Monitoring Lake Nakuru using WSN: a Proposal

By Alice Bett1 , Dr. Julius Kipkemboi2 , Sebastian Buettrich3 and Joan Masai4

1Kenya Wildlife Service 2Egerton University,

3IT University of Copenhagen 4Kenya Education Network

March 2013

Outline

• Introduction

• Management Challenges

• Ongoing Water quality/quantity monitoring

• Proposed project

Park covers an area of 188 Km2 (lake covers about 40 km2, fluctuates with seasons)

Inlets - Rivers Makalia, Nderit, Njoro, Naishi, Larmudiac and Baharini springs.

No outlets - alkaline with an average pH of 10.4

Rainfall: 850mm p.a, bimodal: November to December and April to May

Lake’s catchment area - 1800 km2

Lake Nakuru

Significance

• An important habitat hosting over 400 bird species, 50 species of mammals, and over 500 species of flora

• It is a Ramsar site as well as an Important Bird Area (IBA)

• Significant habitat for conservation of globally and regionally threatened mammal species e.g. the Critically Endangered Black Rhino, Near-threatened White Rhino, Vulnerable Lion, Near-threatened Leopard and endangered Rothschild Giraffe, and numerous grazers

Jointly with Lakes Elementaita and Bogoria - listed as one of the Kenya Lakes System World Heritage Site

Ecological processes - waterfowl migration between the rift valley lakes

Management Challenges

• Destruction of catchment areas

• Pollution - both liquid and solid wastes

• Excessive water abstraction in the catchment

• Siltation

• Climate change impacts

• Invasive plant species (Solanum incanum, Lantana camara, Tarchonanthus camphoratus, Datura, Opuntia spp. etc)

• Urban expansion and poor urban planning

• Lack of dispersal areas

Catchment Destruction

Loss of dense

vegetation

cover between

1973 – 2003

Inside FR: 15,820 ha

Outside FR: 20,960 ha

Total: 36,780 ha

Sources

- Landsat MSS and ETM images. False colour composition

- Forest boundaries: KIFCON project, Forest Department

Legend

Forest Reserves

Lake Nakuru catchment

Lake Nakuru National Park

Land use change

River Njoro

Addressing the challenges

• Research and monitoring to inform management

• Re-afforestation/afforestation campaigns especially in Mau

• Habitat restoration e.g. Euphorbia restoration efforts and invasive species control and management programme

• Management plan preparation and implementation - the Park’s Management Plan is currently being reviewed.

• Translocation of wildlife

• Resource mobilization e.g. Cycle with the Rhino event

• Community involvement in conservation e.g. tree nurseries

• Education and awareness

• Security patrols and anti-poaching campaigns

Cycle with the Rhino event

Water quality and quantity monitoring programme

Parameters

• Physicochemical parameters, nutrients and heavy metals.

• Specific parameters measured - Total depth, Secchi depth, Temperature, pH, Conductivity, Dissolved Oxygen, Alkalinity, Ammonium, Nitrite, Nitrate, Total Nitrogen, Orthophosphate, Total Phosphate, Chlorophyll a, and heavy metals (done annually).

• Sites- River inlets and lake center ( we have 5 sites)

Bathymetry survey

Other Research Interests

• Determine the influence of water quality on aquatic life including water birds, Fish and phytoplankton abundance.

• Regular waterfowl monitoring programme

• Monitoring Climate change and its impacts in the lake through monitoring meteorological parameters

Outputs

Constraints

• Water quality monitoring-Current method is largely manual and time consuming

• Inadequate technical capacity among staff

• Inadequate field equipments and software - e.g. automated weather stations, flow meters/data loggers to measure water discharge data. The only automated data logger at River Njoro is currently unserviceable

• Fails to capture unusual episodes including excessive inflows , fish deaths or waterfowl mortality often occurs unexpectedly. During such periods no limnological or meteorological data is captured

• Inadequate finances to support adequate sample size collection. The frequency of routine fieldwork monitoring is therefore constrained

Proposed project

• WIRELESS SENSOR NETWORK IN LAKE NAKURU

• Expected to enhance the ongoing water quality/quantity monitoring programme by installing wireless sensors to capture real-time data.

• Project site; Lake Nakuru with possibility of including other Rift valley lakes In the region

Parameters

• Within the lake; water depth, water temperature, Electrical conductivity, turbidity, salinity, pH, DO, sediment load (TSS), Total dissolved solids (TDS), phosphate, nitrate, chlorophyll a, Dominant phytoplankton groups - Harmful Algal Blooms (HABS), and associated pigments (phycocyanin, phycoerythrin), pesticides, Heavy metals - Lead (Pb), Cadmium (Cd), Copper (Cu), Zinc (Zn)

Iron(Fe)

Parameters Cont.

