This study aims to respond to the call of the Dali Bai Autonomous Prefecture Ecological Environment Bureau to intensify monitoring of the Erhai Lake area and its main rivers, and conduct long-term and continuous monitoring of the chemical oxygen demand (COD) and dissolved oxygen (DO) in the river channel entering Erhai Lake in Dali Manjiang. By deeply analyzing nearly 170 sets of monitoring data and drawing a relationship diagram between COD and DO, we have a deep understanding of the relationship between these two water quality indicators in the river channel entering Erhai Lake in Dali Manjiang. This study not only provides strong data support for further monitoring and control of the river channel entering Erhai Lake, but also provides a scientific basis for promoting the protection of Erhai Lake. By revealing the relationship between COD and DO, it is possible to more accurately assess the water quality of the river channel entering Erhai Lake, so as to more effectively formulate and implement environmental protection measures and contribute to the sustainable and healthy development of the ecological environment of Erhai Lake.

dissolved oxygen  /  chemical oxygen demand  /  river channel  /  relationship