Research and analysis programme of Rainfall and Water-flow
The Soil Erosion Research
The Soil Erosion Research Station (SERS) is a part of the Israeli ministry of agriculture. SERS is situated near the Ruppin institue north to Netanya. It's main purpose is to investigate water-flow and flood events throughout the country. I started working in SERS in 1999, and eversince I've created there several programme in VB 6.0 and C# .Net which are widely used there and in other organizations.
Radar analysis system - Meteor
Rainfall radar is a radar designed for detecting water drops within clouds. The radar can give a picture at a resolution of about 1 square kilometer of the rain in the entire country and usually every 5 minutes. This data is much more useful than the ground rain gauges data in analyzing the spatial distribution of the rain. In arid region the rain the spatial and time variation of the rain is significant, and therefore the radar is an essential tool in understanding how runoff events are crated.
The programme I've created receives the rain data directly from the radar through a serial port in Ben-Gourion Airport, and transmit it to SERS via FTP protocol. The data is displayed and analysed both online to alert for a coming event and afterwards when trying to understand the causes for a certain flood.
Future Developments : The main problem with radar data is calibrating it correctly from reflected energy units (dBZ) to rainfall units (mm/hour). In the coming month I about to try to use variation method to confront this problem. I'm also about to add algorithms for analysing clouds' speed and direction. This is done in collaboration with researchers from Mekorot company (that operates the radar) in order to be able, one day, to predict the motion of clouds.
A perview of the Meteor :
Water-flow analysis system - Hydramasse
The important value needed to asses a water-flow event is the discharge, meaning the amount of water flowed in a river per unit of time. It is impossible to measure the discharge directly, but measuring the average speed of the flow the area of the cross section will give the discharge using the simple formula P=A*V (P-discharge, V-speed, A-area). However, measuring the average speed is almost impossible, and besides that constantly measuring the speed in small streams requires expensive equipment.
The solution has been devised in the 19th century with formulas that give the discharge from only the cross section area, the slope of the river and a coefficient that represents the amount of friction of the water with the walls and bottom of the river. These formulas are based on an assumption that the water reaches a terminal speed in which the force of friction (depending of that coefficient) are equal to the forces of gravity (depending on the slope of the river). The most common formulas of all in the Manning formula, which has been proved to work very well in many cases.
The programme I've created manages the whole process of data collection and analysis. The programme reads the cross-section data measured in the field, from which it calculates the water depth - discharge calibration graph. Creating the calibration graph for each station is the most complicated task and it requires many additional measurements in order to fit certain parameters or the stream. Using that graph the programme translates the water-depth data from the instruments to discharge that flowed through the stream.
All the data is saved in an MS Access database and later being used for a variety of reports and statistical analysis.
A perview of the Hydramasse :