@InProceedings{ZeriCuCuCuDoGaGu:2022:CoDrPr,
               author = "Zeri, Marcelo and Cunha, Ana Paula and Cunningham, Christopher A. 
                         and Cunha Zeri, Gisleine da Silva and Donato, Keylla and Galdos, 
                         Marcelo Valadares and Guedes, M{\'a}rcia R. G.",
          affiliation = "{Centro Nacional de Monitoramento e Alertas de Desastres Naturais 
                         (CEMADEN) } and {Centro Nacional de Monitoramento e Alertas de 
                         Desastres Naturais (CEMADEN) } and {Centro Nacional de 
                         Monitoramento e Alertas de Desastres Naturais (CEMADEN) } and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universidade Federal de S{\~a}o Paulo (UNIFESP)} and {Rothamsted 
                         Research} and {Centro Nacional de Monitoramento e Alertas de 
                         Desastres Naturais (CEMADEN) }",
                title = "Communicating Drought Propagation in Brazil Using in-situ and 
                         Remote Sensing Data",
                 year = "2022",
         organization = "AGU Fall Meeting",
            publisher = "AGU",
             abstract = "Drought is a climate hazard which evolves into a natural disaster 
                         depending on its intensity, duration and vulnerability of regions 
                         and populations. The onset of drought is caused by negative 
                         rainfall anomalies in time scales of several months 
                         (meteorological drought). Depending on the duration and intensity 
                         of rainfall anomalies, meteorological drought evolves into 
                         agricultural drought, when soil moisture is reduced, affecting 
                         plant development and crop yields over rainfed agriculture. The 
                         impacts of agricultural drought can be inferred using remote 
                         sensing vegetation indices such as the Normalized Difference 
                         Vegetation Index (NDVI) or the Fraction of Absorbed 
                         Photosynthetically Active Radiation (FAPAR), among others. The 
                         combination of rainfall anomalies, soil moisture and vegetation 
                         status can be used to assess the intensity and propagation of 
                         drought. In this work, a drought propagation scheme is presented. 
                         The Drought Propagation Index (DPI) discussed here is based on the 
                         European Drought Observatorys Combined Drought Index (CDI), which 
                         has three stages of drought and two for recovery. While CDI makes 
                         use of soil moisture from a land surface model and FAPAR, DPI is 
                         based on satellite data of soil moisture and vegetation health. 
                         DPIs first stage of drought is warning, related to values of the 
                         Standardized Precipitation Index (SPI) on 1 and 3-months scale; 
                         SPI is calculated using a long-term database of precipitation 
                         records over Brazil. The second stage is observation, when both 
                         SPI and Root Zone Soil Moisture percentile (RZSM) are considered; 
                         RZSM is derived from NASA's Gravity Recovery and Climate 
                         Experiment (GRACE). The third stage of drought is alert, based on 
                         values of SPI and Vegetation Health Index (VHI), derived from 
                         NOAAs satellites (National Oceanic and Atmospheric 
                         Administration). The first level of recovery is based on critical 
                         values of VHI associated with positive values of SPI in the 
                         current month. Finally, the full recovery status is based on 
                         positive values of SPI and normal values of VHI. Preliminary 
                         results show that DPI correctly characterized the propagation of 
                         drought over different biomes in Brazil, especially from 2012 to 
                         2016 over the Brazilian Northeast. Lags between observation and 
                         alert stages differed between biomes due to plants different 
                         resilience to water stress.",
  conference-location = "Chicago, IL",
      conference-year = "12-16 Dec. 2022",
        urlaccessdate = "28 abr. 2024"
}