Cutoffmeander

Midstream sandbank

New channel

Modern cutoff process

Monitoring of Erosion Processes with the Use of Archival Remote Sensing Data

Aerial photographic survey data 1953 (photographic scale 1:17000, aircraft flying height 1100 m)

Aerial photographic survey data 1980 (photographic scale 1:50000, aircraft flying height 7000 m)

WorldView-1 satellite image, 2008 (panchromatic range, spatial resolution 0,6 m)

Monitoring of relief changes and landscape forming processes is one of the methods that can be used to study the modern geodynamics. In the territory of the Republic of Tatarstan (RT) the possibility of investigating geodynamic processes within the oil producing regions is of the greatest interest, since successful development of these regions requires prevention and control of undesirable geo-ecological processes. Today historical data (aerophotos and space images) are of great value, as they allow us to observe tendencies in the relief development and to use relief and landscape as composite and quite sensitive indicators of modern geodynamic processes. We used materials of aerial photographic surveys and WorldView satellite image mosaic as the source data for this research. The research was carried out in the territory of the Cheremshansky district (RT).

Processing of the images obtained in 1953 boils down to the geometric correction and coordinate system determination.

Geometric correction was made using IMAGINE AutoSync module. The average error of transformation is 5 meters.

Then we have loaded transformed images into ArcGIS Desktop in order to compare them.

Comparison of images which were made at different times

Results of analysis of different times data

It is possible to make stereo images and triangulation blocks, since images we used are widely overlapped. Triangulation blocks can be used for creating DEMs and orthophotos. Image pre-processing, stereo pair generation, orthotransformation and DEM extraction were carried out using ERDAS Imagine 2010 and LPS 2010 software.

A set of aerophotos obtained in 1980 has undergone block triangulation, and DEM was generated.

Comparison of the DEM created with the help of photogrammetry and the DEM made through the paper-based topographic maps vectorization shows that they are of same quality.

Stereo pairs and Stereo Analyst ERDAS Imagine window.You can use anaglyph glasses for watching stereo pairs.

DEM created using photogrammetry methods (scale 1:50000)

DEM made through the topographic maps vectorization (scale 1:25000)

Landscape changes

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1953 2008

Technogenic landscape changes

Sparse forest

Gullies and Ravines

Coppice

Channel rectification

Other landscape changes

Stream channel shape changes

debris cone

Observed displacements cannot be explained by calculating errors, because they are around five to six times greater.

Authors: Arthur Fattakhov, Khabibullin Rishat, Sitdikov Ruzil (students of third year), Nugmanov Ilmir, Kadyrov Rail (graduate students). Research of 2010-2012 yy. Scientific adviser - associate professors, Department of Geophysics and GIS technologies Chernova I.Yu. The Russian Foundation for Basic Research ("RFBR") № 12-05-90701-моб_стThe research work was supported by

Modern geodynamics

Figure 2,3: Ravine length at the 1953 year’s image

Figure 1: Channel shape at the 1953 year’s image

The background raster image is a scheme of intensity of neo-tectonic movements. Light colors represent maximal amplitudes and dark colors – minimal ones.

Neotectonically active structures are obviously associated with modern geodynamics. For example, areas of erosional pattern degradation are closely related to areas of neotectonical subsidence, and conversely. This fact can be applied to practical needs too. For instance, we should not advise one to cut wood on a territory of intensively rising watershed, since it may cause such agricultural problems as rapid growth of ravines and soil retrogression and degradation.

IMAGINE AutoSync Workstation

Figure 1,2: Gullies contours.

WorldViev-1image, 2008

Detailed comparative analysis of more than 200 ravine networks in the territory of Cheremshansky district was carried out using the images made during the period from 1953 to 2008.

It allowed us to reveal a large amount of regions with vivid geodynamic processes of both positive and negative sign.

2008

Erosional patterns A and B continue their development in spite of rise in local base level of erosion. After a dike was built ravine network C degraded and turned into system of gullys.

Ravine system D did not undergo any essential alteration. It maybe has formed long before systems A, B and C and is in stable state now.

B

B

A

Comparison of modern geodynamics and neotectonic activity

Changes in forested area size

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WorldV

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Areas areas of young coppice 2008

Forest coverage at the 1953

19531980

river ponding

Ravinegrowth direction

Channel shape at the 2008 year’s image

Channel shape at the 1953 year’s image

Tie points generating

Automatic point measurement (APM) identifies similar features between the input image and the reference image.

2008

Erosional patterns

Neotectonic uplift

ravinegrowth direction(length of a vector is proportional to growth rate of a ravine)

with negative dynamicswith positive dynamics

do not change

research sector number

with negative dynamicsDisplaying of modern geodynamicsAreas

Borders of sites covered by images obtained in 1980

Cross-section line

DTMElevation (m)

km