FOR EFFICIENT WATER MANAGEMENT, IT IS ESSENTIAL TO MAP, MEASURE AND MONITOR EXTENT AND QUALITY OF BOTH SUB SOIL AQUIFERS AND SURFACE FRESH WATER RESOURCES.

FOR A VAST COUNTRY LIKE INDIA, THE TASK IS GIGANTIC AND EXPENSIVE, GIVEN THE SHEER NUMBER OF SITES AND NUMBER OF PARAMETERS TO BE MONITORED.

THIS PAPER DISCUSSES OPTIMUM AND MOST ECONOMICAL INSTRUMENTATION AND MODERN TELEMETRY SOLUTIONS TO ACHIEVE EFFICIENT WATER MANAGEMENT.

ABOUT THIS PAPER

DATA FROM REMOTE LOCATIONS MUST BE MONITORED IN NEAR REAL TIME, TO DO AWAY WITH ANY POSSIBILITES OF HUMAN ERROR IN RECORDING DATA.

EASIEST METHOD FOR AUTOMATIC RECORDING IS TO USE A WATER PRESSURE SENSOR WHICH MEASURES WATER LEVEL (CALLED HEAD) USING RELATIONSHIP THAT PRESSURE IS EQUIVALENT TO 10 KPA FOR EVERY 1 M OF WATER COLUMN FOR PURE WATER OF SPECIFIC GRAVITY 1.00.

BRACKISH WATER IN COASTAL AREAS OFTEN HAS A SPECIFIC GRAVITY AS HIGH AS 1.1 & THEREFORE REQUIRES SPECIFIC GRAVITY CORRECTION IN THE MEASURED VALUE.

THE CHALLENGES

INSTRUMENTATION PLAN MUST BE PROPERLY DESIGNED AND EXECUTED SO AS TO REDUCE TOTAL MONITORING COSTS WITHOUT SACRIFICING QUALITY AND RELIABILITY OF COLLECTED DATA.

IT SHOULD MINIMISE HUMAN INTERVENTION AND AUTOMATICALLY ANALYSE COLLECTED DATA AND PRESENT IT IN RELEVANT TABULAR OR GRAPHICAL FORMS.

IT MUST INCORPORATE A PROPER ALARM SYSTEM TO SEND AUTOMATIC WARNING BY SMS OR E-MAIL

DATA MUST BE AVAILABLE TO AUTHORISED USERS, LOCATED ANYWHERE IN THE WORLD, WITH LEAST POSSIBLE TIME DELAY CONSISTENT WITH USER REQUIREMENT.

THE CHALLENGES

READINGS FROM PRESSURE SENSORS WITH MEASURING RANGE UPTO 30 MWC NEED BAROMETRIC PRESSURE CORRECTION. DAILY VARIATION IN ATMOSPHERIC PRESSURE CAN TYPICALLY BE UP TO 40 MMWC AND OVER A PERIOD OF TIME EVEN 150 MMWC.

FIRST OPTIONS IS TO USE A GAUGE PRESSURE SENSOR WITH ONE SIDE OF ITS PRESSURE MEASUREMENT DIAPHRAGM OPEN TO ATMOSPHERE THROUGH A PAIR OF CAPILLARY TUBES IN THE CABLE AND A DESICCANT CHAMBER.

SECOND OPTION IS TO USE AN ABSOLUTE PRESSURE SENSOR AND APPLY BAROMETRIC PRESSURE CORRECTION TO READINGS OBTAINED. ENCARDIO-RITE OFFERS STATE OF THE ART INDIVIDUAL BAROMETRIC PRESSURE SENSORS WITH EACH PRESSURE SENSOR

MONITORING WATER TABLE

A VARIATION OF PRESSURE SENSOR, KNOWN AS CTD (CONDUCTIVITY, TEMPERATURE, DEPTH) IS AVAILABLE WITH AN INTEGRAL CONDUCTIVITY SENSOR.

CONDUCTIVITY MEASUREMENT GIVES A MEASURE OF SALINITY OF THE WATER FROM WHICH THE DENSITY OF THE WATER CAN BE CALCULATED.

THIS KIND OF SENSOR IS INDISPENSIBLE IN AREAS WHERE THE SALINITY OF THE GROUND WATER VARIES WITH TIME.

