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Research article Flood Vulnerability and Mapping of Flood Evacuation Point District in Gayungan District.
Surabaya City Using a Geographic Information System Citation:
Mafaza.
Sasmi.
Mukasyaf, , & Ibrahim.
Flood Vrnerability Mapping Flood Evacuation Point District in Gayungan Muhammad Rayyan Akbar Mafaza 1.
Annisa Trisnia Sasmi1*.
Aziz Akbar Mukasyaf1.
Mohd Hairy Ibrahim2 Faculty of Geography.
Muhammadiyah University of Surakarta.
Sukoharjo 57162.
Indonesia.
Faculty of Sains Kemanusiaan.
Universiti Pendidikan Sultan Idris.
Malaysia Correspondence: ats678@ums.
District.
Surabaya City Using a Geographic Information System.
Forum Geografi.
Article history:
Received: 13-11-2025 Revised: 03-12-2025 Accepted: 20-01-2026 Published: 30-01-2026 Abstract Gayungan District is one of the areas in Surabaya that frequently experiences flooding.
Generally, flooding can be categorized into two types: first, flooding caused by dry land being submerged by increasing water Second, flooding caused by overflowing rivers/irrigation channels caused by blockages, which increase the volume of water beyond the river's capacity.
The objectives of this study are: .
Identifying flood-prone areas in Gayungan District using GIS-based river buffer analysis.
Analyzing the distribution of evacuation points and their suitability for flood-affected settlements.
Using quantitative descriptive The results show a 300-meter flood coverage zone, with one shelter and worship facility within the flood-affected zone.
Keywords: Floods.
Shelters.
Mapping Introduction Indonesia is a tropical country with only two seasons: the rainy season and the dry season.
During the rainy season, several regions in Indonesia frequently experience disasters, including flooding.
These floods are caused by several factors, both natural and human-caused.
These factors cause water levels to rise and rivers to overflow, ultimately leading to flooding.
Surabaya, the capital of East Java Province and the country's second-largest city, is one of several Indonesian cities frequently hit by flooding.
Surabaya is located in the north of Java Island and borders the Madura Strait.
Gayungan District is one of the administrative districts in Surabaya City with an area of 6.
15 kmA.
The largest village in Gayungan District is Ketintang Village with an area of 2.
97 kmA.
The average temperature in this district is around 28.
3AC with a humidity of around 77.
9%, and a wind speed of 2.
7 knots (BPS Kota Surabaya, 2.
The Surabaya City Government has created policies and measures to address flooding in Surabaya City, but this problem cannot be fully resolved and continues to occur.
This can occur because the existing drainage system is designed only for irrigation purposes, so the existing drainage is unable to accommodate the large volume of water caused by changes in land use (Saud, 2.
Copyright: A 2025 by the authors.
Submitted for possible open access publication under the terms and conditions of the Creative Commons Attribution (CC BY) license .
ttps://creativecommons.
org/licenses/b y/4.
0/).
Mafaza et al.
Drainage is an important and crucial aspect in managing flooding in residential areas.
The drainage system is designed to effectively direct water and reduce/eliminate puddles during The drainage system also serves to minimize soil erosion and increase the soil's water absorption capacity (Aditiya & Soebagio, 2.
Despite its function, flooding in the residential area of Ketintang Village.
Gayungan District, still frequently occurs due to inadequate drainage, sedimentation, and the accumulation of waste in the drainage.
During high rainfall, this area can experience inundation reaching 19.
83 cm for 76 minutes, with an inundated area of 19.
78 hectares (Aditiya & Soebagio, 2.
Floods occur when the water discharge/volume overflows and exceeds the capacity of the river channel due to rainfall, soil infiltration capacity, topographic conditions, and land cover type.
Floods categorized as hydrometeorological hazards and disasters are floods that produce significant damage over a wide area (Sahid, 2.
Floods occur in almost every country in the world, most frequently in urban areas.
This is due to rapid development and migration seeking decent living opportunities in urban areas (Rochman & Prasetya, 2.
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In general, flooding can be categorized into two types.
First, flooding occurs because dry land is submerged by water that has increased in volume.
Second, flooding occurs due to overflowing rivers/irrigation channels caused by blockages, causing an increase in water volume that cannot be accommodated by the river's capacity (Kodoatie & Sugiyanto, 2.
