Support to sustainable development in Lake Turkana and its river basins: Results of modelling of future scenarios of Lake Turkana and its river basins – Technical report – Kenya


EXECUTIVE SUMMARY

Introduction

As part of the tripartite project, including the Federal Democratic Republic of Ethiopia, the Republic of Kenya and the United Nations Environment Programme (UNEP), on ‘Support to Sustainable Development in Lake Turkana and its River Basins’ which is being carried out by the UNEP-DHI Centre on Water and Environment.

The project is co-funded by the European Union Emergency Trust Fund for Africa, through its project on “Support for Effective Cooperation and Coordination of Cross-border Initiatives in Southwest Ethiopia-Northwest Kenya, Marsabit-Borana & Dawa, and Kenya-Somalia-Ethiopia (SECCCI)”. The overall SECCCI objective is to ensure the effective cooperation and coordination of cross border initiatives. The specific objectives of the project ‘Support to Sustainable Development in Lake Turkana and its River Basins’ are the following:

  • Establishing a common scientific understanding of the Lake and its River Basins

  • Set up a monitoring system for Lake Turkana and its River Basins

  • Capacity building in Transboundary Water Management (TWM) and transboundary dialogue activities to build trust, confidence, cooperation and a shared vision

  • Implementing pilot demonstrations for ecosystems rehabilitation

Conclusions

Simulations for the next 20 years predict that climate change may result in a marked increase in inflow to Lake Turkana, primarily from the Omo River, but also increased inflow from Kerio and Turkwel rivers. Such a possible increase in inflow will result in an increasing water level in Lake Turkana. Thus, the flooding which occurred in year 2020, which was considered a rare event, is likely to be become more regular in the future without any adaptation measures. The new evidence of continuing rising lake water levels is partially based on climate change scenarios and a predicted change in rainfall patterns due to climate change. These climate change projections, however, are associated with a degree of uncertainty.

Mutual gains for both basin countries can be achieved if the basin countries develop an arrangement for water cooperation. Possible transboundary mutual gains between Climate Change (CC), Water Resources Developments (WRD) and Rehabilitation and Adaption Measures (RAM) have been identified:

  • Increased irrigation and other abstractions within the basin may help to counterbalance increasing water levels in Lake Turkana due to climate change. Impacts of irrigation on water quality have not been factored in the model. Irrigation will need to be properly managed to avoid negative effects on water quality, such as agricultural nonpoint source pollution.

  • Likewise, reforestation and soil and water conservation measures may also help to counterbalance the impact of climate change. However, the effect of increasing water use will be relatively stronger, due to increased evaporation and less runoff from steep headwater catchments.

  • It will be possible to partly reproduce the seasonality in inflow to Lake Turkana to maintain fish production and at the same time maintain the same Total Hydropower Production in the Ethiopian part of the basin.

  • A cooperation framework should be established to guide planning and development efforts at the basin scale. The project deliverable “Draft Framework on Transboundary Water Management” addresses this.

  • Soil and water conservation and reforestation measures will significantly help reducing the risk of landslides and mudflows as experienced in West Pokot County, Kenya. It is considered that both countries will benefit from when implementing these measures. The benefits will mainly be onsite benefits and will particularly ensure a more efficient and, not least, more sustainable crop production and conversion from other land uses to cultivation.

  • From a global perspective reforestation and agroforestry may also help fighting global warming and help restoring habitat loss.

  • Agroforestry will have two additional advantages: Intercropping crops with leguminous N2-fixing agroforestry species e.g. Acacia and Caleandra, can help replenish nitrogen harvested with crops and thereby maintain the N-balance and reduce the need for artificial fertilizers. Fodder trees can also be an important feed source for livestock and reduce livestock pressure on grassland.

Indicator Framework

An attempt was made to establish a framework that covered all relevant sectors namely: Agriculture, Economy, Energy, Environment, Fishery, Social Welfare, Water Resources and Water Supply & Sanitation. Efforts to collect field data were carried out in the Kenyan part of the basin, to enable the conceptualization and calculation of indicators specific to the project scope and area. These efforts resulted in the calculation of the following indicators:

  • Annual lake water level fluctuations

  • Fish production indicators

  • Households with farm holdings

  • Labour division indicator

  • Net Present Value for hydropower

  • Net Present Value for irrigation

  • Percent of years where water levels result in severe inundation

  • Salinity indicator

  • Settlements affected by inundation

This framework was used in the Planning application to facilitate the evaluation of each scenario as well as comparison of impacts across scenarios and the prioritization exercise using the MCDA method.

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Source link : https://reliefweb.int/report/kenya/support-sustainable-development-lake-turkana-and-its-river-basins-results-modelling

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Publish date : 2021-07-19 15:45:21

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