Apaporn Bulsathaporn. The application of mathematical models for an environmental flow assessment and total maximum daily load (TMDL) of Prachinburi-Bangpakong river. Master's Degree(Environmental Planning for Community and Rural Development ). Mahidol University. : Mahidol University, 2008.
The application of mathematical models for an environmental flow assessment and total maximum daily load (TMDL) of Prachinburi-Bangpakong river
Abstract:
This research assessed the environmental water demand and Total Maximum Daily
Load (TMDL) of Prachinburi-Bangpakong River. This was done by applying the
mathematical models in order to study water quality using studied parameters, including
Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD) to assess the TMDL in
the form of pollutants that had BOD, and evaluate Environmental Flows (EF) or minimum
demand of water reservation.
The study areas and the the river reaches were selected within 146 km inland
freshwater (salanity = 0 ppt). The division of the river reaches was based on the Water
Quality Monitoring Station of the Pollution Control Department, and was divided into the
Reaches 1, 2, 3, 4 and 5, consisting of 1) from PA5 Station to PA4 Station, 2) from PA4
Station to PA3 Station, 3) from PA3 Station to PA2 Station, 4) from PA2 Station to BK15
Station, and 5) from BK15 Station to BK13 Station, which passed through 3 Districts in
Chacheongsao Province and 6 Districts in Prachinburi Province.
Research results using the mathematical models indicated that in studying the water
quality during 1996-2006 in Prachinburi-Bangpakong River, the mean of DO was
between 4.9 - 6.8 mg/L and the mean of BOD was between 1.7 - 2.1 mg/L. Furthermore,
the assessment of the TMDL in the form of BOD found that the mean of the TMDL in
real condition was between 33.5 - 109.9 kg/d and the mean of the TMDL in class 3
condition was between 43.9 - 506.5 kg/d. Environmental Flows Assessment found that the
mean of the water flow in real condition was between 7.6 - 11.7 m3/s and the mean of the
water flow in class 3 condition was between 10 - 53.9 m3/s. This identified condition will
enable better water quality and carrying capacity of the river. Therefore, the water flow in
class 3 condition was limited to EF, which was the minimum demand of water reservation
in the Prachinburi-Bangpakong River.