Terminology. Remote Sensing

Absorptance : The ratio of the radiant energy absorbed by a substance to the energy

it receives.

Band : The specific wavelength interval in the electromagnetic spectrum.

Digital image : An array of digital numbers (DN) arranged in rows and columns,

having the property of an intensity value and their locations.

Digital Number : An intensity value of a pixel in a digital image.

Digital Image Processing : The numerical manipulation of DN values for the purpose

of extracting information about the phenomena of the surface they represent.

Electromagnetic Radiation (EMR) : The Energy propagated through a space or a

medium at a speed of light.

Electromagnetic Spectrum : The continuum of EMR that ranges from short wave

high frequency cosmic radiations to long wavelength low frequency radio waves.

False Colour Composite (FCC) : An artificially generated colour image in which

blue, green and red colours are assigned to the wavelength regions to which they do

not belong in nature. For example, in standard a False Colour Composite blue is

assigned to green radiations (0.5 to 0.6 µm), green is assigned to red radiations (0.6

to 0.7 µm and red is assigned to Near Infrared radiation (0.7 to 0.8 µm).

Gray scale : A medium to calibrate the variations in the brightness of an image that

ranges from black to white with intermediate grey values.

Image : The permanent record of a scene comprising of natural and man-made

features and activities, produced by photographic and non–photographic means.

Scene : The ground area covered by an image or a photograph.

Sensor : Any imaging or non–imaging device that receives EMR and converts it into

a signal that can be recorded and displayed as photographic or digital image.

Reflectance : The ratio of the radiant energy reflected by a substance to the energy

it receives.

Spectral Band : The range of the wavelengths in the continuous spectrum such as

the green band ranges from 0.5 to .6 µ and the range of NIR band 0.7 to 1.1 µ.

Comments

Geography of Landslides. Mitigation and Resilience.

A landslide is a geological event in which a mass of rock, earth, or debris moves down a slope under the force of gravity. Landslides can range in size from small to large and can be triggered by natural events such as heavy rainfall, earthquakes, or volcanic activity, or by human activities such as construction or mining. The geography of landslides is affected by a variety of factors that can increase the likelihood of landslides occurring in a particular area. These factors include slope angle and steepness, the type of soil and rock present, the climate and weather patterns of the region, the presence or absence of vegetation, and human activities such as construction, mining, and deforestation. Areas with steep slopes are more prone to landslides because gravity has a stronger effect on loose soil and rock, making it more likely to move downhill. Similarly, areas with loose, sandy soil or weak, fractured rock are more prone to landslides because they are less stable and more easil...

Geography of Flood. Types. Charector.

The geography of floods refers to the characteristics and patterns of floods in different geographic regions. Floods can occur in various landscapes, such as mountains, plains, coastal areas, and urban environments. The geography of a region plays a significant role in determining the frequency, magnitude, and impacts of floods. Some of the factors that influence the geography of floods include: Topography: The shape and elevation of the land can affect the flow and accumulation of water during a flood. For example, flat terrain can lead to slow-moving and widespread flooding, while steep slopes can result in flash floods and landslides. Climate: Regions with high rainfall or snowmelt can experience more frequent and intense floods, while dry regions may experience flash floods due to sudden, heavy rainfall. Hydrology: The characteristics of a river basin, such as its size, shape, and water flow, can influence the severity of a flood. For example, large river basins with extensive floo...

Flood prone regions India

Floods are natural disasters characterized by the overflow of water onto normally dry land. Various factors contribute to floods, including intense rainfall, rapid snowmelt, storm surges from coastal storms, and the failure of dams or levees. The geographical explanation involves understanding the key components of flood-prone regions: 1. Proximity to Water Bodies: Flood-prone regions are often situated near rivers, lakes, or coastal areas. These locations are more susceptible to flooding as they are in close proximity to large water sources that can overflow during heavy precipitation or storms. 2. Topography: Low-lying areas with gentle slopes are prone to flooding. Water naturally flows to lower elevations, and flat terrains allow water to accumulate easily. Valleys and floodplains are common flood-prone areas due to their topographical characteristics. 3. Rainfall Patterns: Regions with high and concentrated rainfall are more likely to experience flooding. Intense and prol...

Landslides. USGS

Landslides. TYPES OF LANDSLIDES The term "landslide" describes a wide variety of processes that result in the downward and outward movement of slope-forming materials including rock, soil, artificial fill, or a combination of these. The materials may move by falling, toppling, sliding, spreading, or flowing. The animated GIF shows a graphic illustration of different types of landslides, with the commonly accepted terminology describing their features. The various types of landslides can be differentiated by the kinds of material involved and the mode of movement.

Volcano

Large magma chamber Bedrock Conduit (pipe) Base Sill Dike Layers of ash emitted by the volcano Flank Layers of lava emitted by the volcano Throat Parasitic cone Lava flow Vent Crater Ash cloud

Vineesh V, Geography

Search This Blog