The April image shows the same area before the monsoon season began. Both images are in false colors to make it easier to spot flooded areas. Water is navy blue to black, vegetation is bright green, clouds are cyan and bare ground is brown. Seasonal flooding is important for the freshwater swamp southeast of Tonlé Sap (the lake right of center) and for the flood plain bordering the Mekong River, on the right.
In Cambodia, seasonal rains typically fill the Mekong River and spill across the flood plain, although some years bring more water than others. According to news reports, the 2018 rainy season across Cambodia has fluctuated between flood and drought conditions, affecting the region’s agriculture.
Seasonal flooding is also important for the freshwater swamp southeast of Tonlé Sap—Cambodia’s “great lake”—and for the birds and mammals that depend on that habitat. In November 2018, the area was added to the list of Ramsar sites—wetland areas identified as having international importance.
In Thailand, flooding is visible near Bangkok within the Chao Phraya River basin. Areas to the south, in Prachuap Khiri Khan and Chumphon provinces, saw deadly flash flooding after 20 centimeters (8 inches) of rain fell on November 9.