scholarly journals A Study on the Rainfall and Landslides Along Sarawak Road Using the Antecedent Rainfall Analysis

2011 ◽  
Vol 2 (1) ◽  
pp. 1-6
Author(s):  
Tay J. E. ◽  
Selaman O. S.

Sarawak is a state known for its high percentage of clayey soil which is overlaid with "weak" strata. The state has experienced many cases of severe landslides which even resulted to deaths. This study aims to address the correlation between rainfall intensity and landslide occurrences along roads in Sarawak. By using the antecedent rainfall analysis, this study emphasizes on more than 50 cases of landslides which occurred along Sarawak roads in the early 2009. Where, during the month of January marks the most amount of rainfall experienced by the state in that year. Many landslide cases were reported, especially along the stretch of Sarawak roads, leading to injuries and road repair cost. The hyetograph drawn in this analysis provides probability of days of antecedent rainfall that induces landslides as well as the total amount of rainfall during the antecedent period that would lead to landslide occurrence. The intensity of rainfall on the day of landslides itself as well as the highest intensity of rainfall during the antecedent period is also analyzed to establish whether it is a factor leading to the landslide occurrence. The observations and forecasts present in this paper will provide warning system for the members of public as well as the state's civil defense authority before the occurrence of rainfall-induced landslide.

Author(s):  
S.Y. Iryani

Mt. Merapi cold lava disasters in 2010 had caused a lot of public infrastructure and facilities in the area around Mt. Merapi were damaged, due to the occurrence of debris flows triggered by extreme rainfall. Analysis of extreme rainfall characteristics are conducted to determine the pattern of distribution of the amount of hourly rainfall  in the slopes of Mt. Merapi. To reduce the negative impact caused by cold lava flood, it is necessary to plan an Early Warning System (EWS) and the proper evacuation measures. EWS based Rainfall intensity, can refer to the Critical Line Curve. The research  results showed the greatest rainfall intensity occurred in the Mt. Maron station Pwith the cumulative relative frequency of rainfall intensity >20 mm/hr in between the years 1988 to 2010 with 6.74%. Analysis of the incidence of the most extreme hourly rainfall of 14 rainfall stations in the slopes of Mt. Merapi in 1988 to 2010 occurred in kemasan station in 2010 with 621.5 mm in January at 6:00 p.m. to 7:00 p.m. Critical Line Curve Kali Gendol rain station Batur, Deles and Sorosan, non-causing rainfall in the dangerous area is 24 events (13.79%), causing rainfall in the dangerous area is 4 events (2.30%) and non-causing rainfall in the safety area is 146 events (83.91%). Cumulative Relative frequency rainfall intensity >20 mm/hr at rainfall stations close to the Kali Gendol i.e. Batur, Deles and Sorosan rainfall station from the highest to the lowest are   2.74%, 2.33% and 1.70%, respectively.


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1616 ◽  
Author(s):  
Abhirup Dikshit ◽  
Raju Sarkar ◽  
Biswajeet Pradhan ◽  
Saroj Acharya ◽  
Kelzang Dorji

Consistently over the years, particularly during monsoon seasons, landslides and related geohazards in Bhutan are causing enormous damage to human lives, property, and road networks. The determination of thresholds for rainfall triggered landslides is one of the most effective methods to develop an early warning system. Such thresholds are determined using a variety of rainfall parameters and have been successfully calculated for various regions of the world at different scales. Such thresholds can be used to forecast landslide events which could help in issuing an alert to civic authorities. A comprehensive study on the determination of rainfall thresholds characterizing landslide events for Bhutan is lacking. This paper focuses on defining event rainfall–duration thresholds for Chukha Dzongkhag, situated in south-west Bhutan. The study area is chosen due to the increase in frequency of landslides during monsoon along Phuentsholing-Thimphu highway, which passes through it and this highway is a major trade route of the country with the rest of the world. The present threshold method revolves around the use of a power law equation to determine event rainfall–duration thresholds. The thresholds have been established using available rainfall and landslide data for 2004–2014. The calculated threshold relationship is fitted to the lower boundary of the rainfall conditions leading to landslides and plotted in logarithmic coordinates. The results show that a rainfall event of 24 h with a cumulated rainfall of 53 mm can cause landslides. Later on, the outcome of antecedent rainfall varying from 3–30 days was also analysed to understand its effect on landslide incidences based on cumulative event rainfall. It is also observed that a minimum 10-day antecedent rainfall of 88 mm and a 20-day antecedent rainfall of 142 mm is required for landslide occurrence in the area. The thresholds presented can be improved with the availability of hourly rainfall data and the addition of more landslide data. These can also be used as an early warning system especially along the Phuentsholing–Thimphu Highway to prevent any disruptions of trade.


Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2113 ◽  
Author(s):  
Minu Treesa Abraham ◽  
Deekshith Pothuraju ◽  
Neelima Satyam

Idukki is a South Indian district in the state of Kerala, which is highly susceptible to landslides. This hilly area which is a hub of a wide variety of flora and fauna, has been suffering from slope stability issues due to heavy rainfall. A well-established landslide early warning system for the region is the need of the hour, considering the recent landslide disasters in 2018 and 2019. This study is an attempt to define a regional scale rainfall threshold for landslide occurrence in Idukki district, as the first step of establishing a landslide early warning system. Using the rainfall and landslide database from 2010 to 2018, an intensity-duration threshold was derived as I = 0.9D-0.16 for the Idukki district. The effect of antecedent rainfall conditions in triggering landslide events was explored in detail using cumulative rainfalls of 3 days, 10 days, 20 days, 30 days, and 40 days prior to failure. As the number of days prior to landslide increases, the distribution of landslide events shifts towards antecedent rainfall conditions. The biasness increased from 72.12% to 99.56% when the number of days was increased from 3 to 40. The derived equations can be used along with a rainfall forecasting system for landslide early warning in the study region.


2019 ◽  
Vol 19 (4) ◽  
pp. 775-789 ◽  
Author(s):  
Elise Monsieurs ◽  
Olivier Dewitte ◽  
Alain Demoulin

Abstract. Rainfall threshold determination is a pressing issue in the landslide scientific community. While major improvements have been made towards more reproducible techniques for the identification of triggering conditions for landsliding, the now well-established rainfall intensity or event-duration thresholds for landsliding suffer from several limitations. Here, we propose a new approach of the frequentist method for threshold definition based on satellite-derived antecedent rainfall estimates directly coupled with landslide susceptibility data. Adopting a bootstrap statistical technique for the identification of threshold uncertainties at different exceedance probability levels, it results in thresholds expressed as AR = (α±Δα)⋅S(β±Δβ), where AR is antecedent rainfall (mm), S is landslide susceptibility, α and β are scaling parameters, and Δα and Δβ are their uncertainties. The main improvements of this approach consist in (1) using spatially continuous satellite rainfall data, (2) giving equal weight to rainfall characteristics and ground susceptibility factors in the definition of spatially varying rainfall thresholds, (3) proposing an exponential antecedent rainfall function that involves past daily rainfall in the exponent to account for the different lasting effect of large versus small rainfall, (4) quantitatively exploiting the lower parts of the cloud of data points, most meaningful for threshold estimation, and (5) merging the uncertainty on landslide date with the fit uncertainty in a single error estimation. We apply our approach in the western branch of the East African Rift based on landslides that occurred between 2001 and 2018, satellite rainfall estimates from the Tropical Rainfall Measurement Mission Multi-satellite Precipitation Analysis (TMPA 3B42 RT), and the continental-scale map of landslide susceptibility of Broeckx et al. (2018) and provide the first regional rainfall thresholds for landsliding in tropical Africa.


2019 ◽  
Vol 29 (1) ◽  
pp. 65-85
Author(s):  
Victor Marchezini ◽  
Allan Yu Iwama ◽  
Danilo Celso Pereira ◽  
Rodrigo Silva da Conceição ◽  
Rachel Trajber ◽  
...  

