왕송저수지의 수질 및 식물상 조사

Abstract

Wangsong reservoir has a vulnerable structure to water pollution due to eutrophication caused by resuspension of sediments. The purpose of this study is identifying the pollution state of Wangsong reservoir by measuring the water quality and looking into the plants and vegetation around the reservoir. This year, as a result of measuring water quality personally, the average concentration of COD 19.4mg/L, SS 35mg/L, DO 11.6mg/L, T-P 0.133mg/L, T-N 3.200mg/L was investigated. After a review of the whole average water quality of 2012-2015, COD 15.5mg/L as Ⅵ class, TOC 7.9mg/L as Ⅴ class, SS 34.2mg/L as Ⅵ class, T-N 4.4mg/L as Ⅵ class, T-P 0.2mg/L as Ⅵ class, Chl-α 91.4mg/m3 as Ⅵ class, total coliforms 11,621 MPN/100mL as Ⅵ class, fecal coliforms 44,928MPN/100mL as shown in Ⅵ class. Finding on inquiry of plants, flora consists of total 158 taxa, 52 families, 137 species and 21 varieties. The water trophic state of Wangsong reservoir is shown as "Eutrophic" based on Vollenweider, "Hypereutrophic" based on USEPA, "Eutrophic and Hypereutrophic" based on OECD. Among the vegetations found in the reservoir, Nymphaea tetragona, Nelumbo nucifera, Trapa japanica, Oenanthe javanica, Typha angustata, Hydrilla verticillata, Leersia japonica, Miscanthus sacchariflous, Phragmites communis, Zizania latifolia and Spirodelapolyrhiza can remove pollutant by absorbing nutrients, but if you neglect these vegetations, they increase COD concentration in the reservoir by reproducing nutrients(T-N, T-P) had contained in corrosion process. Therefore, it is thought that aggressive action is needed to remove the vegetations by using Algae Harvesting Ship and so on.