Monday, November 28, 2011

Traditional weather forecasting

Weather and climate are the processes and phenomena in the atmosphere which is one of the most important and influential factor on the various activities of life. Attention to the importance of weather and climate information emerging after natural disasters such as floods and droughts, forest fires and smoke pollution in the year - recent years more and more frequent.

Farmers often suffer losses due to crop failure due to drought or flooding. As in the District of filigree, there were approximately 13 thousand hectares of land have puso and failed harvests caused by drought and about 25 thousand hectares of crop failure due to flooding (Kompas, February 22, 2004).

On the other hand, recently there was also water reservoirs often experience shrinkage, resulting in the need for electricity and water requirements for irrigating rice fields is somewhat impeded. The issue is why this incident recurring, without any effort to study the phenomena (data) of the past. One effort to overcome this is to improve water management are highly dependent on rainfall conditions (climate).

This natural phenomenon above is difficult to be controlled and modified, except in a small scale. Climate phenomena can be optimized so that the information about opportunities in particular climatic conditions of extreme climate events (droughts and floods) and forecasting (prediction) climatic conditions that will come to know as early as possible. This effort aims to avoid or minimize the impacts of climate extremes.

Weather and climate forecasting activity has existed since the Hindu kingdom, especially in Java is a "pranata mangsa", which is often called the traditional forecasts. Farmers use a natural phenomenon signs or symptoms are often called nature in forecasting when the rainy season began, when the rainy season stops. Drought can be known by the indicators pranata mangsa. Gadung growth of stem tuber (Dioscorea hispide Dennst) as an example, an indicator of less than 50 days ahead of the rainy season began. Berbunyinya katydid (Tibicen Sp) is an indicator of the dry season is near. Society of South Sulawesi and South Lombok also has an indicator of drought. Unfortunately the use of pranata mangsa are now starting to be abandoned by farmers.

Pranata mangsa is the traditional way the Java community in predicting weather and climate has been used since, based on natural events, so this way the user must "remember" (in the Java language: titen), when to plant and harvest. Traditional prediction accuracy rate is often a bias current, along with the loss of some natural indicators due to the destruction of nature. The use of traditional methods began to be abandoned by society. Some people still use this method only as a horoscope and feel of "occult" is more dominant.

Traditional weather prediction and climate

For thousands of years they have memorized the pattern of the seasons, climate and other natural phenomena, eventually our ancestors make yearly calendar is not based on the calendar Syamsiah (AD) or Komariah calendar (Hijra / Islam) but based on the natural events such as the rainy season, dry season flowering, and the location of stars in the universe, as well as the influence of a full moon on the ebb and flow of sea water.

Javanese and Balinese society called Pranata mangsa (Sunda), Pranoto Mongso (Java) and Kerta Period (Bali). Pranata mangsa is required at the time as a benchmark when determining or will do any work. For example farm implement such as farming or fishing as a fisherman, might as well go abroad to fight. So that they can reduce risk and prevent the high production costs.

"Pranata mangsa" comes from the Javanese, "pranata" which means the procedure or procedures, while the "mangsa" means the season. In the kingdom of Mataram, Sultan Agung created by converting the Javanese calendar year calculation system is based on the circulation of false Saka sun to the earth with the circulation of the moon to the earth, as in AH, but the numbers continue to figures from Saka year. Sultan Agung successfully integrate the Islamic calendar calculation methods and Java (Hindu). Java Calendar contains pawukon and pranata mangsa.

Pawukon regarding disposition of man, the good days to trade, business,-law (wedding day), boyongan (moving house), when to do penance also days of abstinence or Walang Sanger, taliwangke, samparwangke, sarik great, dhendhan kukudan, and other so on. Used to determine the order of mangsa begin tandur (rice), harvesting rice, and planting crops.

Pranata mangsa include the division season (mangsa) and the number of days, activity (activities) farmer, traits - traits that appear (natural signs) in each of the mangsa. In a cycle of 365 days divided into twelve seasons (seasons) or in the Java language "mangsa" with a long day different, Kasa (unity): 41 days (June 23-August 2), Karo (second): 23 days (3 August-26 August), until the season Sada (twelve): 41 days (May 14-June 22) (third circle).

