Quantifying the Resilience of Vegetation and Soil Moisture During Dry Spells Using Satellite Remote Sensing

Abstract:

Manifestations of the constantly intensifying hydrological cycle differ substantially among the various regions of the globe. The spatial distribution, magnitude, as well as timing of precipitation events are being altered globally, resulting in significant biotic implications. Motivated by the pressing need to understand how the different components of natural habitats behave under extreme hydrologic conditions, we quantitatively assessed the response of two major hydrological attributes, namely soil moisture (SM) and vegetation water content (VWC) to rainfall deficiencies. More specifically, using multi-year microwave remote sensing observations, we quantified the changes of VWC and SM during dry spells, as well as their resilience during those periods. Differences among vegetation types, as well as the effect of the duration of the dry spells were also investigated. Finally, spatial patterns and characteristics of the response of VWC and SM to sustained precipitation deficits were identified across the study area, and within each of the major vegetation regimes of the region. This hydro-ecological study provides critical insight into the behavior of two crucial components of the natural ecosystems during prolonged dry periods, which in turn yields useful information on the role of the hydrologic regimes in determining biotic composition and patterns, as well as the regional micro-climatology. Furthermore, this information can significantly contribute towards the achievement of more efficient and precise farming practices at the local level, resulting in the increase of food security and societal well-being.