Changes in vegetation due to volcanic activity, case study: turrialba volcano, costa rica, 2014 to 2017 eruptive period

[摘要] Since October of 2014, the Turrialba volcano began an eruptive cycle involving phreatic and phreatomagmatic eruptions. These eruptions signal an important change in behavior of this volcanic system which between 1886 and 2014 was limited to exhalative activity with isolated phreatic eruptions in 2007 and 2011. Overall, this activity involves physical and chemical changes that affect vegetation and fauna, as well as population centers. This situation is therefore of public interest. Thus, controlling and assessing these changes in order to determine possible affected areas is necessary to manage hazards. A remote sensing approach is shown in this paper using the Normalized Difference Vegetation Index (NDVI) and the Normalized Burn Ratio (NBR) to assess the change in vegetation of the surrounding areas close to the crater. This study was done for the period of 2014 to 2017 with Landsat 8 images. A noticeable change is shown for the 2014 to 2016 period, but a more significant one is shown for the 2016 to 2017 period with an increase of the percentage of affected vegetation.

[学科分类] 地质学