Purpose The purpose of this paper is to study an articulated warning system that provides information about the heritage at risk and encourages a dialogue between the heritage sector, civil defense agencies and local communities. Design/methodology/approach The databases from the National Heritage Institute, National Civil Defense, National Geological Service and National Early Warning System were investigated and the local community provided input which helped form a participatory risk mapping strategy for a warning system in the heritage sector. Findings There is little knowledge of the Brazilian heritage that is at risk and a lack of coordination between the cultural heritage and DRR sectors. This means that there is a need to organize the geo-referenced databases so that information can be shared and the public provided with broader access. As a result, there can be a greater production, dissemination and application of knowledge to help protect the cultural heritage. Practical implications The findings can be included in the debate about the importance of framing disaster risk management (DRM) policies in the Brazilian heritage sector. Social implications The findings and maps of the case study in the town of São Luiz do Paraitinga involve the heritage sector, civil defense agencies and local people and can be used for disaster risk preparedness. Originality/value A DRM program is being formulated in Brazil. However, the kind of strategy needed to incorporate the heritage sector in this program stills needs to be planned, and the knowledge of the cultural heritage at risk is a key factor when faced with this new social and scientific challenge.


2021 ◽  
Vol 30 (4) ◽  
pp. 74-89
Author(s):  
A. V. Ershov ◽  
V. B. Korobko

The article addresses the problem of bridging the divide between the present-day technological advancement, primarily in the field of normative legal and technical regulation of fire safety, and the qualification of persons, authorized to regulate relations in fire safety assurance (hereinafter — “Authorized persons”) in the context of transition of the state regulation of fire safety relations from an obsolete standard target model to a new analytical and scenario-based (risk-oriented) target model used to make decisions in the area of control over the safe condition of the technosphere in view of a sudden increase in the dynamics of sociocultural processes.The Education and Research Supervision Unit of the State Fire Academy of the EMERCOM of Russia (the Ministry for Civil Defense, Emergencies, and Elimination of Consequences of Natural Disasters), responsible for the drafting of suggestions concerning the implementation of point 10, Minutes № 1 of the meeting of the workgroup of EMERCOM of Russia on May 20, 2019 “Regarding the arrangement of interaction with the management authorities of the institutional firefighting service of executive federal authorities and organizations”, has developed “The list of milestones of professional culture for the persons responsible for regulating relations in the field of fire safety for the period of transition from a standard target model to the risk model of controlling, supervisory, and authorization-related activities” (hereinafter — “the List”).This List represents a basic set of conceptual professional milestones, whose attainment enables authorized persons to re-focus their conscience from an obsolete standard paradigm, used to make decisions in the area of fire safety, to a new risk-oriented one.Given the focus of this article, it defines some, or the most significant, milestones of professional risk-oriented culture of authorized persons.


2014 ◽  
Vol 18 (12) ◽  
pp. 4913-4931 ◽  
Author(s):  
D. J. Peres ◽  
A. Cancelliere

Abstract. Assessment of landslide-triggering rainfall thresholds is useful for early warning in prone areas. In this paper, it is shown how stochastic rainfall models and hydrological and slope stability physically based models can be advantageously combined in a Monte Carlo simulation framework to generate virtually unlimited-length synthetic rainfall and related slope stability factor of safety data, exploiting the information contained in observed rainfall records and field-measurements of soil hydraulic and geotechnical parameters. The synthetic data set, dichotomized in triggering and non-triggering rainfall events, is analyzed by receiver operating characteristics (ROC) analysis to derive stochastic-input physically based thresholds that optimize the trade-off between correct and wrong predictions. Moreover, the specific modeling framework implemented in this work, based on hourly analysis, enables one to analyze the uncertainty related to variability of rainfall intensity within events and to past rainfall (antecedent rainfall). A specific focus is dedicated to the widely used power-law rainfall intensity–duration (I–D) thresholds. Results indicate that variability of intensity during rainfall events influences significantly rainfall intensity and duration associated with landslide triggering. Remarkably, when a time-variable rainfall-rate event is considered, the simulated triggering points may be separated with a very good approximation from the non-triggering ones by a I–D power-law equation, while a representation of rainfall as constant–intensity hyetographs globally leads to non-conservative results. This indicates that the I–D power-law equation is adequate to represent the triggering part due to transient infiltration produced by rainfall events of variable intensity and thus gives a physically based justification for this widely used threshold form, which provides results that are valid when landslide occurrence is mostly due to that part. These conditions are more likely to occur in hillslopes of low specific upslope contributing area, relatively high hydraulic conductivity and high critical wetness ratio. Otherwise, rainfall time history occurring before single rainfall events influences landslide triggering, determining whether a threshold based only on rainfall intensity and duration may be sufficient or it needs to be improved by the introduction of antecedent rainfall variables. Further analyses show that predictability of landslides decreases with soil depth, critical wetness ratio and the increase of vertical basal drainage (leakage) that occurs in the presence of a fractured bedrock.


