Transboundary River Basins: Status and TrendsA global, comparative, indicator-based assessment

Paul Glennie

Theme 4: Adapting to change… it’s important to know the baseline

Additional challenges in a transboundary context

286 transboundary river basins, 151 countries, 2.8 billion people.

9 TWAP River Basins PartnersLead

Supporting

THEMATIC GROUPS Baseline Indicators (2010)1. Environmental water stress 2. Human water stress 3. Agricultural water stress

4. Nutrient pollution 5. Wastewater pollution

6. Wetland disconnectivity 7. Ecosystem impacts from dams8. Threat to fish 9. Extinction risk

10. Legal framework11. Hydropolitical tension12. Enabling environment

13. Economic dependence on water resources14. Societal wellbeing15. Exposure to floods and droughts

THEMATIC GROUPS Projected Indicators (2030 & 2050)

1. Environmental water stress 2. Human water stress

3. Nutrient pollution

[Environmental water stress]

4. Exacerbating factors to hydropolitical tension

5. Change in population density

‘business-as-usual’ socio-economic scenario (SSP2) and a continued high GHG emission pathway (RCP8.5) WaterGAP & WBM part of IPCC ISI-MIP project (so harmonization undertaken between GHMs).

Lakes Lake influence

Deltas Relative sea level rise Wetland ecological threat Population pressure Delta governance

TWAP has 5 Components at the project level:

1.Transboundary Aquifers (& SIDS)2.Transboundary Lakes and

Reservoirs3.Transboundary River Basins (RB) 4.Large Marine Ecosystems (LMEs)5.Open Ocean.

- Comparative assessment = relative risk categories (between basins)

- Common relative risk categorization narrative (between indicators)

- Guided by science based thresholds where possible. Partners responsible for defining thresholds.

Relative Risk Category

1 Very low

2 Low

3 Moderate

4 High

5 Very high

Concept of Relative Risk

Key messages & policy implications1. Risks to basins generally projected to increase …2. Most of the projected pressures can be managed, e.g. through:

demand management, efficiency measures, nutrient man. in agriculture, wastewater treatment, transboundary cooperation.

3. Most issues expected to be addressed under the Sustainable Development Goals (SDGs), 2015 – 2030, but countries have responsibility for reaching targets.

4. Commitment needed to improve guidelines for siting new dams, designing dams for multiple purposes, and optimising operation of dams to maximise human benefits and minimise negative ecosystem impacts and sediment trapping.

http://www.geftwap.org http://unepdhi.org Thank you

Interactive data portalhttp://twap-rivers.org