Detection of “guerrilla downpours” by X-band MP radar
ENTRY DATE: 25.12.2014 | LAST UPDATE: 25.12.2014
CATEGORIES:
- Disaster Prevention
- Flood disaster (Soft measures)
TECHNOLOGIES MATURITY:
Has been introduced in Japan and United States
Technology Owners:
Ministry of Land, Infrastructure, Transport and Tourism, Water and Disaster Management Bureau
Needs Address
The need to reduce flood damage and water-related accidents from localized heavy rain and extremely intense rain events (so-called "guerrilla downpours") that occur in urban areas where population and public transportation systems are concentrated.
Adaptation effects
The promotion of evacuation and self-preservation actions, by providing precipitation observation data using X-band MP radar with high temporal and spatial resolution.
Overview and Features
The technology can be used to predict increases in flood damage due to guerilla downpours in small and medium-sized rivers flowing through cities. Such heavy rainfalls feature a large volume of rain falling in a very short time, resulting in potential for flood damage and water accidents occurring, when river levels can rise in a matter of minutes. For disaster mitigation, it is useful to predict heavy rains as accurately and quickly as possible, and to provide information in real time. Detection by X-band MP radar is proposed as a means of doing so. An example in Japan is provided below.
Energy source
Electricity is required to operate the radar system.
Ease of maintenance
Regular inspection and calibration is necessary.
Technology performance
X-band MP radar is a type of weather observation radar that simultaneously transmits and receives horizontal and vertical polarized waves, and can estimate rainfall intensity (even light rain) better than other radar wavelengths.
Considerations
X-band MP radar signals can be weakened by rain and rain clouds, hindering detection performance. The solution is to create a radar network to cover areas more completely in the event observation from one unit drops.
Co-benefit, suitability for developing countries
This technology is being introduced in Japan. Building a network of radar equipment is expensive, but this technology has promise, as it permits high-resolution rainfall detection and disaster prediction.
Information Resources
- Flood Risk Management Approaches As Being Practiced in Japan, Netherlands, United Kingdom, and United States、IER Report 2011.
- XRAIN X-Band MP Radar Rainfall Information:
http://www.river.go.jp/xbandradar/