Flooding is a very serious issue because it directly affects people's lives, so serious efforts are needed to be planned to reduce or even eliminate the risk and impact of flooding (Priyana & Harsini, 2.
In practice, the primary factor, or the factor that contributes most to flooding, is human activity.
This is human activity that is not environmentally conscious, particularly in river basins (DAS) that are categorized as upstream, midstream, and downstream (Suharjo et al, 2.
This is reinforced by the abundant evidence related to human behavior towards the environment, which influences the frequency of flooding, with varying intensities (Priyana et al, 2.
Furthermore, flooding is also influenced by the duration and intensity of rainfall, as well as the ability of the river in the area to drain the water properly (Ulfiana et al, 2.
Steps that can be taken to support flood disaster risk mitigation include the use of Geographic Information Systems (GIS).
GIS is a computer-based system that functions to store, process, analyze, and display spatial data.
GIS has experienced rapid development in recent years and can be applied in various fields, including disaster mitigation and evacuation planning.
One of the main software that can be used is ArcView, developed by ESRI (Wibowo et al, 2.
Structural disaster mitigation efforts require the strategic presence of mitigation shelters, which serve as temporary evacuation sites for affected communities.
Ideally, shelters/evacuation sites are designed as multi-story buildings that are earthquake and tsunami resistant and serve dual functions, such as providing facilities that remain useful even when a disaster does not strike, such as community activity centers, educational facilities, places of worship, or other public facilities (Sipta, 2.
However, in reality, in some areas, evacuation sites are still underutilized and inadequate in terms of facilities and quality.
According to Law Number 24 of 2007 concerning Disaster Management, a disaster is an event that threatens and disrupts people's lives, caused by natural factors, non-natural factors, or human actions/behaviors.
It also results in human, environmental, material, and psychological losses.
Mapping, a branch of geography, plays a crucial role in disaster mitigation efforts because it can help identify the characteristics of the affected earth's surface (Ambarwati & Johan, 2.
Gayungan District is one of the areas in Surabaya frequently hit by flooding.
The resulting standing water, particularly along Jalan Ahmad Yani, often causes traffic jams, with water levels varying, even exceeding the height of minibuses.
To date, there has been no study or research specifically mapping the locations of evacuation shelters for flood disasters in Gayungan District.
Therefore, a study that discusses and maps spatially using GIS is needed to identify and analyze the spatial distribution of shelters.
This research is expected to provide information for the community and relevant local governments to improve disaster mitigation preparedness and minimize disaster risks, particularly flooding.
This research was able to take place because it was rooted in the problem formulations that the author had obtained, including: How are evacuation points .
laces of worshi.
distributed and effective in reaching flood-affected areas? And How can the use of Geographic Information Systems (GIS) support disaster planning? gas flood disaster in the area?.
Furthermore, from the existing problem formulation, the research objectives emerged, this research has two objectives, namely firstly to identify flood-prone areas in Gayungan District using GIS-based river buffer analysis, and secondly the objective is to analyze the distribution of evacuation points and their suitability for settlements affected by flooding.
Furthermore, this research will be useful in the future if it is reviewed and can be read by the general public.
For academics, there will be several uses of this research, including .
providing information about the number, area coverage, and distribution pattern of evacuation points in Gayungan District, .
becoming a guideline and reference for academics to conduct research on evacuation points, especially Gayungan District, .
Providing analysis of the number, area coverage, and distribution pattern of evacuation points in Gayungan District.
In addition to academics, this research also provides benefits to the general public, useful for providing information to the public about the location of evacuation points in Gayungan District, providing information on evacuation point patterns in various sub-districts, as well as the reach of evacuation Mafaza et al.
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points in each residential area in the District.
In addition, it provides information on evacuation points in Gayungan District.
Making it easier for the Gayungan District community to choose which evacuation point will be used by each community.
For the local government, this research is useful for providing information on the distribution pattern and reach of the Gayungan District area, so that it can be a recommendation for the government to establish or build evacuation points for areas in need.
For example, the categories of areas that require development are areas with minimal evacuation points, residential locations that are far from evacuation points, or areas that are difficult to reach from evacuation points.
Research Methods Research Area This study selected the study location in Gayungan District.
