The Thai Meteorological Department (TMD) warned Andaman coastal provinces to brace for potentially heavy flooding caused by tropical cyclone Amphan this week.
Somsak Khaosuwan, director-general of the TMD, said tropical cyclone Amphan, headed from the Bay of Bengal, would bring heavy rain to every Andaman coastal province from yesterday until tomorrow.
Provinces in the trail of Amphan lie in the Andaman coastal zone, running from Ranong to Satun.
Other provinces that can expect heavy downpours are Kanchanaburi, Ratchaburi, Phetchaburi, Prachuap Khiri Khan, Chumphon, Surat Thani and Nakhon Si Thammarat.
Meanwhile, the TMD yesterday announced the official arrival of the rainy season, which typically runs until the end of October.
In term of serious flooding, the TMD forecasts 60% of the South will be affected, with flash-flooding caused by mountain run-off hitting some provinces.
To deal with the wet season, the national water resource management committee chaired by deputy prime minister Prawit Wongsuwan yesterday prescribed eight water management measures to be carried out by June.
Those measures include: Forecasting flood-disaster areas; ordering farmers in 13 areas of the lower Chao Phraya River plains to rush harvesting in order to vacate land to absorb flood run-off from the North; removing and adjusting 625 structures such as bridges and roads that obstruct flood draining paths; and clearing water hyacinths -- plants which clog natural water drainage systems in 19 provinces.
Water hyacinths are also reported to play a role in flooding. According to the Interior Ministry, 128 ponds, rivers and watersheds covering 3,574 rai are clogged by these plants.
Gen Prawit also ordered the Royal Irrigation Department to prepare pumping operations to replenish drying reservoirs on the eastern seaboard.