Basin scale hydrology scenarios to explore Green Water Credits opportunities Peter Droogers, SEI

Questions to be answered  What is the present delivery and use of green and blue water?  What is the potential incremental green and blue water gains?

Why models? Understand current water resources Understand past water resources Options for future - technical - - socio-economic - - policy oriented Trend Past Today Future Remote Sensing Observations Analysis Statistics Models ? Data  Information  Knowledge  Policies

Why modeling tools  Modeling Understanding processes Understanding processes Scenario analysis (what, if) Scenario analysis (what, if)  Green Water Credits Proof of GWC sellers delivery Proof of GWC sellers delivery e.g. less sedimentation, more blue water deliverede.g. less sedimentation, more blue water delivered Proof of GWC buyers benefits Proof of GWC buyers benefits e.g. less siltation, more hydropower generation, more relibale drinking watere.g. less siltation, more hydropower generation, more relibale drinking water

Modeling tools  SWAT Supply analysis, basin scale Supply analysis, basin scale  WOFOST Detailed crop analysis Detailed crop analysis  WEAP Demand size allocation and benefits Demand size allocation and benefits

SWAT Channel/Flood Plain Processes Soil Water Assessment Tool

Land processes

SWAT Upper Tana

 Watershed delineation  Land use  Soils  Climate  HRU  Results

 Watershed delineation  Land use  Soils  Climate  HRU  Results

 Watershed delineation  Land use  Soils  Climate  HRU  Results DRSRS Land use map, 101 classes

 Watershed delineation  Land use  Soils  Climate  HRU  Results

 Watershed delineation  Land use  Soils  Climate  HRU  Results

 Watershed delineation  Land use  Soils  Climate  HRU  Results Hydrological Response Units = unique combinations

SWAT Results  Preliminary Results  Proof of Concept  Initiate Discussions

Actual evapotranspiration

Actual transpiration (Green Water)

Soil evaporation

Blue Water (runoff)

Groundwater recharge

Erosion

Scenarios  Enhance Green Water Use  Reduce Soil Erosion

Erosion reduction (%)

Next Steps  Feedback!  Some additional data  Suggestions for scenarios  Link with other approaches (WOFOST, WEAP)

Thank You