Mapping of Landslide Hazard Distribution in Alo Watershed Gorontalo Regency

Landslide occurrence can be influenced by physical factors and human activities. Thus, research related to the provision of information about landslide distribution in Alo watershed is needed as a basis in enhancing community preparedness in dealing with disasters. The method used in this study is the scoring method based on the Minister of Public Works Regulation No.22 / PRT / M / 2017 which is processed through a geographical information system through the overlay of all physical parameters. The result shows that the Alo watershed area is divided into three vulnerability categories. "Low" category covers 7171.8 ha, "medium" category covers 12008.7 ha, and "high" category covers 5039.5 ha out of 24.221 ha the total area of Alo watershed. Information provided in this research is expected to be able to help the local government in making policies in managing the Alo watershed area and enhancing the understanding of the local community in Alo watershed in dealing with disasters

Oil spill hazard bulletin

Dissemination Method: Web Product weblink: https://glamor.sincem.unibo.it The MSFD, the new Directive on Safety of offshore oil and gas operations (2013) and the European Maritime Safety Agency require robust tools for oil spill hazard mapping, from accidental to operational. In this activity WP7 and Marine Core Service products were coupled to Medslik-II oil spill model in order to produce, on request, an Oil Spill Hazard Bulletin based upon the hazard mapping data generated earlier in the project. This report contains background information and some examples of oil spill hazard bulletins for target Atlantic areas. The web-GIS Portal GLAMOR developed for Task 8.4 “Oil spill hazard mapping and disaster risk reduction best practices” is used to create the information content in the requested bulletins. Please note: bulletins are only produced on a request basis

Applications of remote sensing techniques to county land use and flood hazard mapping

The application of remote sensing in Arizona is discussed. Land use and flood hazard mapping completed by the Applied Remote Sensing Program is described. Areas subject to periodic flood inundation are delineated and land use maps monitoring the growth within specific counties are provided

Banjir Bandang di DAS Batang Kuranji Kec. Kuranji Kotapadang dengan Sistem Informasi Geografis (Sig)

The research aims to map hazard flash flood sand Inundation mapping the spatial distribution(affected by) flash floods and analyze the factors causing flash floods in Batang Kuranji Watershed Sub- District Kuranji Padang. The method used is a 3D analysis of data raster DEM, topographic slope, Slope, flood elevation data, and river network data, for mapping the spatial distribution affected by the flash floods using survey methods to map land units as mapping unit. GPS tracking is then performedin the field to produce spatial distribution maps Inundation (affected by) flash floods and flash floods causing factor data were analyzed using the scoring methodo fland characteristics as determinants offlash flood hazard. From this research, the proportion of flood hazard zones with high hazard category with abroad zone of 1320 ha, or 6,15% of the region Batang Kuranji. Medium hazard zones are an area of 1243 ha or 5,7% of the region Batang Kuranji, and low hazard zones in the study region has an area of 18 885ha with aproportion of 88,15% of the total land area ofresearch Batang Kuranji and spatial distribution of the inundations flash floods in the area along Kuranji watershed in Koto Tangah subdistrict, Kuranji subdistrict, Nanggalo subdistrict, North Padang subdistrict, and Pauh subdistrict. Causing factor flash flood in the research area are mass movement that of caused landform, slope, slopeform, long of slope, and geomorphology process

Rapid methods of landslide hazard mapping : Fiji case study

A landslide hazard probability map can help planners (1) prepare for, and/or mitigate against, the effects of landsliding on communities and infrastructure, and (2) avoid or minimise the risks associated with new developments. The aims of the project were to establish, by means of studies in a few test areas, a generic method by which remote sensing and data analysis using a geographic information system (GIS) could provide a provisional landslide hazard zonation map. The provision of basic hazard information is an underpinning theme of the UN’s International Decade for Natural Disaster Reduction (IDNDR). It is an essential requirement for disaster preparedness and mitigation planning. This report forms part of BGS project 92/7 (R5554) ‘Rapid assessment of landslip hazards’ Carried out under the ODA/BGS Technology Development and Research Programme as part of the British Government’s provision of aid to developing countries. It provides a detailed technical account of work undertaken in a test area in Viti Levu in collaboration with Fiji Mineral Resources Department. The study represents a demonstration of a methodology that is applicable to many developing countries. The underlying principle is that relationships between past landsliding events, interpreted from remote sensing, and factors such as the geology, relief, soils etc provide the basis for modelling where future landslides are most likely to occur. This is achieved using a GIS by ‘weighting’ each class of each variable (e.g. each lithology ‘class’ of the variable ‘geology’) according to the proportion of landslides occurring within it compared to the regional average. Combinations of variables, produced by summing the weights in individual classes, provide ‘models’ of landslide probability. The approach is empirical but has the advantage of potentially being able to provide regional scale hazard maps over large areas quickly and cheaply; this is unlikely to be achieved using conventional ground-based geotechnical methods. In Fiji, landslides are usually triggered by intense rain storms commonly associated with tropical cyclones. However, the regional distribution of landslides has not been mapped nor is it known how far geology and landscape influence the location and severity of landsliding events. The report discusses the remote sensing and GIS methodology, and describes the results of the pilot study over an area of 713 km2 in south east Viti Levu. The landslide model uses geology, elevation, slope angle, slope aspect, soil type, and forest cover as inputs. The resulting provisional landslide hazard zonation map, divided into high, medium and low zones of landslide hazard probability, suggests that whilst rainfall is the immediate cause, others controls do exert a significant influence. It is recommended that consideration be given in Fiji to implementing the techniques as part of a national strategic plan for landslide hazard zonation mapping

