Many farmers have experienced severe drought and heat wave conditions this year. The social and economic effects of drought are nothing new. In fact, since Korea’s Joseon Dynasty (1392-1910) was agrarian and relied heavily on rice crops, the country was particularly sensitive to both drought and torrential rain, and made great efforts to minimize damage.
Professor Jonghoon Kam (Environmental Science and Engineering) at POSTECH and Chang-Kyun Park, a researcher at the Institute of Environment and Energy Technology, developed a self-calibrated Effective Dehydration Indicator (scEDI) through joint research. This new index enabled them to explore 250 years of drought data, from the late Joseon dynasty to the present, and to compare and analyze rainfall records.
EDI, a typical drought severity determination tool, is designed to monitor and characterize drought conditions on a daily scale. The index uses the last 30 years of daily rainfall records. In other words, the reference period determines the EDI values, which makes it difficult to compare the values over a long recording period.
Professor Cam’s research team is the first to propose a self-calibrated EDI and use it to analyze the daily precipitation observed in Seoul from 1777 to 2020. The scEDI that automatically calibrates the behavior of the indicator over time can maintain consistency in comparison by assessing droughts of the same intensity and frequency.
It is worth mentioning that this research used historical records of Annals of the Joseon Dynasty (Joseon Wangju Seloc) and daily precipitation data measured with the Joseon rain gauge (chukwookee). The study showed the value of the unprecedentedly accurate records left by the Koreans in that period.
A comparison of records from the Joseon era and today’s online search results suggests that our ancestors were more sensitive to drought. Most drought damage records and highs of public interest in droughts coincide when droughts are moderate (-1.4 scEDI) and severe (-2.0), respectively.
The results indicate that the effects of socio-economic drought depend on the socio-economic structure. As a valuable tool for quantitative assessment of drought effects, scEDI has the potential to identify droughts with social consequences in advance.
Professor Cam explained: “The scEDI proposed in this study features an automatic calibration corresponding to the climate of the reference period, enabling temporal detection and comparison of droughts (in terms of intensity, duration and intensity). This points to a new research methodology for social networking. Droughts, which have been difficult to Its study is compared to other drought-related categories: meteorological, agricultural, and hydrological.” “Understanding the social impacts of drought and how to address them will provide the Korean public with action plans to prepare for future droughts in advance,” he added.
Recently Posted in Hydrology JournalThe study was supported by the National Research Foundation of Korea (Sejong Science Fellowship Program and Mid-Career Scholars Program) and the National Disaster Management Research Institute (Cooperative Research Method and National Disaster Safety Management Technology).
Materials Introduction of Pohang University of Science and Technology (POSTECH). Note: Content can be modified according to style and length.