scholarly journals Automatic Methodology to Detect the Coastline from Landsat Images with a New Water Index Assessed on Three Different Spanish Mediterranean Deltas

2019 ◽  
Vol 11 (18) ◽  
pp. 2186 ◽  
Author(s):  
Sandra Viaña-Borja ◽  
Miguel Ortega-Sánchez
Keyword(s):  
Remote Sensing ◽  
Satellite Images ◽  
Surface Reflectance ◽  
Landsat Images ◽  
Water Index ◽  
Measuring Techniques ◽  
Pixel Analysis ◽  
Land Covers ◽  
Shortwave Infrared ◽  
Bicubic Interpolation

Due to the importance of coastline detection in coastal studies, different methods have been developed in recent decades in accordance with the evolution of measuring techniques such as remote sensing. This work proposes an automatic methodology with new water indexes to detect the coastline from different multispectral Landsat images; the methodology is applied to three Spanish deltas in the Mediterranean Sea. The new water indexes use surface reflectance rather than top-of-atmosphere reflectance from blue and shortwave infrared (SWIR 2) Landsat bands. A total of 621 sets of images were analyzed from three different Landsat sensors with a moderate spatial resolution of 30 m. Our proposal, which was compared to the most commonly used water indexes, showed outstanding performance in automatic detection of the coastline in 96% of the data analyzed, which also reached the minimum value of bias of − 0.91 m and a standard deviation ranging from ±4.7 and ±7.29 m in some cases in contrast to the existing values. Bicubic interpolation was evaluated for a simple sub-pixel analysis to assess its capability in improving the accuracy of coastline extraction. Our methodology represents a step forward in automatic coastline detection that can be applied to micro-tidal coastal sites with different land covers using many multi-sensor satellite images.

scholarly journals ASSESSMENT OF SURFACE WATER AT THE SOBRADINHO RESERVOIR UNDER THE EFFECTS OF DROUGHT USING MULTI-TEMPORAL LANDSAT IMAGES

2016 ◽  
Vol XLI-B8 ◽  
pp. 387-392
Author(s):  
E. A. Silva ◽  
M. M. Pedrosa ◽  
S. C. Azevedo ◽  
G. P. Cardim ◽  
F. P. S. Carvalho
Keyword(s):  
Remote Sensing ◽  
Surface Area ◽  
Water Bodies ◽  
Environmental Research ◽  
Hydroelectric Power ◽  
Landsat Images ◽  
Water Index ◽  
The Matrix ◽  
Effects Of Drought ◽  
Water Administration

The matrix of energy generation in Brazil is predominantly hydroelectric power. Consequently, the reservoirs need constant monitoring due to the large volume of artificially dammed water. Images from remote sensing can provide reliable information concerning water bodies. In this paper, we use remote sensing imagery to monitor the Sobradinho dam in three different epochs. The objective was to verify quantitatively the area of the dam’s surface reduced due to the drought of 2015, which was considered the worst in history. The approach used water surface area estimations from bands of Landsat5 and Landsat8 satellites which highlight water bodies better from other features present on surface of the Earth. Through the techniques of growth region and normalized difference water index (NDWI), we determined the surface area of the reservoir in 2011 and calculated the decrease caused by the drought. By analyzing the numbers provided by the results it is possible to estimate how the Sobradinho reservoir has been affected by the drastic drought. The results show that the Landsat images enable the monitoring of large reservoirs. Bearing in mind that monitoring is a primary and indispensable tool, not only for technical study, but also for economic and environmental research, it can help establish planning projects and water administration strategies for future decisions about the hydrical resource priority.

scholarly journals EXTRACTING THE WATERLINE FROM LANDSAT IMAGES

2009 ◽  
Vol 12 (12) ◽  
pp. 52-58
Author(s):  
Thao Thi Phuong Pham ◽  
Duan Dinh Ho ◽  
To Van Dang
Keyword(s):  
Remote Sensing ◽  
Satellite Images ◽  
Numerical Models ◽  
Scientific Research ◽  
Remote Sensing And Gis ◽  
Landsat Images ◽  
Shoreline Changes ◽  
Remote Sensing Technology ◽  
Spectral Bands ◽  
Sensing Technology

Remote sensing technology nowadays is one of the most useful tools for scientific research in general and for oceanography in particular. From satellite images, the useful information such as waterline images can be extracte for a large region simultaneously. After tidal adjustments, the waterlines can be used as the observed shorelines which are important inputs for estimating shoreline changes by either using the integration of remote sensing and GIS or using numerical models. Based on the spectral bands of various Landsat images, the paper presents the methods to detect the waterlines in Phan Thiet region in the 40 years period using the images of 1973, 1976, 1990, and 2002 respectively. The extracted results relatively agree with the information of waterline from the images.

