One of the negative influence of climate change is the occurrence of large-scale disasters. All over the world, climate change-related disasters such as torrential rains, heavy snowfalls, floods, and landslides are occurring. For example, the number of torrential rains has increased 1.4 times in the last ten years and is increasing dramatically. In the case of a large-scale disaster, communication and power supply are not available; Typhoon No. 15 in 2019 caused a 20-day power outage in Chiba prefecture, Japan. The power outage also causes the carrier communication network inoperable, leading to a secondary disaster that prevented smooth evacuation instructions. A system that can stably collect weather data and provide evacuation instructions at public facilities in the case of a disaster would greatly contribute to disaster prevention. The authors developed a general-purpose communication module for LPWA-based communication and designed a protocol to build an autonomous mesh communication network. This paper describes the implementation of this developed system for a ground monitoring system using soil sensors and reports on the proof experiment.