Its Association With Thunderstorm Indices Over India

2022 ◽  
Author(s):  
Unashish Mondal ◽  
Subrat Kumar Panda ◽  
Someshwar Das ◽  
Devesh Sharma
Keyword(s):  
Tropical Rainfall Measuring Mission ◽  
Eastern Region ◽  
Lightning Flash ◽  
Time Duration ◽  
Jammu And Kashmir ◽  
Flash Rate ◽  
North Eastern ◽  
Very High Spatial Resolution ◽  
Spatio Temporal ◽  
Imaging Sensor

Abstract Lightning is an electrical discharge - a'spark' or 'flash' as charged regions in the atmosphere instantly balance themselves through this discharge. It is a beautiful and deadly naturally occurring phenomenon. In June 2020, more than a hundred people died in the state Bihar of India only in three days’ span due to lightning events. In this work, Lightning Imaging Sensor (LIS) information from the Tropical Rainfall Measuring Mission (TRMM) satellite with a very high spatial resolution of 0.1 X 0.1 degree has been utilized to create the climatology of India for 16 years from 1998 to 2013. Diurnal, monthly, and seasonal variations in the occurrence of lightning flash rate density have also been analyzed. TRMM satellite low-resolution monthly time series (LRMTS) with 2.5-degree resolution datasets have been used for lightning trend analysis. The diurnal lightning event mainly occurs in the afternoon/evening (1400-1900 Hrs) time duration around 0.001 flashes/km2/hr. The highest lightning occurred in May (0.04 flashes/km2/day) and the least in December (0.005 flashes/km2/day). The distribution of lightning flash counts by season over India landmass is mainly in pre-monsoon (MAM) ranges from 0.248 – 0.491 flashes/km2/day, and monsoon (JJA) ranges from 0.284 – 0.451 flashes/km2/day and decreases afterward. Spatially, the distribution of lightning flashes mainly at North-Eastern region along with Bangladesh, Bihar, Jharkhand, Orissa, and Jammu & Kashmir region. The CAPE and K Index have positively correlated with the flash rate density seasonally but CAPE is more significantly correlated. This study also focused on finding of lightning hotspots region of India district wise and Rajouri district in Jammu and Kashmir got the highest lightning with 121 flashes/km2/yr.

Urban Flood Mapping

2017 ◽  
Author(s):  
Indra Riyanto ◽  
Lestari Margatama
Keyword(s):  
Natural Disasters ◽  
Satisfying Condition ◽  
Three Dimensions ◽  
Urban Flood ◽  
Digital Elevation ◽  
Elevation Data ◽  
Recent Occurrence ◽  
Elevation Model ◽  
Digital Elevation Model Data ◽  
Potential Area

The recent degradation of environment quality becomes the prime cause of the recent occurrence of natural disasters. It also contributes in the increase of the area that is prone to natural disasters. Flood history data in Jakarta shows that flood occurred mainly during rainy season around January – February each year, but the flood area varies each year. This research is intended to map the flood potential area in DKI Jakarta by segmenting the Digital Elevation Model data. The data used in this research is contour data obtained from DPP–DKI with the resolution of 1 m. The data processing involved in this research is extracting the surface elevation data from the DEM, overlaying the river map of Jakarta with the elevation data. Subsequently, the data is then segmented using watershed segmentation method. The concept of watersheds is based on visualizing an image in three dimensions: two spatial coordinates versus gray levels, in which there are two specific points; that are points belonging to a regional minimum and points at which a drop of water, if placed at the location of any of those points, would fall with certainty to a single minimum. For a particular regional minimum, the set of points satisfying the latter condition is called the catchments basin or watershed of that minimum, while the points satisfying condition form more than one minima are termed divide lines or watershed lines. The objective of this segmentation is to find the watershed lines of the DEM image. The expected result of the research is the flood potential area information, especially along the Ciliwung river in DKI Jakarta.

scholarly journals MAT: GIS-Based Morphometry Assessment Tools for Concave Landforms

2021 ◽  
Vol 13 (14) ◽  
pp. 2810
Author(s):  
Joanna Gudowicz ◽  
Renata Paluszkiewicz
Keyword(s):  
Rapid Development ◽  
Assessment Tools ◽  
Lidar Data ◽  
Automatic Extraction ◽  
Sensing Technology ◽  
Digital Elevation ◽  
Elevation Data ◽  
Elevation Model ◽  
Morphometric Assessment ◽  
Morphometric Evaluation

The rapid development of remote sensing technology for obtaining high-resolution digital elevation models (DEMs) in recent years has made them more and more widely available and has allowed them to be used for morphometric assessment of concave landforms, such as valleys, gullies, glacial cirques, sinkholes, craters, and others. The aim of this study was to develop a geographic information systems (GIS) toolbox for the automatic extraction of 26 morphometric characteristics, which include the geometry, hypsometry, and volume of concave landforms. The Morphometry Assessment Tools (MAT) toolbox in the ArcGIS software was developed. The required input data are a digital elevation model and the form boundary as a vector layer. The method was successfully tested on an example of 21 erosion-denudation valleys located in the young glacial area of northwest Poland. Calculations were based on elevation data collected in the field and LiDAR data. The results obtained with the tool showed differences in the assessment of the volume parameter at the average level of 12%, when comparing the field data and LiDAR data. The algorithm can also be applied to other types of concave forms, as well as being based on other DEM data sources, which makes it a universal tool for morphometric evaluation.

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