The pilot study was undertaken with the Yellow River Conservancy Commission and focused on the lower reaches of the basin, an 840km stretch from Xiaolangdi Reservoir (the last major reservoir on the trunk stream) to the estuary.
A holistic environmental flows assessment was completed, focusing on the flow needs of a series of important wetlands and the river delta. Based on the study, two alternate flow regimes were proposed – one represents a low risk to ecological health, and the other a medium risk.
A river health assessment was undertaken, using existing management targets to select appropriate indicators. The indicators related to:
- Instream ecology: data on fish, macroinvertebrates and riparian plants were assessed against reach-specific reference values.
- Delta vegetation: An index for riparian vegetation in the delta was developed, using satellite images to assess the composition of the vegetation in key wetlands and any loss of wetlands to agriculture.
- Water quality: based on the degree of achievement of a target grade.
- Physical form: based on channel capacity and the movement of sediment.
- Hydrology: based on the recommendations of the environmental flows study, as well as using the Flow Health tool.
- Socio-economic factors: including indicators related to water supply, hydropower production, navigation, and flood risk.
A report card was completed describing the results of the river health assessment. A companion report shows different management initiatives across the river basin aimed at improving ecological health.
Technical reports with further detailed information are also available.
Summary of the results of the river health assessment for the lower Yellow River