Open AccessUrban Heat Island in Kathmandu, Nepal: Evaluating Relationship between NDVI and LST from 2000 to 2018
Author(s) -
Bijesh Mishra,
Jeremy Sandifer,
Buddhi Raj Gyawali
Publication year - 2019
Publication title -
international journal of environment
Language(s) - English
Resource type - Journals
ISSN - 2091-2854
DOI - 10.3126/ije.v8i1.22546
Subject(s) - normalized difference vegetation index , urban heat island , environmental science , land cover , vegetation (pathology) , physical geography , urban climate , remote sensing , advanced very high resolution radiometer , land use , geography , urbanization , meteorology , climate change , satellite , geology , medicine , oceanography , pathology , aerospace engineering , engineering , civil engineering , economic growth , economics
The term “urban heat island” (UHI) describes increased surface and atmospheric temperatures in an urban core relative to surrounding non-urbanized areas. Although the phenomenon has been studied to a great extent throughout the world, it is less understood for Kathmandu, Nepal. This study used the Moderate Resolution Imaging Spectro-radiometer (MODIS) 8-day product (MOD11A2) to evaluate land surface temperatures (LSTs), the MODIS-derived Normalized Difference Vegetation Index (NDVI) 16-day product (MOD13Q1) to quantify land surface characteristics, and the MODIS annual land cover classification product (MCD12Q1) to identify major land cover classes. We evaluated the spatial correlation between significant changes in LSTs and NDVI between 2000–2018. Overall, urban (permanently developed areas) LSTs were consistently greater than non-urban (forests and dynamic agriculture lands) LSTs; however, the rate of increase in temperature was higher outside the central Kathmandu developed urban area. Furthermore, significant changes in NDVI values over time were more widespread and not always spatially coincident with significant changes in LST values, particularly for forested land areas. These results provide insight into systematic planning of open and green areas, construction of new infrastructure in peripheral areas, and highlight the challenges in applying traditional UHI conceptual models to rapidly developing urban areas such as Kathmandu, Nepal.