Evolution of Early Warning System for Landslides
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Disaster Advances Vol. 15 (8) August (2022)
Review Paper:
Evolution of Early Warning System for Landslides
Sudani Prashant1* and Patil K.A.2
1. College of Engineering, Pune, SPPU, Maharashtra, INDIA
2. Department of Civil Engineering, COEP, SPPU, Pune, Maharashtra, INDIA
*sudaniprashant93@gmail.com
Abstract to several thousand meters. Based on the type of movement,
A landslide is a disastrous event and harms livelihood falling, sliding and flowing are often seen in the landslide
with varying degrees based on the nature of the studies, Varnes96 defines them as a principle type of
landslide. Such a geological event leads to damages to landslide movement. The mass movement is one of the
catastrophic disasters that have the power to make a deep
the country's valuable infrastructure and resources.
groove on society, as it can cause harm to precious human
Scientifically designed proper and effective remedies lives and properties. It is triggered by several reasons
for such a natural disaster are need-of-hour. We can consisting of an earthquake, rainfall26,74 and a weak layer of
prevent such a hazard by either of two things, first by the earth46. Out of the several triggering factors, rainfall-
delivering proper construction maintenance of slope by induced landslides are mostly expected; several cases of the
stabilizing it or by removing an unstable part of the hill same are also reported from around the world1,10,99.
and second by detecting the hazard before it happens
to move safely costly equipment and people from the The current scenario and historical trends of the devasting
landslide-prone site. Sometimes even after providing landslide reported huge losses including losses of precious
proper stabilization to the slope, it may fail due to human lives and infrastructural losses in both the way: direct
and indirect. Some of them which are recorded as worse in
unavoidable natural climate; it is needful to use early
the history of Indian landslide scenario are listed here: i) The
warning systems (EWS) and monitoring to ensure Chamoli landslide, which reported 70 deaths of people in the
infrastructure and human lives. To monitor and Uttarakhand State of India in 186823, ii) Nainital landslide
develop an EWS, one needs to know the risks that reported in the State of Uttarakhand in 1880, several millions
threaten stability. of rupees got washed into the disasters along with recorded
death toll of 15025, iii) Chamoli landslide in 1970 reported
Again, stability is also affected by more than one factor death toll of 55, iv) Luggarbhati landslide in Himachal
such as the soil's physical and mechanical properties, Pradesh in 1995 responsible for 65 human beings loss, v)
morphology and geology of the earth, presence of Okhimath and Malpa landslides of Uttarakhand in 1998 took
cracks and fissures in the slope of the ground etc. To 380 lives of human, vi) Dharla landslide of Himachal
understand such a complex geological event, the need Pradesh in 2007 reported 62 death toll etc. More than 90%
of the landslides are caused by rainfall76.
to find out these properties is crucial. Such a
complexity shows that developing a landslide, EWS Further, globally between 1971–74, 600 people per year lost
finds complicated task and needs to correlate their precious lives due to landslides82; most of these losses
multidisciplinary knowledge to solve the problem faced were observed in the Pacific province. In Japan, between
during designing and producing an alert system to the 1967–82, 150 persons lost their precious lives due to
society. In this study, a historical trend in the landslides. Also, in the USA, fatalities rate per year due to
advancement of the landslide EWS with existing landslides have exceeded 25.82
warning systems along with their advantages and
disadvantages is discussed; it can be helpful to the Case history on torrential landslide: On 30th July of 2014,
researchers to get an idea about what should be done a devastating debris flow arose in the province of
Maharashtra, India. After torrential rainfall, it wiped out the
to improve to make more efficient landslide early
entire village called Malin in the Pune district of
warning system for landslides. Maharashtra and it costed about 160 deaths and economic
loss of State30. The natural event of heavy rainfall
Keyword: Electrical Resistivity, Early warning, Landslide. precipitation triggered the landslide. Cumulative rainfall
recorded by the Tropical Rainfall Measuring Mission
Introduction (TRMM) in that period was more than 600 mm. It has
Landslide: Landslide is a mass displacement of the earth in resulted in such heavy rain in the area that it led to saturated
a downward and outward direction under gravity triggered soil. This saturation was developed as loose mud and
by natural and human-made factors. The sliding mass of the eventually flowed down after losing its shear strength and
earth may have various soil types including composite soil, gaining momentum, sweeping terraces, walls and ultimately
natural rock and various combinations. The displacement of the village Malin houses79.
the slide also has a wide range, only just a few centimeters
46Disaster Advances Vol. 15 (8) August (2022)
Hillslope was prone to failure because it has a factor of safety regions of the earth also suffer the landslides if adverse
less than one. The slope was triggered by more than one geological factors, steep slope and triggering factors are
factor noted as natural and human-made factors including present29. Moreover, we are often concerned about the fast-
substantial precipitation, non-technical house erection moving landslides only, but it is not a fast-moving slide that
activities on the hills and along the mountain, flattening the can make an extensive loss to the country. In general, a slow-
slope for cultivation and improper rainfall-runoff system85. moving landslide does not require emergency action, but it
Disasters like the one in Malin village, Mumbai – Pune is needed to monitor continuously to defend against the
region, reveal the devastating effects of earth displacement disaster at all levels.
on society.
Need of EWS: A landslide is a geological event that can be
Causes of landslide: A landslide or slope failure may be due defined as a movement of the earth in debris or composite
to natural or hominoid interaction, which may affect the soil solid or massive rockfall under the gravitational forces.
loading condition of the slope, degree of saturation, pore Such a geological event leads to damages to the costly
pressure, loading of the slope, rock strength, the effect of infrastructure and loss of lives of affected people. To save
weather and many more factors that can lead to instability of such an expensive cost, we have to provide proper and
the slope65. Stability is also affected by more than one factor effective remedies. We can prevent such a hazard by either
such as the soil's engineering and mechanical properties, of two things, first by delivering proper construction
morphology and geology of the earth, cracks and fissures in maintenance of slope by stabilizing it or removing an
the ground's slope etc. Every slope was stable before the unstable part of the hill and second by detecting the hazard
slide. Many factors convert the state of landslide into before it happens to move safely costly equipment and
marginally unstable, which reduces the stability of the slope people from the landslide-prone site. Sometimes even after
to a great extent. We can call them primary factors: providing proper stabilization to the slope, it may fail due to
weathering, deforestation, environment, tectonic uplift and natural hazards; in such a situation, it is needful to use early
undercutting the slope's toe. These primary factors cannot warning systems (EWS) and monitoring to protect
make instant instability; they affect the margin of stability infrastructure and human lives.
but finally failed by some triggering event.