Remote Detection of Environmentally Vulnerable Terrain in Terms of Chemical Pollution of Soil and Groundwater

2020 ◽  
pp. 325-340
Author(s):  
Inna Romanciuc ◽  
Natalia Pazynych ◽  
Anton I. Manilov
Keyword(s):  
Remote Sensing ◽  
Environmental Impact ◽  
Data Processing ◽  
Satellite Images ◽  
Remote Detection ◽  
Chemical Pollution ◽  
Soil Humidity ◽  
Water Index ◽  
Humidity Level

Remote sensing is an efficient way to detect environmentally vulnerable terrain, where waste chemicals and excess fertilizers must result to considerable pollution of soil and groundwater. The indicators of such vulnerable formations were analyzed and applied for investigation of ground microdepressions. First indicator was the humidity level that was well recognized from the satellite images by calculation of normalized water index (NWI). Another active indicator used for the detection was the relief. The method of relief plastics joint with morphodynamic analysis was suggested for the data processing. The scheme of water basins and the map of environmentally fragile areas were created by combination of the indicators of soil humidity and topography. On the basis of the created maps, the restrictions for used chemicals can be developed in order to preserve considerable environmental impact of the pollution.

scholarly journals Seis anos de seca: Análise Espaço-temporal dos Espelhos d’água dos Reservatórios do Ceará por Sensoriamento Remoto

2021 ◽  
Vol 14 (4) ◽  
pp. 2220-2241
Author(s):  
Antônio Helton da Silva Barbosa ◽  
Miguel Dragomir Zanic Cuellar ◽  
Melquisedec Medeiros Moreira ◽  
Kátia Alves Arraes ◽  
Camila Saiury Pereira Silva
Keyword(s):  
Remote Sensing ◽  
Satellite Images ◽  
Water Security ◽  
Google Earth ◽  
Landsat Images ◽  
Panchromatic Image ◽  
Rgb Images ◽  
Effects Of Drought ◽  
Remote Sensing Techniques ◽  
Semi Arid Region

n recent years, in the midst of drought and water crisis that has affected several regions of Brazil, in particular the semi-arid region, surface water reserves have been constantly monitored. In this context, the objective of this study was to map and analyze, through Remote Sensing, the dynamics of the water mirrors of the main reservoirs in Ceará, in order to show how the area of the water mirrors of the reservoirs were affected by the precipitations below of the average during the last six years of drought, comprising the years 2012 to 2017. For this, the Google Earth Engine platform was used to analyze Landsat images, comprising the interannual period from 2012 to 2017. For the delimitation of the waters, an enhancement technique was used to convert the RGB images to HVS, creating a panchromatic image and facilitating the process of identifying the water mirrors. Thus, the results indicated that all reservoirs lost area, where some even dried up completely. The results also suggest that the reservoirs located in the hydrographic basins of the wetter climate showed less loss of area compared to those of the drier climate. Due to the high number of reservoirs, the use of satellite images and Remote Sensing techniques are essential to measure the effects of drought on dams. Such information is extremely important for the planning and environmental management of water resources, from the perspective of promoting supply policies and, with this, expanding the capacity to face problems related to water security.

scholarly journals The study of NDVI fluctuation in southern Iraq(Hor Ibn Najim) using remote sensing data

2019 ◽  
Vol 30 (1) ◽  
pp. 1 ◽  
Author(s):  
Eman Saad AL-Obaidey
Keyword(s):  
Remote Sensing ◽  
Information System ◽  
Vegetation Cover ◽  
Supervised Classification ◽  
Satellite Images ◽  
Remote Sensing Data ◽  
Low Density ◽  
Abandoned Land ◽  
Land Covers ◽  
Southern Iraq

