Title |
Evaluation on Pollution Load Characteristics and Influence of Tributaries in the Hwangguji Stream |
Authors |
임수진 ( Su-jin Lim ) ; 임병란 ( Byung-Ran Lim ) ; 이한샘 ( Han-saem Lee ) ; 강주형 ( Joo-hyoung Kang ) ; 안태웅 ( Tae-ung Ahn ) ; 신현상 ( Hyun-sang Shin ) |
DOI |
https://doi.org/10.15681/KSWE.2021.37.4.249 |
Keywords |
Hwangguji stream; Load duration curve; River grade classification; Tributaries; Water quality index |
Abstract |
This study investigated the pollution characteristics of the main pollution zone in the Hwangguji watershed and the influence of the tributary on the main stream. The characteristics of the main pollution zone, including, the water quality index (WQI), stream rating, load duration curve (LDC), delivery load density (DLD), and contribution of the tributary to the mainstream, were evaluated by time-series visual heatmap. The WQI of the mainstream of Hwangguji was lowered to the poor (IV) level from the inflow point of Suwon stream (SW) and the LDC excess rate in the T-P was higher than that of BOD5, especially for the wet season, suggesting that management of non-point source with T-P is preferred. The contribution (%) of the tributaries in the upstream section of Hwangguji watershed were BOD5 14.54%, TOC 15.67%, T-N 5.43%, and T-P 6.97%. In particular, the Suwon sewage treatment plant located in the mainstream showed a high contribution of BOD5 (64.40%) and T-P (53.54%), respectively, due to the high discharge rate (6.019 ㎥/sec). Meanwhile, Sammi and Gal stream have a large impact on the mainstream with high DLD and poor WQI. Thus, both streams were considered as pollution hot spots. These results provide useful basic data for preparing more effective water quality improvement and management plans in the watershed. |