Geoengineering Characterization of the Rock Masses of Northern Face of Jabal ...IJERA Editor
This paper is aimed at the description and the geotechnical characterization of the Tertiary granitic rock masses of the northern face of Sabir Mountain, Taiz city, Yemen, for the first time. For accomplishing this task, direct and indirect approaches are adopted. The direct approach is represented by field and laboratory investigations. Field investigations include discontinuity (joints) measurements/evaluation, applied Rock Mass Rating (RMR) system and Geological Strength Index (GSI) system, in addition to field tests, while laboratory investigations encompass physico-mechanical tests carried out on granitic rock materials. Indirect approach for the estimation of shear strength parameters (c, φ), compressive strength (σcm), tensile strength (σtm) and deformation modulus (Erm) of these rock masses was made by applying the generalized Hoek–Brown failure criterion using geotechnical Roc-Lab software. The laboratory results indicate that the Tertiary granitic rock masses show wide range of variations in their physico-mechanical characteristics owing to degree of weathering /alteration and microfractures. The intact samples of Sabir granitic (Tg) rocks show “Moderate” to “High” density, “Low” to "Medium" porosity, “Good" to "Marginal” water absorption capacity and “Weak” to “Very Strong” strength. Stereographically, three main sets of discontinuities (joints) are identified at each station; however, the fourth joint set occurs, in addition to random joint sets. The discontinuities (joints) trend predominately in NE-SW and NW-SE directions in conformity with the regional structures or faults. According to Jv j/m³ values, the degree of jointing of these rock masses are varied from “Moderate” to “High” jointing. These rocks are categorized as “Fair” to “Excellent” quality, “Fair” to “Good/Very Good” quality and “Poor” to “Very Good” quality classes according to RQD, RMR89 and GSI respectively. Values of the shear strength parameters (c and φ) and the other rock mass parameters (σtm, σc , σcm and Erm) show variations depending on the rock mass quality and properties of intact rock. However, in general the values of the rock mass parameters are found to increase with increase in the quality of rock mass and intact rock properties.
2015 Broken Hill Resources Investment Symposium - Geological Survey of New So...Symposium
"Broken Hill 1:250000 metallogenic special and revised metamorphic facies-isograd maps".
Dr Joel Fitzherbert, Senior Geoscientist, Geological Survey of New South Wales
THE various rocks are classified as according to rock mass classification system as it is used for used for various engineering design and stability analysis of underground structures.
Geoengineering Characterization of the Rock Masses of Northern Face of Jabal ...IJERA Editor
This paper is aimed at the description and the geotechnical characterization of the Tertiary granitic rock masses of the northern face of Sabir Mountain, Taiz city, Yemen, for the first time. For accomplishing this task, direct and indirect approaches are adopted. The direct approach is represented by field and laboratory investigations. Field investigations include discontinuity (joints) measurements/evaluation, applied Rock Mass Rating (RMR) system and Geological Strength Index (GSI) system, in addition to field tests, while laboratory investigations encompass physico-mechanical tests carried out on granitic rock materials. Indirect approach for the estimation of shear strength parameters (c, φ), compressive strength (σcm), tensile strength (σtm) and deformation modulus (Erm) of these rock masses was made by applying the generalized Hoek–Brown failure criterion using geotechnical Roc-Lab software. The laboratory results indicate that the Tertiary granitic rock masses show wide range of variations in their physico-mechanical characteristics owing to degree of weathering /alteration and microfractures. The intact samples of Sabir granitic (Tg) rocks show “Moderate” to “High” density, “Low” to "Medium" porosity, “Good" to "Marginal” water absorption capacity and “Weak” to “Very Strong” strength. Stereographically, three main sets of discontinuities (joints) are identified at each station; however, the fourth joint set occurs, in addition to random joint sets. The discontinuities (joints) trend predominately in NE-SW and NW-SE directions in conformity with the regional structures or faults. According to Jv j/m³ values, the degree of jointing of these rock masses are varied from “Moderate” to “High” jointing. These rocks are categorized as “Fair” to “Excellent” quality, “Fair” to “Good/Very Good” quality and “Poor” to “Very Good” quality classes according to RQD, RMR89 and GSI respectively. Values of the shear strength parameters (c and φ) and the other rock mass parameters (σtm, σc , σcm and Erm) show variations depending on the rock mass quality and properties of intact rock. However, in general the values of the rock mass parameters are found to increase with increase in the quality of rock mass and intact rock properties.
