Influence of EI Nino Southern Oscillation on Precipitation Variability in Northeast Thailand

Influence of EI Nino Southern Oscillation on Precipitation Variability in Northeast Thailand
Northeast Thailand is highly vulnerable to climate variability, often facing recurring issues of floods and droughts that affect both the quality of life and agricultural productivity. Flooding is primarily caused by the overflow of rivers and reservoirs during periods of heavy rainfall, while droughts have become increasingly frequent over the past two decades, resulting in severe water shortages that hinder crop production. Despite the region’s susceptibility to these climate extremes, few studies have explored the relationship between the El Nino Southern Oscillation (ENSO) and its impact on precipitation variability. This study seeks to fill that gap by examining the influence of ENSO on precipitation anomaly (PPTA) in Northeast Thailand, using 30 years of data (1993-2022) from 27 weather stations. Employing Pearson correlation analysis and wavelet coherence, the research uncovers that La Nina events have a stronger influence on precipitation anomaly, with a notable increase in rainfall during La Nina phases. Conversely, El Nino phases are linked to reduced rainfall, exacerbating drought conditions. A key finding is the 4–5-month lag between ENSO events and their impact on precipitation, with the ENSO’s influence fluctuating over time, especially at intervals of 2-7 years. Understanding these dynamics is crucial for better preparedness and management of water resources and agriculture in the region.
𝗞𝗘𝗬 𝗙𝗜𝗡𝗗𝗜𝗡𝗚𝗦

1. The La Nina phenomenon is significantly related to increased rainfall in northeastern Thailand, particularly during periods of strong La Nina events.
2. There is a delay of about 4–5 months between the El Nino phenomenon and its impact on rainfall in northeastern Thailand.
3. The influence of El Nino on rainfall varies over time, especially in cycles of 2–7 years, as indicated by wavelet coherence analysis.