Mapping the Global-Scale Maize Drought Risk Under Climate Change Based on the GEPIC-Vulnerability-Risk Model

Drought is projected to become more frequent and increasingly severe under climate change in many agriculturally important areas. However, few studies have assessed and mapped the future global crop drought risk-defined as the occurrence probability and likelihood of yield losses from drought-at high resolution. With support of the GEPIC-Vulnerability-Risk model, we propose an analytical framework to quantify and map the future global-scale maize drought risk at a 0.5 degrees resolution. In this framework, the model can be calibrated and validated using datasets from in situ observations (for example, yield statistics, losses caused by drought) and the literature. Water stress and drought risk under climate change can then be simulated. To evaluate the applicability of the framework, a global-scale assessment of maize drought risk under 1.5 degrees C warming was conducted. At 1.5 degrees C warming, the maize drought risk is projected to be regionally variable (high in the midlatitudes and low in the tropics and subtropics), with only a minor negative (- 0.93%) impact on global maize yield. The results are consistent with previous studies of drought impacts on maize yield of major agricultural countries around the world. Therefore, the framework can act as a practical tool for global-scale, future-oriented crop drought risk assessment, and the results provide theoretical support for adaptive planning strategies for drought.