This QA is on Quora.
Disaster Risk Management is using the latest technologies and equipment to put out a bush-fire with air water bombers when it is first spotted or ensuring that remote water reservoirs can be be activated by management systems. The locations being decided by using satellite technology to locate critical densities likely to flare-up.
Disaster Management is evacuating the people from their homes when the bush-fire that was not put out when it first flared up was allowed to burn until it destroyed homes and lives.
Unfortunately in Australia, Southern Europe, Canada and California it is Disaster Management rather than Risk Management which has the priority with tragic consequences.