Inundation Height Research Articles

Application of steady flow model to overcome inundation based on eco drainage system in the Port Area of Dobo City, Aru Islands Regency

This research was carried out in inundation that occurred in the Port area of Dobo City, Aru Islands Regency. Inundation that occurs is due to the unavailability of adequate and well-arranged drainage. This research aims to plan a drainage system in the Port area of Dobo City that can overcome the inundation that arises and the influence of tides. Data processing is carried out with two analyzes including hydrological analysis and hydraulic analysis. For hydraulics analysis, this includes cross section planning and drainage system modeling with HEC-RAS 4.0. In conventional drainage in the case of high tides, the results of the modeling show that the overflow of water on the channel that will occur is at an elevation of +2.48 m. After adding a long storage with dimensions of 1.2 m x 3.5 m along 101.6 m and sea walls as high as + 2.48 m. The results of the modeling show that the inundation height that will occur is at an elevation of +0.61 m. Of the several scenarios that are performed for the most optimal two-door openings, which are opened by 30 cm which later the water will be at + 12 cm elevation. Whereas the most optimal one-door openings are opened by 70 cm which later the water will be at + 6 cm elevation.

Vulnerability assessment of atmospheric storage tanks to floods based on logistic regression

Atmospheric storage tanks damaged by floods may lead to severe NaTech accident scenarios, and the vulnerability assessment of process equipment suffered by natural events is a crucial point in NaTech risk analysis. In the present study, limit state equations for failure modes of displacement and buckling are introduced based on load-resistance relationships. The parameterized fragility models that can be used in a wide variety of atmospheric unanchored storage tanks and floods have been developed based on logistic regression (LR), and moreover, the models are assessed and validated by receiver operating characteristic (ROC) curves and available accident data in literature. The effects of filling level and density of storaged liquid, the diameter and height of tank, and the inundation height and velocity of flood on the vulnerability of different failure modes are analyzed using fragility curves. Furthermore, fragility magic cubes are first proposed to obtain critical disaster conditions and critical filling levels in different cases. Finally, corresponding quantitative mitigation measures in different stages such as site selection, design, and operation are proposed based on the results of vulnerability assessment.

Tidal Flood in Pekalongan: Utilizing and Operating Open Resources for Modelling

The open resource materials are used in this research to construct a numerical model and study the tidal flood in Pekalongan City, including the impact of land subsidence. The area of interest is in 6 villages in the north coast of Pekalongan namely, Jeruksari, Pabean, Bandengan, Kandang Panjang, Panjang Baru, and Panjang Wetan. Delft3D, an open ware, is used for numerical modelling. While the input data are obtained from GEBCO for bathymetry, SRTM for topography, and TPXO for tidal constituent. The resulting model shows a decent agreement with field tidal elevation data from Indonesian Navy Tide Tables and GLOSS. After applying the annual land subsidence, compare to flood in May 2018, it is found that the inundation height increases for around 11, 36, and 132 cm in 2019, 2025, and 2050. In 2050, an extreme inundation over 2.5 m is found. Similar with Jakarta flood, to protect the land area, coastal dykes may be proposed. However, for long-term resilience, it is recommended to emphasize efforts in decreasing the land subsidence rate. This study indicates the threat of tidal flood in Pekalongan, thus further studies followed with field survey and more constituents in the modelling are strongly recommended.

Dam Failure Model to Predict Inundation Hazard Map for Emergency Plan

The construction of dams can offer many advantages, but their failure could result in major damages, including loss of life and property destruction. The research aims to model dam failure for Mapping Hazard area including inundation height and arrival time. A key scenario for dam failure is partial breach of embankment dam: overtopping and piping. The overtopping shape modeling was simulated in triangle and trapezoidal shapes. The piping failure modeling is simulated as orifice with rectangular shape. This study was conducted by using the integration of hydraulic modeling, which used a numerical method with Navier-Stoke solver and Geographic Information System (GIS) to assess the risks that could be cause by any damages on Dam failure. Flow simulation of the dam break was performed by using ZhongXing HY-21 software and the results were mapped by using the GIS. The result of the research is overtopping failure was selected for the model with peak discharge maximum (Qmax) is 2089 m3/sec. The fastest arrival time is 0.4 hours (24 minutes). Several villages catagorized as a high-risk area. This inundation hazard map is very important for emergency plan which determines the evacuation routes and coordination scheme with local disaster agency.

