It has been raining consistently for many days now and the Cagayan River has been steadily rising to flood level. I was interested to see some river level data on a Facebook page named CDRRMC but the credibility of it and the information given is questionable. If anyone knows where this data came from I would be pleased to discuss it with the person who posted it. The data on the CDRRMC page here:- https://facebook/photo.php?fbid=1411417072437379&set=a.1399133416999078.1073741841.100007072985550&type=1&theater shows the following data at an unknown location:- Date/Time, Rain Value in mm, Cumulative Rain in mm and the Water Level in cm. The data is shown for a period of 1 hour and 20 minutes during which time the Water Level is seen to steadily drop 300cm whilst the cumulative rain steadily increases by a miniscule 0.5mm. There are also 2 Rain Values each of 0.25mm. I cannot imagine any rain instrumentation that measures in such small values and, furthermore, I have no idea what those values mean. The river level dropping is unexpected given that the river catchment area is now saturated causing all additional rainfall to run directly to waterways causing an increase in water levels. It is possible that this may be related to the tide receding but as I do not know where the measurements are taken, I do not know if that location is tidal. The River Level, which should ideally be stated in metres not cm, is a little over 3.3m but, again, the datum for this level is not stated so I am unsure if this is sea level and at what time. As there are no significant drops or rapids in the last few km of the Cagayan River before it meets the sea, I would expect 3.3m above sea level to be several km inland but I really do not know where. Overall, I find the stated data to be unhelpful. If people are going to post river level data, it needs to be done in a manner that makes it easy for laypersons to understand so that it is a benefit to them. I am very familiar with river level data and I still do not find it helpful. The purpose of this post is to attempt to communicate these issues with the originator so that action can be taken to make the communication of valuable data more understandable to all. I will be sending this same post as a message on that page as I am unable to actually post on that page. In conclusion, and irrespective of what any stated data may or may not inform you, the river will be getting higher before it starts getting lower! So if you are in a low lying area you need to be paying very close attention to the river level near you. Unlike the flash flood caused by Sendong, that dumped a huge amount of water over the Cagayan River catchment area (primarily Bukidnon) in a very short time, the current weather system is similarly dumping a huge amount of water in the same area but not so quickly. I would not expect there to be a similar flash flood but all this water will be quickly finding its way to the Cagayan River causing it to rise steadily and possibly quite fast depending upon rain volume in Bukidnon. Unfortunately, it is impossible to accurately predict flooding without (i) accurate rainfall instrumentation, giving rainfall in cm per hour in specific locations and (ii) accurate river level monitoring equipment in specific locations giving timed data in metres above a known datum level. If any government or organisation is seriously concerned with public safety regarding flooding, it should sensibly install and maintain this measuring equipment and make public all data from it online in current time. AS an example, in the UK we have constant river level monitoring. So, back in my hometown where I used to do my kayak training the current river information can be seen here:- environment-agency.gov.uk/homeandleisure/floods/riverlevels/120732.aspx?stationId=6171 The Philippines has such a long way to go – but I do not see many people making any steps to get there!
Posted on: Sun, 19 Jan 2014 02:30:41 +0000
Trending Topics
Recently Viewed Topics
© 2015