## 3 Results and Discussion
### Spatial Distribution of Benthic Macroinvertebrate Communities Before and After Summer Rainfall
\begin{table}
\begin{tabular}{l l l l l l l l l l l l l} \hline \hline
**Order** & **Family or Genus** & **Month** & **SDU** & **SDL** & **OS** & **SC** & **YC** & **SG** & **JD** & **BS** & **SL** \\ \hline Amphoda & _Gumarus_ spp. & May & 26.6\% & 0.0\% & 0.0\% & 0.0\% & 0.0\% & 0.1\% & 0.0\% & 0.0\% & 0.0\% \\  & Sep & 69.6\% & 0.0\% & 0.0\% & 0.0\% & 0.1\% & 0.0\% & 0.0\% & 0.0\% & 0.0\% \\ Arhynchobdellida & _Erybeldin_ spp. & May & 0.1\% & 0.0\% & 0.3\% & 0.2\% & 0.3\% & 0.2\% & 0.1\% & 0.1\% & 0.3\% \\  & Sep & 0.0\% & 0.2\% & 12.0\% & 2.1\% & 2.7\% & 2.0\% & 1.0\% & 0.2\% & 0.8\% \\ \hline Coleoptera & _Emidrae_ spp. & May & 0.2\% & 1.9\% & 8.3\% & 0.7\% & 0.6\% & 10.6\% & 0.5\% & 0.3\% \\  & _Emidrae_ spp. & Sep & 0.0\% & 9.0\% & 2.4\% & 0.3\% & 2.9\% & 0.1\% & 1.9\% & 0.7\% & 1.7\% \\  & _Emidra_ spp. & May & 0.0\% & 0.0\% & 0.0\% & 0.1\% & 0.1\% & 0.1\% & 0.0\% & 1.0\% & 0.5\% \\  & Sep & 0.9\% & 0.6\% & 1.2\% & 6.6\% & 0.5\% & 4.2\% & 9.6\% & 11.8\% & 1.1\% \\ \hline Decapoda & _Carilina_ spp. & May & 0.0\% & 0.5\% & 0.1\% & 0.3\% & 0.0\% & 0.1\% & 0.0\% & 0.1\% & 0.0\% \\  & Sep & 0.0\% & 4.5\% & 10.9\% & 1.1\% & 0.3\% & 0.2\% & 0.0\% & 0.7\% & 0.3\% \\ \hline Diptera & Chironomide & May & 9.6\% & 21.9\% & 23.5\% & 61.7\% & 51.6\% & 44.3\% & 66.3\% & 36.1\% & 37.8\% \\  & Sep & 5.9\% & 24.1\% & 19.5\% & 30.3\% & 30.3\% & 19.1\% & 28.1\% & 19.5\% & 24.4\% \\  & _Simulium_ spp. & May & 7.4\% & 0.5\% & 0.4\% & 0.7\% & 0.5\% & 0.3\% & 0.1\% & 0.7\% & 1.9\% \\  & Sep & 0.7\% & 0.0\% & 0.3\% & 0.0\% & 0.0\% & 0.1\% & 0.2\% & 0.0\% & 1.1\% \\ \hline Ephemeroptera & _Batelin_ spp. & May & 0.1\% & 0.0\% & 0.2\% & 0.0\% & 3.8\% & 0.7\% & 0.0\% & 3.3\% & 3.4\% \\  & Sep & 0.3\% & 1.5\% & 0.1\% & 0.0\% & 2.0\% & 0.4\% & 0.0\% & 0.0\% & 5.1\% \\  & _Batelin_ spp. & May & 1.5\% & 13.7\% & 4.6\% & 8.8\% & 10.9\% & 1.8\% & 4.7\% & 18.4\% & 9.5\% \\  & Sep & 6.5\% & 4.0\% & 8.2\% & 16.1\% & 7.6\% & 12.8\% & 9.7\% & 2.4\% & 20.2\% \\  & Cenidae & May & 0.1\% & 3.2\% & 0.0\% & 1.1\% & 0.0\% & 0.1\% & 0.4\% & 0.4\% & 0.7\% \\  & Sep & 0.4\% & 0.6\% & 0.0\% & 2.2\% & 0.0\% & 1.5\% & 1.8\% & 15.9\% & 0.9\% \\  & _Chorotepes_ spp. & May & 1.4\% & 2.6\% & 0.7\% & 2.7\% & 2.1\% & 0.8\% & 6.0\% & 7.2\% & 4.0\% \\  & Sep & 0.0\% & 0.8\% & 0.9\% & 0.7\% & 1.6\% & 1.3\% & 2.4\% & 4.0\% & 1.1\% \\  & _Eadjournus_ spp. & May & 4.0\% & 0.0\% & 0.7\% & 2.6\% & 2.9\% & 8.7\% & 2.3\% & 3.2\% & 5.0\% \\  & Sep & 2.2\% & 23.1\% & 3.9\% & 1.4\% & 9.3\% & 11.2\% & 13.5\% & 14.0\% & 12.4\% \\  & _Eporus_ spp. & May & 0.4\% & 0.1\% & 0.0\% & 0.0\% & 1.7\% & 0.1\% & 0.3\% & 0.1\% & 4.4\% \\  & Sep & 1.1\% & 0.0\% & 0.1\% & 0.1\% & 2.4\% & 1.5\% & 0.1\% & 0.0\% & 3.2\% \\  & Sep & 0.1\% & 0.2\% & 0.4\% & 1.1\% & 1.4\% & 1.1\% & 4.5\% & 1.2\% & 0.4\% \\  & Sep & 0.3\% & 0.3\% & 0.3\% & 4.5\% & 2.7\% & 0.1\% & 4.9\% & 3.8\% & 0.6\% \\  & May & 0.0\% & 0.3\% & 0.0\% & 0.1\% & 0.0\% & 0.0\% & 0.0\% & 0.0\% & 0.0\% \\  & Sep & 0.5\% & 8.7\% & 1.9\% & 0.0\% & 0.1\% & 0.0\% & 0.2\% & 0.0\% & 0.1\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The relative abundances of benthic macroninvertebrates in Seomjin River. SDU: Seomjin Dam in the upper site, SDL: Seomjin Dam in the lower site, OS: Oh-Soo, SC: Soon-Chang, YC: Yo-Cheon, SG: Seomjin-Gokeseng, JD: Juan Dam, BS: Bo-Seong, SL: Seomjin River.