Layanan Informasi

Lapan @ Media

Analysis of Flood and Landslide in Kintamani - Bali
20 Feb 2017 • Read : 285 x ,

Flooding followed by landslide that occurred in Songan, Sukawana, and Awan Villages, Kintamani, Bangli, Bali Province (115.25 - 115.50 lon and 8:25 to 8:50 lat) on Thursday, February 9, 2017 at around 23:00 Central Indonesia Time (WITA) caused 12 people died due to landslides buried (BNPB). & Nbsp; The disaster is known to occur as a result of continuous heavy rain since Wednesday, February 8, 2017 and added effect to sloping terrain with many settlements underneath (BBC).

After said disaster, the Centre of Atmospheric Science and Technology (PSTA) LAPAN analyzes atmospheric conditions at the scene before and during disasters. Global climatic conditions observations (both IOD and ENSO) showed normal conditions. Even Madden Julian Oscillation (MJO) is currently in phase 7 and located around the Indian Ocean. Means that the floods and landslides happened was not due to global atmospheric conditions influence, but regional (local) influence.

Figure 1. Water Vapor.

The high rainfall in Kintamani allegedly due to low pressure in the northwest and north of Australia, is characterized by the formation of a tropical storm over northwest Australia on Wednesday, February 8, 2017 at 03.00 am (WITA). The low-pressure has the potential to draw in air mass at Indian Ocean region and believed to be passing through Java and Bali areas, which can lead to potential growth of lot of clouds. Thus, although the area of Bali at the time of disaster is not an area of convergence, the growth of convective clouds is pretty much happening due to mass influx of moisture. (Figure 1).

Figure 2. Himawari-8 Satellite Visualisation (February 9, 2017).

Black Body Temperature (TBB) data visualization of Himawari-8 satellite (Figure 2) on Thursday, February 9, 2017, shows convective clouds began to cover the area of northern Bali (Kintamani) at 21:20 pm with a distribution shown in purple above Bali. The convective cloud growth continues to cover the entire area of Bali at 23:00 pm. This indicates that Bali experience rain with very high intensity for 2 hours.

Figure 3. Rain Intensity (mm/hour) in Kintamani Bali, February 7 – 11, 2017 at 00:00 – 23:59 Z

(February 7, 2017 at 08:00 WITA – February 11, 2017 at 07:59 WITA) from GPM 3IMERGHHL v03 data.

Similar result is demonstrated by the observation of rainfall intensity every 1 hour of Global Precipitation Measurement (GPM) satellite data on 07-11 February 2017 (Figure 3). It is seen that on Thursday, February 9, 2017 from 12:00 UTC (20:00 pm), in the vicinity Kintamani is recorded light rain intensity category (2.6 to 4.6 mm / h) until 13:00 UTC ( 21:00). The intensity of rain was & nbsp; increased to 5.3 mm / h (normal rainfall category) on half-hour later, and continued to increase so it turns into a very dense category (intensity of 22.9 mm / hour; 26.5 mm / hr and 21, 9 mm / h), each occurred at 14:00 UTC (22:00 local time), 14:30 UTC (22:30 pm) and 15:00 UTC (23:00 pm).

Figure 4. Rain intensity (mm/jam) in Kintamani Bali 7 – 11 February 2017 at 00:00 – 23:59 Z

(7 February 2017 at 08:00 WITA - 11 February 2017 at 07:59 WITA) from GPM 3IMERGHHL v03 data.

Observations of rainfall also performed on Global Satellite Mapping of Precipitation (GSMAP) data. GSMAP daily rainfall observations data also showed similar result. The intensity of rainfall in Kintamani on February 9, 2017 is fairly high (& gt; 110 mm / day). Based on this, it can be concluded that the floods with landslides occurring in Kintamani caused by the high intensity of rainfall in the region, supported by the low pressure in the Northwest and Northern Australia which potentially attract air mass in the Indian Ocean region, causing many growing convective clouds producing rain on it. 

Written by: Dissemination Team of Center of Atmopheric Science and Technology (PSTA) - LAPAN

Cover image source: Aktual

Related Posts
No Related posts

Kontak kami :
Jl. Dr. Djunjunan No. 133 Bandung 40173 Telepon (022) 6012602, 6037445 Fax. (022) 6014998, 6037443