ECOHYDROLOGY AS THE FRAMEWORK FOR SUSTAINABLE UTILISATION OF WATER IN THE NAIVASHA BASIN (KENYA)

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Description

Location

Demosite Location
Demosite Location

Sketch

Demosite Location

Information about lithology/geochemistry:

Pleistocene Gamblian sediments-Tertiary and Quaternary pyroclastic and lacustrine deposits/Sandy clays and clay loams eroding from the wider catchment enter the lake basin from the River Malewa.


Main Description

  • Lake Naivasha (fig. 1) is the second largest freshwater lake after Lake Victoria in Kenya. Drainage from two perennial rivers, the Malewa (Nyandarua Mountains) river and the Gilgil river (Rift Valley escarpment ridges).
  • Lake Naivasha is surrounded by the major source of cut flowers and vegetables in Kenya (productivity of export crops: 1,4-2,1 t per year).
  • This project is funded by European retailer buyers of flowers from Lake Naivasha and additionally, Lake Naivasha is a RAMSAR site since 1995 (over 300 species of birds).

Conserve Ecohydrological processes in natural ecosystem

YES

Enhance ecohydrological processes in novel ecosystem

YES

Apply complementary Ecohydrological processes in high impacted system

YES


This table presents the different categories of ecosystem services that ecosystem can provide, divided in:

Provisioning Services are ecosystem services that describe the material or energy outputs from ecosystems. They include food, water and other resources.

Food: Ecosystems provide the conditions for growing food. Food comes principally from managed agro-ecosystems but marine and freshwater systems or forests also provide food for human consumption. Wild foods from forests are often underestimated.


Fresh water: Ecosystems play a vital role in the global hydrological cycle, as they regulate the flow and purification of water. Vegetation and forests influence the quantity of water available locally.

Regulating Services are the services that ecosystems provide by acting as regulators eg. regulating the quality of air and soil or by providing flood and disease control.

Erosion prevention and maintenance of soil fertility: Soil erosion is a key factor in the process of land degradation and desertification. Vegetation cover provides a vital regulating service by preventing soil erosion. Soil fertility is essential for plant growth and agriculture and well functioning ecosystems supply the soil with nutrients required to support plant growth.

Ecosystem services "that are necessary for the production of all other ecosystem services". These include services such as nutrient recycling, primary production and soil formation.

Habitats for species: Habitats provide everything that an individual plant or animal needs to survive: food; water; and shelter. Each ecosystem provides different habitats that can be essential for a species’ lifecycle. Migratory species including birds, fish, mammals and insects all depend upon different ecosystems during their movements.

Cultural Services corresponds nonmaterial benefits people obtain from ecosystems through spiritual enrichment, cognitive development, reflection, recreation, and aesthetic experiences.

Tourism: Ecosystems and biodiversity play an important role for many kinds of tourism which in turn provides considerable economic benefits and is a vital source of income for many countries. In 2008 global earnings from tourism summed up to US$ 944 billion. Cultural and eco-tourism can also educate people about the importance of biological diversity.

Lifezones

Demosite Location
Life zone
Tropical
Premontane
Dry forest

Precipitation
PPT(mm/yr): 650.0

Temperature
T(ºc): 25.0

Elevation of demosite: 1884.0 meters above sea level
Humidity: Sub-Humid
PETr (by year): 2.27

EH Principles

Distribution of ecosystems and their relevant processes (ex: metabolism=water and nutrient uptake and retention; biomass production)

ECOHYDROLOGY ENGINEERING SOLUTIONS

Protection of Cyperus papyrus (fig.2) fringe through replantation in the riparian area.

Phytotechnology

Artificial islands were planted onshore in ponds with papyrus to be anchored offshore in selected locations.

Phytotechnology

Major Issues

  • Encroachment of riparian areas
  • Decrease of water level of the lake due to water over abstraction
  • Invasive species such as the common carp and the Louisiana crayfish

Social ecohydrological system

EH Objectives

Water:
Biodiversity
Services
Resilience

EH Methodology

  • Apply the three principles of the EH paradigm to each part of the ecosystem under stress 1) Water in rivers – available for domestic use but clean and adequate supplies 2) Water in lake – reduced algal growth to minimise supply risks, support of fisheries through the food chain 3) Vegetation – to maintain evapotranspiration to sustain local rainfall and maintain temperatures

Catchment Ecohydrological sub-system

Objectives

  • Apply the EH principles to return the Lake Naivasha basin ecosystems to sustainable use, through instilling an understanding of the role of the water cycle in supporting human existence and the context of sustainable Ecosystemm Services within the framework of Christianity, which is fundamental to the vast majority of the basin’s population

  • Stakeholders

  • Researchers (Universities)

  • Water Ambassadors

  • Local workers in the export horticultural industries

  • Lake Naivasha Growers Group

  • LNRA

  • Imarisha Naivasha Trust

  • Nakuru County Government

  • Lake Naivasha Fisherman’s Beach Management Units

  • Catchment Sociological sub-system

    Activities

    • Establishing educational programmes for the local stakeholders and communities such as training « Water Friendly Farmers » and « Water Ambassadors »

    • Restoring dams on small impoundments and building cattle drinking troughs below them, using cleaning action of natural wetland plants to clarify water

    • Modelling the economic costs of water by all users (agriculture, industry, tourism) to propose a voluntary ‘conservation levy’ that can maintain ecosystem health

    • Establish an Equitable Payment for Watershed Servies project

    Expected Outcomes

    • Reduction of eutrophication, restoration of lake-shore vegetation, reliable water domestic & industrial water, sustainable fisheries yields


    Latest Results

    • The complex (unpredictable) linkage between rainfall, resulting flood pulse, P and uptake by floating plant mats (water hyacinth) has been better understood.

    • The ecohydrological relationship between the alien carp, which dominates the gillnet fishery and the native tilapias, which are predominantly removed by illegal fishing, has been unravelled.

    • The ecosystem services of the lake and basin have been better quantified.

    Contacts

    David Harper

    • dmh@le.ac.uk
    • http://www.le.ac.uk/
    • University of Leicester

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