scholarly journals Low-Cost Solution for Assessment of Urban Flash Flood Impacts Using Sentinel-2 Satellite Images and Fuzzy Analytic Hierarchy Process: A Case Study of Ras Ghareb City, Egypt

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Mohammed Sadek ◽  
Xuxiang Li
Keyword(s):  
Natural Hazards ◽  
Forest Fires ◽  
Satellite Images ◽  
Flash Flood ◽  
Low Cost ◽  
Regional Scale ◽  
Warning System ◽  
Geographical Information ◽  
Hierarchy Process ◽  
Sentinel 2

Natural hazards are indeed counted as the most critical challenges facing our world, represented in floods, earthquakes, volcanoes, hurricanes, and forest fires. Among these natural hazards, the flash flood is regarded the most frequent. In this work, we utilized two Sentinel-2 satellite images, before and after the flash flood, SRTM and photos captured by using a helicopter. This paper aims at three prime objectives. Firstly, the flood influence is determined on the city of Ras Ghareb, Egypt, based on analyzing free satellite data (Sentinel-2 images). Secondly, fuzzy the analytical hierarchy process (FAHP) method and a geographical information system (GIS) are integrated for flood risk analysis and evaluation in the flood-prone area. Finally, such a flood vulnerability map is used as an index to assist the decision-makers prepare for probable flooding. FAHP is preferable as it can cater to the uncertainties in data and analysis. As a result, FAHP is appropriate to determine the flood-vulnerable area in cities especially due to the matching with the most destroyed areas identified by the change detection between the two Sentinel-2 images. Then, the decision-maker can depend on Sentinel-2 images to estimate the flood influence through a regional scale or applying the FAHP on cities susceptible to flash floods in case of unavailable satellite images to contribute in establishing an early warning system enough to the evacuation of the risky areas.

scholarly journals Multihazard susceptibility assessment: A case study – Municipality of Štrpce (Southern Serbia)

2021 ◽  
Vol 13 (1) ◽  
pp. 1414-1431
Author(s):  
Uroš Durlević ◽  
Ivan Novković ◽  
Tin Lukić ◽  
Aleksandar Valjarević ◽  
Ivan Samardžić ◽  
...  
Keyword(s):  
Natural Hazards ◽  
Forest Fires ◽  
Flash Flood ◽  
Index Method ◽  
Potential Index ◽  
Significant Step ◽  
Fourth Step ◽  
Ecological Importance ◽  
Hierarchy Process

Abstract The municipality of Štrpce (Southern Serbia) is an area located within Šar Mountain National Park, which is of great ecological importance. Due to the vicinity of settlements, it is necessary to analyze the terrain's susceptibility to natural hazards. The main goal of this research was to determine locations that are highly vulnerable at times of natural hazards (such as earthquakes, erosion, torrential flooding, snow avalanches, and forest fires). The first step in this research was to analyze seismic hazards for a 475 years return period (VII–VIII MCS for the observed area), which was possible by means of Geographic Information Systems. The second step was to determine the intensity of erosion and total sediment production using the Erosion Potential Model. The third step was related to the analysis of the potential of torrential floods using the Flash Flood Potential Index. The Avalanches Potential Index method was used as the fourth step. The fifth step included the analysis of a terrain susceptibility to the occurrence of forest fires. Following the five criteria analysis, weight coefficients were assigned to each of the analyzed parameters by using the Analytical Hierarchy Process (AHP), which provided results of the total susceptibility to natural hazards of the territory of Štrpce. Results indicated that over 45% of the municipality is highly or very highly susceptible to various natural hazards. This article represents a significant step toward a better understanding of natural hazards and it provides a unique knowledge basis for establishing the management and mitigation guidelines and measures, not only within the researched area but at regional and national levels as well.

scholarly journals Understanding Spatial Variations in Earthquake Vulnerabilities of Residential Neighborhoods of Mymensingh City, Bangladesh: An AHP-GIS Integrated Index-based Approach

2019 ◽  
Author(s):  
Md. Shaharier Alam ◽  
Shamim Mahabubul Haque
Keyword(s):  
Developing Countries ◽  
City Planning ◽  
Low Cost ◽  
Composite Index ◽  
Spatial Variations ◽  
Geographical Information ◽  
Earthquake Risk ◽  
Cost Approach ◽  
Earthquake Vulnerability ◽  
Hierarchy Process