Surabaya City with the variable Evacuation Point (Educational facilities and places of worshi.
The method used in this study is a descriptive quantitative and qualitative approach.
According to the Big Indonesian Dictionary (KBBI), quantitative refers to something based on quantity or amount, which is a part of energy that cannot be further divided.
Quantitative data is data in the form of numbers or data converted into numbers .
This type of data can usually be analyzed using statistical methods or techniques.
This data can also be in the form of numbers or scores, which are often obtained through data collection tools with answers in the form of a score range or questions that are assigned specific values (Putri, 2.
Population is a generalization area consisting of: objects or subjects that have certain qualities and characteristics that are determined by researchers to be studied and then conclusions drawn (Suriani et al, 2.
In conclusion, a population is a comprehensive collection of objects that are of interest to researchers.
The object of this study is the shelter in Gayungan sub-district.
Data Colecction and Processing This research uses secondary and primary data sources.
Secondary data obtained from BPS and the Surabaya City website already provides the names of educational facilities, places of worship and locations of educational facilities and places of worship.
so that researchers can access the location of these facilities using Google Earth to obtain coordinate points.
The primary data used is buffer data obtained from processing carried out using Arcmap.
The data is presented in part Table 1.
Data Source Data Source Usability SHP Settlement INA Geoportal Create a map of flood-prone SHP Administrative Boundary INA Geoportal Making a map of regional administrative boundaries SHP River.
Gayungan District Coordinate points of places of worship Data on the distribution of flood impacts Buffer 300 m Flood affected locations based on population INA Geoportal Google Earth Obtained from the results of management using Arcmap Reach points obtained from plotting the reach points of places of worship To determine the shelter Knoing how dense the settlement is Knowing the number of shelter points distributed To determine which parts are affected by the flood Knowing the reach of shelters to flood-prone areas To determine the shelter Data processing technique consist of several step as follow:
Import all shapefiles .
ivers, admin boundaries, coordinate points of places of worshi.
into Arcmap Mafaza et al.
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Performing the River Buffer Process (Opening Arctoolbox-Analysis Tool-Proximity-Buffe.
Displaying Places of Worship Points (Enter Excel data in cxv format - right click XY Data Display XY Data - Export as shapefile - add different symbol.
Overlay settlement and buffer data (Arctoolbox-Analysis tool-Overlay-Intersect/identify-Input 1: Settlements.
Input 2 River Buffe.
Adding Administrative Boundaries (Admin Boundary Shapefile - Different Line Symbolization (District Boundary: Thick Line.
Village Boundary: Dotted Lin.
) Adding Location Labels (Right Click Layer-Properties-Label.
Map Layout (Layout view-Map Title-Legend-North arrow-Scale-Inset Location mapCompiler's Nam.
Data Analysis Method The analytical method used is Buffer.
Buffer in Geographic Information Systems refers to an area generated around a point, line, or polygon that encompasses the entire area within a certain distance from the element.
This area is depicted by GIS as a new polygon.
The term 'negative Buffer' can also be applied to polygons to measure the distance inward from the edge of a regional Buffers can be applied to both raster and vector data model problems.
A Buffer Zone is an area associated with a map object, be it a point, line, or area .
By creating a buffer, a coverage area will be formed or protect spatial features on the map .
uffer area object.
with a certain distance.
Therefore, the area created from this graph is used to determine the spatial distance of the map object from other objects around it.
Results and Discussion This research produced a map, namely the Flood Buffer Map and Evacuation Point Distribution in Gayungan District.
Surabaya City.
Based on GIS that provides spatial data and results by showing areas vulnerable to flooding and the distribution of evacuation locations in Gayungan District.
Surabaya City.
The map was created through a series of spatial data processing processes, which include buffer analysis, overlay, and visualization of evacuation locations focused on religious facilities in Gayungan District such as mosques and churches.
The resulting map also aims to provide insight, information, and accurate notification of flood risk vulnerability in Gayungan with the readiness of facilities to evacuate in affected areas.
Figure 1.
Feasibility Evaluation Map of Ngembak Landfill in Purwodadi Subdistrict.
Grobogan Regency in Mafaza et al.
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One of the important things that needs to be considered in this study is the determination of areas at risk of flooding, the determination is done by analyzing the tampon zone which is 300 meters from the river network that passes through Gayungan District.