2015 Broken Hill Resources Investment Symposium - Geological Survey of New So...Symposium
"Broken Hill 1:250000 metallogenic special and revised metamorphic facies-isograd maps".
Dr Joel Fitzherbert, Senior Geoscientist, Geological Survey of New South Wales
THE various rocks are classified as according to rock mass classification system as it is used for used for various engineering design and stability analysis of underground structures.
Evaluation of Structural Geology of Jabal OmarIJERD Editor
The proposed Jabal Omar Development project includes several multi-storey buildings, roads, bridges and below ground structures. Dykes and joints are the most common geological features in the area; they vary in thickness and orientation. The spacing between adjacent discontinuities largely control the size of individual blocks of rock masses which govern the stability of rock structures. The shearing and faulting system normally associated with tectonic movement making the area very weak, highly weathered and unstable. All Structural geological units analyzed using stereographic projection
Provenance, tectonic setting and diagenesis of the Mn-Fe coated terrigenous c...iosrjce
The arkosic and subordinate quartz-arenitic Mn-Fe coated terrigenous clasts were discovered to
occur in association with manganese nodules hosted by weathered Mn-Fe rich alluvial-fluvial sediments of the
Tertiary period in Carletonville area. The weathered Mn-Fe rich alluvial-fluvial sediments form the modern soil
profiles in the study area. The Scanning Electron Microscope and petrographic studies of the terrigenous clasts
indicated elevated content of manganese oxide precipitated in pore spaces between the framework grains as
well as forming surface coatings on hand specimen. These clasts are mined with manganese nodules in the study
area. The manganese nodules were formed from in situ concentration of Mn-oxide due to surficial weathering of
the underlying Mn-rich dolomites of the Malmani Subgroup and then concentrated as Mn-rich residues,
encircling rock fragments in soil profile. In contrast, Mn-Fe coated terrigenous clasts and the alluvial-fluvial
sediments were sourced from older geological basins. Therefore, the purpose of the study were to construct a
possible source area of Mn-Fe coated clasts and Mn-rich alluvial-fluvial sediments which hosted Mn-nodules in
the mine area and from the results deduce the overall source of manganese that is mined in the area. On the
basis of framework compositional analysis, the sediments were found to have been sourced from metamorphic
and granitic origins in a cratonic interior to recycle orogen and sedimentation occurred in low plain,
temperate, humid to subhumid climate. The sediment sources resembled the properties of the Archean granites
and gneisses of the Witwatersrand Supergroup and Rand Anticline ridge (quartzite formation) exposed far off
along the northern part of the study area on a high topographic mountain.
forms and distribution of potassium along a toposequence on basaltic soils of...IJEAB
The study was conducted in Vom, Jos Plateau state in the Southern Guinea Savanna zone of Nigeria to accentuate the forms of potassium distribution associated with topographic positions. The study area lies between longitudes 080 45’ 01” and 80 47’ 56’’ E, latitudes 90 43’ 17’’ and 90 45’ 15’’ N, with an elevation of about 1270m above sea level. A stratified purposive sampling procedure was adapted, where four landscape positions were identified using Global Positioning System (GPS). The crest, upper slope, middle, and lower slope positions were identified, each representing changes in geomorphology. Two pedons were georeferenced at each topographic position, where they were sunk and described. Result show that the forms of K varied with topographic positions. Potassium distribution varied from surface to subsurface in different topographic positions. Water soluble K was higher at crest surface (0.0569 cmolkg-1) and decreased with soil profile depth. Exchangeable K has highest value of 0.1317 and 0.1308 cmol/kg-1 at both lower slope positions in general. Non exchangeable K values where higher at all surfaces than the subsurfaces of topographic positions. HCl soluble K values were higher at lower and upper slopes surface, moderately at middle and least at crest slope positions. Total K values were higher at upper slope subsurface, middle, and lower slope surface with low variations at the crest positions. However, the distribution of the K forms did not shown a well – defined trend with respect to topographic positions.