Abstract. Mymensingh city is highly earthquake vulnerable due to its geological setting, existence of three faults, viz., Dauki Fault, Madhupur Blind Fault and Sylhet-Assam Fault in its close vicinity, and liquefaction susceptible soil type. Recently an attempt has been made to assess earthquake risk of the city by Comprehensive Disaster Management Programme II, of Government of Bangladesh using FEMA developed HAZUS tool which requires usage of enormous resources and expertise. Poorly resourced city planning authorities of developing countries are seldom equipped with such financial and human resources, and as a result, the inclusion of earthquake risk analysis, more specifically, information regarding spatial variations of earthquake risk is very often found missing in their physical planning exercises. This paper aims to assess the spatial variation of earthquake vulnerability of residential neighbourhoods of Mymensingh city, employing an index-based low cost approach which could provide a reasonably accurate result with minimum resource and expertise requirements. Analytical Hierarchy Process and Weighted Linear Combination are combined with a Geographical Information System to prepare a composite index considering 23 different parameters, stemming from geological, structural, socio-economic and systematic dimensions of earthquake vulnerability. The findings of the reseach show that out of 241 residential neighbourhoods of Mymensingh city, 51 are observed to be highly vulnerable, while, 123 and 67 are medium and low vulnerable respectively. Besides, the spatial distribution of earthquake vulnerable neighbouhoods in Mymensingh City, observed in the current study has also been compared with spatial distributions observed in two similar previous studies and observed found to be reasonably close. This justifies the validity of the current low cost approach for wider application in cities of resource starved developing countries.

Community Based Flash Flood Early Warning System: a Low-cost Technology for Nepalese Mountains

2018 ◽  
pp. 87-92
Author(s):  
Basanta Raj Adhikari ◽  
Nagendra Raj Sitoula
Keyword(s):  
Operating System ◽  
Early Warning ◽  
Flash Flood ◽  
Low Cost ◽  
Warning System ◽  
Early Warning Systems ◽  
Ultrasonic Sensor ◽  
Environmental Cost ◽  
High Tech ◽  
Processing Unit

Every year, flood impose substantial economic, social and environmental cost on Nepalese community through direct damage to residential, commercial, educational and structures. Moreover, the flood destroys animal farm, commercial stock and records and other content of the building and pollutes the water. Early Warning Systems are important to save such lives and properties which involves computer, satellite data and high accurate operating system but this system is very costly in terms of installation as well as operation and maintenance leading to hindrance in the sustainability of the system. However, high-tech technology is very expensive and not feasible in Nepal and therefore low-cost and easy operating system is needed in the rural parts of Nepal. The system includes Solar panel, Siren, Ultrasonic sensor, processing unit, and battery. The ultrasonic sensor sense water level and the siren will automatically start. The threshold can be set up according to the space and time. Bulletin of Department of Geology, vol. 20-21, 2018, pp: 87-92

scholarly journals Forest Fire Area Detection by Using Landsat-8 and Sentinel-2 Satellite Images: A Case Study in Mugla, Turkey

2020 ◽  
Author(s):  
Bahadir Kurnaz ◽  
Caglar Bayik ◽  
Saygin Abdikan
Keyword(s):  
Forest Fire ◽  
Forest Fires ◽  
Satellite Images ◽  
Near Infrared ◽  
Kappa Statistics ◽  
Landsat 8 ◽  
Important Place ◽  
Burn Scar ◽  
Object Based ◽  
Sentinel 2

Abstract Background: Forests have an extremely important place in the ecosystem in terms of ensuring social and environmental balance. The biggest danger for forests that have this importance is forest fires due to various reasons. It is extremely important to estimate the formation and behavior characteristics of fires in terms of combating forest fires. Using the satellite images obtained with the developing technology for this purpose provides great convenience in the detection of the fire areas and the severity of the fire affected. In this study, forest fire that occurred in the Zeytinköy region of Muğla province was investigated using remotely sensed images. According to the reference data provided by the General Directorate of Forestry (GDF), 425 hectares of area was destroyed by fire. In this study, it is aimed to extract burn scar by applying seven vegetation indexes on Sentinel-2 and Landsat-8 satellite images. Additionally, forest fire areas have been determined with the object-based classification technique. Results: As a result of the study, when the obtained results are compared with the values obtained from GDF, it is determined that object based analysis of Sentinel-2 provided the highest accuracy with 98.36% overall accuracy and 0.976 kappa statistics. Comparing the results of spectral indices of Sentinel-2 and Landsat-8, Sentinel-2 resulted better results in all indices. Among the indices RdNBR and dNDVI obtained better results than other indices with Sentinel-2 and Landsat-8, respectively. Conclusions: In general, it has been determined that Sentinel-2 data is more suitable than Landsat-8 satellite images for determining Turkish red pine forest fired areas. Red and near infrared based images can be used for rapid mapping of fired areas. The results also indicated that the indices provided by multi-temporal Sentinel-2 data can assist forest management for rapid monitoring of fire scars and also for evolution of reforestation after fire.

