AN OVERVIEW OF REMOTE SENSING Essays

AN OVERVIEW OF REMOTE SENSING Essays AN OVERVIEW OF REMOTE SENSING Essay AN OVERVIEW OF REMOTE SENSING Essay Chapter TWO LITERATURE REVIEW 2.0: Introduction Most major metropolitan countries face the turning jobs of urban conurbation, loss of natural flora and unfastened infinite, and a general diminution in the extent and connectivity of wetlands and wildlife home ground ( U.S Geological Survey, 1999 ) . Almost everyone has seen these alterations taking topographic point in their local environment but without a clear apprehension of neither the causes of these alterations or their impacts. Most of the land-use alterations occur without a clear and logical planning with any purpose to their environmental impact ( Ahadnejad, 2002 ) . Land usage alteration is influenced by temporal and spacial factors that interact This chapter will reexamine all available literature associating to this undertaking within the available clip to give penetration to what land usage and land screen are, alterations in land usage and land screen, the assorted causes of land-use and land-cover alteration, effects of land-use and land-cover alteration on environmental variables and poetry visa, the effects of land-use and land-cover on societal variables and poetry visa, the application of GIS/Remote Sensing in analyzing land-use and land-cover alteration, the restriction and some past plants done on the subject. 2.1: Land Use AND LAND COVER A modern state, as a modern concern, must hold equal information on many complex interconnected facets of its activities in order to do determinations ( Andersonet Al., 1976 ) . Land usage is merely one such facet, but knowledge about land usage and land screen has become progressively of import as the Nation plans to get the better of the jobs of haphazard, uncontrolled development, deteriorating environmental quality, loss of premier agricultural lands, devastation of of import wetlands, and loss of fish and wildlife home ground ( Andersonet Al., 1976 ) . Land usage informations are needed in the analysis of environmental procedures and jobs that must be understood if living conditions and criterions are to be improved or maintained at current degrees ( Andersonet al. ,1976 ) . 2.0.0 AN OVERVIEW OF REMOTE SENSING Remote Sensing is the scientific discipline and art of obtaining information about an object, country, or phenomenon through the analysis of informations acquired by a device that is non in contact with the object country or phenomenon under probe ( Lillesand and Keifer, 2004 ) . There are broad scope of applications of Remote Sensing including Meteorology, Engineering, Geomorphology, Climatology, Geology, Land Use and Land Cover categorization, function and function, Agriculture, oceanology, Urban and Regional Planning, Environmental Planning and Health. This thesis seeks to research and explicate the application of Remote Sensing in Land Use and Land Cover categorization, function and change.A Information transportation in the field of Remote Sensing is ever accomplished by the usage of electromagnetic radiation measured at different wavelengths which will be discussed subsequently in the class of this research. 2.0.1 TYPES OF REMOTE SENSING The types of Remote Sensing could be grouped based on either the energy beginning or in regard to the wavelength parts ( Richards and Jia, 2006 ) . Based on beginning of energy, Remote Feeling Systems that make usage of detectors that detect the reflected or emitted electro-magnetic radiation from the of course available energy from the either the Sun or the Earth itself are called Passive Remote Sensing while Remote Feeling Systems that make usage of detectors that provide their ain beginning of energy for light are known as Active Remote Sensing ( Lillesand and Kiefer, 2004 ) . The wavelengths at which detectors measures the spectral coefficient of reflection of object scopes from the Gamma Rays to the Radio Radio Waves. But with regard with wavelength part, the scopes applied in Remote Sensing include: Optical Remote Sensing devices which operates in the seeable, close infrared, in-between infrared and short moving ridge infrared parts of the electromagnetic spectrum sensitive to wavelengths runing from 300 nanometers to 3000 nanometer. Thermal Remote Sensing Sensors