Integrated horizontal-scan remote sensing for landslide imaging and evaluationteraelement
An example of hyperspectral imaging and LIDAR integration for the detection of landslide parameters (presented at Geological Remote Sensing Group meeting in London, 2011).
Evaluation of Structural Geology of Jabal OmarIJERD Editor
The proposed Jabal Omar Development project includes several multi-storey buildings, roads, bridges and below ground structures. Dykes and joints are the most common geological features in the area; they vary in thickness and orientation. The spacing between adjacent discontinuities largely control the size of individual blocks of rock masses which govern the stability of rock structures. The shearing and faulting system normally associated with tectonic movement making the area very weak, highly weathered and unstable. All Structural geological units analyzed using stereographic projection
Provenance, tectonic setting and diagenesis of the Mn-Fe coated terrigenous c...iosrjce
The arkosic and subordinate quartz-arenitic Mn-Fe coated terrigenous clasts were discovered to
occur in association with manganese nodules hosted by weathered Mn-Fe rich alluvial-fluvial sediments of the
Tertiary period in Carletonville area. The weathered Mn-Fe rich alluvial-fluvial sediments form the modern soil
profiles in the study area. The Scanning Electron Microscope and petrographic studies of the terrigenous clasts
indicated elevated content of manganese oxide precipitated in pore spaces between the framework grains as
well as forming surface coatings on hand specimen. These clasts are mined with manganese nodules in the study
area. The manganese nodules were formed from in situ concentration of Mn-oxide due to surficial weathering of
the underlying Mn-rich dolomites of the Malmani Subgroup and then concentrated as Mn-rich residues,
encircling rock fragments in soil profile. In contrast, Mn-Fe coated terrigenous clasts and the alluvial-fluvial
sediments were sourced from older geological basins. Therefore, the purpose of the study were to construct a
possible source area of Mn-Fe coated clasts and Mn-rich alluvial-fluvial sediments which hosted Mn-nodules in
the mine area and from the results deduce the overall source of manganese that is mined in the area. On the
basis of framework compositional analysis, the sediments were found to have been sourced from metamorphic
and granitic origins in a cratonic interior to recycle orogen and sedimentation occurred in low plain,
temperate, humid to subhumid climate. The sediment sources resembled the properties of the Archean granites
and gneisses of the Witwatersrand Supergroup and Rand Anticline ridge (quartzite formation) exposed far off
along the northern part of the study area on a high topographic mountain.
forms and distribution of potassium along a toposequence on basaltic soils of...IJEAB
The study was conducted in Vom, Jos Plateau state in the Southern Guinea Savanna zone of Nigeria to accentuate the forms of potassium distribution associated with topographic positions. The study area lies between longitudes 080 45’ 01” and 80 47’ 56’’ E, latitudes 90 43’ 17’’ and 90 45’ 15’’ N, with an elevation of about 1270m above sea level. A stratified purposive sampling procedure was adapted, where four landscape positions were identified using Global Positioning System (GPS). The crest, upper slope, middle, and lower slope positions were identified, each representing changes in geomorphology. Two pedons were georeferenced at each topographic position, where they were sunk and described. Result show that the forms of K varied with topographic positions. Potassium distribution varied from surface to subsurface in different topographic positions. Water soluble K was higher at crest surface (0.0569 cmolkg-1) and decreased with soil profile depth. Exchangeable K has highest value of 0.1317 and 0.1308 cmol/kg-1 at both lower slope positions in general. Non exchangeable K values where higher at all surfaces than the subsurfaces of topographic positions. HCl soluble K values were higher at lower and upper slopes surface, moderately at middle and least at crest slope positions. Total K values were higher at upper slope subsurface, middle, and lower slope surface with low variations at the crest positions. However, the distribution of the K forms did not shown a well – defined trend with respect to topographic positions.