The determination of this distance is based on the provisions recommended in the guidelines made by BNPB and research by JICA, which states that the range of 250-500 meters from the river is an alert area, therefore in lowland areas such as Surabaya is considered/categorized in the alert zone for flood disasters.
The analysis findings represent residential areas within this 300-meter tampon zone as having a high level of vulnerability to flooding.
Gayungan District is particularly vulnerable in Ketintang and Dukuh Manunggal Villages, both of these areas have high population densities, coupled with drainage infrastructure that is not yet fully ready to drain and accommodate high-intensity rainwater.
Next, a merger was performed to combine settlement data with river zones through an overlay.
The results show that the majority of dense settlements in Gayungan District are located in areas potentially affected by flooding.
This result emphasizes the importance of detailed, structured, and more systematic disaster mitigation planning in Gayungan District.
Furthermore, historical data related to flooding incidents from the Surabaya City Regional Disaster Management Agency (BPBD) and information from various media, both online and conventional, can also be used as references to validate the existing results.
This indicates a match between the mapped flood-prone areas and previously recorded flood incidents.
Regarding the provision of mitigation/evacuation locations, this study obtained results that can identify ideal locations for shelters, which in this study are based on places of worship.
The distribution of shelters shows a strong concentration in the western area of Gayungan District, which is geographically safer because it is in a higher area than other areas and far from the river This is also related to the density of settlements and existing facilities in the area.
However, the results also show that there is one mosque shelter located within the 300-meter buffer range, which is interpreted as a high risk of flooding.
This indicates the need for a re-evaluation of the shelter location, as well as the need for recommendations for alternatives that can be done, such as raising the shelter or relocating the location to a safer area.
To support research on the accessibility of shelters to affected areas, proximity analysis was used to measure the distance between settlements and the nearest evacuation site.
This method allows for the identification of areas lacking adequate access to evacuation facilities, thus providing a basis for consideration in the addition or relocation of shelters in the future.
However, this study did not include an analysis of shelter capacity due to limited non-spatial attribute data.
Therefore, in the next development phase, it is recommended to align data on the physical capacity of shelters, supporting facilities, and the estimated number of affected residents, so that planning can be carried out more accurately and efficiently.
Overall, this study/research has had a significant impact on efforts to reduce the risk and impact of flooding in densely populated urban areas, such as Gayungan District.
The resulting map serves not only as a means of representing and visualizing data, but also as a basis for providing insights for developing disaster mitigation policies and strategies by relevant parties.
With this spatial information, stakeholders can conduct risk assessments and evaluations more systematically and with greater focus, and position points appropriately and according to community needs.
Conclusion This research produced a map of the 300-meter flood buffer in Gayungan District.
Surabaya City.
Furthermore, evacuation shelters, including religious facilities like mosques and churches, were However, one shelter in Gayungan District remains affected by the flooding.
Therefore, an evaluation and relocation are necessary to maximize and optimize the provision of shelter services for evacuation.
The resulting maps serve not only as a means of representing and visualizing data, but also as a basis for providing insights for relevant parties in developing disaster mitigation policies and strategies.
With this spatial information, stakeholders can conduct risk assessments and evaluations more systematically and with greater focus, and position points appropriately and according to community needs.
Mafaza et al.
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Acknowledgements The author would like to express their gratitude to the Faculty of Geography.
Universitas Muhammadiyah Surakarta, which from the beginning to the end of the research process has provided all the facilities and opportunities for us to carry out and complete the research until the final stage.
would also like to express our thanks to the researchers previous research results that can be an inspiration for us in carrying out research as well as agencies, both government and private, that provide data for free.
Author Contributions Muhammad Rayyan Akbar Mafaza.
Annisa Trisnia Sasmi.
Mohd Hairy Conceptualization:
Ibrahim.
methodology: Muhammad Rayyan Akbar Mafaza.
Aziz Akbar Mukasyaf.
Muhammad Rayyan Akbar Mafaza.
writingAioriginal draft preparation:
Muhammad Rayyan Akbar Mafaza.
writingAireview and editing: Annisa Tisnia Sasmi.
Aziz Akbar Mukasyaf.
Muhammad Rayyan Akbar Mafaza.
All authors have read and agreed to the published version of the References