This study was carried out to determine the nature of the land cover in the area of Hor Ibn Najim and its surroundings. These changes had occurred changes in the environmental conditions between 1986 and 2016. Remote sensing(RS) and geographic information system (GIS) techniques were used to monitor changes in the region as well as changes in NDVI values. Satellite images of Landsat 5 and 7 with sensors TM and ETM +, were used respectively. The extraction of land covers in the region was executed by the application of the supervised classification processes. The area has been classified in to six main land categories (water bodies, low density of vegetation cover, high density of vegetation cover, wetlands, abandoned land and land suitable of agriculture).

scholarly journals ASSESSMENT OF SURFACE WATER AT THE SOBRADINHO RESERVOIR UNDER THE EFFECTS OF DROUGHT USING MULTI-TEMPORAL LANDSAT IMAGES

2016 ◽  
Vol XLI-B8 ◽  
pp. 387-392
Author(s):  
E. A. Silva ◽  
M. M. Pedrosa ◽  
S. C. Azevedo ◽  
G. P. Cardim ◽  
F. P. S. Carvalho
Keyword(s):  
Remote Sensing ◽  
Surface Area ◽  
Water Bodies ◽  
Environmental Research ◽  
Hydroelectric Power ◽  
Landsat Images ◽  
Water Index ◽  
The Matrix ◽  
Effects Of Drought ◽  
Water Administration

The matrix of energy generation in Brazil is predominantly hydroelectric power. Consequently, the reservoirs need constant monitoring due to the large volume of artificially dammed water. Images from remote sensing can provide reliable information concerning water bodies. In this paper, we use remote sensing imagery to monitor the Sobradinho dam in three different epochs. The objective was to verify quantitatively the area of the dam’s surface reduced due to the drought of 2015, which was considered the worst in history. The approach used water surface area estimations from bands of Landsat5 and Landsat8 satellites which highlight water bodies better from other features present on surface of the Earth. Through the techniques of growth region and normalized difference water index (NDWI), we determined the surface area of the reservoir in 2011 and calculated the decrease caused by the drought. By analyzing the numbers provided by the results it is possible to estimate how the Sobradinho reservoir has been affected by the drastic drought. The results show that the Landsat images enable the monitoring of large reservoirs. Bearing in mind that monitoring is a primary and indispensable tool, not only for technical study, but also for economic and environmental research, it can help establish planning projects and water administration strategies for future decisions about the hydrical resource priority.

scholarly journals Cartographie De La Dynamique Spatio-Temporelle Des Parcours Naturels Des Troupeaux Transhumants Dans Les Communes De Banikoara Et De Karimama Au Benin (Afrique De L’ouest)

2016 ◽  
Vol 12 (32) ◽  
pp. 251 ◽  
Author(s):  
Nourou Toko Issiaka ◽  
Ousséni Arouna ◽  
Ismaïla Toko Imorou
Keyword(s):  
Remote Sensing ◽  
Transition Matrix ◽  
Crop Residues ◽  
Food System ◽  
Riparian Forests ◽  
Landsat Images ◽  
Cattle Breeding ◽  
Appreciable Increase ◽  
Land Covers

Cattle breeding in the Districts of Banikoara and Karimama is characterized by semi-nomadic and transhumance with a food system based on the exclusive use of rangelands and crop residues; in this context, the risk of degradation of these rangelands are so high. The aim of this research is to assess the physiognomy changes recorded in these rangelands from 2000 to 2013.The techniques of the remote sensing in particular the classification of the Landsat images ETM+ of 2000 and OLI-TIRS of 2013 were used. The transition matrix was produced using the Intersect function of the software ArcGIS 10.1. In the same way, the programs "PontiusMatrix22" and "Intensity Analysis02" were used to measure the intensity and the speed of land covers units changes.Thus, the surface of riparian forests and the woodlands and savannas woodlands passed respectively from 1.86 % and 12.69 % in 2000 to 1.82 % and 6 % in 2013.Tree and shrub savannas knew a progressive evolution of their surface which passed from 37.55 % in 2000 to 40.51 % in 2013. In addition, the mosaics of fields and fallow which are used as surfaces of pasture in dries season also knew an appreciable increase in their area which passed from 47.02 % in 2000 to 51.73 % in 2013. In total, there was a regression of forest formations in favor of savanna and anthropogenic formations.The highest speed changes was recorded on the level of woodlands and savannas woodlands.

