Don\'t Just Modify the Rains

After heavy floods that hit Jakarta recently, we hope there will be efforts made to modify the rain so that heavy floods will not occur again. Moreover, more heavy rains are expected to fall within the next few days.

KOMPAS/RIZA FATHONI

Crew members of a CN-295 aircraft from Air Force Squadron 2, flown by pilot Capt. Gilang and co-pilot Sec. Lt. Kukuh and that took off from Halim Perdanakusuma airbase, sprinkle salt over clouds during a weather modification operation (TMC) over the Sunda Strait on Jan. 3 (3/1/2020).

The Meteorology, Climatology and Geophysics Agency (BMKG) has cooperated with the Agency for the Assessment and Application of Technology (BPPT) to reduce rainfall in Greater Jakarta or the Jabodetabek area through weather modification techniques.

Heavy rains accompanied by lightning are expected to occur in a number of areas until Thursday (1/23/2020). According to the BMKG, the rain will fall Aceh, North Sumatra, West Sumatra, Riau, Bengkulu, Jambi, Lampung, Greater Jakarta, all provinces in Java, Kalimantan, Sulawesi, Bali and Papua.

In Jakarta, it has been warned that the residents in South Jakarta and East Jakarta need to be especially vigilant. Rain engineering through weather modification technology (TMC) is not new at all. It was Vincent Joseph Schaefer, a US chemist and meteorologist, who in 1946 tried to seed clouds by sowing dry ice from an airplane, and succeeded in forming snow.

Weather modification technology has been developed rapidly and has been used in more than 60 countries for various purposes. The US, for example, used this technology to prevent rain when dropping soldiers during the Vietnam war. Thailand utilizes the technology to manage agricultural production.

KOMPAS/RIZA FATHONI

An official from the Agency for the Assessment and Application of Technology explains the route of a cloud seeding operation conducted over the Sunda Strait on Jan. 3 (3/1/2020). The mission was part of efforts to mitigate floods in Greater Jakarta. It aimed to trigger rain around the Sunda Strait and eventually reduce rainfall down to 30-40 percent in Greater Jakarta.

This technology entered Indonesia in 1977 and continues to be developed by researchers at the BPPT’s weather modification technology center. TMC can help increase, reduce and move rainfall for various purposes: preventing high rainfall that can cause flooding, preventing drought and overcoming smoke pollution.

However, keep in mind that TMC is only one way to deal with flooding. It is also very expensive. In 2013, the National Disaster Mitigation Agency (BNPB) disbursed Rp 13 billion (US$928,570) to reduce 30 percent of rain in Jakarta, the success of TMC is determined by many factors such as the condition of cloud seedlings to the direction and strength of the wind.

Therefore, local governments in flood-prone areas need to work on integrated flood management. In Jakarta, for example, according to the Geospatial Information Agency, nearly 80 percent of the area is covered with concrete and asphalt floors. As a result, water does not easily seep into the ground, which leads to high runoff and floods.

Overcoming the floods needs a comprehensive countermeasure method.

The naturalization method with absorption wells and biopores is good, but it is not the main solution because its function is more to maintain the availability of ground water. It needs reservoirs, dams and pounds to accommodate when heavy rains occur for a long time.

The naturalization method needs to be supported with a normalization method to increase the capacity and accelerate flowing water: dredging reservoirs and rivers, making a complete drainage system with polders and pumps, and if necessary creating an underground dam network. In conclusion, don\'t just modify the rain. Overcoming the floods needs a comprehensive countermeasure method.