# OneMap Drought Monitoring Analysis Based on Statistical Models
## 4 Conclusions  
As climate change exacerbates extreme events such as drought, there is a growing need for an integrated drought index combining meteorological, agricultural, and hydrological drought indices. To this end, in this study, a OneMap drought index based on a multivariate statistical model was developed. After evaluating the accuracy of the corrected OneMap drought index based on the self-organizing migrating algorithm optimization technique, it was found that the applicability of the OneMap drought index and its ability to regenerate drought were excellent for ground and satellite data. Despite several efforts to cope with drought as a crisis type, some political and practical difficulties remain with regards to drought management. In particular, although a joint task force (TF) representing related ministries was organized to respond jointly to crises and develop a cooperative system, the concerned ministries and individual agencies are still judging the crisis stage based on their own standards and implementing separate measures. Since multiple ministries and agencies are involved, the subjectivity of local governments that should play a primary role in disaster management and dependence on the central government is often mentioned as an underlying issue. Therefore, the Ministry of Public Administration and Security, which operates a joint TF with related ministries, should issue an integrated forecast and warning for administrative districts and operate a well-organized response process, such as preliminary preparation and emergency measures, in line with these integrated forecasts and warnings, coordinating and directing related ministries and local governments. However, since it is difficult to intuitively understand a drought situation because various maps are provided depending on the division of ministry-specific business fields, a new framework is required to integrate the information available and assess the situation comprehensively. The OneMap drought index developed in this study can provide reasonable and scientific drought information for use in forecasts and warnings. Although the actual drought forecast and warning operation information and the drought monitoring information calculated using the drought index exhibited similar spatial and temporal changes, there was a significant difference in the degree of drought stage determined. To tackle these issues, weight correction of forecast and warning information and spatial accuracy for the long-term drought monitoring assessment should be improved. Furthermore, for the utilization of integrated drought forecasting and warning technology, the integrated-drought stage should be based on the integrated drought forecast and warning issuance of the Ministry of Public Administration and Security, except when the forecast and warning stage is determined at the \"Situation Judgment Meeting (Crisis Evaluation Meeting)\", in accordance with the drought disaster crisis management standard manual. If tangible damage can be minimized by immediately operating existing emergency water supply measures and water supply stabilization measures, it may be possible to apply a \"caution\" level of adjustment mechanism and public communication method. When joint measures of related ministries are implemented, it is important to systematically establish step-by-step measures of related organizations (local governments, each ministry) for \"concerted action\". It is also necessary to calibrate the step-by-step drought response systems of other institutions to suit the action plan for each stage of integrated drought. Conceptualization, Resources, Formal analysis, Writing--original draft, J.-S.K. and S.-Y.P. ; Conceptualization, Methodology, Writing--review & editing, J.C. and J.-H.L. ; Methodology, Writing--review & editing, D.W. and H.-C.Y. All authors have read and agreed to the published version of the manuscript. We appreciate the support of the State Key Laboratory of Water Resources and Hydropower Engineering Science, at Wuhan University.