We can imagine as landslide occurs in an area; rumble sound with a speed of soil materials, falling trees, and rocks rubbing together. Moreover, quiet air blows suddenly to voice mingled with landslide movement. Afterwards, as the landslide materials met with barrier at the front until creating a boom sound.
It comes across into our mind when Ponorogo landslide occurred at Tangkil Sub village, Banaran, Ponorogo, East Java in early April (1/4/2017). Local residents were aware about potential landslide that might trigger a disaster. At night, they moved to safer houses at their neighbors, at daylight they worked at their ginger field. However, they were not able to escape from the raging landslide that finally buried tens of the local residents. Subsequent landslide is still potential along with potential rains with high intensity.
Based on the 2017 data of the National Disaster Management Authority (BNPB), total number of landslide occurrences until end of March is 251. The landslide results 20 people killed and missing, 991 damaged houses with the category of medium to heavy damaged, as well 8.649 people affected.
Meanwhile in a period of 2012 – 2017, as many as 2.581 occurrences of landslide have hit several places in the country. Total dead or missing victims is 1.061. It is a fact that the landslide is deadly disaster in Indonesia. BNPB records that a series of landslide occurrences takes place in January up to March, in which the peak of rainy season occurs. The landslide categorized as hydro-meteorological disaster is potentially occurred in 274 regencies and cities such as in along Bukit Barisan in Sumatera, southern and central Jawa, Bali, Nusa Tenggara, Sulawesi, Maluku and Papua. As many as 40,9 million population is exposed to medium and high category of landslide.
Potential threat of landslide is actually able to be mitigated and hindered. Some notes of BNPB regarding with triggers of the landslide are as follow.
- The rate of environmental degradation is much faster than the recovery effort. The rate of forest destruction on average 750,000 to 1 million hectares per year, while the government’s ability to conduct forest rehabilitation maximum average of 250,000 hectares per year.
- Function river tends to decrease or watersheds (DAS) are critical. Critical lands in Indonesia is about 24.3 million hectares.
- Increased need productive land for agricultural purposes, industrial or settlements not matched by the spatial arrangement based disaster, including urbanization.
- The behavior of people who still do not pay attention to the environment (make the river landfills, illegal logging).
- Global warming, climate change and extreme weather has exacerbated the impact of disasters.
- Ability disaster mitigation in general is still inadequate, both structural and non-structural mitigation.
To address the threat of the potential hazard, various stakeholders such as governments, communities and relevant stakeholders seek measures for disaster risk reduction. One possibility is to relocate to a safe place but somehow this solution is always constrained by the availability of land and the provision of access to infrastructure. Moreover, local residents might have challenges towards attachments on recent place of living, culture, as well with the social.
Implementation of well-managed spatial is one of key solutions to reduce risks of the hazard. The government authorities as the focal point of disaster management in the region recommends sterilization landslide-prone areas that have not been developed into a settlement. Need a moratorium on settlement construction in areas prone to landslides and should be used as a protected area. On the other hand, the efforts of reforestation, afforestation, soil and water conservation can be done as a prevention.
In addition, local residents inhabiting in areas prone to landslide need to acquire knowledge and mitigation measures, both structural and non-structural. Currently landslide early warning system (LEWS) has been applied in several areas, but one of the obstacles is the limited production of early warning devices as part of the system.