Anticipate Collateral Hazards in 2023
Climate-related disasters will be the biggest challenge that must be faced in the coming years. Even so, geology-related disasters that could strike at any time risk becoming a major disruption.
The La Nina phenomenon, which has been going on for the last three years, is expected to decline from December 2022 before fading in February 2023. This will present a relatively normal rainy and dry season throughout 2023.
The forecast for the 2022/2023 rainy season by the Meteorology, Climatology and Geophysics Agency (BMKG) shows that at the peak of the rainy season in January 2023, as many as 72 percent of regions in Indonesia will receive moderate rainfall, while 28 percent of areas will experience high rainfall. Rainfall is generally expected to be in normal conditions, except for Aceh where rainfall is predicted to increase and northern Papua where rainfall will be less.
As La Nina fades, the risk of wild fires will also increase again, so we have to watch out for it in the 2023 dry season. Previously, during the last three years, the risk of wild fires has relatively decreased due to the wet dry season.
Even in the normal climate mode next year, we must also continue to anticipate hydrometeorological disasters such as the Seroja tropical cyclone anomaly which had a very damaging impact on East Nusa Tenggara on 2021.
The trend of rising temperatures that are happening globally, including in Indonesia, can also have an impact on health and productivity. Siswanto's research from BMKG in the journal Meteorological Society of Japan in the beginning of 2022 shows a trend of significant increase in surface temperature on the island of Java since 1981. The highest rate of increase in surface air temperature was recorded in South Tangerang, Banten, reaching 0.46 degrees Celsius per decade and DKI Jakarta by 0.4 degrees Celsius per decade.
The report by Nicholas H Wolff and his team in the journal Lancet Planetary Health in 2021 found that in the past 16 years the trend of increasing daily maximum temperature in Berau, East Kalimantan, has averaged 0.95 degrees Celsius. Apart from being triggered by global trends, the increase in temperature in Berau is mainly due to massive deforestation.
Wolff also found a link between a 1 degree temperature increase in Berau and an increase of 7.3-8.5 percent in deaths from all causes, or 101-118 additional deaths per year in 2018. This increase in temperature also causes an increase in unsafe working time by 0.31 hours per day in deforested areas. This can affect work productivity, especially those who work outdoors such as farmers and fishermen.
The climate crisis will also reduce the productivity of the agricultural sector. The latest research by Edvin Adrian and Elza Surmani from the National Research and Innovation Agency (BRIN) shows that Indonesia could lose the economic value of rice by an average of IDR 42.4 trillion per year in 2051-2080 and increase to IDR 56.45 trillion per year in 2081-2100. This decline in production, both due to hydro-meteorological disasters and increasingly intense pest attacks due to global warming, has actually occurred since the last few years.
Disaster from Geographical Conditions in Indonesia
If hydrometeorological disasters become a global concern along with global climate change, Indonesia also has disaster risks originating from our unique geographical conditions. Being in a very active plate collision zone makes our country very vulnerable to earthquakes, tsunamis and volcanic eruptions.
Even though their frequency is relatively small compared to hydrometeorological disasters, the impact and scale of damage caused by geological related disasters can be very large. The impact can be bigger if the hydrometeorological disaster occurs in conjunction with a geological disaster so that it triggers collateral damage.
For example, earthquakes, tsunamis and volcanic eruptions which can be followed by landslides or flash floods. This is for example during the eruption of Mount Semeru in East Java on December 4 2021 which coincided with heavy rain which eroded the pile of material around the mouth of the crater and triggered hot clouds of avalanches and lava floods that failed to be anticipated.
The 5.6 magnitude earthquake that destroyed thousands of houses and killed hundreds of people in Cianjur, West Java, on Monday (21/11/2022) served as a reminder of the high risk of geological disasters in Indonesia. An earthquake, with a larger scale followed by a tsunami, could occur in most of the Indonesian archipelago at any time.
BMKG data shows that since 2013 there has been a trend of increasing earthquake activity in Indonesia, both in number and strength. If in 2013 the number of earthquakes in Indonesia was 4,234 times, in 2016 there were 5,646 times, and then in 2018 there were 11,920 times. Meanwhile in 2021 there will be 11,395 times.
Seismic experts have warned that there are a number of tectonic zones in Indonesia that store great energy and are approaching a recurring cycle. Several tectonic zones that need to be watched out for include the subduction in the Sunda Strait and southern Java, the Mentawai subduction, the Sumatran land fault in the Aceh Besar-Banda Aceh segment, the Maluku Sea, the Banda Sea, as well as a number of land faults on Sulawesi Island and land faults in Papuan.
In addition, seeing the scale of the destruction in Cianjur, which was shaken by a relatively small earthquake, we should also make the threat of earthquakes originating from land faults on Java Island a focus of mitigation. The island of Java, whose population has quadrupled during the 20th century, has many active faults that can trigger earthquakes with shallow sources.
Jakarta also experiences repeated strong earthquakes, some of which have been very damaging. The first documented strong earthquake occurred on January 5, 1699, which occurred during heavy rain. Apart from bringing down many buildings, the earthquake caused large landslides on Mount Gede Pangrango and Mount Salak.
Until now there is no technology that can predict when an earthquake will occur. It could be this week, this year, or next year. However, with the population growing exponentially and most of them living in the danger zone, casualties and losses can be enormous.
Thus, disaster mitigation must be integrated into our development. New buildings, especially public buildings, that violate the red disaster risk zone are no longer allowed, while existing buildings must be strengthened. The lesson from Cianjur is that the government can actually budget incentive funds for the poor to be able to retrofit houses in the red zone so that they are earthquake resistant.
In addition to mainstreaming disaster-safe infrastructure development, it is also important to invest in strengthening human resource capacity. Awareness of disaster risk must be built and the correct response when a disaster occurs must be cultivated.
Without investing in mitigation, every movement of development will again be beaten back by disaster after disaster whose intensity and frequency will increase. Of course, the economic losses would be magnified. Not to mention, the risk of loss of life, which cannot be estimated.