Availability of Double-Tube Flood Mark Stream Gauge

Abstract

It is commonly accepted that absolute immunity from flood damage is not physically possible even in the distant future because of unpredictability of several natural forces which might cause unprecedented situation. Even so, with proper planning and continuous effort we can certainly look forward to an appreciable diminution of distress with an accelerated implementation of flood management measures. It is commonly accepted that the measures to mitigate flood losses need to be given the most efforts wherein flood damage assessment is the primary measure of mitigation. This has been viewed mainly as a physical method of protection from floods. To make the measures to mitigate flood losses, it first needs to effectively measure the flood influence in which flooded area and height may be the most desired measures for each of typhoon-induced flood events. On the other hand, sophisticated hydraulic modeling tools are now available to help us estimate the scale of we face from typhoon-induced flooding from a computational perspective. The flood scale in terms of area and height of typhoon-induced flood events may be the major contribution to feedback for the calibration of those sophisticated hydraulic modeling tools. Thus, a flood mark recording device is highly required to be re-examined for its use in such an increasing demand. It’s commonly accepted that a new generation of device should put economic, environmental, simple and practical considerations into its design concept. This becomes the main purpose of this study to modify an old-fashioned stream gauge to a better device, named as Double-Tube Flood Mark (DTFM) stream gauge. A number of DTFM stream gauges were installed in the low-lying plains to experience floods for recording their flood heights as a measure of flooded areas. For a comparative purpose, we set up the electronic stream gauges of the stilling well, which measured the height of a float in a hole dug alongside a stream channel. In addition, we also used other types of stream gauge include the pressure transducer, which inferred the depth of water in a stilling well by measuring the pressure of the column of water inside. The gage height values, taken at regular intervals, were recorded by depending on the technology--transmitted electronically to the dedicated databases. The verification showed a satisfactory result as expected. As a general conclusion, the field installment of a DTFM steam gauge is easy and fast. In the mean time, the cheap cost largely increases its placement at all kinds of possible locations to provide high accuracy of flood measures for the calibration of sophisticated hydraulic modeling.