Three researchers from Thailand presented on their study estimating annual cadmium load into Songkhla Lake via surface runoff. They used the TREX model to simulate cadmium transport under different scenarios. The model was calibrated and validated against measured data with relative errors of 5-30%. Scenario analysis found that increasing fertilizer use or changing fertilizer type could increase cadmium levels in runoff. The U-Tapao watershed was identified as highest risk due to soil and land use factors. Reducing cadmium in fertilizers could significantly lower cadmium transport into the watershed.

1. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Estimating Annual Cadmium Load
via Surface Runoff
into Songkhla Lake, Thailand
Kitipan Kitbamroong, Ph. D
G.Padmanabhan, Ph. D
Penjai Sompongchaiyakul, Ph. D

2. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Problem
 Increasing agricultural activities in the
catchments of Songkhla Lake have the
potential to increase cadmium accumulation
in the lake.
 Cadmium was found in the lake sediments
 Cadmium is common in phosphate rocks
 Surface runoff and associated sediment flow
are the major mechanisms of transport of
non-point source pollutants

3. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Research Objectives
 To develop a database for non-point source
cadmium transport modeling of the Lake
Basin from the surrounding drainage area.
 To carry out a scenarios analysis of the
cadmium transport to the lake from the
surrounding drainage areas to assist
environmental decision makers.

4. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Methodology
 A spatially distributed cell-based model is
proposed.
 Data to be assembled from local sources on
landuse, soils, fertilizers, and practices.
 Meaningful scenarios will be constructed
 For each scenario, the model runs will be
analyzed.
 Results will be presented to the decision
makers.

5. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Non-Point Source Models
 Available models:
 MIKE SHE
 SWAT
 BASINS
 TREX
 AnnAGNPS
 Criteria
 Predominant land use: agricultural
 Data input requirements: local
 Integration with GIS: Arcview
 Metals transport

6. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Model and Scenarios Used
 Non point source pollution modeling of
cadmium
 TREX (Two-dimenstional Runoff, Erosion, and
eXport model)
 Scenarios
Three scenarios were tested:
 Significant increase and decrease of fertilizer
usage.
 Change in types of fertilizer applied.
 Change in the application rate of fertilizer for
certain crops.

7. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
TREX
 Two-dimensional Runoff, Erosion, and Export
model is a generalized rainfall-runoff watershed
model with a framework for modeling sediment
and contaminant transport.
 Based on the CASC2D watershed model with
chemical transport and fate processes from the
USEPA WASP and IPX series of stream water
quality models
 Three main components: 1) hydrology 2)sediment
transport, and 3) chemical transport and fate.

8. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
TREX

9. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Research Activities Flow Diagram
Model
Source
Mgt Tools
SFA
Pre-Processing
Post-Processing
GIS

10. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
GIS
 The acquired information was compiled in a
Geographical Information System (GIS) –
ArcView.
 The TREX model was run and the result
presented within ArcView.
 Pre-processing of data and post processing
of the model results were done in the GIS
platform.

11. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Watershed Delineation
Figure 3-7 Steps performed during watershed delineation

12. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
8 Watersheds

13. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Model calibration
 The model parameters subject to the
calibration were
 hydraulic conductivity
 soil erodibility
 flow resistance
 crop management factor
 chemical distribution coefficients.

14. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Model calibration
Chemical distribution coefficients – depending
on metal of interest

15. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Model calibration
 Parameters of the model are perturbed until
an acceptable difference between measured
and model-generated output is obtained.

16. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Model validation
 The model is run here with the calibrated
parameters to compare the performance of
the model with measured data (Suviboon,
2006; Leekpai, 2006).

17. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Calibration
 20 Stations
 Precipitation runoff
 Sedimentation Loss
 Cd content in sediment
 Relative error between
5-20%

18. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Verification
 220 sampling
points
 Precipitation runoff
 Sedimentation Loss
 Cd content in
sediment
 Relative error
between 10-30%

19. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
 hydraulic conductivity

20. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
 soil erodibility

21. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
 flow resistance

22. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
 crop management
factor

23. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Cadmium
 Model Performance
 Calibration pts
 Validation pts

24. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Scenario Analysis (1.1)
 Increase Fertilizer
usage by 10%

25. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Scenario Analysis (1.2)
 Increase Fertilizer
usage by 50%

26. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Scenario Analysis (1.3)
 Decrease usage by
10%

27. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Scenario Analysis (1.4)
 Decrease usage by
50%

28. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Scenario Analysis (2)
 changing types of
fertilizer
 7.19 mg/kg cadmium  7.27 mg/kg cadmium

29. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Scenario Analysis (2)
 changing types of
fertilizer

30. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Scenario Analysis (3)
 change of crops grown
in the area

31. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Conclusion
 Substance Flux Analysis
 41,745 tons/year of phosphorus, and 273
kg/year of cadmium from phosphate fertilizer
were induced into SLB.
 The stock calculation for phosphorus and
cadmium were found to be 248.7 tons/year
and 62.8 tons/year respectively.

32. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Conclusion
 TREX Modeling
 U-Tapao watershed had the highest potential of
phosphorous and cadmium transportation in the
sediment runoff.
 Factors promoting includes;
 run off – high runoff
 elevation – steep slope
 soil erodibility – high erosion
 organic matter – high
 pH –acidity
 crop management – horticultural crops
 clay – high percentage
 total metal – high

33. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Conclusion
 Scenario Analysis
 A total of three scenarios were demonstrated
and tested in U-Tapao sub watershed.
 Alone by changing the fertilizer formula, from high
to low contaminated cadmium lead towards a
significant decrease of cadmium contribution to
the watershed.

34. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Acknowledgements
 Asst. Prof. Dr. Chatchai Ratanachai (PSU)
 Dr. Manaskorn Rachakornkij (CU)
 Lecturers and staffs of NRC-EHWM

35. International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
International Conference on Environmental and Hazardous Substance Management: Towards a Green Economy, Bangkok, Thailand.
May 21-23, 2013
Q&A