PUB Working Group 6-5 (WG6-5): Study on ecologically vulnerable basins in China

Objectives:

• To explore the relationship between hydrological cycle and ecosystem vulnerability:
  investigate quantitative, qualitative and conjunctive approaches to assess water resources
  
  
• To investigate methods of evaluating ecological water demand:
  investigate and compare catalogue and water balance-based methods
  
  
• To predict the impact of land use change on the hydrological cycle:
  improve methods for estimating evapotranspiration, using SVAT-distributed modelling and time-variant-Gain-distributed modelling approaches with remote sensing information, and a conceptual modelling approach
  
  
• To assess water resources under the changes of climate and human activities in the three catchments
  

Most of catchments in China, especially in northern China are now suffering disrupted ecological changes, such as river flow -drying out in the Yellow River and Haihe River, the serious water pollution, flood disaster and among others. The initial and the most important task of the prediction problems in ungauged basins in China is to sort out how to assess the water resource in the changed environment, how to calculate ecological water demand which has been ignored for many years in water resources management and how to raise the accuracy of hydrological forecasting. As both the gauged and ungauged basins in China all have been heavily disturbed by human activities.

We gather participants from different research backgrounds on the common variables of interest in the same specific catchments, which is then able to make an inter-comparison of the approaches. The best method which needs less data and still provides high accuracy will be chosen. The first results from this working group provides ne w insights for the prediction in basins suffering ecological disruptions, which is the base to extend the methods to the ungauged basins which are now also suffering these changes. Importantly, the different approaches have very different information requirements – this enables the identification of a hierarchy of preferred methodologies given practical requirements for prediction in data-sparse or ungauged basins. Additionally, this process can be seen in reverse - this permits the identification of data required, given the accuracy required of the analysis.

Building on these results, the integration of the activities may be evaluated – when the different approaches are integrated into a common framework, are the methodologies mutually beneficial? In other words, can uncertainty be reduced through any synergies achieved after integrating these diverse approaches?

Finally, the comparability within working groups enables similar comparability between working group. New insights associated with the performance of different methodologies in different environments are therefore enabled representing significant value -adding to the PUB exercise.

Study Areas

• Wuding catchment (30,000 km²) in the loess plateau of the Yellow River basin
• Chaobai catchment (4,854 km²) of Haihe River in North China
• Heihe Catchment (130,000 km²) in Northwest China

Key Participants:

• Dr Jun Xia
• Yaning Chen
• Dr Xingguo Mo, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences
• Dr Lijun Li, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences
• Dr Suxia Liu, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences
• Dr Ping Xie, Wuhan University
• Dr Huaien Li, Xi’an University of Technology
• Dr Yanjun Shen, Institute of Industrial Science, University of Tokyo
• Dr Guangxing Zhang, Institute of Geography and Agriculture Research in Northeast China, Chinese Academy of Sciences
• Dr Zhengtao Cong, the Department of Hydraulic Engineering, Tsinghua University
• Dr Dawen Yang, the Department of Hydraulic Engineering, Tsinghua University