Integrated horizontal-scan remote sensing for landslide imaging and evaluationteraelement
An example of hyperspectral imaging and LIDAR integration for the detection of landslide parameters (presented at Geological Remote Sensing Group meeting in London, 2011).
Landslide Risk Reduction Plan for Pashupati Monument Zone (Kathmandu Valley ...Akrur Mahat
The risk of natural hazards on cultural heritage is a crucial issue that demands a multi-disciplinary approach to address it appropriately and efficiently. The significant loss of heritage due to recent Gorkha earthquake 2015 has highlighted the lack of risk assessment of cultural properties and implementation of comprehensive risk reduction plan. The monitoring and evaluation of the state of conservation of individual cultural heritage property are the fundamental and essential task in the overall assessment of vulnerability.Conservation plan of action for the monuments and environment should be formulated and prioritized by heritage value of the property. Also, the safeguarding cultural properties from natural hazards also requires a comprehensive strategy that includes risk assessment and the participation of all stakeholders. This study tries to assess the vulnerability of cultural heritage property and find out the level of landslide risk which will help to prepare landslide risk reduction plan for the effective management of the every cultural property within the Pashupati Monument Zone.
A combination of extensive field survey, local and expert knowledge has been used to extract information of landslide and monument.A landslide hazard susceptibility map of Pashupati Monument Zone has been prepared using frequency ratio model in GIS software.Parameters considered are slope aspect, slope angle, elevation, drainage distance, geology and land use. The vulnerability of 290 monuments have evaluated through a combination of multiple criteria as the state of conservation and a heritage value, a combination of both served as an input factor for the physical vulnerability of the cultural properties of the entire zone. Landslide risk has been calculated combining the landslide hazard susceptibility and vulnerability of monuments within the cultural heritage site.
Final results show that Pashupati monument zone has 15% high, 31% medium landslide hazard area.Similarly, out of 290 monuments 5% (15 nos) lies in high and 38% and 57 % are in medium and low landslide risk.Findings depict that the cultural properties assessed in this area are mostly affected in the Slesmantak forest area (master plan B1 zone) where high hazard landslide area has founded.Finally, some recommendations are proposed related to conservation of environment and monuments in the Pashupati Monument Zone.
Key Words:
Cultural heritage, Heritage value, State of conservation, Landslide hazard mapping, Risk Assessment, Landslide Risk Reduction plan.
Vulnerability Zonation Mapping for Landslides' Occurrence Using GIS and Remot...Kosmas Stampoulidis
This presentation shows the creation of a landslide vulnerability map. The latter is developed using Geographic Information Systems (GIS) and Remote Sensing methods. Seven separate maps that include land cover, lithology, distance from road and hydrographic network, altitude, orientation and slope gradient in the study area, which is the Municipality of Pogoni in the region of Epirus, northwestern Greece, are created. Then, these maps are calibrated with weighting factors and combined with a linear method. In the final map, three landslide vulnerability zones, low, medium and high, are represented. The creation of this map may result in credible future location of infrastructure, identification of vulnerable spots and settlements and selection of the most appropriate and safer land use in the region.
