ENSO Influence on Agricultural Drought Identified by SPEI Assessment in the Peruvian Tropical Andes, Mantaro Valley

Abstract

Agricultural drought is a serious threat for those locations where one of the most important economic activities is crop production, which occurrence has been rising due to climate change. In addition, different kinds of phenomena could exacerbate agricultural drought frequency, duration, and severity. For example, El Niño Southern Oscillation (ENSO), which mostly occurs in the tropical western and central pacific, directly affects the Peruvian territory. This study aims to understand ENSO's influence on agricultural drought in the Mantaro Valley, Peru since it is one of the most important agricultural lands in the country without clear scientific information linked to drought and ENSO events. For drought assessment using the Standardized Precipitation Evapotranspiration (SPEI) index and for ENSO events through a documentary and numerical analysis under Oceanic Niño Index (ONI) with information from several scientific recent papers to integrate information and formulate a clear event influence understanding. The results show that within Mantaro Valley along its four provinces and their six meteorological stations, 70% of agricultural drought events occurred when ENSO was present between 1990-2021. Also, the severity straight correlation percentage between both, ENSO and SPEI events is quite variable between 9.09%-70%. It is important to keep analyzing those stations with few data since it can provide a new scenario deportment and track new ENSO forecasting methods to rise adaptive capacity and guarantee national and international food security which has as an important supplier to the Mantaro Valley, Peru.