To implement the proper and efficient warning system, the
The major landslide was triggered by the rainfall alone; following objects should be fulfilled: i) Maintaining efficient
earthquake and snowmelt are also triggering events that can and errorless operational flow; ii) Effectively delivering
make slope unstable97. Human interaction is also often seen warning of instability and iii) Providing important soil
in the form of the non-technical construction activities on the properties regarding slope performance. As long as the risks
hill and undercutting of the toe of the hill can favor the are known and a sufficient, suitable monitoring system is
trigger; it is well seen in the worse landslide called the Malin provided, remedial engineering and safety measures can be
slide of Pune31. Intense rainfall is the most crucial landslide taken13.
triggering event for both near-surface and deep-seated
failure. Infiltrating rain fills the present voids of the soil Landslide Early Warning System: The different
which reduces the suction pressure and which can impart researchers gave several definitions for the early warning
extra tensile strength to the slope. The increasing water in systems. One can define it as the “designed device that can
voids of the slope caused higher pore water pressure which monitor to completely prevent or at least diminish the hazard
is further accountable for the strength loss of the slope90. To on livelihood, costly properties of the country and the
monitor these hydrological processes in the slope saturation environment”66. EWS is defined by United Nations
evolution, flow path, permeability of the soil and International Strategy for Disaster Reduction-2019
geotechnical properties of the soil consisting slope are (UNISDR) as “the set of aspects needed to produce and issue
essential. timely and significant risk threatening information to public,
societies and government organizations who are vulnerable
The insight of the fifty worst disastrous landslides in 2008 by a hazard so that they can be prepared and act
listed by Re77 exposes that landslide failures are appropriately with the strategic plan and in a sufficient time
accompanied by one-fifth part of all calamitous events to reduce the possibility of injury or damage.” After all,
instead of an exclusive event. A demonstrative instance is whatsoever be the explanation of the EWS, they used as a
the 2001 Kutch earthquake in the Gujarat region, India risk mitigation object by analyzing the probable cause of the
which caused extensive loss of life and properties. Over hazard and their intensity level; it gives warning to the
20,000 people were reported as dead and about 1.7 lakhs are concerned human beings and organizations to take proper
injured. Such an event has proven to be more favorable for a action to minimize the harm case of a probable forthcoming
mass movement and there are number of landslides causing disastrous event.
loss of lives and properties too after the earthquake.
On the other hand, it must be clear that an EWS is not just a
Further, instability of the slope is not only due to high- monitoring system or forecasting tool, but along with that, it
mountainous areas of the earth; numbers of the lower-alpine incorporates additional aspects like the identification of
47Disaster Advances Vol. 15 (8) August (2022)
intensity of risk, possible safe evacuation and emergency event often subjected to other catastrophic hazards like
strategies, societal perspectives and most importantly public earthquakes and hydrological floods, which require
responsiveness. All these aspects are essential and if any of additional attention and protective measures. In the direction
these aspects fails, it will lead to the collapse of all chains of developing and implementing warning and monitoring
and in the end, all systems became useless. systems for landslide researchers from several countries got
participated and tried to map the landslide but due to lack of
To ensconce the critical place from such a hazardous event, the fund, it was forced to remain in prototypic approach as it
we must have to equip such a position with the proper plan does not attract public sector investment due to its count as
and strategy to minimize the country's loss, human lives and personal damage8.
economic deprivation. Schuster and Highland83 provide the
four common types of the approach which are often used to History of Landslide Early Warning System
counteract the hazardous event like a landslide, First by From the end of the 20th century to date, many researchers
avoiding the hazard by not allowing the infrastructural have made an effort to establish an EWS for the landslide.
development in the area which is vulnerable to slide, Different methods, statistical and physical and model-based
secondly by strengthening the slope which is prone to slide approaches were used to reach a conclusion and give the
using appropriate engineering means, thirdly by taking care threshold-based or FOS-based warning. Also, from the
of existing infrastructure which is already constructed on history of developing LSEWS, we can see the
such a vulnerable land and fourthly by implementing the instrumentation variation used with time for field and off
warning system against the landslide event in advance so fieldwork. An extensive effort was made in literature survey
that loss can be prevented. to prepare a detailed historical development in landslide
early warning system and here it was displayed in table 1 by
First, mitigation measures seem best suited to easiness, but taking some of the well-known researchers work into
it is not possible where infrastructure already existed. ‘Also, consideration so it can be helpful to researchers in future to
methods of protective measures for a landslide by getting an idea about what was being used till date and what
engineering means are non-economical and they are not is still needed to improve.
feasible for massive earth mass92,93. Badoux et al4 noted that
the region affected by a landslide is in no case an exclusive
Table 1
Historical Advancement of Landslide monitoring and warning system
S.N. Year/ EWS/ Method Adopted for Main Instrument used Additional Land Slope type
Place Monitoring slope monitoring triggering tool slide
factor type
1 1998/US Monitoring Simple Monitoring/ Rainfall Remote sensing TDR Rock Open mine
Using displacement and techniques Fall slope
pore pressure data65
2 1990/ Monitoring Pore-water pressure Rainfall Piezometers -- Debris Natural
California monitoring using flow slope
artificially water
supply42
3 1985/Utah Monitoring Manual monitoring, By Displacement Extensometer, -- Debris Natural
graphical plot of Inclinometer, Radio flow slope
displacement vs. time12 telemetry
4 1990/ Monitoring By analyzing the Rain and Triaxial and Box shear -- Debris Natural
Budapest rainfall and moisture snowfall flow slope
effect on the landslide34
5 1977/ Analysis By model study / Rainfall Pore pressure and Hydrological -- Natural
Canada Groundwater flow groundwater profile modeling tool slope
system and slope
stability87
6 1990/ Investigation By Geophysical The water Geophysical methods -- -- Natural
Netherland method64 table, slope
Rainfall
7 1971/ EWS By soil and rock Rainfall, Soil -- -- -- Natural
San dynamic Para. slope
Francisco characteristics48
8 1987/ EWS By empirical and Rainfall Rain gauge station and -- Debris Natural
California theoretical analysis51 time series analysis of flow slope
rainfall
48Disaster Advances Vol. 15 (8) August (2022)
9 1980/ Monitoring By displacement Movement Inclinometer, Sensors, -- Sliding Natural
Nevada monitoring using slope
sensor6
10 1987/ Monitoring By Aquatic emission Rainfall and Accelerometer, -- Rotatio Natural
Colorado and monitoring50 Movement Inclinometer, Ground nal slope
sensor, Water locator
11 1994/ Monitoring By creep monitoring41 NA Creep measuring -- -- Natural
China device slope
12 1995/ Geo-hazard By using SAR Movement Synthetic aperture Radar Slump Natural
Canada assessment techniques86 radar Software And slope
packages Block
13 1993/ Monitoring By the use of Movement Inclinometer, -- Rotatio Natural
Italy displacement of the extensometer, nal slope
slide72 geophone and
accelerometer.