which operates in the thermic scope of the electromagnetic spectrum and records the energy emitted from the Earth features in the wavelength scope of 3000 nanometer to 5000 nanometer and 8000 nanometer to 14000 nanometers with the old scope related to high temperature phenomenon like forest fire, and subsequently with the general Earth characteristics holding lower temperature. Microwave Remote Sensing Devices which records the backscattered microwaves in the wavelength scope of 1 millimeters to 1 m of the electromagnetic spectrum. Most of these detectors have their ain beginning of energy ( active ) which has given them edge over other types of detectors because of their independency to endure and solar radiation. 2.0.2 ELECTRO MAGNETIC RADIATION ( EMR ) Harmonizing to Lillesand and Kiefer, ( 2004 ) , Electromagnetic radiation frequently abbreviated E-M or EMR is a signifier of energy that reveals its presence by the discernible effects it produces when it strikes the affair. Since energy is involved, it could farther be explained as the energy propagated through infinite in the signifier of bantam energy packages called a proton that exhibits both wave-like and particle-like belongingss. This signifier of energy conveyance differs from other manners of energy conveyance such as conductivity and convection in that electromagnetic radiation takes the signifier of self-propagating moving ridges in a vacuity. There are several types and categories of electromagnetic radiation harmonizing to the frequence of the moving ridge which includes wireless moving ridges, microwaves, THz radiation, infrared radiation, seeable visible radiation, ultraviolet radiation, X-rays and gamma beams in order of increasing frequence and diminishing waveleng th. For a assortment of grounds, there are some wavelengths of electromagnetic radiation that are more normally used in Remote Sensing than other wavelengths ( Robert,et al. ,2005 ) . Distant Feeling Technology makes usage of the broad scope Electromagnetic Spectrum from a really short moving ridge Gamma Ray to a really long Radio Wave . Electromagnetic Spectrum Beginning:Education.co.uk Detectors on board Remote Sensing Platforms are used to enter electromagnetic radiation. As stated earlier, Remotes Sensing could be active or inactive based on the energy beginning. Concentrating on inactive Remote Sensing, utmost temperature and atomic activity on the surface of the Sun allows the emittance of a wide and uninterrupted scope of electromagnetic radiation. This electromagnetic radiation emitted from the Sun interacts with the ambiance, and interacts with the ambiance before being detected by a distant detector system in the air or in orbit ( Raber,et Al., 2005 ) . Some of the energy gets absorbed by mark stuffs like H2O and stones on the Earth s surface and these stuffs get heated as a consequence. The captive energy is so re-emitted at longer wavelength thereby doing the stuffs that absorbed the Sun s energy to go electromagnetic radiation themselves. A inactive Sensor like Landsat ETM+ and ASTER, which are both utilized in this research, will enter the electromagnetic radiation or spectral coefficient of reflection of mark stuffs based on the spectral declaration designed on the detector. Active detectors that emit their electromagnetic radiation are chiefly two types: Radar ( Radio Detection and Ranging ) , which harnesses microwave energy, and LIDAR ( Light Detection and Ranging ) , which harnesses the near-infrared or seeable energy ( Raber,et Al., 2005 ) . 2.0.4 REFLECTANCE OF ELECTROMAGNETIC ENERGY Based on the atomic construction of Earth s objects, different objects absorb and emit electromagnetic radiation at different wavelengths of the electromagnetic spectrum ( Campbell, 2003 ) . In the seeable spectrum, these differences in brooding efficiency histories for the color fluctuations we see. Green workss for illustration appear that coloring material to the oculus because they reflect greater sum of green visible radiation than of bluish or ruddy visible radiation. Ploting the spectral coefficient of reflection degree of a given object or phenomenon by wavelength outputs a spectral coefficient of reflection curve, or spectral signature which harmonizing to Raberet Al.