Remote sensing for resources development and environmental management: Remote sensing for resources development and environmental management

damen, m. c. j.

Bibliographic data

Multivolume work

Persistent identifier:: 856342815

Title:: Remote sensing for resources development and environmental management

Sub title:: proceedings of the 7th international Symposium, Enschede, 25 - 29 August 1986

Year of publication:: 1986

Place of publication:: Rotterdam; Boston

Publisher of the original:: A. A. Balkema

Identifier (digital):: 856342815

Language:: English

Additional Notes:: Volume 1-3 erschienen von 1986-1988

Editor:: Damen, M. C. J.

Document type:: Multivolume work

Volume

Persistent identifier:: 856641294

Title:: Remote sensing for resources development and environmental management

Sub title:: proceedings of the 7th international Symposium, Enschede, 25 - 29 August 1986

Scope:: IX Seiten, Seiten 551-956

Year of publication:: 1986

Place of publication:: Rotterdam; Boston

Publisher of the original:: A,. A. Balkema

Identifier (digital):: 856641294

Illustration:: Illustrationen, Diagramme

Signature of the source:: ZS 312(26,7,2)

Language:: English

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Editor:: Damen, M. C. J.

Editor:: International Society for Photogrammetry and Remote Sensing, Commission of Photographic and Remote Sensing Data

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2016

Document type:: Volume

Collection:: Earth sciences

Chapter

Title:: 5 Non-renewable resources: Geology, geomorphology and engineering projects. Chairman: J. V. Taranik, Liaison: B. N. Koopmans

Write comment:: Wegen zu enger Bindung kommt es teilweise im Original zu Textverlust.

Document type:: Multivolume work

Structure type:: Chapter

Chapter

Title:: The study of mass movement from aerial photographs. Varoujan Kh. Sissakian

Document type:: Multivolume work

Structure type:: Chapter

677 ain scarp ( CROWN ) Minor scarp \ \ \ Zpnt 0/ dtprtuiti Zon, ./ bu Iging rit rip pit 3S movement Ld L. Royster). i as indica- t because it sually few of firming a ki- { to be pro- ie amount of ated from ae- le offset of icl, 1969). for the mass be recogni- listed bel- by thick co- an steep slo- ting surface aorly conso- lidated soils and pelitic soils interbedded with hard rocks (flysch) are extremely like ly to give rise to mass movements (Terzaghi, 1950). Such combination of rocks can be easily recognized from aerial photographs, hence the cause can be known. 3.2 Weathering: Rocks loose their cohesion due to weathering, specially mechanical weathering which incr eases the possibilities of water penetration, this leads to an increase of the pore press ure and consequantly decreases the cohesion and internal friction angle. This will trigg er the movements on slopes. Weathering phenomena are visible in aerial photographs of large scales only. 3.3 Vegetation: It is well known fact that vegitation incr eases the stability of slopes, as plant co ver provides protection against surficial slides and erosion (Cotechia,1978). However (Prandini et.al. 1977) declear that some au thors believe that deforestation helps to stabilise slopes. Others believe that the an gle of repose of a slope covered by vegita tion is 60 but it decreases to 36 when is barren from vegetation. The roots of plants play role in keeping the stability of slopes, on the other ftand they play role in désintégration of materials during penetration. The weight of large trees also might disturb the equilibrium due to overloading of slopes. Changes in vegetation can be easily obser ved from aerial photographs, but their rela tionship with mass movements has to be deter mined in the field.. 3.4 Human activities: Some mass movements occur due to human activ ities like quarrying excavations, terracing of slope for agricultural purposes, defores tation, blasting etc., such factors can be observed on aerial photographs if the photo graphy is made after ward. 3.5 Tectonic activities: Any sudden change of slopes due to tectonic activity like fault may lead to mass movement, especially when the slope is in critical eq uilibrium and can be triggered due to any reason. Obviously faults can be easily recognized from aerial photographs, hence the cause of any mass movement phenomenon which occur in faulted area may be explained due to trigg ering of the fault. 4.PREDICTION OF MASS MOVEMENT Aerial photographs help in the prediction of different types of mass movement. Their int erpretation before starting any engineering work is highly reccomended. Construction activities for engineering works can trigg er the potential areas and as soon as move ment has started they can be stopped only with great difficulties and high costs. Prediction of mass movement from aerial photographs can be done by observing the following clues (1-9), but it can't be esti mated when they will start to move, since they may never move: 1. Cracks on steep slopes, when big enough to be visible on the photographs. 2. Thick colluvial soil on steep slopes. (Gray et. al. 1977). 3. Clear bedding planes dipping towards the slope. (Barton, 1977). 4. Highly saturated areas and seepage zones. 5. Old mass movement areas. 6. Active erosion at the foot of slopes. 7. Areas showing disturbed vegitation. 8. Hummocky surfaces. 9. Small depressions on slopes. The author believes that most of the above mentioned clues are recognizable from aerial photographs, but it is neccessary to remined that the existance of one of the mentioned cues must not be considered as a certain in dication for prediction of mass movement. 5 DATING AND ACTIVITY OF MASS MOVEMENT The age of the mass movement can be estima ted from aerial photographs; approximately by recognizing few aspects which are ment ioned below (E.-E,), whereas the activity of the movement i.e. wether it is active or not, recent or old can be known adequately, spe cially in large scale photographs (1:3 000 and larger): 5.1 Vegetation The age of trees or shrubs can be estimated from their heights, which can be measured from aerial photographs, hence the age of the tree which occur on the movement area indicates, roughly the age of the movement. Comparision between the age of the trees, which occur on the movement area and the surroundings, also indicates the age of the movement. 5.2 Erosion Erosion processes indicate the activity of the movement only. These easily can be ob served from aerial photographs, hence jthe activity of the phenomenon can be known, which is very important in planning differ ent human activities. 5.3 Human activities Recent and activé mass movement areas are usually abandoned from human activities, Re cognition of abandoned houses, roads, farms, quarries etc. may indicate and lead to a ro ugh estimation of the movement. Obviously such recognitions are easily done from aer ial photographs, especially recently photo graphed photographs. 5.4 Recognition of sedimentation processes If any movement is covered or taken place by/in terrace, alluvial fans, colluvial dep osits etc. then the estimation of the age of the sedimentation processes indicates, roug hly the age of the movement. But the estima tion of the age must be done very carefully,

Access restriction

Copyright

fullscreen: Remote sensing for resources development and environmental management (Volume 2)

Multivolume work

Volume

Chapter

Chapter

Table of contents

Cite and reuse

Volume

Chapter

Image

Image fragment

Citation links

Citation recommendation