14 1999/ Monitoring Use of GIS Surface Hyperspectral -- -- --
Netherland Technology17 monitoring imagery, Digital
photogrammetric,
15 1997/ Prediction By use of probability Rainfall Rainfall Data Statistical Debris Natural
Hongkong estimation on rainfall flow slope
time-series data35
16 2001/ EWS By use of combined Rainfall Tipping bucket-type CHASM Debris Natural
Malaysia hydrology and stability rain gauge flow slope
model (CHASM) 57
17 2001/ EWS By use of displacement Displacement Soil strainmeter and -- -- --
Malaysia Monitoring47 rate data logger
18 2002/ Monitoring By use of GPS61 Movement GPS -- -- --
France
19 2002/ Warning By use of Displacement Displacement GPS sensor -- -- Natural
Germany system monitoring54 rate slope
20 2002/ Early By rainfall and Movement Inclinometer, Rainfall -- -- --
Italy warning displacement threshold58
21 2003/ Monitoring By displacement Movement GBSAR -- -- --
Italy analysis through SAR
interferometer89
22 2005/ Monitoring By Field monitoring28 Movement Inclinometer, -- -- --
Italy Extensometer, TDR
cable, Piezometers,
Rain gauge,
Datalogger, GPS
23 2004/ Italy EWS By rainfall based Rainfall Data collected -- -- --
threshold2
24 2006/ Italy Monitoring By Linear Synthetic Displacement Linear Synthetic -- -- --
Aperture Radar rate Aperture Radar
displacement
measurement18
25 2007/USA EWS By triggering as rainfall Rainfall & Rainfall Data -- -- --
and earthquake44,45 EQ
26 2008/ EWS By live integration Rainfall Weather forecast -- -- --
New model80
Zealand
27 2008/ Prediction By satellite rainfall Rainfall Rainfall Data -- -- --
USA estimate45
28 2008/ Monitoring By GB-SAR69 Movement GB-SAR, GPS, -- -- --
Italy
29 2010/ Landslide By geophone network53 Vibration Geophones, Moisture -- -- --
India detection sensor, Pore pressure
transducer
30 2010/ Monitoring By measuring Displacement GB-SAR, GPS, -- -- --
Italy and EWS displacement rate19 rate
31 2009/ Monitoring Based on the Rainfall, Field and laboratory -- -- --
China and EWS topographical, Groundwater testing equipment
49Disaster Advances Vol. 15 (8) August (2022)
geological and
hydrological condition56
32 2011/ EW Based on the Rainfall Rainfall data, Rain -- -- --
Italy mathematical models16 gauge
2012/ EWS By Displacement Displacement Extensometer, Web GIS Rock Natural
Italy Monitoring49 rate Thermometer, Rain Fall
gauge
33 2012/ EWS By GIS and GPS based Displacement GIS & GPS with -- -- --
China early warning system55 rate sensor
34 2013/ EWS By using a Limit Rainfall Rainfall data, ER -- - --
Germany Equilibrium model92 testing, Field
instruments
35 2013/ Monitoring By FEM Software84 Rainfall Rainfall and total -- -- --
India station
36 2013/ Monitoring Based on antecedent Rainfall Rain gauge ASWS model Debris Natural
China soil water status and flow
rainfall5
37 2013/ EWS Based on the Empirical Rainfall Rainfall measuring -- -- --
Italy model40 instrument
38 2014/ EWS By wireless sensor Rainfall Rain gauge, Pore Stability Debris Natural
India network and limit pressure sensor, model flow
equilibrium analysis75 Inclinometer sensor,
Moisture sensor
39 2014/ EWS By the Limit Rainfall Rainfall data GIS -- Natural
Italy Equilibrium model36 slope
40 2014/ EWS Electrical resistivity88 Rainfall 4D-ERT Technique, NA Deep- Natural
Italy Automatic seated slope
inclinometer
41 2015/ EWS Using measuring of Rainfall Tiltmeter sensor, NA Debris Natural
Japan change in tilting angle Water moisture sensor flow slope
of the subsurface layer94
42 2015/ EWS Using an Artificial Rainfall Rainfall data ANN Debris Natural
Italy neural network73 flow slope
43 2016/ Monitoring Based on displacement Displacement GPS units, a Shape NA Slow- Natural
Canada monitoring60 rate Accel Array (SAA), Movin slope
satellite In SAR and g
crack extension Landsl
meters, & piezometers ide
44 2016/ Monitoring Based on ground-based Rainfall GPS, Tiltmeter, -- Rotatio Natural
UK monitoring techniques95 Inclinometer, Slope nal and slope
monitoring sensor, translat
Piezometers ional
45 2017/ EWS By Factor of safety Rainfall Rainfall station, soil SEEP/W, Debris Natural
Vietnam analysis37 moisture, pore SLOPE/W flow slope
pressure and
movement sensor with
a wireless data
transmission system
46 2017/ EWS By kinematic Displacement Corner reflector and -- Roto- Natural
Italy monitoring9 rate Satellite SAR translat slope
interferometry ional
47 2017/ Monitoring By statistical analysis22 Rainfall In place inclinometer, Multilinear Debris Natural
India Piezometers, Rain Regression flow slope
gauge model
48 2019/ EWS By displacement Displacement Inclinometer, -- Debris Natural
India monitoring33 Piezometers, flow slope
extensometer
Currently available different methods of ‘However, it is more accurate to say viewers cannot detect
Monitoring and EWS the phenomenon that preceded the failure of landslide’91.
Sometimes the landslide occurs without any sign of warning Therefore, the understanding of the phenomenon behind the
and hence it seems surprising to the eye-witnesses. slide is crucial. For that purpose, sound and efficient
50Disaster Advances Vol. 15 (8) August (2022)
monitoring systems have to be equipped on the vulnerable 2013, water-based ground threshold was derived by
site to recognize the potential landslide failure. Ashland3 using monitoring of the required parameter
through instrumentation. A warning is also based on rainfall
Researchers have developed several approaches to uncover based on a regional scale calculated using cumulative
the phenomenon of occurrence of the landslide in all rainfall precipitation data. Recently, snowmelt in the slope
respects. A wide range of probable approaches to detect stability monitoring is also incorporated to get an effective
phenomenon behind slide was presented to understand the rainfall threshold, giving less possibility of false alarm than
complete picture of the slide including measurement of the the previous system.
surface and subsurface movement by the direct or indirect
method, collection of the required data such as geotechnical One more such long-term warning system for the landslide
and hydrological and the use of the simulation was established in the San Francisco bay provenance, which
models5,21,31,33,39,52,53,58,72,75,78,80,92-94. was effectively used for the tens of years from 1986 to 1995.
After Campbell's14 work in 1975, the threshold-based
Landslide monitoring can be categorized into two broad warning system was developed which was entirely based on
types called local and regional scale landslide monitoring the study site's rainfall data51. The entire warning system was
approaches. On a local scale, only site-specific landslides are advanced with the United States Geological Survey (USGS)
taken into consideration and monitored effectively while on and the National Weather Service (NWS). The USGS
the other hand, the regional scale monitoring approach handled the project where NWS provided the rainfall
covers entire regions98. The initial steps are to prepare a precipitation data forecasted two times a day. Forecasted
landslide vulnerability map to identify the landslide's data by NWS were checked through a rainfall gauge and
vulnerable site on a large scale. While on the local scale, one along with that, monitoring of pre-defined threshold was
of the first steps should be field investigation and boreholes also done. The pre-defined threshold was calculated based
and clear the substrata picture68,98. Along with the statistical on the previous landslide information and corresponding
model constructed on records of slides and probability of rainfall data. Before communicating the final warning to the
occurrence, the knowledge of geotechnical investigations, community or the associated government body, expert
displacement analysis and modeling approaches must be opinion of USGS and NWS was incorporated to reduce the
required to reduce the rate of false alarming39. Cornforth et possibility of false alarm.
