Assessments of Drought Impacts on Food Security using Satellite-Based Products in Cambodia

Drought is characterized by the lack of water sources caused by the early end or delays in the expected seasonal rainfall and has affected humans, livestock, the agricultural sector, and, in particular, and food security. In recent years, drought indices are quantitative indicators that describe drought levels by assimilating data into a single numerical value from one or more variables, such as precipitation, runoff, and evapotranspiration. Previous studies have produced detailed reports on indices used to track drought impacts, and several drought indices have been established from climate and satellite data. The agricultural drought was selected to use in this study due to the available local data and lower agricultural production. The main objective of this study is to assess the impact of drought frequency and severity in Cambodia using different drought indices (Standardized Precipitation Index (SPI), and the Normalized Difference Vegetation Index (NDVI)). It represents abnormal wetness and dryness with user-defined time duration by comparing precipitation departure from the cumulative probability distribution of precipitation over the same region and period. It used rainfall data from meteorological stations from 1985-2017. It is calculated for 1 to 12-month timescales. NDVI uses the Advanced Very High-Resolution Radiometer (AVHRR) reflected red and near-infrared channels to calculate if the vegetation is healthy, or unhealthy and sparse. NDVI data have been collected for a period of 33 years (1985-2017) from the National Oceanic and Atmospheric Administration’s (NOAA’s).