Diurnally-micrometeorological responses to different vegetation cover in a highly-deforested tropical area in Nan, Northern Thailand, during the early Asian summer monsoon

Abstract

This work aims to investigate diurnal-micrometeorological patterns for different vegetation covers; a hill evergreen forest, an integrated cropland, and a monoculture cropland in Nan, Northern Thailand. Biogeophysical effects of deforestation and cropland expansion on the local meteorological patterns are discussed. Results obtained from the analysis of satellite imagery suggest significant forest conversions from year 2001 to 2011/12. Field observations were taken during the early Asian summer monsoon season. The results indicate that the forest exhibited the highest day-night temperature difference, in which latent heat flux and surface roughness, in connection with wind speed, play important roles. Different cultivation practices (monoculture vs. integrated) clearly affected daytime sensible heat flux, resulting in colder nights at the monoculture cropland. Based on the findings in this study, an overall warming trend, especially at night, and higher short-term rainfall are likely to be associated with deforestation and cropland expansions.

Keywords

• tropical climate
• deforestation
• cropland expansion
• land cover
• meteorology