al27 suggested real-time observing the water pressure in the
sheared zone and correlating it with the rainfall data and As listed by Canon15 in 1988, the initial threshold that
appropriate instability is an outstanding feature of landslide triggered the landslide was based on the rainfall and annual
monitoring. cumulative rain intensity. After Keffer et al51 in 1987, this
threshold was adjusted to account for the soil's void ratio and
Regional landslide earl warning systems are primarily based water content. To know the debris flow initiation, minimum
on the probabilistic approach, which is modeled based on threshold, which can initiate the flaw, was also found out and
records of the slide in the region and hence it can only issue implemented. This minimum debris flow threshold shows
warnings like 60% probability of slide for a particular that the rainfall below this value may not lead to a slide of
region; site-specific slopes can not be identified98. On the the slope, while on the other hand, above threshold value
other hand, a site-specific or local landslide warning system leads to significant slope movement of debris.
can provide additional information of threshold which can
be monitorable. Excellence of these thresholds provides the After an in-depth study on this subject, the rainfall in the area
time to take protective measures such as alarming the people would not receive the same kind of precipitation, so the rain's
vulnerable to the disastrous event, closure of highways and spatial resolution requirement came up to provide an
bridges, evacuation of people and other required sets of efficient threshold. In 1992, warning system was
disastrous actions. Palm et al70 noted that Site-specific incorporated as radar interpretation to solve the issue. It
landslide early warning systems is often applied because shows that integrating such a procedure into a warning
they can replace the engineering steps of slope stabilization system collapses due to a lack of reliable relationship
during protective measures. Commonly used monitoring between radar reflectivity and field measurements. In an
systems generally used displacement and pore water early warning system related to possible disasters, social
pressure as a triggering factor and were analyzed by different aspects are important and challenging. USGS and NWS have
approaches to mape the warning trigger. had different points of view on the developing landslide
EWS; USGS wants to interpret the system's structure as a
Regional Landslide Warning System: Baum et al7 stated trial research model of which alarming thresholds are by-
that in 1984, one of the recent landslide EWS was developed products. While on the other hand, NWS wants reliable and
for Utah, USA. The requirement of such a warning system effective prediction and warning.
was understood after the large debris flows which were
caused by the snowmelt. Their first step system primarily Here in this system, USGS considers EWS as entirely
worked based on the presented threshold which depends on scientific, which was alarming to warn the people about
the study site's rainfall, displacement and temperature. After hazards to react appropriately. But in such a case, a guideline
51Disaster Advances Vol. 15 (8) August (2022)
for the people about how to work under warning should be generated for 20-hour precipitation, including 4 hours of
required. Moon et al67 stated that people intentionally forecasted precipitation. After the 1980s, the threshold was
attracted toward the landslide-prone area during an alarming modified for greater efficiency based on the hourly rainfall
time or severe hazard to save their house or feed animals due threshold limit for warning the hazard.
to lack of such instructions. After 1995 this warning system
was shutdown because USGS was not affording the cost to However, societal and geotechnical advancement since the
continue the service. 1980s transformed attention toward warning conversation.
GSI based approach was being utilized and forecasting was
After shutting down the landslide EWS established in San made based on spatially varying landslide susceptibility.
Francisco bay provenance, the USA, based on their Entire areas of the provenance were represented in the cells
experiences, USGS and National Oceanic and Atmospheric used to measure different properties containing slopes. The
Administration (NOAA) developed a warning system for possible landslides were then calculated based on the
landslide prone burden area in southern California, this area spatially variable susceptibility model of slope failure. EWS
was prone to the rainfall-induced debris flow. In the present used to issue the warning if more than 15 avalanches are
warning system, the warning system's end-user demands expected. The recent advancement radar outputs from the
were assessed before the system was set up. To develop and short-range warning of Intense Rainstorms in Localized
build the most effective warning system, USGS developed Systems (SWIRLS) is considered to monitor the cell blocks
one education program in which they invited the and improve the warning system's efficiency24.
meteorologists and interested researchers to explain the
hydrology that affects the debris flow and their Local Landslide Monitoring and Early Warning System:
characteristics. After considering scientific advances Noferini et al69, established the monitoring system for
associated with hydrology that affect the mass movement landslides dependent on the displacement monitoring in the
and others, the quantitative rainfall forecasts compared to the United Status. For displacement monitoring, they used an
previous system. These statistically-based empirical and inclinometer. The inclinometer system was equipped with
physical prototypes were considered to get a piece of displacement sensors that provided the displacement
information about mass movement's susceptibility, probable information with high accuracy of 0.001 inches. The
volume and flow distances. displacement sensor covered the 600 m long portion of the
slide, which is connected with the central computer system.
In 2007, Schuster et al83 stated that the most significant The threshold-based warning system was generated using
innovative and efficient landslide EWS is established in displacement and corresponding deformation information of
Hong Kong, the provenance of China. Hong Kong’s the slope. The statistical-based threshold was calculated as
provenance is vulnerable to landslide occurrences and 0.250 inches. This shows that the movements up to 0.250
consequently damages; the area also has a dense population inches are acceptable after that landslide can be expected.
living under the mass movement's risk. The terrain has
significantly less space. The ground weather shows that it Harp et al42 assessed the pore pressure response during the
can be having an hourly rainfall intensity exceeding 150mm failure of the slope. They performed the detailed
along with low pressure and cyclone.62 After two experimental investigation for these in two sites, one in Utah
catastrophic landslides in 1972 and 1976, which cost 100 and the other in southern California. They used to provide
fatalities and other losses, the Geotechnical Control Centre the artificial water to the slope by irrigation in the studied
was formed to diminish the probable hazard known as sand to evaluate the pore pressure evolution using previously
Geotechnical Engineering Office (GEO). This office was deployed piezometers at the site. Continuous observing of
responsible for the slope design, slope stabilization, pore pressure from beginning of the slide to the failure has
monitoring and warning of the landslide21. been done at both sites. From the data analysis, it has been
concluded that the pore pressure reading shows the sudden
As we have seen above in Hong Kong's provenance, two decrements before 5 to 50 minutes of the failure. The output
catastrophic debris flows happened in 1972 and 1976. of the study has the potential to help in warning the hazard
Among these two, after the landslide disaster in 1972, where rainfall is the primary threshold in landslide initiation.
rainfall triggered landslide and the appropriate threshold
level was first established by Lumb59 in Hongkong, which Farkas34 performed the monitoring study for rainfall-
was several times then revised to get reliable threshold value induced landslides in the country named Budapest. He
of rainfall. After the 1976 disaster, which costed 100 lives incorporated the combined results of field and laboratory
and other economic losses, in 1977, Hong Kong’s GEO measurements. Rain gauge and piezometer were adopted for
initiated installing and operating the landslide warning the field monitoring.
system. This landslide warning system was entirely rainfall
based considering their effect on the mass movement. The On the other hand, geotechnical parameters and slope
system's technical concept is based on interpreting the stability were examined in the laboratory with varying water
rainfall data obtained from 100 rainfall gauges yielding a set content correlated with the rainfall to establish the moisture-
of different rainfall thresholds. Initially, warnings were based threshold.