Lecture Notes of Environmental Engg-II as per solapur university syllabus of TE Civil,
Prepared by
Prof S S Jahagirdar,
Associate Professor,
N K Orchid college of Engg and Technology,
Solapur
Civil Technical questions word presentationpremsai05
This consists of various basic civil engineering questions.This can used for screening members in first rounds.The key will be sent to you when u comment and send your mail id
During his reign, Louis XIV fought four wars: The War of Devolution, the Franco-Dutch War, the Nine Years' War, and the War of the Spanish Succession. In each of these wars, Louis sought to attain personal glory while strengthening France at the expense of other European powers. While Louis' legacy can often be controversial, he left France a more powerful country than he found it.
For more instructional materials, visit my website: www.tomrichey.net
Geomatics Based Landslide Vulnerability Zonation Mapping - Parts Of Nilgiri D...IJERA Editor
Landslide includes a wide range of ground movements, such as rock falls, deep failure of slope, and shallow debris flows. Although gravity acting on an over steepened slope is the primary reason for a landslide. The Nilgiri Hills (Mountains) of Tamil Nadu, India are prone to landslides, which often result in considerable damage to private property, public infrastructure, and loss of life. The mapping of LVZ includes, the preparation of various thematic layers from different data sources, such as Survey of India topographic sheets, Satellite data, Geological Survey of India maps etc. These landslides are typically the result of the structural failure of thick laterite soils that have been saturated by heavy rains during the monsoon season. . GIS have proved to be useful tools for analyzing and managing landslide related data. GIS has been widely used in quantitative estimation landslide susceptibility. The methodology adopted for the identification of landslide vulnerable zones, and suggestion of remedial measures based on the vulnerability of landslides on different terrain parameters per unit area. Through this study, it is evinced again that the geomatics technology is a proven tool for landslide studies in order to properly understand, identify and suggest remedial measures.
Remote Sensing Technique as Exploration Tool for Ground water in Parts of the...theijes
The study area lies within latitudes 8°00' – 9°00'N and longitudes 11°30' – 12°30'E. Analysis of remote sensing imageries of part of the Upper Benue Trough of Nigeria was carried out on a scale of 1:100,000. The aim of this study includes the structural interpretation of the remote sensing data and the identification of the lineament and drainage patterns associated with the area to infer the influence of such structures on the economic potential of the basin. Results of the structural analysis revealed numerous lineaments. Trend analysis of the lineaments plotted on a rose diagram using the strikes and lengths of the entire lineaments revealed structural trends predominating in the NE-SW direction. The absence of visible lineaments in parts of the area may not indicate absence of geological structures. Some of these lineaments were found on some drainages showing that the drainages in those areas are structurally and tectonically controlled. The areas where the lineaments cross each other are indicative of groundwater availability and there correspond to regions of mean topographic height of about 900m
Methodological procedures to landslide risk mapping in brazilian slums
1. Methodological procedures to landslide
risk mapping in Brazilian slums
Presenter
Luciana Pascarelli Santos
Authors
Eduardo Soares de Macedo(1), Kátia Canil(1), Fabrício Araujo Mirandola(1), Fabiana Checchinato Silva(1), Marcelo
Fischer Gramani(1), Agostinho Tadashi Ogura(1), Alessandra Cristina Corsi(1), Luciana Pascarelli Santos(2)
(1) Institute for Technological Research – IPT , São Paulo (SP), Brazil
(2) São Paulo City Council, São Paulo (SP), Brazil
2. Description of mapping methodology
In this methodology, the factors that make assessment and risk analysis are
simplified, grouped and analyzed qualitatively, from direct observation in the
field. In this sense we have evaluated the following factors, considered essential
to risk analysis:
• typology of the expected process and its probability or possibility of occurrence;
• vulnerability of urban settlements; and
• potential damage.
3. Stages of the mapping methodology
In accordance with the requirements, the specific objectives of the performed activities
were the following:
• to obtain low-altitude oblique photos of the areas at risk from helicopter overflights;
• identify the sectors with different degrees of probability of occurrence of destructive
processes (landslides on slopes and/or washouts of stream banks) and enclose them in the
oblique photos;
• indicate the number of threatened houses or buildings that could be affected due to the
occurrence of the destructive processes mentioned above;
• present alternative measures to control the identified risks;
• design a database containing the results of the mapping.