( 2005 ) is the Remote Sensing key to separating between one type of mark and another. Typical Spectral Reflectance Curves for Soil, Vegetation and Water Beginning:Lillesand and Kiefer, 1994 2.2.0 CAUSES OF LAND USE AND LAND COVER CHANGE Identifying and understanding the major causes of land-use and land-cover alteration requires a clear apprehension of both how homo s decision-making procedures on land-use and how specific environmental and societal variables interact to act upon these determinations. It is besides really necessary to understand that determinations on land usage are made and influenced by environmental and societal variables across a broad scope of spacial graduated tables, from family degree determinations that influence local land usage patterns, to policies and economic forces that can change land usage regionally and even globally ( Eric and Helmut 2007 ) . The Land-use and Land-cover alteration theoretical account is normally governed by two wide complex sets of droving forces human demands ( social-economic factors ) and environmental characteristics and procedures ( biophysical factors ) ( Lambin, 2001 ) . 2.2.1 PROXIMATE VERSUS UNDERLYING CAUSES Harmonizing to Eric et al. , ( 2001 ) , the causes of land-use and land-cover alteration can be divided into two classs: Proximate ( direct or local ) andUnderlying ( indirect or root ) . The proximate, direct or local causes of land-use and land-cover alteration explains how and why local land screen and ecosystem procedures are modified straight by worlds, while implicit in causes explain the broader context and cardinal forces underpinning these local actions ( Eric et al. , 2001 ) . Proximate causes by and large operate at the local degree such as single farm land, individual families or simple communities while the implicit in causes of land-use and land-cover alteration originate from degree higher than the local degree including territories, states, or state ( regional ) or even planetary degrees, though complex interplays between these degrees of organisation are common. As a consequence of these complex interplays, underlying causes besides tend to be complex, formed by inte ractions of societal, political, economic, demographic, technological, cultural, and biophysical variables ( Eric et al. , 2001 ) . Some local-scale factors originate internally within the local degree and are hence endogenousto determination shapers and under local control. However, implicit in causes are usuallyexogenous ( arise externally ) to the local communities pull offing land and are therefore unmanageable by these communities. In general, implicit in causes tend to run more diffusely, frequently by changing one or more proximate causes. 1. Anderson, J. R, Hardy, E. E. , Roach, J. T. , and Witmer, R.E. , 1976, A Land Use and Land Cover Classification System for Use with Remote Sensor Data, United States Department of the Interior, Washington, United States Government Printing Office 2. Eric F. Lambin, B. L. Turner, Helmut J. Geist, Samuel B. Agbola, Arild Angelsen, John W. Bruce, Oliver T. Coomes, Rodolfo Dirzo, Gunther Fischer, Carl Folke, P. S. George, Katherine Homewood, Jacques Imbernon, Rik Leemans, Xiubin Li, Emilio F. Moran, Michael Mortimore, P. S. Ramakrishnan, John F. Richards, Helle Skanes, Will Steffen, Glenn D. Stone, Uno Svedin, Tom A. Veldkamp, Coleen Vogel and Jianchu Xu, 2001, Causes of Land-Use and Land-Cover Change: Traveling Beyond the Myths, Global Environmental Change, Volume 11, Issue 4, PP 261 269 3. Global Land Cover Facility, 2009, Measuring Man s Impact: Global Land Cover Change, Available online hypertext transfer protocol: //glcf.umiacs.umd.edu/services/landcoverchange/ , Last accessed 11Th December, 2009 4. Lillesand, T. M. And Kiefer, R. W. , ( Ed ) , 2004, Remote Sensing and Image Interpretation, New York, John Wiley A ; Sons 5. Mohsen Ahadnejad, 2002, Environmental Land Use Change Detection Assessment Using Multi-temporal Satellite Imagery, GIS Development Conference Proceedings, Map Asia, 2002 6. Raber, G. , Tullis, J. , Jenson, J. , ( 2005 ) , Remote Sensing Data Acquisition and Initial Processing, Earth Observation Magazine, July 2005 issue 7. Richards. J. A. , and Jia, X. , 2006, Remote Sensing Digital Image Analysis, Springer Verlag Berlin Heideelberg, Germany 8. USGS, 1999, Analyzing Land Use Change in Urban Environment, USGS Fact Sheet188-99