Laserfiche WebLink
<br />. i <br /> <br />. I <br /> <br />. <br /> <br />. I <br /> <br />from the NWS. Most of the required elements can be purchased "off the <br /> <br /> <br />shelf." The NWS has installed a few flash flood alarm gage systems in <br /> <br /> <br />connection with IFLOWS to test their performance and effectiveness. Figure 11 <br /> <br /> <br />is a schematic illustration of a typical flash flood alarm system. <br /> <br />A more sophisticated gage, consisting of a radio/electronics signaling package <br /> <br />and antenna in a self-contained enclosure, has been developed by a private <br /> <br />firm. A water-level sensor pipe uses a pressure sensor to provide a single- <br /> <br />level alerting. When an alarm is triggered at the remote station, an <br /> <br />identifier signal is sent to the control station. <br /> <br />The following table lists the advantages and disadvantages of flash flood <br />alarm gages. <br />Flash Flood Alarm Gages <br /> <br />Advantages <br /> <br />o Relatively inexpensive <br /> <br />o Simple operation <br /> <br />o Provide instant audio/ <br /> <br />visual alarm <br /> <br />Disadvantages <br /> <br />o Warn of flood condition <br /> <br />only, no indication of <br /> <br />magnitude <br /> <br />o Beeper-activated warning <br /> <br />reaches key people <br /> <br />o Lead time usually short <br /> <br />o Usually require community <br /> <br />expertise in electronics <br /> <br />41 <br />