ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Friday, March 14, 1997 TAG: 9703140033
SECTION: EDITORIAL PAGE: A-10 EDITION: METRO
The marriage of meteorology and hydrology is producing information that could make flood warnings more timely.
TIMELY warning of floods can help save lives and property. Just ask Western Virginians. They can recall the devastation of inundations where there were no such alerts: the unpredicted big flood of 1985, or episodes of localized flash flooding that in minutes turn mountain creeks into raging torrents.
Forecasters can't predict what they can't know. Many times - the recent Ohio River floods are an example - they're aware well in advance that a big-league weathermaker is on the way. What's lacking, however, are the data enabling them to pinpoint where and to what extent flooding might occur. Generally, this can't be done until 24 hours or less before the event.
But earlier warnings may be on the way. The reason: The heretofore separate disciplines of meteorology, which studies the behavior of water in the atmosphere, and hydrology, which studies the behavior of water on the ground, are being cross-pollinated by computer modeling.
It's no secret, of course, that water in the atmosphere affects water on the ground: A lot of rain tends to bring on flooding.
But in the aftermath of the record Mississippi River floods in 1993, researchers discovered that the process works both ways. A lot of water on the ground also affects how much more it will rain.
Since then, reports the Christian Science Monitor, "hydrometeorologists" have been busy using computers to combine hydrological data about stream flow - the impact of soil type, level of urbanization in the watershed, and so forth - and meteorological data about rainfall and snow melt.
The more comprehensive such data, the more accurate can be the formulas for the effect on water flow of various rainfall scenarios. The more accurate the formulas, the earlier and more precise can be the warnings of flooding.
Perhaps you can't do anything about the weather. But humans can use their wits to keep learning more about the weather, so they can take steps to soften the impact when nature turns harsh.
LENGTH: Short : 42 linesby CNB