MONITORING GROUND WATER

ON RIGHT IS A TYPICAL DATALOGGER WITH A BOREHOLE WATER LEVEL SENSOR.

THE NARROW

CYLINDRICAL HOUSING ALLOWS DATALOGGER TO BE INSTALLED AT GROUND LEVEL INSIDE A BOREHOLE FOR PROTECTION FROM VANDALISM.

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BORE HOLE WATER LEVEL SENSOR WITH DATA LOGGER

Holding plate

Sensor cablewith vent tube

Piezometer

Borehole

Datalogger withbattery & desiccant

DATALOGGER USED FOR GROUND WATER MONITORING ALLOW UNATTENDED FUNCTION FOR UPTO FIVE YEARS FROM A SET OF LITHIUM BATTERIES MAKING THEM SUITABLE FOR DEPLOYMENT AT REMOTE SITES WHERE FREQUENT BATTERY REPLACEMENT IS A LOGISTIC PROBLEM. THESE DATALOGGERS HAVE SUFFICIENT MEMORY TO ALLOW STORAGE OF DATA FOR SEVERAL YEARS. ONE SUCH DATALOGGER A HAS 8 MB FLASH RAM AND CAN STORE UPTO 2,995,930 DATA POINTS

OPTIONS ARE AVAILABLE FOR HAVING THE DATALOGGER IN A 50 MM DIAMETER CYLINDERICAL HOUSING (AS ILLUSTRATED IN PREVIOUS SLIDE) OR A RECTANGULAR METAL DIECAST/PLASTIC MOUDED BOX.

DATALOGGING

FOR DATA RETREIVAL FOLLOWING OPTIONS ARE AVAILABLE: MOBILE PHONE OR PDALAPTOP COMPUTERGSM/GPRS NETWORKRF TRANSMISSION UPTO A RANGE OF AROUND 10

KM. IN INDIA, A FREQUENCY OF 865 MZ IS AVAILABLE FOR THIS PURPOSE.

ALL THESE OPTIONS ARE ILLUSTRATED IN THE NEXT THREE SLIDES.

DATA RETRIEVAL

BLUETOOTH

4 CORE CABLE WITH VENT

TUBE

EPP-60 V/EPP-30V PRESSURE SENSOR

LAPTOP OR MOBILE PHONE WITH

APPLICATION SOFTWARE

USB/BLUETOOTH

USER PC

DATALOGGER ESCL-10VT

LOGGER ESCL-10VT WITH GSM/GPRS

MODEM

4 CORE CABLE WITH VENT TUBE

EPP-30/60 V PRESSURE SENSOR

ENCARDIO-RITE WDMS SERVER

REMOTE USER PC

INTERNET

LOGGER ESCL-10VT WITH RF-865 MODEM

4 CORE CABLE WITH VENT TUBE

EPP-60 V/EPP-30V PRESSURE SENSOR

*FIELD/REMOTE RF-865 MODEM

REMOTE PC

RS 232 LINK

RF LINK

SURFACE FRESH WATER BODIES THAT NEED TO BE MONITORED INCLUDE STREAMS, RIVERS, RESERVOIRS, AND OFTEN CANALS OR CHANNELS DISCHARGING INTO OR OFF TAKING WATER FROM OTHER WATER BODIES.

V-NOTCH WEIRS TOGETHER WITH WATER LEVEL SENSORS ARE USED TO MEASURE VOLUME OF WATER FLOWING THROUGH THE SMALLER CHANNELS WITH UNIFORM RECTANGULAR CROSS SECTION. IN WIDER OPEN CHANNELS OR CANALS A COMBINATION OF WATER LEVEL AND FLOW MEASUREMENT SYSTEM IS USED.

THE MEASURED VALUE OF FLOW AND LEVEL IS LOGGED BY A DATALOGGER AT PREDETERMINED INTERVALS.

MONITORING SURFACE WATER

SURFACE WATER MONITORING MAY REQUIRE FASTER MEASUREMENT AND REPORTING TIME FOR SURFACE WATER PARAMETERS AS FIELD CONDITIONS CAN CHANGE AT A FAST RATE. IN SOME CASES UPDATE RATES OF 1 HOUR OR LESS MAY HAVE TO BE EMPLOYED.

