A Remote Sensing Analysis of the Impact of Land Cover Change on Surface Temperature in Nairobi: 1984-2010.

摘要

Changes in land use and land cover resulting from direct and indirect human actions predate written human history. They have catastrophic consequences all over the world. Due to rapid population increase expected around the world and mostly in developing countries and the need to provide housing, food and jobs coupled with inadequate knowledge and finances to cope with the consequences resulting from these changes, developing countries are bound to be seriously affected. It is therefore important to study these changes and offer recommendations on how to mitigate the effects. To achieve this, Landsat 4-5 TM (1984, 1988 and 2010 of Nairobi were digitally processed using ERDAS Imagine into 6 major classes and then analyzed for change. Surface temperatures were derived from converting Digital Numbers of each image pixel into spectral radiance and then surface temperatures. The chi-square test of the data obtained after analysis shows that the changes seen were statistically significant. The study also found that there was an overall increase in the minimum surface temperature. Built up areas had higher temperatures compared to open or forested grounds. Temperatures in built-up areas near forested areas were much lower than those further. Additional research on the relationship between land use change and temperature with emphasis on primary sourced data that can corroborate the information obtained from the remotely sensed data is recommended. Increased network of meteorological monitoring stations within Nairobi metropolitan area to provide sufficient data needed for a study of this much significance is also recommended.