Identifikasi Genangan Banjir yang Terjadi di Kecamatan Cikampek, Kabupaten Karawang

<p><em>Cikampek District is one of the sub-districts in the Karawang Regency located in the Southeast part of the Karawang Regency area. Cikampek sub-district is one of the areas that is growing rapidly due to the development of industrial allotment areas and urban settlements. This study aims to determine the flood inundation that must be addressed immediately. The research method was carried out by observation in the field and interviews with related parties. Based on the results of research in the District of Cikampek, there was inundation with an area of 274 Ha, inundation height of 10-40 cm, drainage time of 3 hours / day, and inundation frequency (9 times / year) due to overflow of secondary drainage channel namely Cikaranggelam River. There are three priority areas that the drainage system must immediately address, namely Desa Cikampek Selatan, Dawuan Tengah and Dawuan Barat.</em></p>

KAJIAN KENAIKAN MUKA AIR LAUT DAN TINGGI GENANGAN (ROB) PADA TAHUN 2023, 2028, DAN 2033 DI KOTA SAUMLAKI, KABUPATEN MALUKU TENGGARA BARAT

Kota Saumlaki berlokasi di Kabupaten Maluku Tenggara Barat tepatnya pada Pulau Yamdena. Kota ini terletak pada wilayah pesisir yang menjadikannya bersentuhan langsung dengan kondisi eksternal seperti pasang surut. Adapun subduksi lempeng Indo-Australia dan Eurasia yang terletak di sebelah Barat Laut Saumlaki menjadikannya semakin rentan terhadap perubahan muka air laut. Penelitian ini dilakukan dengan tujuan untuk mengetahui besar kenaikan muka air laut berdasarkan analisis data pasang surut tahun 2014-2018 dan memprediksi tinggi genangan yang akan menutupi pantai pada 2023, 2028 dan 2033. Metode yang digunakan dalam penelitian ini adalah metode kuantitatif bersifat studi kasus. Penelitian ini menggunakan data pasang surut wilayah Saumlaki yang didapat dari Badan Informasi Geospasial (BIG) yang kemudian diolah untuk mendapatkan nilai MSL (Mean Sea Level) bulanan dan tahunan. Berdasarkan penelitian yang dilakukan diketahui laju kenaikan muka air laut Kota Saumlaki, Kabupaten Maluku Tenggara Barat adalah 3,75cm/tahun dan termasuk ke dalam tipe pasang surut campuran condong ke harian ganda (Mixed Semi-Diurnal) dengan bilangan Formzahl pada 2018 = 0,602, nilai MSL = 383cm; nilai LLWL = 226,4cm; nilai HHWL = 541cm; nilai ZO = 314cm. Prediksi tinggi genangan di Kota Saumlaki, Maluku Tenggara Barat pada 2023 = 175,75cm; pada 2028 = 194,5cm; dan pada 2033 = 213,25cm.

Hubungan Antara Pola Tutupan Lahan Terbangun Dan Laju Infiltrasi Air Hujan

Kupang City is an area in Indonesia which has a relatively low number of rainy days. This causes the supply of clean water or drinking water in Kupang City to decrease. The high infiltration rate not only increases the amount of water stored in the soil, but also reduces flooding and erosion caused by run off. This study aims to model the relationship between infiltration and discharge capability for each type of samples land by using linear regression method. For this reason, a water absorption test was conducted on the built up area based on the infiltration rate. The results of experiments and calculations using linear regression shown that area often received heavy load such as vehichles had lower infiltration rate leading to slow inundation height decrease. While areas rarely received heavy load had higher infiltration rate. Even though the difference is only around 2-3 cm / 5 minutes, it indicates that the availability of open areas is still needed to support the implementation of the zero run-off model in urban built areas

