The ecosystem in the Gwangju Stream has taken a wide range of disturbance such as the discharging water of sewage treatment plant, the lake water and the river water from different water system over the past decade. This study was figured out some significant influence factors by analyzing the relationship between biotic and abiotic factors in the urban stream. Abiotic components included 15 water quality variables which were measured in five sampling sites along the stream from October 2014 to July 2015, whereas the benthic macroinvertebrates found in those sites were used to estimate various biotic indices representing the ecological status of the community. The results of correlation analyses indicated that abiotic factors by human activities affected on the inhabitation of benthic macroinvertebrates more than biotic factors. The results of cluster analyses and ANOVA tests also showed that biotic and abiotic characteristics were clearly different in season. The main influence factors of cluster analysis by sites were NH3-N, EPT(I) and DO. It was considered that more various statistical analyses would be necessary to find some different relationships and influence factors between biotic and abiotic variables in the urban stream.

Abstract
 INTRODUCTION
 MATERIALS AND METHOD
  1. Survey period and study sites
  2. Physicochemical water quality analysis
  3. Sampling and identification of benthicmacroinvertebrates
  4. Analyses of functional groups
  5. Statistical analyses
 RESULTS AND DISCUSSION
  1. Water quality
  2. Distribution of benthic macroinvertebrate fauna
  3. Dominant species and community indices
  4. Analyses of functional groups
  5. Statistical analyses
 CONCLUSION
 REFERENCES

• Yoon, Sang-Hoon(Health & Environment Research Institute of Gwangju) Corresponding Author
• Suk-Kyeong Jung(Health & Environment Research Institute of Gwangju)
• Gwang-Yeob Seo(Health & Environment Research Institute of Gwangju)
• Young-Gwan Cho(Health & Environment Research Institute of Gwangju)