Assessment of urbanization impacts in Tegucigalpa urban greenness via normalized difference vegetation index

Abstract

Urban vegetation is essential to develop sustainable, habitable, and healthy cities. Urbanization in large cities may be detrimental to urban vegetation when urban planning is scarce. Tegucigalpa, Honduras's capital city, had an atypical 8-year period of intensive urbanization, which may have modified urban vegetation. Excessive tree removal and reduced urban greenness reports became abundant in local media. This paper aimed to determine if urbanization indeed modified Tegucigalpa's urban greenness to a detrimental level. A Landsat-8 imagery survey was conducted to assess Tegucigalpa's urban vegetation dynamics via the normalized difference vegetation index (NDVI) for the 2013–2021 dry and rainy seasons. The results revealed a stable trend for the dry seasons NDVI remaining in constant proximity to 0.11 while increasing steadily to around 0.17 during the rainy seasons due to precipitation watering vegetation. Negligible fluctuations (<0.1) occurred throughout the study period, suggesting urbanization most likely did not shrink urban vegetation to the extreme extent stated by Honduran media. The NDVI provided a scientific basis for assessing Tegucigalpa's vegetation changes, preventing potential environmental conflicts. Although most researchers have reported that urbanization decreases NDVI in large cities, others found that urbanization does not always produce vegetation degradation and suggested that climatic variables are significant factors determining vegetation growth. Nevertheless, the steadily low NDVI in Tegucigalpa suggests the absence of sustainable urban planning to increase urban vegetation. Urban trees are central to sustainable urban planning; therefore, afforestation policies should be considered by Tegucigalpa's government and policymakers.