4. Description of mapping methodology
In the areas selected by the council were performed:
• a survey of the area occupation characteristics and its infrastructure
CATEGORY OF
CHARACTERISTICS
OCCUPATION
Densely occupied areas, with basic
Consolidated area
infrastructure.
Areas in process of settlement,
adjacent to areas of established
Partially consolidated
occupation. Density of occupation
area
ranging from 30% a 90%. Reasonable
basic infrastructure.
Expansion areas, remote and distant
from urban nucleus. Low density of
Split area
occupation (up to 30%). Devoid of basic
infrastructure.
In such cases, characterize the area
Mixed area with regard to occupation density and
implementation of basic infrastructure
5. Description of mapping methodology
• risk mapping procedures using geological and geotechnical surface investigations in order
to identify the types of gravitational mass movements
CHARACTERISTICS OF THE
PROCESSES
MOVEMENT/MATERIAL/GEOMETRY
- several (internal) displacement planes / -
very low to low (cm/year) velocities that
decrease with depth / - constant, seasonal
CREEP
or intermittent movements /- soil, deposits,
altered/fractured rock /- undefined
geometry
- few (external) displacement planes / -
medium (m/h) to high (m/s) velocities / -
small to large volumes of material
- variable geometry and material / PLANAR:
SLIDES
thin soils, soils and rocks with one weakness
plane / CIRCULAR: homogeneous thick soils
and very fractures rocks / WEDGE: soils and
rocks with two weakness planes
- no displacement planes / - free fall- or
inclined plane-type movement / - very high
(several m/s) velocities
FALLS - rocky material / - small to medium
volumes / - variable geometry: flakes,
plates, blocks, etc. / BOULDER ROLLING /
TOPPLING
- many displacement surfaces (internal and
external to the moving mass) / - movement
similar to that of a viscous liquid / -
development along drainage / - medium to
FLOWS
high velocities / - soil, rock, debris and
water mobilization / - large volumes of
material / - extensive range, even in flat
areas
6. Description of mapping methodology
• as well as the constraints of the destabilizing processes, evidence of instability and
indication of the development of destructive processes. Thus the prevailing destabilizing
processes will be identified, delimiting and characterizing the risk sectors.
MOVEMENT
SITE CHARACTERIZATION
EVIDENCE
- Natural slope - Presence of blocks - House
- Cut slope of rock/boulders/rock cracks/landfill
- Slope height walls - Trees/poles/walls
- Compacted fill - Presence of inclination
- hauled fill trash/debris - Etch-plains
- Distance from - Amphitheater - Landslide scars
home Landfill - Swollen walls
- Declivity - Occupation of - Erosion features
- Unfavorable headwaters - Stream margins
structures in undermining
soil/rock
PRESENCE OF
PRESENCE OF WATER
VEGETATION
- Surface concentration of stormwater - Trees
- Release of wastewater into surface - Undergrowth
- Presence of septic tanks/sewage/water - Deforested area
mains - Farming area
- Upwelling water
- Leakings
7. Field activities
The materials to be used to obtain the support information and product to the risk
mapping are:
• vertical aerial photos, with appropriate scale, up to 1:5.000;
• copies of the plano-altimetric maps, basis for the indicated mapping areas;
• information on risk areas, such as development records and/or occurrences of instability
processes, copies of technical reports and expert opinions previously prepared, any
intervention guidelines proposed (implemented or not) etc.;
• technical publications, geological, geotechnical, geomorphological and slope angle maps,
with information on areas indicated for risk mapping;
• copy of the street guide page on which is located the chosen mapping area.
