Research And Application Of Reservoir System Emergency Operation Model In Xijiang River Basin

Xijiang River Basin, an important industrial and agricultural concentration region of Guangxi province, is located in the Zhujiang-Xijiang economic zone. With a high diversity river system, Xijiang River basin is well developed with a large number of reservoirs. How to take advantage of reservoir operation to minimize the damage caused by emergency floods and pollution incidents is surely of great importance to Xijiang economy. There being, however, frequent floods and river pollutions, insufficient overall management of reservoir system operation makes the present emergency operation a difficult research.For the research of flood control, ecological protection, as well as emergency pollution incidents treatment in Xijiang River Basin, the reservoir system emergency operation models were firstly established in this paper, based on high-precision flow and water quality computation. And then, the models were applied in the flood control and emergency pollution incidents treatment with a multi-mode of rivers and reservoirs joint operation in this basin. The main contents are summarized as follows:(1) After Some introductions about the recent floods and water pollution incidents, the corresponding control measures and reflected shortcomings of reservoir emergency management were summarized from the practices. According to the summarization, this paper reviewed the relevant research progress at home and abroad in the fields of flow and water quality computation, flood and pollution emergency control measures with reservoir system operation.(2) Firstly, a river flow computation model was established based on the dynamic and kinematic wave equations, and then compared with the MIKE 11 model in a case study. Secondly, another model used for reservoir flow computaion was set up considering different impoundment and flow conditions, and some special discussions were made about the solutions of the 2-D flow model as well as calibration of the calculated discharge and stage. Thirdly, a convection-diffusion model was then put forward for the computation of water quality in different dimensions, and some cases were listed for the analysis of 1-D and 2-D water quality models, as well as the application conditions of 1-D model. Also, based on the flow model, an identification model of contaminant point source was developed at the same time, and the model ran well in another case study. Finally, all these models were compared and combined for the multi-mode joint operation of rivers and reservoirs.(3) The main rivers and tributaries in Xijiang River Basin were selected as the case area to study the problem of emergency flood control, and a model of reservoir system emergency operation was established considering the overcapacity of flood control and the combination of reservoir flood routing with still and dynamic capacity. Then a rule based on a classification of flood and its control was proposed for the operation. With the established model and proposed rule, some researches on the flood routing and evaluation of corresponding operation scheme was carried out. The results showed that it might differ a lot in the appropriate schemes for different types of flood, and the reservoirs with flood control capacity should be operated with those without flood control tasks when faced with an emergency flood. Also, the temporal and spatial compensation in reservoir capacity should be made good use of, as well as the operation time and overcapacity of flood control. In addition, a 1-D hydrodynamic model was applied in the risk and benefit calculation under different Xijin Reservior operation schemes to control the whole Xijiang River basin flood with a designed frequency of 20 years, which provided further analysis in the appropriate operation scheme for this type of flood control.(4) The feasibility and practicability of reservoir system emergency operation for pollution dilution in Xijiang River Basin were discussed and analysed. After that, the Hejiang River was selected as a case area to study the emergency treatment of sudden water pollution incidents. With the collected data and established operation model, some problems about identification of contaminant point source and water pollution dilution in reservoir system were studied in case of the 2013 water pollution iIncident in Hejiang River. And a final suggested plan was made out from the operation time and control discharge as for the Shuangdao Reservoir.(5) All the models established were integrated in modularization according to their functions at the end of this paper. And a Human-Computer Interaction software platform, which was designed for the multi-mode and multi-functional emergency decisions and operations in Xijiang River Basin, was developed after a model package.