scholarly journals Temporal monitoring of Ghamu bar glacial lakes using remote sensing and GIS

2019 ◽  
Vol 7 (1) ◽  
pp. 18
Author(s):  
Alamgeer Hussain ◽  
Dilshad Bano
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Remote Sensing Data ◽  
Remote Sensing And Gis ◽  
Glacial Lake ◽  
Lake Area ◽  
Glacial Lakes ◽  
Landsat Images ◽  
Water Index ◽  
Normalized Difference Water Index

The trends of glacial lakes formation and glacial lake outburst flooding events have been increased across Himalayan Karakorum Hindu Kush (HKH) ranges during last decade due to increase in global warming. This research is addressing the temporal monitoring of ghamu bar glacial lakes using remote sensing and GIS. Landsat images of 1990, 2000, 2010 and 2015 were used to map temporal glacial lakes using normalized difference water index (NDWI) index. The results of normalized difference water index were validated through modified normalized difference water index and field photographs. Temporal variability shows that, glacier lake area has been increase from 1990 to 2015. In 1990 total area of lake was 0.052 sq, which further increased 0.0423 in 1995 than it decreases to 0.314 in 2000 due to detached of debris cover moraine from glacier tongue and it reach 0.0846 sq.km in 2005. The area gradually increased up to 0.1296 sq.km in 2010 and it goes up to 0.157 sq.km 2015. The overall increase in area are expanding at an accelerated rate in past two decades, indicating that Darkut glacier is more vulnerable toward climate change through increase in size and volume ofghamu bar glacial lakes. There is need for vigilance in monitoring of ghamu bar glacial lake through high resolution remote sensing data and development of Geo-database enabling more details about past and future lakes behaviors toward climate change impacts.    

The machine training in problems of satellite images’s processing

Metrologiya ◽  
2020 ◽  
pp. 15-37
Author(s):  
L. P. Bass ◽  
Yu. A. Plastinin ◽  
I. Yu. Skryabysheva
Keyword(s):  
Remote Sensing ◽  
Neural Networks ◽  
Computer Vision ◽  
Satellite Images ◽  
Vision Systems ◽  
Earth Remote Sensing ◽  
Practical Applications ◽  
Convolution Neural Networks ◽  
Computer Vision Systems ◽  
Trained Neural Network

Use of the technical (computer) vision systems for Earth remote sensing is considered. An overview of software and hardware used in computer vision systems for processing satellite images is submitted. Algorithmic methods of the data processing with use of the trained neural network are described. Examples of the algorithmic processing of satellite images by means of artificial convolution neural networks are given. Ways of accuracy increase of satellite images recognition are defined. Practical applications of convolution neural networks onboard microsatellites for Earth remote sensing are presented.

Application of Remote Sensing in Agriculture

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Jan Piekarczyk
Keyword(s):  
Remote Sensing ◽  
Precision Agriculture ◽  
Crop Production ◽  
Satellite Images ◽  
Crop Yields ◽  
Spatial Scales ◽  
Strong Relationship ◽  
Physical Parameters ◽  
Agricultural Crop ◽  
Remote Sensing Methods

AbstractWith increasing intensity of agricultural crop production increases the need to obtain information about environmental conditions in which this production takes place. Remote sensing methods, including satellite images, airborne photographs and ground-based spectral measurements can greatly simplify the monitoring of crop development and decision-making to optimize inputs on agricultural production and reduce its harmful effects on the environment. One of the earliest uses of remote sensing in agriculture is crop identification and their acreage estimation. Satellite data acquired for this purpose are necessary to ensure food security and the proper functioning of agricultural markets at national and global scales. Due to strong relationship between plant bio-physical parameters and the amount of electromagnetic radiation reflected (in certain ranges of the spectrum) from plants and then registered by sensors it is possible to predict crop yields. Other applications of remote sensing are intensively developed in the framework of so-called precision agriculture, in small spatial scales including individual fields. Data from ground-based measurements as well as from airborne or satellite images are used to develop yield and soil maps which can be used to determine the doses of irrigation and fertilization and to take decisions on the use of pesticides.

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