Acknowledgements. Global Waters for Sustainability Program (GLOWS-FIU),. USAID, Sadaani National Park(Tanzania), Archbold. Biological Station and the ...
LOW-COST, OPEN-SOURCE HYDROLOGY MONITORING ROMAN EVARIST
1,
AMARTYA SAHA
2,
CHRIS DUTTON
3
1 – ADATECH, MOROGORO, TANZANIA; 2 - ARCHBOLD BIOLOGICAL STATION, FL, USA; 3 – YALE UNIVERSITY, CT, USA
Water Level Monitoring: Ultrasonic Distance Ranger
WHY OPEN SOURCE ? $$$
–
PROFESSIONAL
SENSORS,
DATALOGGERS
AND
TRANSMITTERS ARE EXPENSIVE, POSING A HURDLE TO LARGESCALE DEPLOYMENT. ESPECIALLY IN DEVELOPING COUNTRIES WHICH HAVE VERY LITTLE ENVIRONMENTAL MONITORING.
Tx Rx
Principle:
MAINTENANCE – REPAIRS ARE EXPENSIVE AND TIME
Sound wave transmitted, bounces back from water surface onto receiver. Time elapsed between sending and receiving signal noted.
CONSUMING, INVOLVING MANUFACTURER COUNTRIES.
Distance to water level = Speed of sound / (0.5*Time taken for total journey)
SHIPPING
EQUIPMENT
TO
Left: water level measurement at Wami River, Sadaani National Park, Tanzania
OPEN SOURCE TECHNOLOGIES CAN COST 5-30% OF THE
Components: Maxbotix Ultrasonic Ranger Sodaq Mbili board 3W Solar panel, 3.7V Lithium Polymer battery 100 microfarad capacitor for power smoothening
Ultrasonic ranger-based water level with 3Watt solar panel positioned adjacent to a pressure transducer for comparative measurements at the MacArthur Agro-ecological Research Center, Florida. Data read at 1 minute intervals and averaged every 15 minutes, and is stored on a micro SD card.
COST, AND WITH TRAINING, LOCAL TECHNICIANS CAN REPAIR AND SWAP OUT ELECTRONIC COMPONENTS.
AN OPEN-SOURCE MONITORING SYSTEM AN ARDUINO OR SIMILAR MICROPROCESSOR BOARD THAT CAN BE PROGRAMMED TO:
•
COMMUNICATE WITH A VARIETY OF SENSORS
•
GATHER AND STORE DATA ON A MICRO-SD CARD
•
TRANSMIT DATA VIA CELL MODEM/RADIO/BLUETOOTH
Water Flow Monitoring: Electronic Hall-effect flowmeter Principle: Every revolution of propeller sends 2 square wave pulses, and the frequency of pulses is related to flowspeed. For General Oceanics 2031H flowmeter, Flowspeed (cm/s) = 13.44 * Number of pulses per second
Components: General Oceanics 2031H electronic flowmeter Sodaq Mbili board 3W Solar panel, 3.7v Lithium Polymer battery 3.3V – 5V step-up voltage booster (Sparkfun Electronics) Pelican waterproof case
Challenges: Slow flows in estuaries Entanglement with branches Ultrasonic rangers do not work under choppy conditions nor in a pipe for groundwater levels because of scatter
Acknowledgements Flowspeeds in a river need to be measured at the same depth relative to the water surface. Hence a flowmeter is mounted on a buoy, made from a heavyduty plastic petrol can in Tanzania (right).
Global Waters for Sustainability Program (GLOWS-FIU), USAID, Sadaani National Park(Tanzania), Archbold Biological Station and the Open Source Electronics Community.