scholarly journals High-resolution urban air quality monitoring using sentinel satellite images and low-cost ground-based sensor networks

2020 ◽  
Vol 171 ◽  
pp. 02002
Author(s):  
Joseph Gitahi ◽  
Michael Hahn
Keyword(s):  
Satellite Images ◽  
Meteorological Data ◽  
Low Cost ◽  
Correlation Coefficients ◽  
Urban Environments ◽  
Average Correlation ◽  
Second Stage ◽  
Aerosol Distribution ◽  
Level Monitoring ◽  
Sentinel 2

Satellite remote sensing aerosol monitoring products are readily available but limited to regional and global scales due to low spatial resolutions making them unsuitable for city-level monitoring. Freely available satellite images such as Sentinel -2 at relatively high spatial (10m) and temporal (5 days) resolutions offer the chance to map aerosol distribution at local scales. In the first stage of this study, we retrieve Aerosol Optical Depth (AOD) from Sentinel -2 imagery for the Munich region and assess the accuracy against ground AOD measurements obtained from two Aerosol Robotic Network (AERONET) stations. Sen2Cor, iCOR and MAJA algorithms which retrieve AOD using Look-up-Tables (LUT) pre-calculated using radiative transfer (RT) equations and SARA algorithm that applies RT equations directly to satellite images were used in the study. Sen2Cor, iCOR and MAJA retrieved AOD at 550nm show strong consistency with AERONET measurements with average correlation coefficients of 0.91, 0.89 and 0.73 respectively. However, MAJA algorithm gives better and detailed variations of AOD at 10m spatial resolution which is suitable for identifying varying aerosol conditions over urban environments at a local scale. In the second stage, we performed multiple linear regression to estimate surface Particulate Matter (PM2.5) concentrations using the satellite retrieved AOD and meteorological data as independent variables and ground-measured PM2.5 data as the dependent variable. The predicted PM2.5 concentrations exhibited agreement with ground measurements, with an overall coefficient (R2) of 0.59.

Development and Testing of a Low-cost Water Level Sensor and a Mobile based Real-time Flood Warning System for the Flash Flood Prone North Eastern part of Bangladesh

2020 ◽  
Vol 10 ◽  
Author(s):  
Nova Ahmed ◽  
Md. Sirajul Islam ◽  
Sifat Kalam ◽  
Farzana Islam ◽  
Nabila Chowdhury ◽  
...  
Keyword(s):  
Water Level ◽  
Real Time ◽  
Flash Flood ◽  
Low Cost ◽  
Warning System ◽  
Outdoor Environment ◽  
Flood Warning ◽  
North Eastern ◽  
Flood Warning System ◽  
North Eastern Part

Background: The North-Eastern part of Bangladesh is suffering from flash flood very frequently, causing colossal damage to life and properties, especially the vast croplands. A distributed sensing system can monitor the water level on a continuous basis to warn people near the riverbank beforehand and reduce the damage largely. However, the required communication infrastructure is not available in most of the remote rural areas in a developing country like Bangladesh. Objective: This study intends to develop a low-cost sensor based warning system, customizing to the Bangladesh context. Method: The system utilizes a low-cost ultrasound based sensor device, a lightweight mobile phone based server, low-cost IoT sensing nodes, and a central server for continuous monitoring of river stage data along with the provision of storage and long-term data analytics. Results: A flash flood warning system developed afterward with the sensors, mobile-based server, and appropriate webbased interfaces. The device was tested for some environmental conditions in the lab and deployed it later in the outdoor conditions for short-term periods. Conclusion: Overall, the warning system performed well in the lab as well as the outdoor environment, with the ability to detect water level at reasonable accuracy and transmit data to the server in real time. Some minor shortcomings still noted with the scope for improvements, which are in the way to improve further.

scholarly journals Remote sensors of Vegetable Activity to protect areas resistant to low soil moisture

