Satellite remote sensing of land use changes in and around San Jose, CostaRica

Using AVHRR imagery, the effects urbanization on surface microclimate durin g a 7-year period in San Jose Costa Rica and its surroundings are expressed as changes in fractional vegetation cover scaled surface temperature, surf ace wetness, and surface evapotranspiration. Scatterplots of fractional veg etation cover versus scaled surface temperature depict elongated clusters a long which pixels undergoing urbanization migrate toward lower vegetation c over higher surface temperature, less evapotranspiration, and generally dry er surfaces. This urbanization occurred largely in response to pasture and low-density urban areas changing to high-density urban areas. The evolution in surface microclimate accompanying these changes differs considerably fo r the various types of urban surfaces, but ultimately the pixels become vir tually indistinguishable from one another as urbanization becomes advanced. On the other hand deforestation, which occurred as trees were replaced by crops, did not result in large changes in surface temperature and wetness a nd may have produced increases with time in evapotranspiration. (C) Elsevie r Science Inc., 1999.