Probabilistic evaluation of vegetation drought likelihood and its implications to resilience across India

Abstract

Vegetation distribution and growth are significantly affected by changing climate conditions. Understanding the response of vegetation to hydroclimatic disturbances such as droughts is crucial in context of climate change. The sensitivity of terrestrial ecosystem to drought is difficult to measure because of problems related to drought quantification, variable response of vegetation types and changing climate-vegetation dynamics. Since, India is hugely dependent on its vegetation and cropland, identifying the impact of droughts on vegetation is essential. In this study, we estimate the likelihood of vegetation droughts across India in changing scenarios of temperature, precipitation and soil moisture content. We also study the resilience of vegetation cover to disturbances induced by a dry condition. From the investigation, it is observed that at least half the area of 16 out of 24 major river basins is facing high chances of vegetation droughts due to lowered soil moisture levels. The croplands are most likely to be affected by drought, which is of paramount concern for country's food security. Further investigation suggests that at least one-third area of 18 river basins is non-resilient to vegetation droughts. Moreover, >50% of each vegetation type is non-resilient, which points out the fragility of country's terrestrial ecosystems. This study facilitates the understanding of vegetation drought hotspot regions, factors risking the terrestrial ecosystem and their ability to withstand such conditions. These findings provide useful insights for policy makers to develop effective strategies for vegetation drought mitigation and sustainable ecosystem management. © 2019 Elsevier B.V.