Field survey and evacuation behaviour during the 2018 Sunda Strait tsunami

ABSTRACTOn the 22nd of December 2018 the shorelines of Sunda Strait, Indonesia, were hit by tsunami waves generated by the flank collapse of the Anak Krakatau volcano. The authors conducted a field survey of the affected areas in both Sumatra and Java islands to collect information on tsunami inundation and run-up heights, damage patterns at each coastal community, and the evacuation behaviour and tsunami awareness of the affected people. The survey results showed that in Sumatra island inundation heights of more than 4 m were measured along the coastline that was situated to the north-north-east of Anak Krakatau, while less than 4 m were measured along the north-western direction. Inundation heights of over 10 m were measured at Cipenyu Beach (Pandeglang Regency) in Java island (south-south-eastern direction from Anak Krakatau). A questionnaire survey conducted by the authors revealed residents’ perception of danger and evacuation patterns during the event. The results indicate the importance of having an operational tsunami warning system in Sunda Strait and the establishment of an appropriate evacuation plan so that residents can start evacuation immediately and reach a safe place without facing severe congestion along evacuation routes.

Flood Control On Secondary Sub Catchment Cerme Kidul In Drainage Systems Of Primary Canal Cerme Kidul kec. Cerme kab. Gresik

Cerme District is located in South Gresik area which has an area of 71.73 km2. This area is located above the height of ± 4m sea level. While the slopes of the Cerme District are in the range 0-2% with a slope to the north. The land-use plan map of Cerme sub-district should be designated as an industrial area and residential area which is still inundated at several points. One of these puddles is in the left-hand cerme drainage system, especially in the secondary sub-catchment cerme kidul. The inundation height is between 20-30cm with inundation ± 2-4 hours. This final project can find out the results of the planned debit calculation using existing land use and land use plans, the difference in the calculation of the debit reaches 60%. While the calculation of canal capacity using planned land use can be known that 2 "safe" and 8 channel segments "need normalization".

Source Model for the Tsunami Inside Palu Bay Following the 2018 Palu Earthquake, Indonesia

AbstractOn 28 September 2018, a strike‐slip earthquake occurred in Palu, Indonesia, and was followed by a series of tsunami waves that devastated the coast of Palu Bay. The tsunami was recorded at the Pantoloan tide gauge station with a peak amplitude of ~2 m above the water level and struck at high tide. We use the Pantoloan tsunami waveform and synthetic aperture rada displacement data in a joint inversion to estimate the vertical displacement around the narrow bay. Our inversion result suggests that the middle of the bay was uplifted up to 0.8 m, while the other parts of the bay subsided by up to 1 m. However, this seafloor displacement model alone cannot fully explain the observed tsunami inundation. The observed tsunami inundation heights and extents could be reproduced by a tsunami inundation simulation with a source model that combined the estimated vertical displacement with multiple subaerial‐submarine landslides.

Tsunami Simulations of the Sulawesi Mw 7.5 Event: Comparison of Seismic Sources Issued from a Tsunami Warning Context Versus Post-Event Finite Source

The 28 September 2018 Sulawesi earthquake generated a much larger tsunami than expected from its Mw = 7.5 magnitude and from its dominant strike-slip mechanism. Within a few minutes after the earthquake, the tsunami devastated the seafront of Palu bay, destroying houses and infrastructures over a few hundred meters. Coastal subsidence and slumping at various locations around the bay were also observed. There is debate in the scientific community as to whether submarine landslides and shore collapses contributed to the generation of strong and destructive waves locally. The objective of this study is threefold: first, to determine whether standard seismic inversions could predict the source in the context of tsunami early warning; second, to define a new seismic source built from optical image correlation and based on the geological and tectonic context; third, to assess whether the earthquake alone is able to generate up to 9-m wave heights at the coast. Numerical simulations of the tsunami propagation are performed for different seismic dislocation sources. Nonlinear shallow water equations are solved by a finite-difference method in grids with 200-m and 10-m resolutions. The early CMT focal solutions calculated by seismological institutes show dominant strike-slip mechanisms with a homogenous slip distribution. These sources produce maximum tsunami heights of 40-cm on the coast of Palu city. Two heterogeneous sources are tested and compared: the USGS “finite fault” model calculated from seismic inversion and a new “hybrid” source inferred from different techniques. The latter is based on a segmented fault in agreement with the geological context and built from both from seismic parameters of a CMT solution and the observed horizontal ground displacements. This source produces water wave heights of 4 to 5-m in the Palu bay. The observed inundation heights and distances are reproduced satisfactorily by the model at Pantoloan and at the southwestern tip of Palu bay. However, the “hybrid” source is unable to reproduce the largest 8 to 12-m water heights as reported from field surveys. Thus, even though this “hybrid” source produces most of the reported tsunami energy, we cannot exclude that the numerous coastal collapses observed in Palu bay contributed to increase the local tsunami run-up.

