Main Participants: LYU Juan, QU Yanping, SU Zhicheng, ZHANG Qiang, WANG Dangxian, HE Hai, NI Shenhai, MA Miaomiao, ZHANG Xuejun, YANG Xiaojing, GAO Hui, JIANG Tianliang, JING Lanshu, JIANG Xiaoming, WANG Xingwang

China’s special natural geography and climate conditions make it one of the world’s most frequently affected and severely impacted countries by droughts. As the nation enters a new phase of development, there is an increased demand for more effective drought preparedness, mitigation, and risk reduction measures. There is a pressing need to improve the capacity and effectiveness of integrated technological support across the entire drought preparedness system through modern and scientific methods. In particular, addressing the weakness in understanding the mechanisms behind the large scale and extended droughts, as well as developing technologies for their monitoring, forecasting, and risk prevention, has become extremely necessary, urgent, and of significant importance.

·   The mechanisms and evolution patterns of large scale drought disasters.

·   High-precision drought monitoring and integrated assessment technologies tailored to land surface environmental characteristics.

·   Multi-scale drought forecasting and prediction technologies based on the coupling of multiple climate models and multiple land surface models

·   Dynamic assessment and preparedness technologies for drought risks based on the process of drought occurrence.

·   Having revealed the mechanisms behind large scale drought disasters in a changing environment, developed a drought sequence reconstruction technology based on natural evidence, historical records, and archaeological data, reconstructed dry/wet condition change sequences at a resolution of 100 years since the Holocene epoch and at a resolution of 20years over the past 2,000 years, and provided insights into the future patterns of drought evolution.

·   Having devised a technique for calculating meteorological drought indices for short-sequence, high-density meteorological stations based on climate values of peripheral long-sequence Gamma distribution function parameters, developed data integration technologies such as high-density ground-based observations, satellite remote sensing monitoring, and land data assimilation systems, and built an integrated drought assessment model taking into account land surface conditions.

·   Having developed a monthly rolling drought forecasting technology based on atmospheric-hydrological coupling, which integrates precipitation probability prediction, fine simulation of drought processes, grid parameters of large-scale models and other techniques, and created a quarterly drought prediction model based on circulation system anomaly and machine learning.

·   Having revealed the drought response mechanisms of different hazard-bearing bodies such as agriculture, cities and ecosystems, developed a dynamic assessment technology for drought risks based on the drought process response mechanism, and created an emergency water supply coordination model and a multi-agent, multi-target and multi-process large scale drought risk prevention and decision-making model

The research findings have been widely applied to the flood preparedness system of the Ministry of Water Resources (MWR). The integrated drought assessment technology based on the land surface conditions has been included in the MWR's catalog of advanced practical water technologies and recognized as an excellent demonstration project for smart water managment. This technology has been applied to the national integrated drought monitoring and early warning platform, as well as in similar platforms in provinces such as Hunan, Anhui, Shaanxi, and Jilin. The high-precision, multi-source data integrated drought monitoring and assessment technology has been incorporated into the National Climate Centre's service system, providing nationwide services. This technology offers scientific data for national and provincial disaster prevention and mitigation decision-making processes. Furthermore, numerous, policy consultation reports regarding typical and major drought events during 2019-2022 have been submitted to relevant authorities, such as the General Office of the CPC Central Committee, the General Office of the State Council, the Ministry of Science and Technology and the Department of Flood and Drought Disaster Prevention of the MWR. Six of these reports have been cited or included in the publications of the two General Offices and have been recognized by the government authorities.

Fig.1 Dry/wet condition changes in different regions since the Holocene epoch on different time scales

Fig.2 Meteorological drought monitoring at short-sequence, high-intensity stations based on high-intensity data standardized climate fields

Fig.3 Integrated regional drought assessment technology taking into account land surface conditions

Fig.4 Technical framework for dynamic assessment of agricultural, urban and ecological drought risks