Author(s):  
Bappaditya Koley ◽  
Anindita Nath ◽  
Subhajit Saraswati ◽  
Kaushik Bandyopadhyay ◽  
Bidhan Chandra Ray

Land sliding is a perennial problem in the Eastern Himalayas. Out of 0.42 million km2 of Indian landmass prone to landslide, 42% fall in the North East Himalaya, specially Darjeeling and Sikkim Himalaya. Most of these landslides are triggered by excessive monsoon rainfall between June and October in almost every year. Various attempts in the global scenario have been made to establish rainfall thresholds in terms of intensity – duration of antecedent rainfall models on global, regional and local scale for triggering of the landslide. This paper describes local aspect of rainfall threshold for landslides based on daily rainfall data in and around north Sikkim road corridor region. Among 210 Landslides occurring from 2010 to 2016 were studied to analyze rainfall thresholds. Out of the 210 landslides, however, only 155 Landslides associated with rainfall data which were analyzed to yield a threshold relationship between rainfall intensity-duration and landslide initiation. The threshold relationship determined fits to lower boundary of the Landslide triggering rainfall events is I = 4.045 D - 0.25 (I=rainfall intensity (mm/h) and D=duration in (h)), revealed that for rainfall event of short time (24 h) duration with a rainfall intensity of 1.82 mm/h, the risk of landslides on this road corridor of the terrain is expected to be high. It is also observed that an intensity of 58 mm and 139 mm for 10-day and 20-day antecedent rainfall are required for the initiation of landslides in the study area. This threshold would help in improvement on traffic guidance and provide safety to the travelling tourists in this road corridor during the monsoon.


Author(s):  
Volodymyr Smolianiuk ◽  
Mykola Balan

The purpose of the article. Identify the nature of challenges, threats, dangers and risks as destructive factors of social, man-made and natural origin; to prove the priority of the category “threat” as a kind of risk in the domestic legislation on national security; to argue the thesis about Ukraine’s belonging to “risk societies”; point to the further complication of the process of producing various threats and challenges against the state and society. Scientific novelty. Based on the use of the current legal framework of Ukraine on national security, the existence of a process of continuous accumulation of risks in key areas of the state and the transformation of Ukrainian society on this basis into a “society of risk” is proved. Emphasis is placed on accelerating this process in the context of the hybrid war launched by Russia against Ukraine in 2014. Social development dictates the need for a clear verbal designation of destructive factors against the interests of the majority (national interests). The terms describing their likely or real impact on society were “challenges”, “threats”, “dangers” and “risks”. The natural step of their substantive definition and meaningful filling was their implementation in the conceptual and categorical apparatus of national security theory. In a broad sense, national security is proposed to be considered a state of protection of national interests and values, both from challenges, threats and dangers, and risks. The most widely used term in Ukraine’s socio-political realities is the “threat” that is widely represented in national legislation on national security. The total number of threats in modern Ukraine is steadily increasing. According to Western analytical developments, the excessive spread of threats in basic social spheres (economic, political, social, spiritual, cultural, etc.) gives reason to qualify Ukraine as a “risk society”. The situation is complicated by the hybrid war being waged by the Russian Federation against Ukraine and other democratic countries. It is advisable to present the modern hostilities initiated by Russia as a process of continuous production of threats (risks), the total effect of which should be the destruction of the Ukrainian statehood. In such circumstances, Ukraine should accelerate the process of development (updating) and practical implementation of key strategic documents – the National Security Strategy, the Military Security Strategy, the Cyber Security Strategy, the Public Security and Civil Defense Strategy, the Strategy for the Development of the Defense Industrial Complex. But for the time being, such documents are either substantially outdated or missing at all. Conclusions. Society, based on its complex nature, built on unity and the struggle of opposites, feels the constant impact of challenges, threats and dangers (risks), which it generates. There are no unified and generally accepted interpretations of challenges, threats, dangers and risks. Each country offers its own formats of their interaction and mutual transformation. The most widely used of these are “threats” (Ukraine) and “risks” (Western countries). The total number of risks in which Ukraine is directly or indirectly involved is steadily progressing. Accordingly, modern Ukraine is a clearly defined “society of risks.” Under the pressure of numerous challenges, threats and dangers, Ukraine as a “society of risks” abandons the unambiguous (linear) formulation of threats to national security inherent in specific public spheres, and their legislative consolidation. The state provides for the preparation and periodic updating of a number of strategies (national security, military security, cybersecurity, other documents), which should contain a list of major threats that currently exist in state and social development. Key words: challenge, threat, danger, risk, national security, hybridization of threats, risk society.


