Hydrodynamic And Water Quality Of Lakes

Firstly, this paper proposed that taking lakes which have some links as lakes group to analyze, dividing lakes group into different types according to the relationship and connection between lakes. Secondly, giving theoretical analysis of hydrodynamic and water quality laws between different lakes group based on SMS software. Thirdly, simulating the flow and concentration field of lakes group under different flow, water quality condition, verifying the theoretical analysis and the law and analyze upstream of the lake water quality impacts on downstream lakes. Lastly, analysis the sensitivity of main parameters in RMA2 and RMA4 model combined with the actual situation of lakes in punan area. The results show:(1)Propose the concepts of lakes group and give examples to illustrate that the group is a number of independent but interrelated, interacting lakes both in quantity and quality, and the group is connected by lakes, rivers and dam.(2)According to the regional water lakes and the links of lake, lakes are divided into 3 types; when lakes group only has two lakes, according to the connection between the lakes, the lakes group are divided into 9 types;(3) Initial flow 1.0m3/s, each additional 1 hour, flows increase 1.0m3/s until 50.0 m3/s, the import and export flows showed a linear correlation can be expressed as y = ax+b; the initial flow 1.0m3/s,one hour after the flow increased to 10.0 m3/s, and then maintain constant, the lake outlet remained at a low flow state in a short time, but as time changes, export flows increased rapidly, reached after a certain time, the basic balance;(4) Import and export of different relative positions and different ways to connect directly affect the diffusion of pollutants, when the main waterway through the lake's central, and import and export of basic in a straight line position, the most conducive to the spread of pollutants; only when the main waterway through the part of the lake, and the location of both the import and export side on the same side, the most detrimental to the spread of pollutants;(5) When the entrance flow rate of 1.0m3/s, the first 24h, import and export CODMn concentration exponent can be approximately expressed as y = AxB; the first 144h, the concentration of import and export CODMn a linear relationship;(6) Lake area 6km2, 4m depth, the flow rate were 30,10,20m3/s, the first 24h, import and export of various types of lakes, a linear relationship between concentration CODMn;(7) When the lake area is expanded from 6 km2 to 10 km2, water depth is constant, flow 50,20,30m3/s, the first 24h, import and export of various types of lakes, a linear relationship between concentration CODMn; and when the lake area is reduced to 2 km2, the flow rate of 10m3/s, three types of lakes, the concentration of import and export CODMn a linear correlation;(8)Lakes group in punan area involved in general water connection benefit dispersal of pollutants, management focused on goldfish Waterfront, especially the lower part of the lake;(9)Diffusion coefficient and the roughness of the relatively small impact on the calculation results, while the diffusion coefficient and the attenuation coefficient on the calculation more sensitive.