Monitor and study horizontal and verticals changes at land surface using remote sensing and gis technology case of study wenchuan area

Editor's Notes

• #2: Aim: The aim of this thesis is to studyNeotectonic and movement of plate in Wenchuan area by processing, to analysis and interpretation of aerial photographs images and satelliteimages,toidentificationofrangeoffaultsandthedirectionofplatemovementin study area, to monitor changes on surface by follow phenomena in same area during periodsoftime.Andtoshowtheeffectofplatemovementofriverview.
• #3: On May 12, 2008, earthquake struck Wenchuan 7.9 MW eastern edge of the Tibetan plateau, destroyed cities along the northwest margin of the Sichuan Basin, caused more than 80,000 dead and 380,000 wounded
• #4: The active tectonic map of the study area and around it, shows the different kind of the fault,wheretherearereveres,strike-slipruptures(Figure3-2). Sequence was imbricate and emplaced eastward over the lower structural sequence in Late Triassic to Middle Jurassic time. Transitional units between the two structural sequences are generally not found. Thrust sheets override the older fore deep deposits, and thrust contacts are sealed in places by Middle Jurassic strata, constrainingthe end of thrusting to the pre–Middle Jurassic. The fore deep deposits continue into the Late Cretaceous, but large post–Middle Jurassic, pre-Oligocene structures have not been identified.TheMesozoicthrustcomplexanditsunderlyingautochthonwererefoldedand thrust eastward in Cenozoic time. Cenozoic folding of the Precambrian basement is well expressed in the Baoshan and Pengguan massifs (Figs.3-3 and3-4). Along the southwestern margin of the Sichuan Basin, Eocene and probable Oligocene red beds are deformed by northeast-trending folds and thrust faults that merge northward into the LongmenShan.TheserocksconstraintheCenozoicdeformationinthisareatohavebeen initiatedinthelateorpost-Oligocene.
• #5: Determine the study area with four coordinates and the use of satellite images Land sat 2, 4 and 7 in order to monitoring horizontal changes and plate movements. Digital elevations images (DEM) used to monitor vertical change as well as understanding the mechanism of horizontal movements in the selected area. Due to the lack of data for the same satellite during a period of 40 years .has been study- specific years that necessary data are available and make comparisons between them. as well as the benefit from the program Google Earth free as the software provided with aerial photographs and satellite images with geographical coordinates of and the advantage in the use of landmarks apparent on all pictures between the year 2005-2010 as points of GPS. Study materials& DATA METHODOLOGY and results Remote sensing is used as a tool to extract information about the land surface structure, composition or subsurface, but is often combined with other data sources providing complementary measurements. Multispectral data can provide information on lithology or rock composition based on spectral reflectance. Radar provides an expression of surface topography and roughness, and thus is extremely valuable, especially when integrated with another data source to provide detailed relief. Remote sensing is not limited to direct geology applications - it is also used to support logistics, such as route planning for access into a mining area, reclamation monitoring, and generating base maps upon which geological data can be referenced or superimposed Geological applications of remote sensing include the following: surficial deposit / bedrock mapping - lithological mapping, structural mapping - sand and gravel (aggregate) exploration/ exploitation, mineral exploration - hydrocarbon exploration, environmental geology – geobotany,baseline infrastructure - sedimentation mapping and monitoring Event mapping and monitoring - geo-hazard mapping - planetary mapping Geological application of remote sensing includes the following: Materials: Satellite images and set programs (ENVI 4.6.1, global mapper13, ArcGIS, Google earth, Photo shop.   Data methodology and results .1 Processing stage::-geometric correction: Geometric correction: conversion of data to ground coordinates by removal of distortions from sensor geometry ,enable mapping relative to data layers enable and comparison .The used images (land sat 2,4,7) were provide with coordinated of four corner of the images which used for geometric correction.   2-special processing image transformation, Image filtering, Final processing: To access images cover the study area .there was cutting from some images which was bigger than study are or combining some images to cover study area Image enhancement: in order to aid visual interpretation, visual appearance of the objects in the image can be improved by image enhancement techniques such as grey level stretching to improve the contrast and spatial filtering for enhancing the edges
• #8: GoogleearthitssoftwareprovidefreesatelliteandArialimages. Herewewilltakeagroupofparameters (house,school,etc....) andclear thatappearon allimagesasapointofGPSandthatofothersispossiblethattherewillbeachangeinits positionduetohumanactivity. For example: Select one corner of a school, write its coordinates, then select the same corner on another photo during a different time period and determine the coordinates. After that convert geographic coordinates (photos in Google has been taken with geographic coordinates) to the coordinates (X., Y) then compared between new coordinatestheoldcoordinates. Choose some clear points (these points cover most of the study area) before and after earth quake in Wenchuan (12may2008) then compare between the coordinated of same pointbeforeandafterearthquack(ontowdifferentimagesforsamepoint’s