By Wezi Tjaronda WINDHOEK Although authorities would like to predict extreme events in order to mitigate their impacts, natural hazards will always be difficult to predict because of the many elements that influence each other, a geophysician has said. Associate Professor in Statistical Geophysics at the University of Kiel Dr Christian Goltz said yesterday that predictions of such events were impossible because they happen rarely and are irregular. He was speaking yesterday during a talk on Natural Hazards, a Modern Physics Perspective that covered extreme phenomena with a generic reference to floods, droughts, market crashes, tsunamis and earthquakes. Goltz said natural hazards were complex and complicated and would remain as such because of the many factors that are involved. He said even if people knew about them, they did not understand the rules. He said people in most cases knew how rain fell but did not understand how the rain would turn into a big disaster such as floods. "How can you predict the disaster if you don't understand how it happens?" he wondered, adding that the hazards happened on an irregular basis and with no periodicity. He said that most events happened with a smaller magnitude and rarely turned into bigger events, and until people are able to observe the system, there is no way they could predict such events. He said when small earthquakes happen every year, bigger ones were superimposed and happened randomly on top of what was already taking place. "We have rains all the time but sometimes we also have extreme events such as floods," he said. In this case, it is likely that if there is big natural hazard, it is likely to repeat itself because such events were clustered. "There is tendency in nature that when a big event happens, it is more likely another one will happen soon because driving forces continue to work," he added. The best thing authorities could do in case of floods in northern Namibia was to mitigate the impacts, by resettling people that live close to the oshanas and build drainage networks and dams. Namibia Equity Brokers (Pty) Ltd organised the talk because market crashes follow the same patterns of natural hazards. Goltz said financial markets crashed after a very long time but when they happen a whole economy can be blown away. Market crashes, disease outbreaks and natural hazards, said he, follow the same pattern.
2008-04-22 00:00:00 10 years ago