Watershed Reactor Analysis, CO2 Eco-function and Threshold Management Study

• Main Authors: David Da-Wei Tsai, 蔡大偉
• Other Authors: 陳鴻烈
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/97034146177017825128

博士 === 國立中興大學 === 水土保持學系所 === 100 === For the sustainable development, the integrated watershed management is the most authentic and practical technology to reach this goal. This study took advantage of the multidisciplinary technology to accomplish the management with multiple purposes on the basis of dynamic balancing in ecosystem. There were three focused purposes in this study related to the integrated watershed management: (1) HYDRAULICS: reactor analysis of the water bodies in a watershed: the analyses demonstrated the plug-flow reactor (PFR) characteristics in high rate pond (HRP) to be a suitable alternative to imitate a river in lab. The differentiation criteria developed from the hydraulic index analyses could differentiate the complicated water flows in nature for the ecosystem imitation in laboratory. Moreover, this study indicated the unique and the innovative “distance method” could successfully describe the degree of short-circuiting and mixing in all type of reactors according to the short-circuiting index senses. The identification of short-circuiting level would be the key to improve reactor design and management strategy. (2) PRIMARY PRODUCER: the potential of algal CO2 sequestration in a watershed: The utilization of natural water medium which came from water body directly without any extra nutrition addition, demonstrated the potential to adopt the algal function for CO2 bio-fixation in a watershed. Both HRP and continuously stirred tank reactor (CSTR) achieved the high algal biomass production. The high CO2 uptake rate of 162 mg/L/day in HRP and 175 mg/L/day in CSTR with the extremely high and stable consumption efficiency of 123 % in HRP and 131% in CSTR displayed the impressive potential of the fixation capability in a watershed through land use management. By the mathematical analyses, this study confirmed the lab systems which mimicked the ecosystem could have better uptake rates and consumption efficiencies than the general systems in literature with artificial medium because the natural process was replicated inside the lab. From the growth condition analysis, all the parameters except over-saturated oxygen of DO indicated that the HRPs were close to natural system. Furthermore, the excellent CO2 sequestration data provided a clue from the freshwater algae for the “remaining unidentified carbon sink” of an ecological mystery today. (3) ECO-FUNCTION: disaster prevention, environmental quality control and CO2 storage by watershed management: Although Taiwan is a vulnerable and fragile country threaten by multiple hazards, this study indicated the land use management could enormously improve the vulnerability of calamities. Furthermore, the historical policy in Taiwan was proved to be the rationale to explain the tremendously increased frequency and magnitude of catastrophes, pollution and carbon storage eco-function reduction. Hopefully this innovative study would help us to know the hydraulic characteristics in a watershed better, to suggest the most proper and practical strategy for the greenhouse gas reduction of the global carbon cycle in land and to develop the proper management strategy for the sustainable use of natural resource.