In this research item, we identify legal barriers to the experimentation and implementation of weather control measures, and, relying mainly on literature review, examine disaster countermeasure-related legislation and the theoretical trends surrounding it, to develop a method to reflect the unique conditions of weather control measures in the legal system and a mechanism to compensate for the negative effects of weather control measures. Specifically, we are: (1) clarifying the procedural and organizational issues in the legal system related to water-related disaster countermeasures, (2) examining individual water-related disaster emergency countermeasures, (3) clarifying the theoretical trends surrounding Japan's flood control policy, (4) examining the insurance system contributing to weather control, and (5) considering the national compensation system contributing to weather control. Based on these results, we aim to formulate an action plan necessary for the resolution of legal issues related to weather control.

• (1) We mainly examined (a) the legal characteristics of forecasting service licenses under the Meteorological Service Act and (b) the legal status of municipal mayors under the Water-related Disaster Countermeasures Legislation. Regarding (a), we confirmed that the licensing system still has the important intent of ensuring homogeneity and reliable implementation of meteorological services in international organizations. On the other hand, considering the broadening of (b) following successive revisions of the Flood Prevention Act in this century, and particularly the authority of municipal mayors under the Basic Act on Disaster Countermeasures, which seamlessly links social welfare and disaster prevention, it was confirmed that coordination with the authority of municipal mayors is essential even in large-scale water disaster cases where weather control is required. In addition, (c) a comparative study of the flood control plans of each prefecture is ongoing, and it has become clear that there is little description of liaison and coordination with the Technical Emergency Control Force (TEC-FORCE) of the MLIT.
• (2) We have systematically reviewed the dam operation rules for making accurate decisions in an emergency, starting from the River Act, keeping in mind that "integrated operation" has been implemented in recent years, in which downstream conditions and the conditions of other dams are considered, and that compensation is provided for losses caused by prior release operations. In doing so, we specifically confirmed that, in formulating dam operation rules/regulations, consultation procedures are to be carried out to reflect the opinions of interested parties.
• (3) We reviewed also the changes in flood control planning since the Meiji era, and recognized that, with the current reassessment of how people live and even river basin conservation from the perspective of flood risk management, there is a budding trend to consider a wide range of stakeholders in flood risk management and to comprehensively adopt flood risk management measures, and that the basis for accepting weather control as the measure is beginning to be established.
• (4) We analyzed the debate on water damage compensation clauses in fire insurance in Japan, especially on the subdivision of the uniform nationwide water damage premium rate. In the process, we clarified the unclear Risk-announcement effect of the premium rate and the unclear incentive effect of the rate to encourage disaster mitigation and proposed the view that water damage compensation in fire insurance, which has been regarded as private insurance based on the principle of private autonomy, may be approaching "public insurance".
• (5) After comprehensively listing the individual laws that establish provisions related to state compensation, we analyzed the legislative intent, mechanism, operation, etc. of the Immunization Act belonging to the intersection of state redress and loss compensation. As a result, it became clear that in the case of weather control, where a variety of damages can be expected, more difficulties can be expected in determining the causal relationship and the amount of compensation than in the case of immunization.

We are going to delve into the issues in 2. above by referring to relevant foreign legislation, judicial precedents related to water-related disasters, and the Space Activities Act including the regulatory measures in accordance with various treaties and the special provisions for indemnity contracts.