52Disaster Advances Vol. 15 (8) August (2022)
Pochini et al72 developed a real-time monitoring structure for of 45 m deep pipe. Recorded readings were then used to
a mass movement in their study performed in Italy. They broadcast to the remote station located in Italy. The
used the inclinometer, extensometer and geophones for monitoring networks also consist of complete set of
recording the information regarding the displacement. piezometric tubes for measuring real-time pore pressure in
Continuous monitoring was performed to full fill the aim of the field. Interpretation of the inclinometers' results detects
real-time monitoring of mass movement. In the end, the the significant displacement at a shallower depth which
authors used graphs to present the result of the monitoring seems to continue with a rotational failure sleep surface.
effectively. They presented displacement Vs. time graphs Designed software can send an alarm to the person in charge
showing that the portion of the slope situated between 15 to in case of displacement that exceeds the pre-established
20-meter depth from the top is deforming at a higher rate threshold. Also, it is able to make a self-check of the system.
than underneath strata. Deformation of such specific layers The authors concluded a nine-day time lag between the
shows the indication of the slope movement initiated, which maximum rainfall and the respective maximum
can be turned into massive failure at any instance of the time. displacement to help design a rainfall-induced warning
system by completing the data's study and analysis.
In 1995, Singhroy86 used integrated remote sensing
advances to assess the landslide hazard in Canada. The Lauterbach et al54 and Krauter et al52 described Germany's
author used Synthetic Aperture Radar (SAR) to monitor landslide warning system. They primarily used GPS for
hazardous natural landslide. SAR works on the time taken monitoring the displacement in southern Germany. Annual
by the rays emitted to receive back to the receiver with their movements of the hill were observed as 1 to 2 cm. Mass of
known velocities, which shows the displacement. The study the slope detected as moving has a calculated volume
indicates that the SAR provides the millimeters’ accuracy amount of 700,000 m3. The entire monitoring system was
and it can be used without an installed contact sensor on the equipped with five measuring points which have an accuracy
slope, which might have a chance to bury in the hill after of 1 mm. In the case of the threshold warning, the immediate
failure or may lose its function due to slight movement. connection was made with the expert and if the warning was
found valid, immediate action could be taken, for example,
Finlay et al35 provided their valuable effort in landslide closure of the road.
monitoring research by deriving the relationship between the
precipitation and the possibility of slope failure using Schmidt et al80 presented one live-integration model for
mathematical and probability approaches. The rainfall landslide monitoring and warning purposes in 2008. They
amount and their intensity and antecedent rainfall also developed the early warning prototypic model for the study
influence rainfall-induced landslides. The mathematical site, which was situated in New Zealand. The probabilities
model developed was working on the data recorded by the of the landslide's failure were determined based on the
rain gauge placed on the study site. The developed physically-based model using quantitative weather forecast.
correlation model has used the linear, quadratic and cubical Predictions of the model were having a significant degree of
types of correlation. The relationship shows that the linear uncertainty that was assessed by the probabilistic approach.
model does not yield an accurate result, but the other two, The landslide warning system remained in the prototypic
namely quadratic and cubic, were provided with a state and was discontinued due to not functioning correctly.
satisfactory result. The large degree of uncertainty in
predicting the landslide numbers was seen in the relation Intrieri et al49 designed the landslide early warning system
because geology, geometry and drainage was not and implementation in Italy in 2012. The warning system
incorporated. was mainly designed for the site-specific landslide, which
consisted of the rock wedge's probable mass movement. The
Glawe and Lotter39 state their extensive research about estimated volume of the wedge of rock mass was 182,000
effective and efficient warning systems. Also, in the same m3, which threatened the blockage of two transport roads
era, Cornforth et al27 in 1996 provided wide knowledge of with a significant in-country economy. As listed by the
the effect of water pressure on instability and according to authors, this site was being studied in 2004. In this study, the
them, measuring it continuously is one of the outstanding authors emphasized covering all aspects that are needful to
features for landslide monitoring, which can provide monitor the landslide including the geology of the slide, risk
efficient warning results. They also mentioned the great assessment, displacement characterization of the landslide,
importance of the connection between precipitation and pore monitoring system and instrumentation choice. The system
pressure to set out the pore water pressure-based threshold. consists of setoff wire extensometer to record the
This implementation of geotechnical knowledge in a displacement of a slide and one thermometer was used for
landslide investigation and EWS seemed in the ‘warning the monitoring of the temperature of the site, so it can be
systems’ enacted after 2000. used entirely to incorporate the effect of the snowmelt. The
entire system was developed in such a way so that it collects
Lollino et al58 installed a complex landslide monitoring the data at every minute and uploads it on the web-based
network in Italy. This network consists of inclinometers that services.
record the measurements twice a day on every 50 cm depth
53Disaster Advances Vol. 15 (8) August (2022)
The monitoring threshold was assessed by interpreting failure which seemed helpful in the early warning. So, at a
recorded data using suitable empirical relationships and later stage, two study sites were defined, one in Japan and
proper statistical analysis. To maintain simplicity in the the other in China for performance evaluation and setting out
monitoring system, only three warning levels were adopted the threshold-based alert. The study site was equipped with
which defined the ordinary level, attention level and an the tilt sensor, wetness sensor and microelectromechanical
alarming level. Attention level was defined based on the system (MEMS). For the investigation of deformation of the
velocity threshold, while on the other side, alarm level was deep layer, another set of equipment was also installed. A
issued only after the experts' consultation. Along with the slope failure test was adopted which was in practice applying
expert opinion, redundancy and data were also incorporated, the artificial rainfall on the slope. At this site, even the same
so that the possibility of the false alarming can be avoided. distinct behavior of the tilting angle was found at the slope's
The groundwater simulation also has been done before going face before the slope's failure.
for the alarm level.
Falac et al33 established a rainfall-based warning threshold
This integrated a physically-based model into a landslide for shallow landslides depending on rainfall intensity-
warning for the Swabian Alb territory of Germany in 201392. duration and antecedent precipitation investigation using
Their research combined hydrology and stability using the rain gauge data and landslide records. A wireless sensor-
finite element method (FEM) based model CHASM based network was equipped on the Garwal Himalayas
(combined hydrology and stability model). The EWS region including an inclinometer, extensometer, weather
developed by the authors mainly depended on the threshold station and pore water pressure sensor for time-dependent
rainfall. They have used useful rainfall data collection and monitoring of the rainfall and displacement. Interpretation of
forecasting methods to have proper and accurate rain data the monitoring shows the positive correlation between
collection. They used to adopt the two significant steps: limit rainfall and displacement, which shows a possibility of the
equilibrium analysis for hydrology and slope stability defining threshold based on rainfall-displacement analysis.
analysis and subsequently implement the model results into
the warning. Input data used to model the early warning are: Critical Appraisal on currently available EWS
stratification of the subsurface, soil parameters, ground As long as the risks are known and a sufficient, suitable
saturation, precipitation and location of the failure plane. monitoring system is provided, remedial engineering and
They used seismic refraction and geo-electrical method to safety measures can be taken13. To monitor and develop an
access the subsurface information. EWS, one needs to know the risks that threaten stability.