FLOOD HAZARD MAPPING USING GIS SPATIAL ANALYSIS FUNCTIONS IN BALEENDAH, BANDUNG, WEST JAVA

<em><span lang="IN">Flooding is the most devastating hydro-meteorological hazard in Baleendah. Therefore, communities in Baleendah needs more attention because they suffer the impacts every year. This paper focused on mapping flood hazard in the 1-km2 area in Baleendah. The study used spatial analysis functions in ArGIS. Also, an on-site survey was conducted to know the height of inundation by floods within the study area. The resulting flood hazard map shows that all communities are exposed to flood hazard with the total number of 5349 houses inundated by floods. The degree of inundation is divided into three (03) levels, low (0-0.5 m), moderate (0.5-1.5m), and high (above 1.5m). Positive attitude towards early actions and early warning systems, collaboration among disaster relief institutions and local government are recommended for reduction of flooding disaster risk.</span></em>

Effect of Shallow Slip Amplification Uncertainty on Probabilistic Tsunami Hazard Analysis in Subduction Zones: Use of Long-Term Balanced Stochastic Slip Models

The complexity of coseismic slip distributions influences the tsunami hazard posed by local and, to a certain extent, distant tsunami sources. Large slip concentrated in shallow patches was observed in recent tsunamigenic earthquakes, possibly due to dynamic amplification near the free surface, variable frictional conditions or other factors. We propose a method for incorporating enhanced shallow slip for subduction earthquakes while preventing systematic slip excess at shallow depths over one or more seismic cycles. The method uses the classic k−2 stochastic slip distributions, augmented by shallow slip amplification. It is necessary for deep events with lower slip to occur more often than shallow ones with amplified slip to balance the long-term cumulative slip. We evaluate the impact of this approach on tsunami hazard in the central and eastern Mediterranean Sea adopting a realistic 3D geometry for three subduction zones, by using it to model ~ 150,000 earthquakes with M_{w} from 6.0 to 9.0. We combine earthquake rates, depth-dependent slip distributions, tsunami modeling, and epistemic uncertainty through an ensemble modeling technique. We found that the mean hazard curves obtained with our method show enhanced probabilities for larger inundation heights as compared to the curves derived from depth-independent slip distributions. Our approach is completely general and can be applied to any subduction zone in the world.

LIVELIHOOD CHANGES OF FISHERMAN COMMUNITY DRIVEN BY CLIMATE CHANGE: A CASE STUDY IN SEMARANG COASTAL REGION, CENTRAL JAVA, INDONESIA

Purpose of Study: Climate change has triggered sea level rise so as to increase the height of tidal inundation (rob)in coastal areas. Fishermen face the highest risk since their livelihoods and settlement are directly adjacent to the sea in compared with other communities. This paper describes how fishermen living in the flood-prone areas can survive from the flood triggered by climate change. The house renovation certainly requires a lot of funds thus encouraging the fishermen to seek alternative sources to obtain higher income. Most of the fishermen in coastal Semarang change their livelihood from fishing to cultivating green mussels. They utilize the coastal areas inundated by the tidal flood to cultivate green mussels.
 Methodology: The approach used in this study was qualitative with the case study method. Sample cases were selected using snowball sampling. Data were collected through in-depth interviews with informants.
 Results: The results showed that fishermen living on the coast of Semarang have to face tidal floods with an increasingly high inundation by an average of 1 m/10 years. The increasing height of tidal flood from year to year has forced the fishermen to renovate their houses raising the building approximately every 10 years. The renovation certainly requires a lot of funds thus encouraging the fishermen to seek alternative sources to obtain higher income. Most of the fishermen in coastal Semarang change their livelihood from fishing to cultivating green mussel. They utilize the coastal areas inundated by the tidal flood to cultivate green mussels.
 Implications/Applications: However, green mussel cultivation successfully gains higher income as well as-as more sus- tainable than fishing. Statistically, it is evidenced by the capability of the fishermen in renovating their houses from pre- venting them inundated by the tidal flood.