• Inflowing rivers;

• River discharge,

• Total Suspended Solids

• Nutrients - Nitrates, ammonia,Phosphates,

• Heavy metals - Lead (Pb), Cadmium (Cd), Mercury (Hg), Iron (Fe)

• Pesticides

Meteorological data

Rainfall

Evapotranspiration,

Relative humidity (RH),

Ambient temperature,

Wind speed/direction

Solar radiation

Commercially available sensors

CS512 DO sensor OBS 3+ Turbidity/ suspended solids

Hydrolab - MS5 Multi-parameter sensor SUNA V2 UV Nitrate sensor

Minipack CTD Chl a sensor

Commercially available sensors…

Water depth sensor

Parameter Unit Sensor Manufacturer Number of

sensors

required

1 Electrical

conductivity

uS/Cm CS547 sensor Campbell Scientific,

USA

10

2 pH CSIM11 sensor Campbell Scientific,

USA

10

3 Temperature oC CS547 sensor Campbell Scientific,

USA

10

4 Dissolved oxygen mg/L CS512 Campbell Scientific,

USA

10

5 Salinity ppm 10

6 Ammonia mg/L Idronaut nitrate

sensor

Idronout , Italy 10

7 Nitrates mg/L SUNA V2 UV/

ProPS-UV

Satlantic USA/ Trios,

Germany

10

8 Soluble reactive

phosphorus

mg/L 10

Water depth m D1501 minidiver 5 4

Parameter Unit Sensor Manufacturer No. of sensors

required

8 Soluble reactive

phosphorus

mg/L 10

10 Lead mg/L 710

11 Cadmium mg/L 10

12 TSS and Turbidity mg/L OBS-3+ Campbell Scientific,

USA

10

13 Chlorophyll a ug/L Minipack CTD

sensor

Chelsea

Technologies Group

Limited UK

5

14 Discharge and

velocity

M3/S Acoustic Doppler

Current Profiler

(ADCP)/

Improvised

sensor

5

15 Weather data (ET,

RH, Rain, Ambient

T, wind speed and

dir.)

Several Weather hawk Campbell Scientific 1

Arduino compatible sensors

Parameter Unit Sensor Manufacturer Number of

sensors

required

1 Electrical

conductivity

uS/cm EC sensor Atlas Scientific, NY 10

2 pH pH sensor Atlas Scientific, NY 10

3 Temperature oC Temperature

sensor

Atlas Scientific, NY 10

4 Dissolved oxygen mg/L Dissolved oxygen

sensor

Atlas Scientific, NY 10

5 Salinity ppm 10

6 Ammonia mg/L 10

7 Nitrates mg/L 10

8 Soluble reactive

phosphorus

mg/L 10

Water depth m 4

Parameter Unit Sensor Manufacturer No. of sensors

required

8 Soluble reactive

phosphorus

mg/L 10

10 Lead mg/L 10

11 Cadmium mg/L 10

12 TSS and Turbidity mg/L 10

13 Chlorophyll a Ug/L 5

14 Discharge and

velocity

M3/S Medium flow

sensor

Atlas Scientific, NY 5

15 Weather data (ET,

RH, Rain, Ambient

T, wind speed and

dir.)

1

Ardruino compatible sensors

DS18B20 Temperature Sensor Kit Thermometer Probe +

Plugable Terminal For Arduino

EC sensor

PH sensor

Proposed sites

Site

1. Mouth of River Njoro

2. Mouth of River Makalia

3. Mouth of River Nderit

4. Baharini springs

5. Sewage drain

6. Lake - 3 sites

7. Install one location upstream of major rivers

8. Weather station to be located inside the park next to the offices

Proposed sensor location sites

Sensor location

Proposed Units

Frequency Options

• 2.4GHz

• 868MHz

• 433MHz

Lower frequencies – longer reach, better

penetration, lower data rates

WSN Technology Options

• 802.11 (Low Power WiFi)

• Zigbee

• 802.15.4 (Low rate WPAN)

• GSM is not an option

Remarks • The radio link simulations below are meant for

link feasibility assessment and are subject to change depending on site survey results

• Note that a decision for network frequencies to be used is still open

Out of Africa – Research Offices

Out of Africa – Treatment Plant Inlet

Out of Africa – Lake Station1

Partners

• Egerton University, Department of Biological sciences

• Kenya Wildlife Service

• Kenya Education Network (KENET)

• IT University of Copenhagen, Denmark

• ICTP, Trieste, Italy

Q & A