Idzam.docx

MAPPING OF GIS-BASED LANDSLIDE PRONE AREAS IN BATU Moh. Idzham Furqoni Geografi, Fakultas Ilmu Sosial, Universitas Negeri Malang [email protected]

ABSTRACT Batu City is located in a mountainous area and is designated as a hilly area prone to landslides by the East Java National Disaster Management Agency (BNPB) as an area prone to landslides. Landslides are difficult to prevent with certainty, but efforts can be made to minimize the occurrence of landslides in areas prone to landslides. Landslides in Batu City can disrupt the mobility and harm the community because access to mobility or roads in the rock city consists of steep slopes and hills. So that mapping of landslide prone areas will help to minimize the occurrence of landslides. Therefore, the author took the title of mapping of GIS-based landslide prone areas in Batu City so that it could help the community update and monitor the area that was made a point of landslides. Key word : (GIS) geographic information system, Batu City, Landslide Prone Areas.

INTRODUCTION Batu City is located in a mountainous area including Panderman Mountain (2010 m), Welirang Mountain (3156 m), Mount Arjuno (3339m) and set by the East Java National Disaster Management Agency (BNPB) as a hilly area prone to landslides. Landslides cannot be prevented for certain, but we can make efforts to minimize the occurrence of landslides in areas + prone to landslides. Landslides in Batu city can interfere with the smooth mobility and detriment of the community because access to mobility or the road there consists of steep slopes and hills. The mapping of landslide-prone areas will help to minimize the occurrence of landslides. Along with the times and advances in technology now we can map an area

with the precision we want to use a device that is currently widely used, namely GIS (Geographic Information System) or in Indonesia itself better known as GIS. GIS-based Landslide Mapping Mapping in Batu City can help communities update and monitor areas that are prone to landslides in order to minimize the loss of many victims and losses when landslides occur. Natural disasters as one of the natural phenomena can occur at any time, anywhere and at any time, so that they can cause material and immaterial losses to the lives of the people. Landslides are one of the natural disasters that often cause loss of property and casualties and cause damage to facilities and infrastructure that can have an impact on economic and social conditions. Landslides are a process

of equilibrium that causes the movement of soil and rock mass from a higher place to a lower place. The movement occurs because of the force factor which is located on uneven ground or called the slope. THEORETICAL BASIS Landslide According to the Directorate of Volcanology and Geological Disaster Mitigation (2005) states that landslides may also be called land movements. Defined as a mass of soil or a mixture of clay, gravel, sand, and greedy material and lumps and mud, which move along the slope or out of the slope due to the gravitational factor of the earth. The factors that cause the movement on the slope also depend on the condition of the rock and the soil making up the slope, the structure of the geology, rainfall, cover vegetation and land use on the slopes which are combined with erosion-prone signs, but broadly distinguishable as natural and human factors. According to the Directorate of Volcanology and Geological Disaster Mitigation (2005) Batu City Batu City was a city that was established in 2001 as a division of Malang Regency, namely with the legal basis of Law No. 11/2001 dated June 21, 2001. Previously the area of Batu City was part of the Development Zone 1 Unit (SSWP 1) of North Malang. Astronomically Batu City is located at 112 ° 17'10.90 ″ - 122 ° 57'11 ″ East Longitude and 7 ° 44’55.11 ″ - 8 ° 26'35,45 South Latitude.

Geographic Information System Geographical information systems are computer-based systems for capturing, storing, checking, integrating, manipulating, and displaying data with digital maps (Turban, 2005) Geographic Information Systems (GIS) or also known as the first Geographic Information System (GIS) in the 1960s aims to resolve geographical problems. Meanwhile, according to Prahasta, (2002) GIS is a technique of overlaying / overlaying (overlaying) some spatial data and information using mathematical formulations to produce a new geographical theme. The basic type of spatial analysis that can be used to explore spatial characteristics and attributes of combining data layers is an overlay. Overlay is a process of overlapping several thematic maps in a series of spatial conclusions (Eko Budiyanto, 2010). Overlay used to answer questions about geographical features located above other geographical features. In geoprocessing, overlay is a geometric intersection of several datasets to combine, delete, change, or update features in the output dataset. Overlay helps answer one of the basic questions of GIS software, namely: "What is above what" so that it can answer important questions related to geography. ArcGIS software offers several techniques for conducting overlay analysis. The use of the technique depends on the question you want to answer or the case being studied, the types of features in the input data, and the features you want to display in the output. Overlay operations, such as Intersect, Identity, and Union can produce different geometries in the output, but the overlay's main importance is that the

attributes are combined from the input. Overlays are not just operations that combine or split geometry features based on the spatial relationship of features, but the true strength of an overlay is the fact that attributes are combined when features intersect and are maintained in the output attribute table. The overlay process is used as a mix of various indicators derived from thematic maps to become an analysis map. This map of analysis is finally used as the basis for drawing conclusions for the case under investigation.

RESULT

METHODOLOGY The methodology used in this article is the analysis of secondary data. Data analysis technique According to Noeng Muhadjir (1996: 104), data analysis is an attempt to find and organize systematically the results of observations, interviews, and others to improve the understanding of researchers about the case under study and present it as findings for others. In this study using data analysis techniques in the form of:

Figure 1. lansdslide prone maps batu city From the existence of landslide prone maps that been made, it can be a bridge for the community to understand the vulnerability of landslide in the Batu City so that people who initially do not lnow become more alert to landslide.

1. Overlay Analysis (Map Overlay) 2. Scoring Method From the existence of landslide prone maps that have been made, this can be a bridge for the community to understand the vulnerability of landslides in Batu City so that the initial people do not know to be more alert to landslides.

DISCUSSION Based on the results, a map in the form of "rock city landslide vulnerability map", from the map can be seen and analyzed regarding the contents that can be taken directly, namely some areas in Batu City have a level of vulnerability from very low to very high. As in the map that has been made the level of vulnerability to landslides is high to very high located in the northern rock city area precisely in the area of Sumbergondo village, Tulugrejo and surrounding areas, and there are also areas south-west of the rock city covering

Oro-oroombo village, Tlekung and its surroundings. This can happen because in these areas the area is close to the foot of the mountain where Arjuno and Gunun Kawi are located so that the slope of the slope is quite high to very high. Whereas for areas that have a low level of landslide vulnerability that is found in the central or central area of the city itself, the area is classified as landau and many settlements are found so that the level of landslide vulnerability is relatively small. CONCLUSION Based on the research that has been conducted on the mapping of Gis-based landslide prone areas in Batu City, the following conclusions can be drawn : a. This Geographic Information System is used to process the data of the Regional Disaster Management Agency (BPBD) of the city of Batu about the risk of landslides. b. This Geographic information system is a bridge of information to the general public to find out the condition of areas prone to landslides. c. Areas that have a high to very high level of landslide are found in the northern part of the city of rock, namely in the tulungrejo sub-district, sumbergondo and surrounding areas and the southwestern area of the stone city precisely in the orooroombo sub-district, tlekung and surrounding areas, low landslide vulnerability that is found in the central area or center of the rock city itself. REFRENCE [DVMBG] Direktorat Vulkanologi dan Mitigasi Bencana Geologi.

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