Spatio-Temporal Distribution of Landslides in Java and the Triggering Factors

Abstract

Java Island, the most populated island of Indonesia, is prone to landslide disasters. Their occurrence and impact have increased mainly as the result of natural factors, aggravated by human imprint. This paper is intended to analyse: (1) the spatio-temporal variation of landslides in Java during short term and long-term periods, and (2) their causative factors such as rainfall, topography, geology, earthquakes, and land-use. The evaluation spatially and temporally of historical landslides and consequences were based on the landslide database covering the period of 1981 – 2007 in the GIS environment. Database showed that landslides distributed unevenly between West Java (67 %), Central Java (29 %) and East Java (4 %). Slope failures were most abundant on the very intensively weathered zone of old volcanic materials on slope angles of 30O – 40O. Rainfall threshold analysis showed that shallow landslides and deep-seated landslides were triggered by rainfall events of 300 – 600 mm and > 600 mm respectively of antecedent rainfall during 30 consecutive days, and many cases showed that the landslides were not always initiated by intense rainfall during the landslide day. Human interference plays an important role in landslide occurrence through land conversion from natural forest to dryland agriculture which was the host of most of landslides in Java. These results and methods can be used as valuable information on the spatio-temporal characteristics of landslides in Java and their relationship with causative factors, thereby providing a sound basis for landslide investigation in more detail.

The Compatibility of a GIS Map of Landslide-Prone Areas in Kendari City Southeast Sulawesi with Actual Site Conditions

“…Previous research has applied GIS with overlay in different locations. Shahabi & Hashim (2015) employed GIS-based statistical models and remote sensing data with the overlay method to create a landslide susceptibility map in Cameron Highlands area of Malaysia, while Hadmoko et al (2017) overlaid annual isohyets to establish the distribution of landslide occurrence in Java that increases in every interval class, and the highest in 2500-3000 mm. Hartono & Nasikh (2017) employed map analysis using the intersect type of overlay with scoring to produce a landslide potency map of Batu-East Java.…”

“…The main GISbased landslide capability in spatial contexts is spatial analysis in landslide digital maps. According to Hadmoko et al (2017) spatial analysis conducted landslides triggering from the causative factor. According to Guzzetti et al (2012) in an inventory map landslide information is shown as a combination of points, polylines, and polygons.…”

“…Suwarno et al (2016) suggested that the level of education, knowledge, information, and the economy affects the community, particularly in land management on high slopes, and also suggested that the hilly environment it should be maintained. In addition, Hadmoko et al (2017) stated that conversion of forests to rice fields is the main cause of landslides in Java.…”

Pengaruh Zona Jenuh Air Terhadap Kestabilan Lereng Di Weninggalih, Kabupaten Bandung Barat

“…Pulau Jawa merupakan wilayah dengan kepadatan penduduk tertinggi dan sangat rentan terhadap kejadian longsor, salah satunya yaitu Provinsi Jawa Barat. Berdasarkan inventarisasi data kejadian longsor, 67% kejadian longsor yang ada di Pulau Jawa terkonsentrasi di Provinsi Jawa Barat (Hadmoko et al, 2017). Berdasarkan data informasi bencana Indonesia dalam satu dekade terakhir (2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019), rata-rata kejadian longsor per tahun di Jawa Barat cukup tinggi dengan jumlah mencapai 256 kejadian/tahun (BNPB, 2019).…”

Analysis of Mapping Forest, Settlement, and Rice Field Areas in Konawe Selatan District, Indonesia

“…This was backed up by BPS (2020) data showing 77 flood cases and 17 landslide cases which indicated that there are human effects on land usage that does not accordance with its function. Therefore, land-use planning needs to pay serious attention to the regional capacity because changes in conservation areas such as deforestation cause flooding, landslides, and erosion (Appannagari, 2018;Hadmoko et al, 2017;Hamdani et al, 2014;Sejati et al, 2019).…”