Remote Sensing of environmental impacts of highway construction: A case study of the Wujing Highway in Hunan Province, China

Abstract:

Extensive construction of highways has wide impacts on transportation, travel, economic growth, cultural exchange, biodiversity and species migration. However, the studies associated with the change of ecological process in spatial and temporal caused by highway construction remains rare. Here, taking the Wujing highway in Hunan Province of China as a case, we used the BDACI-RS(Before-During-After-Control-Impact-Remote-Sensing) approach to capture the spatial and temporal impacts on environment before, during, and after highway construction realistically. The results showed that:1) The land use and land cover changed drastically after the construction of highway, the forest, cropland reduced 28% and 4%, respectively, the losses in these land covers were mainly caused by the expansion of built-up area, which increased by 33% during the study period. 2) In the dynamic processes of change in overall landscape pattern of highway, the changing differences in landscape indices of various landscape types were obvious and were primarily related to land use type. 3) For the variation of normalized difference vegetation index (NDVI), normalized difference moisture index (NDM) and land surface temperature (LST) in a time series, the road-effect zone was asymmetric and variable longitudinally along the road, the impact fades away with distance from the highway. 4) The environment quality index (EQI) in 0-100m buffer showed the fastest reduction from 2014, and that in 100- 500m and 500-1000m buffer showed less reduction after the highway construction, but the EQI showed increase trend when the construction was completed. This study develops a new approach using BDACI-RS approach to assess the spatial and temporal impacts of highway construction, which provides suggestions for implementing more appropriate policies that will alleviate the impact of highway construction on the environment.

Keywords: environmental impacts, buffer analysis, BDACI-RS, environment quality index