WATER QUALITY MONITORING SHOULD ALSO BE AN INTEGRAL PART OF WATER CONSERVATION PROGRAM TO MONITOR POLLUTION DUE TO HUMAN ACTIVITIES OR OVER EXPLOITATION.

A RANGE OF SMALL SIZE ELECTRONICS WATER QUALITY SENSORS ARE AVAILBLE FOR ONLINE MONITORING. THESE INCLUDE PARAMETERS LIKE BOD, COD, DOC, DO, NO3-N, NO2-N, NH4-N, pH, CONDUCTIVITY, TURBIDITY, COLOUR TSS, CHLORINE, CHLORIDE ETC.

MONITORING SURFACE WATER

AS COMPARED TO WATER LEVEL, WATER QUALITY MEASUREMENT SYSTEMS FOR UNATTENDED AUTOMATIC MONITORING ARE EXPENSIVE AND ARE ALWAYS NOT NECESSARY.

POLLUTION LEVEL OF GROUND WATER, CHANGES RELATIVELY SLOWLY; SO A MANUAL SAMPLING & LAB TEST METHOD CONDUCTED ONCE EVERY FEW WEEKS MAY BE SUFFICIENT TO EFFECTIVELY MONITOR WATER QUALITY IN A PARTICULAR BOREHOLE. IN A RIVER OR LAKE, THE ABOVE CRITERIA HOWEVER DOES NOT HOLD GOOD.

ONLINE MONITORING OF WATER QUALITY ALLOWS THE POLLUTION LEVEL OF WATER AT REMOTE LOCATIONS TO BE MONITORED CONTINUOUSLY IN NEAR REAL TIME FROM A CENTRAL LOCATION AND REQUIRES VERY LITTLE SKILLED OR UNSKILLED MANPOWER.

MONITORING WATER QUALITY

SYSTEMS ARE AVAILABLE FOR ONLINE MONITORING WHICH ALLOW SIMULTANEOUS MONITORING OF ANOTHER IMPORTANT PARAMETER “RAINFALL” WHICH AFFECTS WATER LEVEL IN THE GROUND, RIVERS AND LAKES. THIS PROVIDES VALUABLE INFORMATION ON CORRELATION BETWEEN RAINFALL AND MAGNITUDE OF PERCOLATION OF RAIN WATER INTO ACQUIFER OVER A PERIOD OF TIME.

RAIN GAUGES ARE INSTALLED IN THE OPEN AND SUBJECT TO DIRECT SUNLIGHT AND WEATHER. FOR REMOTE LOCATIONS, HEAVY DUTY RAIN GAUGES WITH STAINLESS STEEL HOUSING SHOULD BE SPECIFIED AS THEY CAN WORK FOR DECADES WITHOUT DEGRADATION AND TURN OUT TO BE MORE ECONOMICAL IN THE LONG RUN.

MONITORING RAINFALL

THE NEXT FIVE SLIDES ARE SCREENSHOTS FROM A WEB DATA MONITORING SYSTEM. THE FIRST TWO SLIDES SHOWS THE TOPOGRAPHICAL MAP OF THE AREA BEING MONITORED. CLICKING ON THE DESIRED LOCATION DISPLAYS THE DATA IN NEAR REAL TIME.

WEB DATA PRESENTATION

SCREEN SHOT OF ONLINE DATA MONITORING OF WATER TABLE & TEMPERATURE IN BOREHOLE. SPECIALLY NOTE 0.2 DEG C VARIATION IN

TEMPERATURE OVER A PERIOD OF ONE YEAR

SCREEN SHOT OF ONLINE DATA MONITORING OF RAINFALL, BAROMETRIC PRESSURE AND WATER TABLE

SCREEN SHOT OF ONLINE DATA MONITORING OF SEVERAL WATER QUALITY PARAMETERS

Plot LatestpH_units: wms_manta 8.350Plot LatestSpCond_mS/cm: wms_manta 0.888Plot LatestHDO_mg/L: wms_manta 7.480Plot LatestCl_mg/L: wms_manta 81.70Plot LatestNH4_mg/L-N: wms_manta 2.600Plot LatestNO3_mg/L-N: wms_manta 35.40

wms_manta: PARAMETER-1

T20132150002013317000

THANK YOU

VISIT BOOTH NO. 1, HALL A TO SEE LIVE DEMONSTRATION OF ALL THESE SYSTEMS