Spatiotemporal Droughts Assessment in Perspective of Climate Change Scenerios and Forecasting Using Arima Models

Abstract

Abstract Drought risk has always been linked with an increase of human-induced climate change. Major drought occurrences have claimed the lives of over 10 million people in the last century, resulting in economic losses of several hundred billion US dollars on a global scale. In this study drought prone areas were identified by using Standardized Vegetation Index (SVI) where the probability of vegetation condition deviation from “normal” was calculated based on Normalized difference vegetation Index (NDVI). Alongside Man Kendall trend analysis was performed to observe the trends over a period of time. The best forecasting Autoregressive Integrated movement average (ARIMA) was also applied for the period of 2021–2070. The results of SVI indicated an increasing trend for the period of 1990–2020 in all climatic zones of Pakistan however the severity and extent were more in Zone D and E (arid and semi-arid mountainous ranges) as compared to the other climatic zones. The results of ARIMA model forecast indicates that Zone E will face extreme droughts in near future for the period of 2021–2070 followed by Zone C and D that will face moderate droughts in the given time period. Overall forecast results indicated that by the end of 21st century approximately 80 percent of the total land of Pakistan will be under subject to frequent droughts.