2021 ◽  
Author(s):  
Fernando Roque
Keyword(s):  
Rainy Season ◽  
Early Warning System ◽  
Satellite Images ◽  
Low Cost ◽  
Warning System ◽  
Napa Valley ◽  
Remote Sensors ◽  
Cost Strategy ◽  
Drought Conditions ◽  
Low Cost Strategy

Corte de Madera has a high vegetable activity measured by satellite despite the extreme drought conditions of the State during the years 2020-2021. Napa Valley suffered a severe decline in vegetable activity just after the rainy season of 2020 in April. It happened before the wildfires that affect the region in August 2020. Dixie region had a declining rainy season of 2020 and 2021 (November to April). The wildfires started in August. Satellite images could be a low-cost strategy to build an Early Warning System for wildfires.

scholarly journals Understanding Spatial Variations in Earthquake Vulnerabilities of Residential Neighborhoods of Mymensingh City, Bangladesh: An AHP-GIS Integrated Index-based Approach

2020 ◽  
Author(s):  
Md. Shaharier Alam ◽  
Shamim Mahabubul Haque
Keyword(s):  
Developing Countries ◽  
City Planning ◽  
Low Cost ◽  
Composite Index ◽  
Spatial Variations ◽  
Geographical Information ◽  
Earthquake Risk ◽  
Cost Approach ◽  
Earthquake Vulnerability ◽  
Hierarchy Process

Abstract Mymensingh city is highly earthquake vulnerable due to its geological setting, existence of three faults, viz., Dauki Fault, Madhupur Blind Fault and Sylhet-Assam Fault in its close vicinity, and liquefaction susceptible soil type. Recently an attempt has been made to assess earthquake risk of the city by Comprehensive Disaster Management Programme II, of Government of Bangladesh using FEMA developed HAZUS tool which requires usage of enormous resources and expertise. Poorly resourced city planning authorities of developing countries are seldom equipped with such financial and human resources, and as a result, the inclusion of earthquake risk analysis, more specifically, information regarding spatial variations of earthquake risk is very often found missing in their physical planning exercises. This paper aims to assess the spatial variation of earthquake vulnerability of residential neighbourhoods of Mymensingh city, employing an index-based low cost approach which could provide a reasonably accurate result with minimum resource and expertise requirements. Analytical Hierarchy Process and Weighted Linear Combination are combined with a Geographical Information System to prepare a composite index considering 23 different parameters, stemming from geological, structural, socio-economic and systematic dimensions of earthquake vulnerability. The findings of the reseach show that out of 241 residential neighbourhoods of Mymensingh city, 51 are observed to be highly vulnerable, while, 123 and 67 are medium and low vulnerable respectively. Besides, the spatial distribution of earthquake vulnerable neighbouhoods in Mymensingh City, observed in the current study has also been compared with spatial distributions observed in two similar previous studies and observed found to be reasonably close. This justifies the validity of the current low cost approach for wider application in cities of resource starved developing countries.

scholarly journals Natural Hazards in Sao Vicente (Cabo Verde)

2018 ◽  
Vol 11 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
Bruno Martins ◽  
Luciano Lourenço ◽  
Sílvia Monteiro
Keyword(s):  
Natural Hazards ◽  
Flash Flood ◽  
Flood Hazard ◽  
Regional Scale ◽  
Point Of View ◽  
Vulnerability Factors ◽  
Cabo Verde ◽  
Flooding Hazards ◽  
Main Factors ◽  
The City

Abstract São Vicente island (República de Cabo Verde) lies within the Sahelian zone and faces a number of natural hazards, of which the most significant ones are erosion and gully formation, desertification and flash flooding hazards. Based on examples, we set out to examine the main factors involved in the development of these natural hazards from a regional point of view, while simultaneously assessing the importance of anthropic action as a structural factor. The investigation of Lazareto’s gullies (located to the west of Mindelo) aimed to determine the main factors of the gullies formation. It also sought to demonstrate that the gullies’ formation is a reliable indicator of the high rates of erosion on a regional scale. The approach to the desertification hazards was based on farmers’ perception related to the evolution of agricultural production, strategies to mitigate drought and desertification issues, consequences and future prospects based on a set of interviews conducted in Ribeira da Vinha. Finally, the intense rainfall event that occurred on August 26, 2008 was analysed to identify the main vulnerability factors of the city in light of the flash flood hazard.

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