A new method for avalanche hazard mapping using a combination of statistical and deterministic models

International audienceThe purpose of the present paper is to propose a new method for avalanche hazard mapping using a combination of statistical and deterministic modelling tools. The methodology is based on frequency-weighted impact pressure, and uses an avalanche dynamics model embedded within a statistical framework. The outlined procedure provides a useful way for avalanche experts to produce hazard maps for the typical case of avalanche sites where historical records are either poorly documented or even completely lacking, as well as to derive confidence limits on the proposed zoning. The methodology is implemented using avalanche information from Iceland and the Swiss mapping criteria, and applied to an Icelandic real world avalanche-mapping problem

Flood hazards studies in the Mississippi River basin using remote sensing

The Spring 1973 Mississippi River flood was investigated using remotely sensed data from ERTS-1. Both manual and automatic analyses of the data indicated that ERTS-1 is extremely useful as a regional tool for flood mamagement. Quantitative estimates of area flooded were made in St. Charles County, Missouri and Arkansas. Flood hazard mapping was conducted in three study areas along the Mississippi River using pre-flood ERTS-1 imagery enlarged to 1:250,000 and 1:100,000 scale. Initial results indicate that ERTS-1 digital mapping of flood prone areas can be performed at 1:62,500 which is comparable to some conventional flood hazard map scales

Use of Satellite Data to Map Flood Extension Around the City of Saint-Louis in the Senegal River Estuary

In this project the issue of flood hazard mapping has been addressed from the perspective of different mapping scale in a GIS environment. The flood hazard map is particularly handy for the planners and administrators for formulating remedial strategy

Considerations on geomorphological maps for territorial planning in the Modena Apennines (Northern Italy)

This contribution shows, through some examples, that the current instability processes sometimes do not completely correspond (concerning presence, location, state of activity and/or extent) with those mapped by PTCP Hydrogeological Hazard Maps, which is the document used by the Province Administration for its territorial planning. <br><br> The differences highlighted are due to different causes. One of them is the fact that the PTCP Hydrogeological Hazard Maps are practically derived from the Regional Geological maps in which superficial deposits have secondary importance, while bedrock and structural-tectonic aspects are given the highest relevance. Another cause is represented by the very active and intense geomorphological dynamics of the Apennines which may produce or reactivate instability conditions. <br><br> An important aspect to underline is that the PTCP Hydrogeological Hazard Maps identify areas with planning constraints, which have effects at a municipal scale; it does so by starting from a cartographical basis whose primary aim is not the definition of instability processes and whose updating is not homogeneous. <br><br> Taking into account this aspect, the PTCP Hydrogeological Hazard Maps should be updated not only on the base of traditional geological mapping, but also following the criteria of detailed geomorphological mapping which can precisely define the genesis, dynamics and morphometry of instability phenomena. <br><br> An important consideration, in relation to territorial planning, is that the PTCP Hydrogeological Hazard Maps should be used just as a "base document", which requires more necessary detailed deepening at the municipal scale, accomplished through accurate geomorphological mapping, at least for the areas that are going to be urbanized. <br><br> The geomorphological mapping should also update those elements of the landscape which could have changed from the official topographic base map. <br><br> Detailed geomorphological mapping, possibly undertaken with the methodology proposed in this paper, could be given in charge also to professional geologists in accordance with standard procedures set in collaboration with the Provincial Administration

Multi-hazard risk assessment using GIS in urban areas: a case study for the city of Turrialba, Costa Rica

In the framework of the UNESCO sponsored project on “Capacity Building for Natural Disaster Reduction” a case study was carried out on multi-hazard risk assessment of the city of Turrialba, located in the central part of Costa Rica. The city with a population of 33,000 people is located in an area, which is regularly affected by flooding, landslides and earthquakes. In order to assist the local emergency commission and the municipality, a pilot study was carried out in the development of a GIS –based system for risk assessment and management. The work was made using an orthophoto as basis, on which all buildings, land parcels and roads, within the city and its direct surroundings were digitized, resulting in a digital parcel map, for which a number of hazard and vulnerability attributes were collected in the field. Based on historical information a GIS database was generated, which was used to generate flood depth maps for different return periods. For determining the seismic hazard a modified version of the Radius approach was used and the landslide hazard was determined based on the historical landslide inventory and a number of factor maps, using a statistical approach. The cadastral database of the city was used, in combination with the various hazard maps for different return periods to generate vulnerability maps for the city. In order to determine cost of the elements at risk, differentiation was made between the costs of the constructions and the costs of the contents of the buildings. The cost maps were combined with the vulnerability maps and the hazard maps per hazard type for the different return periods, in order to obtain graphs of probability versus potential damage. The resulting database can be a tool for local authorities to determine the effect of certain mitigation measures, for which a cost-benefit analysis can be carried out. The database also serves as an important tool in the disaster preparedness phase of disaster management at the municipal level