Projected Spatiotemporal Dynamics of Drought under Global Warming in Central Asia

Zhang Zhang,Ma Ma,Zhao Zhao,Li Li,Han Han,Brindha Brindha

doi:10.3390/su11164421

Abstract

Drought, one of the most common natural disasters that have the greatest impact on human social life, has been extremely challenging to accurately assess and predict. With global warming, it has become more important to make accurate drought predictions and assessments. In this study, based on climate model data provided by the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP), we used the Palmer Drought Severity Index (PDSI) to analyze and project drought characteristics and their trends under two global warming scenarios—1.5 °C and 2.0 °C—in Central Asia. The results showed a marked decline in the PDSI in Central Asia under the influence of global warming, indicating that the drought situation in Central Asia would further worsen under both warming scenarios. Under the 1.5 °C warming scenario, the PDSI in Central Asia decreased first and then increased, and the change time was around 2080, while the PDSI values showed a continuous decline after 2025 in the 2.0 °C warming scenario. Under the two warming scenarios, the spatial characteristics of dry and wet areas in Central Asia are projected to change significantly in the future. In the 1.5 °C warming scenario, the frequency of drought and the proportion of arid areas in Central Asia were significantly higher than those under the 2.0 °C warming scenario. Using the Thornthwaite (TH) formula to calculate the PDSI produced an overestimation of drought, and the Penman–Monteith (PM) formula is therefore recommended to calculate the index.

Highlights

Drought is a natural phenomenon that deteriorates the affected region’s ecological environment due to long-term deficits in precipitation and subsequent shortages in water supply [1,2]
The frequency of drought in most parts of Turkmenistan was between 20% and 40%, with certain regions in southern Turkmenistan exhibiting values greater than 40% and certain areas even exceeding 60%, which represented a high frequency in Central Asia
In the context of global warming, the relationship between short-wave radiation and potential evapotranspiration estimated using the Thornthwaite formula based on a certain latitude and temperature will change, which will lead to an error in the calculation of the potential future evapotranspiration [65]

Summary

Introduction

Drought is a natural phenomenon that deteriorates the affected region’s ecological environment due to long-term deficits in precipitation and subsequent shortages in water supply [1,2]. Drought affects the growth of crops and influences global food prices, and contributes to political unrest [3]. Drought poses a serious threat to social and economic development: it caused the loss of over $200 billion between 1980 and 2014 [7] and has become the most serious natural disaster threatening human life and property [4]. According to the “Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC)” [8], global warming will have an extremely negative impact on human and natural ecosystems. It is necessary to predict and assess the risk of drought that may occur in the event of future global warming in order to adopt measures to reduce the damage caused to people’s lives and livelihoods

Methods

Findings

Discussion

Conclusion