Again, stability is also affected by more than one factor such
Bai et al5 carried out extensive research to analyze landslide as the soil's physical and mechanical properties, morphology
occurrence with rainfall. A complete study was carried out and geology of the earth, presence of cracks and fissures in
at China. They took rainfall as the primary and principal the slope of the ground etc. To understand such a complex
triggering agent for landslide instability and the same geological event one need to find out these properties as
triggering factor was used to predict slope failure. In this crucial. Such a complexity shows that developing a landslide
study, the authors incorporated the effect of the past EWS is a complicated task and need to correlate
precipitation (antecedent rainfall) on the instability of the multidisciplinary knowledge into it to solve the problem
slide. An antecedent soil water status (ASWS) model was which would be faced during designing and producing alert.
used to derive previous rainfall’s effect on the slope. The
threshold limit for the alarming debris flow was derived Even with the availability of efficient analytical landslide
from considering both antecedent and hourly rainfall effects simulation models and technical advancement to predict the
on the slope. behavior of mass movement, general steps are needed to
follow for slope stability practice, including in-depth
The output of the study shows that for the presence of higher geotechnical exploration and monitoring. The most
antecedent rainwater in the slope, less daily rainfall is advanced warning system depends on the derived threshold
required for triggering the hazard, while on the other side, if of affected internal and external factors of landslide and
lesser antecedent rainwater is present in the slope, then experimental investigation such as model results.
higher rain will be required for triggering a landslide. Based
on the study, it is possible to define minimum and maximum Besides these pros and cons, only a few predictive systems
triggering threshold, minimum below which probability of exist where the extreme benefit is taken of existing all the
landslide would insignificant while over maximum possibilities of predicting mass movement and prediction
threshold, landslide can be expected. models, besides the availability of the required necessary
input which can generate the essential warning such as data
Uchimura et al94 developed a simple monitoring system for like rainfall precipitation prediction and scientific
rainfall-induced landslide in 2015. In the preliminary stage advancement in the intelligent computer system and easy
of the study, the model slope was designed in scale and their internet availability. Many landslide vulnerable sites are still
tilt angle was monitored up to the failure level. Distinct not equipped with such an EWS.
behavior was seen in the slope's tilting angle before the
54Disaster Advances Vol. 15 (8) August (2022)
Currently, available landslide early warning systems are References
mostly rainfall intensity-duration-based, derived by 1. Abubakar A., Habashy T.M., Lin Y. and Li M., A Model-
empirical equations or statistical approaches. Such warning Compression Scheme for Nonlinear Electromagnetic Inversions,
systems set the threshold based on the landslide experience, Geophysics, 77(5), doi: 10.1190/geo2011-0494.1 (2012)
which does not cover the other relevant parameters,
contributing to slope stability and deformation 2. Aleotti Pietro, A Warning System for Rainfall-Induced Shallow
Failures, Engineering Geology, 73(3–4), 247–65, doi:
characteristics40,71. Threshold like this are not fulfilling their
10.1016/j.enggeo.2004.01.007 (2004)
existence in all respect and in the end, it gives a false alarm.
Furthermore, the present existing warning system 3. Ashland F.X., Characteristics, Causes and Implications of the
concentrates on displacement monitoring or focusing only 1998 Wasatch Front Landslides, Utah (No. 105) (2003)
on a few triggering parameters, resulting in a higher false
alarming rate of the warning system. Very few examples 4. Badoux Alexandre, Graf Christoph, Rhyner Jakob, Kuntner
exist which incorporated the slope stability and hydrology Richard and McArdell Brian W., A Debris-Flow Alarm System for
model along with rainfall monitoring. Limit equilibrium the Alpine Illgraben Catchment: Design and Performance, Natural
stability model can provide the right kinds of results but its Hazards, 49(3), 517–39, doi: 10.1007/s11069-008-9303-x (2009)
correlation with other variables is also missing in the
5. Bai Shibiao, Jian Wang, Benni Thiebes, Chen Cheng and Yipeng
currently available literature.
Yang, Analysis of the Relationship of Landslide Occurrence with
Rainfall: A Case Study of Wudu County, China, Arabian Journal
Conclusion of Geosciences, 7(4), 1277–85, doi: 10.1007/s12517-013-0939-9
Landslide remains an unsolved problem for researchers from (2014)
the past due to complex mechanism of sliding and other
natural and human-made factors that seem to be responsible 6. Bailey D.J., Land Movement Monitoring System, Bulletin of the
for every landslide. In the literature, two types of monitoring Association of Engineering Geologists, 17(4), 213–21 (1980)
and warning systems for the avalanche are available, known
7. Baum Rex L. et al, Regional Landslide-Hazard Assessment for
as regional and local scale of landslide EWS. Regional-scale
Seattle, Washington, USA, Landslides, 2(4), 266–79, doi:
covers the entire region while local extent; only site-specific 10.1007/s10346-005-0023-y (2005)
landslides are monitored and warned the hazard level. Here
regional one is the cheapest and most accessible, but its 8. Baum Rex L. and Godt Jonathan W., Early Warning of Rainfall-
probability of false alarm is high compared to the local one Induced Shallow Landslides and Debris Flows in the USA,
as it did not cover the detailed monitoring. On the other Landslides, 7(3), 259–72, doi: 10.1007/s10346-009-0177-0 (2010)
hand, the local landslide's accuracy and early warnings
covered all aspects of the landslide, but its cost of monitoring 9. Bovenga Fabio, Guido Pasquariello, Roberta Pellicani, Alberto
and warning is high. Refice and Giuseppe Spilotro, Landslide Monitoring for Risk
Mitigation by Using Corner Reflector and Satellite SAR
Interferometry: The Large Landslide of Carlantino (Italy), Catena,
Presently lot of work has been done in the direction of the 151, 49–62, doi: 10.1016/j.catena.2016.12.006 (2017)
landslide warning issuance, but it still does not yield efficient
results. Most of the work consists of monitoring the slope 10. Brand E.W., Landslides in Southeast Asia, A State-of the Art
only and the warning was issued based on the records of the Report, In Proc. 4th Int. Symp. Landslides, Toronto, Canada (1984)
slide, which would not provide an adequate warning as it did
not cover the other aspect of the stability. Each landslide 11. Bolaños-Guerrero Michel, Marulanda Johannio and Thomson
early warning should be designed on the aspect of the Peter, Advances in rapid assessment of damaged buildings by
requirement of the end-user. A further available warning earthquakes, Disaster Advances, 14(5), 99-113 (2020)
system includes only a few parameters that would monitor.
12. Butler Dwain K., Llopis Jose L., Dobecki Thomas L., Wilt
The warning should be required real-time based so that each
Michael J., Corwin Robert F. and Olhoeft Gary, Comprehensive
user can see the monitoring process on their device on Geophysics Investigation of an Existing Dam Foundation:
different warning scales to live without fear of hazard. Engineering Geophysics Research and Development, Part 2,
Geophysics, 9(9), 44–53, doi: 10.1190/1.1439782 (1990)
Some of the early warning systems nowadays developed
based on the wireless network that can send the data to the 13. Call R.D. and Savely J.P., Open Pit Rock Mechanics, Surface
remotely available point where it got interpolated through Mining, 2(4), 860–82 (1990)
various softwares including stability model and another
probability model that yield the real-time FOS based 14. Campbell R.H., Soil Slips, Debris Flows and Rainstorms in the
Santa Monica Mountains and Vicinity, Southern California, US
warning. Such a system provides an accurate and acceptable
Government Printing Office (1975)
result, but its cost of implementing and monitoring is high.