Rapid tsunami loss estimation using regional inundation hazard metrics derived from stochastic tsunami simulation

This study explores the development of rapid tsunami loss estimation approaches that are based on regional inundation hazard metrics, such as representative inundation height and inundation area. In post-tsunami situations, these inundation hazard metrics can be inferred from remotely-sensed images. Using a probabilistic tsunami loss model for the Tohoku region of Japan, rapid tsunami loss estimation models are developed by regressing predicted tsunami losses against regional inundation hazard parameters, which are derived for coastal cities and towns in Miyagi Prefecture from 4000 stochastic tsunami simulations. Using numerous earthquake sources of moment magnitudes between 7.5 and 9.1 facilitates the robust development of a quick tsunami loss estimation tool. Special considerations are given in investigating the effects of coastal topography (plain versus ria) and the potential bias due to errors in estimating inundation heights and areas on tsunami loss. Performances of the new approaches are compared with conventional methods that are based on earthquake magnitude, source-to-site distance, and offshore tsunami wave profiles. The loss models based on regional inundation area outperform other approaches and thus are recommended for regional tsunami loss estimation.

The Study of Area Infiltration Rate by Using Biopori Holes as an Effort to Reduce Water Level and Groundwater Conservation

The expansion of land development for settlement and other infrastructure has impact for lessen of green open space that serves to absorb rainwater. Accordingly to that, there is a need of effort to increase the absorbtion rate of rainwater into the ground; one of the methods is using biopori holes. The area that uses as a sample to observe the infiltration rate using biopori holes is Kopelma Darussalam, Banda Aceh. The aim of this study is to measure the infiltration rate before and after the application of biopori holes, find out the amount of holes that required, discover the differences of ground water level every 2, 5, and 10 years return period and find out the amount of water that absorbed to ground water. The data which uses to calculate the water level is the annual maximum daily rainfall, land area under forest cover and texture, and infiltration rate. Meanwhile, the data which uses in order to calculate the volume of water infiltrated into the soil in each month is monthly rainfall data, land area which classified by the cover and texture and infiltration rate. Inundation height at annual maximum rainfalll plan for 2, 5, and 10 years return period with using 100, 160 and 400 holes for each 100 m2 is lower from 9.01% to 77.43% compared to not using biopori holes. In addition, the amount of water that infiltrated after using biopori holes is increasing up to 4120 m3 for each month.

The September 28th, 2018, Tsunami In Palu-Sulawesi, Indonesia: A Post-Event Field Survey

On September 28th, 2018, a powerful earthquake (Mw 7.5) struck the Island of Sulawesi in Indonesia. The earthquake was followed by a destructive and deadly tsunami that hit the Bay of Palu. A UNESCO international tsunami survey team responded to the disaster and surveyed 125 km of coastline along the Palu Bay up to the earthquake epicentre region. The team performed 78 tsunami runup and inundation height measurements throughout the surveyed coastline. Measured values reached 9.1 m for the runup height and 8.7 m for the inundation height, both at Benteng village. The survey team also identified ten large coastal sectors that collapsed into the sea of Palu Bay after the earthquake. The distribution of the measured tsunami data within Palu Bay exhibits a clear localised impact suggesting the contribution of secondary non-seismic local sources to the generation of the tsunami. Findings of the field reconnaissance are discussed to provide an insight into the remaining debated source of the Palu tsunami.