8. Log LOCALIZAÇÃO DA ÁREA
FICHA PARA AVALIAÇÃO DE ÁREA DE RISCO
A log is a tool to determine the potential of Endereço: Área nº:
accidents through field surveys carried out in order SITUAÇÃO DA ÁREA (VIDE MODELOS ANEXOS)
to identify risk situations. The cards used in field ( ) Encosta ( ) Margem de córrego ( ) Encosta + Margem de córrego
CIRCUNST ÂNCIAS EM QUE SE DESENVOLVEM OS PROCESSOS
surveys should contain the aspects to be analyzed
MARGEM DE CÓRREGO ENCOSTA
(check list), allowing the professional come to a
conclusion as to the risk of the analyzed area.
Distância observada:______ m Distância observada:______ m
( ) Concentração ou lançamento de águas em superfície ( ) Pontos de infiltração ou minas
( ) Presença de vegetação. Qual? ________ ( ) Área desmatada ( ) Presença de lixo e entulho
( ) Trechos aterrados ou escavados ( ) Outros. Citar:_______________
EVIDÊNCIAS DE PROCESSO DE INSTABILIZAÇÃO
( ) trincas/rachaduras ( ) degraus de abatimento ( ) muros embarrigados
( ) cicatrizes de escorregamento ( ) árvores/postes inclinados ( ) outros. descrever:___________
Nº DE MORADIAS (A SEREM) HÁ POSSIBILIDADES DE CONVIVÊNCIA
EFETIVAMENTE ATINGIDAS COM O RISCO? POR QUÊ?
GRAU DE PROBABILIDADE DE OCORRÊNCIA DE PROCESSO DE INSTABILIZAÇÃO
( ) R1 – Baixo ( ) R2 – Médio ( ) R3 – Alto ( ) R4 – Muito Alto
RESPONSÁVEL PELAS INFORMAÇÕES:
9. Overflight
Overflights by helicopter should be preceded by flights planning supported by technical field visits in
order to obtain coordinates from the GPS readings.
Besides the programming of helicopter overflights, all the technical material will allow the
optimization of the field activities, as well as a preliminary analysis of the areas to be mapped,
allowing for a fast and efficient mapping.
10. Description of mapping methodology
The risk sectors will be delimited with the indication of the probable destabilizing processes, that is,
landslides on natural slopes or cutting slopes and embankments. The criteria for judging the
probability of the destabilizing processes of occupied slopes landslides kind, as well as the
parameters analyzed for further procedures.
PROBABILITY DEGREE
R1 - Low Risk R3 - High Risk
Concerning to evaluated Concerning to evaluated
indicators, the area shows indicators, the area shows high
low risk to develop landslides risk to develop landslides
processes processes. Relevant indicators
of instability processes can be
observed
R2 - Medium Risk R4 - Very High Risk
Concerning to evaluated Concerning to evaluated
indicators, the area shows indicators, the area shows very
medium risk to develop high risk to develop landslides
landslides processes. Just processes. Almost all the
some indicators of instability indicators of instability
processes can be observed. processes can be observed. It is
the most critical condition.
11. Representation of sectors in the oblique photos
For the representation of the sectors at low-altitude oblique photos the following procedures,
criteria, symbols and conventions were adopted
• on the oblique photos, with the delimited risk factors the identification of the houses to be removed is
done with the letter “r”;
• in cases where the same sector is represented in more than one oblique photo, preference should be
given to the photo where the sectors can be better seen and their boundaries more precise.
12. Final Comments
For The risk mapping allows an assessment of the areas aiming to provide immediate, medium and
long term solutions for the slums in the most critical situation.
The obtained results will enable the city administration develop a strategic plan of interventions to
reduce and control the mapped risks, enabling the cost estimate for the suggested interventions for
each sector and the establishment of sequence of priorities for the implementation in accordance
with the technical criteria.
An example of applying this methodology can be seen in the paper entitled “Mapping of geological
at-risk areas in the city of São Paulo: issues and results from the largest survey of risk in Brazil”,
present in session "Landslide risk assessment and management" of the Second World Landslide
Forum.