2021 ◽  
Author(s):  
Stella Shekhunova ◽  
Svitlana Stadnichenko ◽  
Natalia Siumar ◽  
Maryna Aleksieienkova

<p>Among all exogenous geological processes that develop in the Transcarpathian region, landslides are the most common ones. Considering the multifactorial nature of landslide formation and the difficulty of their prediction, landslides are a potential factor of emergency occurrence. According to the data provided by the State Emergency Service of Ukraine and the State Geological Information Fund of Ukraine, as of 01/01/2020, 3 288 landslides of 385.21 sq. km total area were mapped and entered in the region cadastre; six of those activated fully or partially on the area of 0.030096 sq. km. Therefore, the aim of this study is to identify the main and derived geological factors that determine the spreading and activation of landslides in the Transcarpathian region by employing spatial statistical analysis.</p><p>The initial information is represented by : 1) the database and landslide inventory map for the Transcarpathian region (compiled by the authors); 2) the relief horizontal corresponding to the topographical background of the scale 1:200 000, and 3) the tectonic disturbance map derived from a geological map of the scale 1:100 000. To establish the spatial patterns of landslide formation, the effects of the territory relief, its derivatives, structural and tectonic conditions on the distribution of landslides have been analyzed.</p><p>In addition, the region examined is the territory with a significant level of anthropogenic impact on the geological environment, which creates a number of man-made factors affecting the formation and activation of landslides, such as cutting of slopes, deforestation, slope plowing, excessive cattle grazing, mining activities, etc.</p><p>That can be exemplified by the destructive activation of an ancient landslide on the Tysa River right bank between Bila Tserkva and Velykyi Bychkiv villages. During the railway construction, the slope was cut to a height of 10–15 m, and landslide prevention works were not carried out. As a result, after a few years, a landslide developed there, which inflicted heavy costs of constructing a retaining wall. But the retaining wall was built on a shear body above the sliding mirror. In the spring of 2004, the displacement intensified, destroying the retaining wall. Periodically, a shift tongue blocks the Uzhhorod–Rakhiv highway roadbed.</p><p>The analysis shows that a significant number of landslides have not reached their baseline, i.e., under unfavorable conditions, their activation is possible.</p><p>Thus, the abovementioned anthropogenic activities tend to overlap natural landslide formation factors, increasing the risk of landslide hazards in the Transcarpathian region.</p><p>As a result, the spatial patterns of landslide occurrence have been determined by processing a large array of primary cartographic information. Subsequent mapping of the areas, based on the obtained reliable characteristic limit values of established landslide formation factors (steepness, altitude, the spatial orientation of slopes, connection with structural and tectonic heterogeneities) provides a forecast map for the most likely areas of landslide occurrence in the Transcarpathian region.</p><p>This study was initiated in the framework of the project ImProDiReT-783232 ‘Improving Disaster Risk Reduction in Transcarpathian Region, Ukraine’ (funded by the EU DG-ECHO) and also supported with governmental co-financing for the NAS of Ukraine under the state budget program CPCEL 6541230.</p>


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