Twenty-Five Years (1992–2016) of Global Tsunamis: Statistical and Analytical Overview

The paper presents the analysis of global tsunami occurrence from 1992 to 2016. During this 25-year period, 290 tsunamis in marine basins and tsunami-like events in inland waters were registered. While this period represents less than 1% of the total catalog duration (ca. 4000 years), it contains almost 12% of the total number of historical events and nearly 54% of the total run-up and inundation depth measurements. The latter is mainly due to the data obtained in the field surveys of two trans-oceanic mega-tsunamis that occurred within this period—the December 26, 2004 Indian Ocean tsunami (1625 total measurements) and the March 11, 2011 Tohoku tsunami (6271 total measurements). Among 290 registered tsunamis and tsunami-like events, there were 95 damaging or potentially-damaging events that had maximum run-up or inundation height > 1 m and 32 destructive tsunamis that resulted in human fatalities. As throughout history, the Pacific continues to be the main tsunamigenic region with 223 events (77%) that occurred within its basin; 26 events (9%) occurred in the Indian Ocean, 26 events (9%) in the Atlantic, and 15 events (5%) in the Mediterranean region. Six tsunami-like events occurred in internal basins (rivers and lakes). The complete statistics of the recent tsunamis in the form of their distribution over type of sources, validity, fatalities and damaging effects, intensity, and warning efficiency are presented. The paper also outlines and discusses the existing problems with data compilation, cataloging and distribution, and discusses incompleteness of run-up and wave-form data for a considerable number of non-damaging tsunamis, even those resulting from strong (magnitude higher than 7.5) submarine earthquakes.

A New Approximate Method for Quantifying Tsunami Maximum Inundation Height Probability

Regional and global tsunami hazard analysis requires simplified and efficient methods for estimating the tsunami inundation height and its related uncertainty. One such approach is the amplification factor (AF) method. Amplification factors describe the relation between offshore wave height and the maximum inundation height, as predicted by linearized plane wave models employed for incident waves with different wave characteristics. In this study, a new amplification factor method is developed that takes into account the offshore bathymetry proximal to the coastal site. The present AFs cover the North-Eastern Atlantic and Mediterranean (NEAM) region. The model is the first general approximate model that quantifies inundation height uncertainty. Uncertainty quantification is carried out by analyzing the inundation height variability in more than 500 high-resolution inundation simulations at six different coastal sites. The inundation simulations are undertaken with different earthquake sources in order to produce different wave period and polarity. We show that the probability density of the maximum inundation height can be modeled with a log-normal distribution, whose median is quite well predicted by the AF. It is further demonstrated that the associated maximum inundation height uncertainties are significant and must be accounted for in tsunami hazard analysis. The application to the recently developed TSUMAPS-NEAM probabilistic tsunami hazard analysis (PTHA) is presented as a use case.

Development of a Potentially Hazardous Pro-Glacial Lake in Aksay Valley, Kyrgyz Range, Northern Tien Shan

Debris flows caused by glacial lake outburst floods (GLOFs) are common hazards in mountain environments. The risk posed by glacial lake outburst hazards is particularly evaluated where the lower reaches of catchments are populated. A potentially dangerous lake has been identified adjacent to the Uchitel Glacier in Northern Tien Shan. This lake formed between 1988 and 1994 on the site of a retreated glacier in the upper part of the Aksay Valley. In this study we consider the possibility of an outburst of this pro-glacial lake in the future. The study involved bathymetry mapping of the lake, detailed profile sections of the valley, flow rate measurements on the Aksay river, and monitoring of the lake development using satellite images. Modelling of secondary debris flow inundation heights and hazard footprints has been undertaken. The outburst of this lake could cause powerful debris flows posing a threat to permanent residents living downstream, in the Ala-Archa Valley. Monitoring of the lake over the past ten years suggests certain changes in the runoff to the subsurface, and an increase in lake depth is observed. Glacial lakes with subsurface drainage are considered to be the most hazardous type as the knowledge of drainage channels functioning is still very limited and, thus, the timing of an outburst is hard to predict. Development of monitoring approaches to support forecasting of these hazards is of paramount importance to safety in mountain territories globally.