It also needs lots of data to be interpreted which is again 15. Cannon S.H., Rainfall That Resulted in Abundant Debris-Flow
complicated. Nowadays, we need the researchers to focus on Activity during the Storm, In Landsides, floods and marine effects
making real-time based cost-effective landslides without of the storm of January 3-5, 1982, in the San Francisco Bay Region,
compromising the warning quality. California, 27–33 (1988)
55Disaster Advances Vol. 15 (8) August (2022)
16. Capparelli Giovanna and Pasquale Versace, FLaIR and SUSHI: 30. Ering Pinom and Sivakuma Babu G.L., Probabilistic Back
Two Mathematical Models for Early Warning of Landslides Analysis of Rainfall Induced Landslide- A Case Study of Malin
Induced by Rainfall, Landslides, 8(1), 67–79, doi: Landslide, India, Engineering Geology, 208, 154–64, doi:
10.1007/s10346-010-0228-6 (2011) 10.1016/j.enggeo.2016.05.002 (2016)
17. Carrara A., Guzzetti F., Cardinali M. and Reichenbach P., Use 31. Ering Pinom, Kulkarni Ramesh, Kolekar Yashwant, Dasaka
of GIS Technology in the Prediction and Monitoring of Landslide Satyanarayana Murty and Sivakuma Babu G.L., Forensic Analysis
Hazard, Natural Hazards, 20(2–3), 117–35, doi: of Malin Landslide in India, IOP Conference Series: Earth and
10.1023/A:1008097111310 (1999) Environmental Science, 26(1), doi: 10.1088/1755-1315/26/1/
012040 (2015)
18. Casagli N., Farina P., Leva D. and Tarchi D., Application of
Ground-Based Radar Interferometry to Monitor an Active 32. Falae Philips Omowumi, Kanungo D.P., Chauhan P.K.S. and
Rockslide and Implications for Emergency Management, Dash Rajesh Kumar, Renewable Energy and Its Innovative
Landslides, 49, 157–73, doi: 10.1007/978-1-4020-4037-5_9 Technologies, Springer Singapore (2019)
(2006)
33. Falae Philips Omowumi, Prasanna Kanungo Debi, Chauhan
19. Casagli Nicola, Filippo Catani, Chiara Del Ventisette and Pradeep Kumar Singh and Dash Rajesh Kumar, Electrical
Guido Luzi, Monitoring, Prediction and Early Warning Using Resistivity Tomography (ERT) Based Subsurface Characterisation
Ground-Based Radar Interferometry, Landslides, 7(3), 291–301, of Pakhi Landslide, Garhwal Himalayas, India, Environmental
doi: 10.1007/s10346-010-0215-y (2010) Earth Sciences, 78(14), 1–18, doi: 10.1007/s12665-019-8430-x
(2019)
20. Chan R.K.S. and Pun W.K., Landslip Warning System in Hong
Kong, Geotechnical News, 22(4), 33–35 (2004) 34. Farkas J., Action of Rainfall and Moisture Increase to Develop
Landslides, Periodica Polytechnica Civil Engineering, 34(3–4),
21. Chan R.K.S., Challenges in Slope Engineering in Hong Kong, 201–13 (1990)
Geotechnical Engineering, 38(3), 255 (2007)
35. Finlay P.J., Fell R. and Maguire P.K., The Relationship
22. Chaturvedi P., Srivastava S. and Kaur P.B., Landslide Early between the Probability of Landslide Occurrence and Rainfall,
Warning System Development Using Statistical Analysis of Canadian Geotechnical Journal, 34(6), 811–24, doi: 10.1139/t97-
Sensors’ Data at Tangni Landslide, Uttarakhand, India, In 047 (1997)
Proceedings of Sixth International Conference on Soft Computing
for Problem Solving, Springer Singapore (2017) 36. Formetta Giuseppe, Valeria Rago, Giovanna Capparelli,
Riccardo Rigon, Francesco Muto and Pasquale Versace, Integrated
23. Chauhan Shivani, Sharma Mukta and Arora Manoj K., Physically Based System for Modeling Landslide Susceptibility,
Landslide Susceptibility Zonation of the Chamoli Region, Garhwal Procedia Earth and Planetary Science, 9, 74–82. doi:
Himalayas, Using Logistic Regression Model, Landslides, 7(4), 10.1016/j.proeps.2014.06.006 (2014)
411–23, doi: 10.1007/s10346-010-0202-3 (2010)
37. Gian Quoc Anh, Duc Tan Tran, Dinh Chinh Nguyen, Viet Ha
24. Cheung P.Y., Wong M.C. and Yeung H.Y., Application of Nhu and Dieu Tien Bui, Design and Implementation of Site-
Rainstorm Nowcast to Real-Time Warning of Landslide Hazards Specific Rainfall-Induced Landslide Early Warning and
in Hong Kong, In WMO PWS workshop on warnings of real-time Monitoring System: A Case Study at Nam Dan Landslide
hazards by using nowcasting technology, 9–13 (2006) (Vietnam), Geomatics, Natural Hazards and Risk, 8(2), 1978–96,
doi: 10.1080/19475705.2017.1401561 (2017)
25. Clay J.M., Nainital: A Historical and Descriptive Amount,
Government Press, United Provinces, Allahabad (1928) 38. Glade T. and Crozier M.J., Landslide Hazard and Risk:
Concluding Comment and Perspectives, Landslide Hazard and
26. Collins Brian D. and Znidarcic Dobroslav, Stability Analyses Risk, Wiley, 493–516 (2005)
of Rainfall Induced Landslides, Journal of Geotechnical and
Geoenvironmental Engineering, 130(4), 362–72, doi: 10.1061/ 39. Glawe U. and Lotter M., Time Prediction of Rock Slope
(ASCE)1090-0241(2004)130:4(362) (2004) Failures Based on Monitoring Results, In Landslides, 1551–55
(1996)
27. Cornforth D.H. and Mikkelsen P.E., Continuous Monitoring of
the Slope above an Excavation within a Marginally Stable 40. Greco R., Giorgio M., Capparelli G. and Versace P., Early
Landslide, In Landslides, 1539–44 (1996) Warning of Rainfall-Induced Landslides Based on Empirical
Mobility Function Predictor, Engineering Geology, 153, 68–79,
28. Corsini Alessandro, Pasuto A., Soldati M. and Zannoni A., doi: 10.1016/j.enggeo.2012.11.009 (2013)
Field Monitoring of the Corvara Landslide (Dolomites, Italy) and
Its Relevance for Hazard Assessment, Geomorphology, 66(1–4 41. Guifang L.U., Formation and Monitoring and Forecast of
Spec. Iss.), 149–65, doi: 10.1016/j.geomorph.2004.09.012 (2005) Jimingsi Landslide, The Chinese Journal of Geological Hazard
and Control, 5, 376–83 (1994)
29. Van Den Eeckhaut M., Poesen J., Dewitte O., Demoulin A., De
Bo H. and Vanmaercke-Gottigny M.C., Reactivation of Old 42. Harp Edwin L., Wells Wade G. and Sarmiento John G., Pore
Landslides: Lessons Learned from a Case-Study in the Flemish Pressure Response during Failure in Soils, Bulletin of the
