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The U.S. National Weather Service records weather related fatalities, defined by the particular weather condition. In 2013, the NWS reported 82 fatalities over 21 states related to flash and river flooding. Of these 82, 45% occured in a vehicle, likely trying to cross flooded roadways.
The U.S. National Weather Service records weather related fatalities, defined by the particular weather condition. In 2013, the NWS reported 82 fatalities over 21 states related to flash and river flooding. Of these 82 cases, 45% happened in a vehicle, likely trying to cross flooded roadways. In one case in a municipality in southern California, a vehicle was swept away resulting in the death of the driver. The incident occurred on a bridge, which is frequently washed over by flash flood waters during periods of heavy rain, surprising unsuspecting motorists. A subsequent lawsuit cost the city nearly $500,000 in settlement.
At the time of the accident, city workers were tasked with driving to the roadway site to visually monitor for roadway wash over conditions. When wash over appeared imminent, a crew would erect barricades to block the roadway. However, as rain/flash flood events often occurred overnight, or at times when workers might not be available, this method proved unreliable. Unpredictable conditions made it difficult to ensure that operating procedures be strictly followed. City maintenance managers recognized that an automated solution must be implemented to reliably alert them to imminent roadway wash overs.
After extensive online research, city officials identified the KELLER GSM i remote data transmission unit as a possible solution. This GSM unit operates by transmitting water level or pressure data over GSM cellular networks. Level data can be collected via a variety of instruments, which provide either standard analog (4-20mA, 0-5 VDC, 0-10VDC, etc.) or digital RS485 i / SDI12 i outputs. The primary advantage of this system is the ability to send remote alerts to maintenance workers making them aware of the imminent roadway wash overs regardless of the time of day.
After consulting KELLER America, a system including the GSM and an Acculevel submersible level transmitter was specified for installation at key locations prone to flooding. KELLER America provided technical support for the setup, installation, and programming of the system, allowing the responsible city workers to receive an SMS alert indicating rising water. After the implementation, the city transitioned from manually placed, temporary barricades to permanent swinging gates, which close when flash floods occur.
KELLER could offer the National Weather Service a complete solution for the task in hand by combining a precise liquid level sensor, a remote transmission unit and customised software. A system that recognises the signs of flash floods and reports immediately. The crucial points for the National Weather Service were that the product was readily available and it delivered a simple, fast and highly reliable message via SMS.
Water level monitoring on water dams is a basic measurement. The main requirements are the reliability (lightning protection) and very high accuracy. The 36 X W level probes can fulfil all those requirements providing added value in form of MODBUS i communication.
In Poland several hundred KELLER PAA-36 X W level probes have been installed in numerous water dams. Generally, the capillary solutions with relative pressure sensors are not acceptable, due to humidity problems. Thanks to RS485 i MODBUS communications all the absolute sensors of PAA-36 X W can easily communicate with barometric sensors also operating via MODBUS. The very strong additional lightning protection made the level probes almost "immortal" - since 2009 there has not been a single failure as it used to happen quite frequently in the past. Apart from the lack of humidity problems using the absolute sensors provide extraordinary long term stability and a total accuracy of 0,05…0,1% in real conditions.
With its 175 canals and numerous waterways on its outskirts, Venice is in danger of sinking. Worsening climate change and global warming are causing sea levels to rise, bringing unusually high tides and flooding to the city. Venice has also been sinking for some years now due to the groundwater that is being pumped out from underneath its lagoon. Despite identifying the problem, it has only been possible to slow the process rather than stop it entirely. A system of gates known as MOSE has been devised to help rescue the situation.
Built on a lagoon, Venice was declared a UNESCO World Heritage Site in 1987. It is spread across 118 islands and its historical districts, built mainly on marshland, are connected by a network of waterways, the most important of which is the Grand Canal.
The Grand Canal and the Rialto Bridge
High tides and flooding are the city’s constant enemies, with escalating climate change leaving no hope of relief. Increasingly, Venice is also combatting subsidence as its sandy subsoil sinks by a few millimetres every year. Go back 100 years and it lay around 25 centimetres higher out of the water than it does today. When its industries moved to the outskirts of the city in the 1960s, there was a great need for fresh water, so groundwater was simply pumped out from under the lagoon. However, this too is now causing Venice to sink. Although the problem was identified in the 1960s, restricting the volume of water being pumped could not stop the process entirely.
Residents are alerted when the sea level rises too high, enabling them to prepare for the impending “acqua alta” (“high water”). However, sandbagged doorways, wooden walkways and water pumps are not a long-term solution for saving the city. Rising water levels are particularly common in Venice in autumn and winter, with the number of floods having doubled over the past 40 years.