Picture of Pranata mangsa

Twelfth season then classified into four general season (first circle) is the dry season (88 days), harbor (first shift: 95 days), rainy (94/95 days), and mareng season (second shift: 88 days). Activities of farmers (second circle) for each mangsa rotates counter-clockwise direction starting with the first mangsa / gauze with the activity of planting crops in the fields, the second month / karo growth of crops to fall mangsa to the twelfth / Sadha with the activity of the rice harvest rice and paddy fields. In addition to the activities of farmers, pranata mangsa also provide traits or natural phenomenon that occurs for each mangsa, ie mangsa first (June 22-August 2), a natural phenomenon that happens is the wind from the northeast to the southwest, high temperature, smaller springs, autumn leaves and bare trees, grasshoppers and insects lay their eggs.

By order of mangsa farmers can plan when to start planting and reaping the rewards, such as planting rice in paddy fields can be performed on mangsa kapitu Kanem and the fall on November 10th - February 3rd. On mangsa that is characterized by winds from west to east, tight, wet weather, cold, lots of rain, rambutan, durian, mangosteen began to cook, especially in Kanem mangsa, mangsa kapitu are characterized by winds from the west, the weather is wet, cold and rainy, frequent floods, bird foraging difficult. Rice harvest is expected to fall on mangsa kasapuluh, dhestal and Sadha. Natural phenomenon that happens is the wind blowing from the southeast, and remain strong, a little rain, birds make nests, hot temperatures, bulbous plants and birds incubate aging.

Pranata mangsa include mangsa (season), dina tumapaking mangsa (days to start the season), day length, and features - features the season (candraning mangsa).

Pranata Mangsa during the year:
  1. Kasa (Kahiji) June 22/23 - 2 / 3 August. Planting season crops.
  2. Karo (Kadua) 2 / 3 August - 25/26 August. Planting season crops germinate give up both.
  3. Katiga (Katilu) in August 25/26 - 18/19 September. Season potatoes sprout, harvest crops.
  4. Kapat (Kaopat) September 18/19 - 13/14 October. Wells dry season, kapok fruit, planting bananas.
  5. Kalima (Kalima), 13/14 October - 9 / 10 November. Rainy season, the trees sprout acid, turmeric leaf, young trees.
  6. Kanem (Kagenep) 9 / 10 November - 22/23 December. Season fruits are getting old, began working the fields.
  7. Kapitu (Katujuh) December 22/23 - 3 / 4 February. Season floods, storms, landslides, began tandur.
  8. Kawolu (Kadalapan) 2 / 3 February. Season the rice to rest, many caterpillars, many of diseases.
  9. Kasonga (Kasalapan) 1 / 2 March - 26/27 March. Paddy flowering season, turaes (countryman insects) rang busy.
  10. Kadasa (Kasapuluh) March 26/27 -19/20 April. Season rice contains but still green, the birds make nests, planting crops on dry land.
  11. Desta (Kasabelas) April 19/20 - 12/13 May There is still time for crops, the birds feeding their children.
  12. Sada (Kaduabelas) 121/13 22/23 April-June. Stacking hay season, the signs of cold air in the morning.
Note: the rice cropping system still once a year (IP100)

Traditional weather prediction and climate is local, such as the order of prey only applies to people on the island of Java. Similarly with other traditional means such as Palontara to society Sulawesi, Kala on Sunda, Porhalaan in Batak, Wariga in Bali. Forecast system it is generally still used traditional dryland farmers (rainfed), the success of the plant is largely determined by rainfall. Currently, the use of the traditional way, especially some institutions prey Java community so many have forgotten and do not use anymore.
In the midst of rapid environmental degradation and land switch function, a natural phenomenon which is very useful for farmers began to trouble used as a benchmark. As an illustration of this now, just hours of 21:00 was just cock crowed, but was usually the first rooster crow about at 00.00. Consequently, although the order of prey is still used, but often biased and less adaptive, given the indicator go missing, along with environmental degradation, the impact of greenhouse gases, and global hot.

Modern Weather Prediction

Utilization of weather forecasting models with a new modern technique has accuracy about 70%, while for climate forecasting (season) is still below 50%. In addition, because it is still common and macro level, the model forecasts has yet to be utilized for areas more specific such as agriculture, fisheries, prevention of catastrophic forest fires, floods or drought. This needs to be understood the limitations of climate forecasting models in a modern way, because the models are still produced today comes from the meteorologists in the hemisphere subtropics, so we need a validation for the application in the tropics. In addition, the data required in the design of climate forecasting models are often not available and human resources to penggembangan model is still very limited.

There are limitations to the two ways mentioned above, the development efforts of the weather and climate forecasting models need to be done, especially in a modern way. Efforts include the development of models forecasting techniques, design models, and human resources. Another effort is to integrate the traditional way (local) and how modern (global) in predicting weather and climate, so that it can increase the level of accuracy.

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