Ardennes (Belgium), Soil Use and Management, 23(2), 200–211, Geological Society of America, 102(4), 428–38, doi:
doi: 10.1111/j.1475-2743.2006.00079.x (2007) 10.1130/0016-7606(1990)1022.3.CO;2 (1990)
56Disaster Advances Vol. 15 (8) August (2022)
43. Hita C., Parlanti E., Jambu P., Joffre J. and Amblès A., Landslides in Indonesia Using Satellite Remote Sensing and
Triglyceride Degradation in Soil, Organic Geochemistry, 25(1–2), Geospatial Datasets, Landslides, 7(3), 317–24, doi: 10.1007/
19–28, doi: 10.1016/S0146-6380(96)00107-6 (1996) s10346-010-0219-7 (2010)
44. Hong Yang and Adler R.F., Towards an Early-Warning System 57. Lloyd D.M., Wilkinson P.L. and Othmann M.A., Predicting
for Global Landslides Triggered by Rainfall and Earthquake, Landslides: Assessment of an Automated Rainfall Based Landslide
International Journal of Remote Sensing, 28(16), 3713–19, doi: Warning System, In Kks Ho and Ks Li, Geotechnical Engineering-
10.1080/01431160701311242 (2007) Meeting Society's Needs, Balkema, 135-139 (2001)
45. Hong Yang and Adler Robert F., Predicting Global Landslide 58. Lollino G., Arattano M. and Cuccureddu M., The Use of the
Spatiotemporal Distribution: Integrating Landslide Susceptibility Automatic Inclinometric System for Landslide Early Warning: The
Zoning Techniques and Real-Time Satellite Rainfall Estimates, Case of Cabella Ligure (North-Western Italy), Physics and
International Journal of Sediment Research, 23(3), 249–57, doi: Chemistry of the Earth, 27(36), 1545–50, doi: 10.1016/S1474-
10.1016/S1001-6279(08)60022-0 (2008) 7065(02)00175-4 (2002)
46. Hsu Sung Chi and Nelson Priscilla P., Material Spatial 59. Lumb Peter, Slope Failures in Hong Kong, Quarterly Journal
Variability and Slope Stability for Weak Rock Masses, Journal of of Engineering Geology, 8(1), 31–65, doi: 10.1144/
Geotechnical and Geoenvironmental Engineering, 132(2), 183– GSL.QJEG.1975.008.01.02 (1975)
93, doi: 10.1061/(ASCE)1090-0241(2006)132:2(183) (2006)
60. Macciotta Renato, Hendry Michael and Derek Martin C.,
47. Husaini O. and Ratnasamy M., An Early Warning System for Developing an Early Warning System for a Very Slow Landslide
Active Landslides, Quarterly Journal of Engineering Geology and Based on Displacement Monitoring, Natural Hazards, 81(2), 887–
Hydrogeology, 34(3), 299–305, doi: 10.1144/qjegh.34.3.299 907, doi: 10.1007/s11069-015-2110-2 (2016)
(2001)
61. Malet J.P., Maquaire O. and Calais E., The Use of Global
48. Ingmire Thomas J. and Tito Patri, An Early Warning System Positioning System Techniques for the Continuous Monitoring of
for Regional Planning, Journal of the American Planning Landslides: Application to the Super-Sauze Earthflow (Alpes-de-
Association, 37(6), 403–10, doi: 10.1080/01944367108977390 Haute-Provence, France), Geomorphology, 43(1–2), 33–54, doi:
(1971) 10.1016/S0169-555X(01)00098-8 (2002)
49. Intrieri Emanuele, Giovanni Gigli, Francesco Mugnai, 62. Malon A.W., Risk Management and Slope Safety in Hong
Riccardo Fanti and Nicola Casagli, Design and Implementation of Kong, HKIE Transactions Hong Kong Institution of Engineers,
a Landslide Early Warning System, Engineering Geology, 147– 4(2–3), 12–21, doi: 10.1080/1023697X.1997.10667719 (1997)
148, 124–36, doi: 10.1016/j.enggeo.2012.07.017 (2012)
63. Massey J.B., Mak S.H. and Yim K.P., Community Based
50. Jurich David M. and Miller Russell J., Acoustic Monitoring of Approach to Landslide Risk Reduction, In Geotechnical
Landslides, Transportation Research Record, 1, 30–38 (1987) Engineering Meeting Society’s Needs, Proceedings of the
Fourteenth Southeast Asian Geotechnical Conference, 141–47
51. Keefer David K. et al, During Heavy Rainfall, (November) (2001)
(1987)
64. McCann D.M. and Forster A., Reconnaissance Geophysical
52. Krauter E., Lauterbach M. and Feuerbach J., Methods in Landslide Investigations, Engineering Geology, 29(1),
Hangdeformationen-Beobachtungsmethoden Und Risikoanalyse, 59–78, doi: 10.1016/0013-7952(90)90082-C (1990)
Geo-International & Forschungsstelle Rutschungen, 16, 1–6
(2007) 65. McHugh Ed. and Girard Jami M., Detecting problems with
mine slope stability (2000)
53. Kunnath Abishek Thekkeyil and Ramesh Maneesha V.,
Integrating Geophone Network to Real-Time Wireless Sensor 66. Medina-Cetina Zenon and Farrokh Nadim, Stochastic Design
Network System for Landslide Detection, First international of an Early Warning System, Georisk, 2(4), 223–36, doi:
conference on sensor device technologies and applications, 167– 10.1080/17499510802086777 (2008)
71, doi: 10.1109/sensordevices.2010.38 (2010)
67. Moon A.T., Wilson R.A. and Flentje P., Developing and Using
54. Lauterbach M., Krauter E. and Feuerbach J., Landslide Size Frequency Models, In Landslide Risk
Satellitengestuetztes Monitoring Einer Grossrutschung Im Bereich Management, 691-700 (2005)
Eines Autobahndamms Bei Landstuhl/Pfalz, Geotechnik, 25(2),
97-100 (2002) 68. Nakamura H., Field Instrumentation and Laboratory
Investigation, In Landslides: evaluation and stabilization, 541–48
55. Li Xue Ping and Yun An Li, Design of GIS-Based Monitoring (2004)
and Early-Warning System of Landslide Hazard in Diao Zhongba,
Energy Procedia, 16(Part B), 1174–79, doi: 10.1016/ 69. Noferini Linhsia, Massimiliano Pieraccini, Daniele Mecatti,
j.egypro.2012.01.187 (2012) Giovanni Macaluso, Carlo Atzeni, Matteo Mantovani, Gianluca
Marcato, Alessandro Pasuto, Sandro Silvano and Fabrizio
56. Liao Zonghu, Yang Hong, Jun Wang, Hiroshi Fukuoka, Kyoji Tagliavini, Using GB-SAR Technique to Monitor Slow Moving
Sassa, Dwikorita Karnawati and Faisal Fathani, Prototyping an Landslide, Engineering Geology, 95(3–4), 88–98, doi:
Experimental Early Warning System for Rainfall-Induced 10.1016/j.enggeo.2007.09.002 (2007)
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