The man-made greenhouse effect causes the atmosphere to heat up, with consequences including the melting of the world’s glaciers. In Greenland, for example, scientists have observed significant losses in the ice shelf and have calculated that more ice melts in summer than is able to form in winter. The resulting increase in sea levels is threatening low-lying countries.
Rise in the sea level
A system of gates has now been devised to keep the Adriatic Sea away from the city. In 2001, the Italian government voted to instigate the MOSE (“Modulo Sperimentale Elettromeccanico”, or “Electromechanical Experimental Module”) flood prevention project, which uses steel gates to hold back high tides at the three entrances to the Venetian Lagoon. Secured by concrete piles, the gates are 20 metres wide, 5 metres thick and up to 30 metres high. When there is a danger of high tides, air is pumped into the gates, which rise to form a protective barrier and block off the lagoon like a floodwall. When the water is at a normal level, the gates lie submerged beneath it. The project envisages 79 of these steel gates covering a total length of 1.5 kilometres.
The MOSE gate system
The customer built digital (bus) profilometers that use KELLER’s high-precision series 33X and 35X transmitters with IP68 protection. The profilometers have been installed in the concrete piles and monitor the structure of the caissons.
This solution guarantees extreme precision – down to one-hundredth of a millimetre over a length of several kilometres – and represents a major advance in quality compared to the technologies used to date in similar applications.
The Federal Service for Hydrometeorology and Environmental Monitoring of Russia “Roshydromet” is increasing the use of water level monitoring systems to keep an eye on surface water levels and temperatures in rivers and lakes.
Some time ago, six departments of the Federal Service began to employ an automatic and autonomous hydrological system manufactured by KELLER AG für Druckmesstechnik. The monitoring system has to provide measurements that are highly accurate and transparent as Russian state-owned institutions must control the security and confidentiality of their own data.
The water level monitoring system consists of a 36 XW hydrostatic level sensor, which serves to measure pressure and temperature, and a GSM i -2 autonomous remote transmitter, which is used for automatic data collection and transmission. The GSM-2 modules are also equipped for measuring low pressure.
The GSM box has to transmit stable readings and work consistently and independently over several years and in extreme weather conditions, such as temperatures as low as -40° C. This is because Roshydromet’s northern divisions use KELLER AG systems in the Gulf of Finland and the Barents Sea. The former is an elongated bay in the Baltic Sea, south of Finland, while the latter is situated north of the country and flows into the Arctic Ocean, where temperatures can sink to -35 °C.
The hydrostatic system uses level sensors in the water to monitor the state of the ice. All GSM-2-based monitoring systems are equipped with autonomous still and video cameras for security purposes to protect against theft and vandalism. Most GSM boxes are installed in hydrologically secure chests in close proximity to the water monitoring system.
Roshydromet’s northern division
The hydrostatic systems have been gathering precise measurements every hour for several years now. This data is transmitted to Roshydromet every twelve hours via GSM/GPRS.
Measurements are only deleted every five to seven years as this is when the lithium battery also needs changing. No other maintenance work is required throughout this entire period.
Roshydromet’s northern division installed 22 hydrostatic systems fitted with safety recorders in the Arkhangelsk region in 2016.
In October 2017, the Siberian division of Russia’s Federal Service supplied twelve GSM-2 modules with level transmitters (image). This part of Russia is another where icy temperatures pose the greatest challenge as the air temperature can sink as low as -38 °C. In addition to the security cameras, the installations are also fitted in metal cases surrounded by metal fencing to prevent any kind of vandalism (image). The video recorder is linked up to the GSM-2 module, which sends a message to the Siberian division if somebody gets inside the metal fencing.
Siberian division of Russia’s Federal Service
In November 2017, four hydrostatic systems were installed in Roshyrdomet’s central Chernozem region, where the air temperature can drop to -25 °C. Vertical masts made from steel tubing, which require miniature GSM modules, have been used to build these hydrological measuring stations. On the inside of the mast there are modules with a diameter of just 57 mm (two inches). The benefit of this installation is that the measuring station remains hidden and protected from flooding. It monitors the ice levels on rivers and is also fitted with an autonomous camera for security purposes.
Roshyrdomet’s central Chernozem region
There are also two systems at Roshydromet’s test site in the Novgorod region, where they are also connected to a rain catcher in addition to the installations mentioned above.
Rain Catcher at Roshydromet’s test site in the Novgorod region