Classification factors Landslide classification

1 classification factors

1.1 a1) type of movement
1.2 a2) involved material
1.3 a3) activity
1.4 a4) movement velocity
1.5 b1) age of movement
1.6 b2) geological conditions
1.7 b3) morphological characteristics
1.8 b4) geographical location
1.9 b5) topographical criteria
1.10 b6) type of climate
1.11 b7) causes of movements

classification factors

various scientific disciplines have developed taxonomic classification systems describe natural phenomena or individuals, example, plants or animals. these systems based on specific characteristics shape of organs or nature of reproduction. differently, in landslide classification, there great difficulties because phenomena not repeatable; being characterised different causes, movements , morphology, , involving genetically different material. reason, landslide classifications based on different discriminating factors, subjective. in following write-up, factors discussed dividing them 2 groups: first 1 made of criteria utilised in widespread classification systems can determined. second 1 formed factors have been utilised in classifications , can useful in descriptions.

a1) type of movement

this important criterion, if uncertainties , difficulties can arise in identification of movements, being mechanisms of landslides particularly complex. main movements falls, slides , flows, topples, lateral spreading , complex movements added these.

a2) involved material

rock, earth , debris terms used distinguish materials involved in landslide process. example, distinction between earth , debris made comparing percentage of coarse grain size fractions. if weight of particles diameter greater 2 mm less 20%, material defined earth; in opposite case, debris.

a3) activity

the classification of landslide based on activity particularly relevant in evaluation of future events. recommendations of wp/wli (1993) define concept of activity reference spatial , temporal conditions, defining state,

the distribution , style. first term describes information regarding time in movement took place, permitting information available on future evolution, second term describes, in general way, landslide moving , third term indicates how moving.

a4) movement velocity

this factor has great importance in hazard evaluation. velocity range connected different type of landslides, on basis of observation of case history or site observations.

b1) age of movement

landslide dating interesting topic in evaluation of hazard. knowledge of landslide frequency fundamental element kind of probabilistic evaluation. furthermore, evaluation of age of landslide permits correlate trigger specific conditions, earthquakes or periods of intense rains. possible phenomena occurred in past geological times, under specific environmental conditions no longer act agents today. example, in alpine areas, landslides of pleistocene age connected particular tectonic, geomorphological , climatic conditions.

b2) geological conditions

this represent fundamental factor of morphological evolution of slope. bedding attitude , presence of discontinuities or faults control slope morphogenesis.

b3) morphological characteristics

as landslide geological volume hidden side, morphological characteristics extremely important in reconstruction of technical model.

b4) geographical location

this criterion describes, in general way, location of landsides in physiographic context of area. authors have therefore identified landslides according geographical position possible describe alpine landslides , landslides in plains , hilly landslides or cliff landslides . consequence, specific morphological contexts referred characterised slope evolution processes.

b5) topographical criteria

with these criteria, landslides can identified system similar of denomination of formations. consequently, possible describe landslide using name of site. in particular, name of locality landslide happened specific characteristic type.

b6) type of climate

these criteria give particular importance climate in genesis of phenomena similar geological conditions can, in different climatic conditions, lead totally different morphological evolution. consequence, in description of landslide, can interesting understand in type of climate event occurred.

b7) causes of movements

in evaluation of landslide susceptibility, causes of triggers important step. terzaghi describes causes internal , external referring modifications in conditions of stability of bodies. whilst internal causes induce modifications in material decrease resistance shear stress, external causes induce increase of shear stress, block or bodies no longer stable. triggering causes induce movement of mass. predisposition movement due control factors determining in landslide evolution. structural , geological factors, described, can determine development of movement, inducing presence of mass in kinematic freedom.