Optimized agriculture activity in response to reservoir hydrological operation to reduce nutrients input and increase the water quality in the Three Gorges Reservoir (China)

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Description

Location

Demosite Location
Demosite Location

Sketch

Demosite Location

Information about lithology/geochemistry:

Purple sand stone: 49% Sand shale: 35% Limestone dolomite: 11% Others: 5%


Main Description

  • Pengxi River, a tributary of the Yangtze, in the Three Gorges Reservoir, a high impacted ecosystem
  • China Three Gorges Reservoir, the largest one in China. Large scale seasonal operation for hydropower production and flood control
  • Water supply; Agriculture; Biological primary production; Biodiversity maintenance; Environmental purification

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.
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.


Maintenance of genetic diversity: Genetic diversity is the variety of genes between and within species populations. Genetic diversity distinguishes different breeds or races from each other thus providing the basis for locally well-adapted cultivars and a gene pool for further developing commercial crops and livestock. Some habitats have an exceptionally high number of species which makes them more genetically diverse than others and are known as ‘biodiversity hotspots’.

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

Lifezones

Demosite Location
Life zone
Subtropical
Montane
Moist Forest

Precipitation
PPT(mm/yr): 1300.0

Temperature
T(ºc): 14.0

Elevation of demosite: 175.0 meters above sea level
Humidity: Humid
PETr (by year): 0.72

EH Principles

Quantification of the hydrological processes at catchment scale and mapping the impacts

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

Ecological engineering (integration, dual regulation and biotechnologies in catchment scale for enhancement of ecological potential)

ECOHYDROLOGY ENGINEERING SOLUTIONS

Human-induced, low-intensity restoration (NbS)“phytotechnology”:Mulberry or willow bushses Limited crop planting

Phytotechnology

Limited free livestock pasturing

Faunatechnology

Low-cost wastewater treatment infrastructure

Ecohydrological Infrastructure

restoring the terrestrial community adaptive to reservoir operation, and optimize human activity in reservoir drawdown area

Ecohydrological Infrastructure
Faunatechnology
Phytotechnology
Hydrological Flow

“pulse effect” during floods 20 days to 30 days flooded mainly affect 160m or below

Hydrological Flow

Major Issues

  • 1) Droughts: Drying, cracking and erosion
  • Sedimentation of floating solid wastes
  • 2) Intensive land use: Intensive and unrestricted farming practice, in turn stimulate erosion and nutrients release
  • 3) Vegetation recover and re-flooded periodically: OM and nutrients release
Which: reservoir drawdown area, the decrease in ecosystem service and Algal blooms occurred after the impoundment of the TGR

Social ecohydrological system

EH Objectives

Water:
Biodiversity
Services
Resilience
Cultural Heritage

EH Methodology

  • Reduce nutrients input

  • Increase water renewal

  • Reduce anthropogenic perturbations

  • Reduce the water level fluctuations

  • Habitat and plant restoration

  • Solid waste removal

  • Limit or reorganize farming activities

  • Optimize land-use and removal of OM after drawdown


Catchment Ecohydrological sub-system

Objectives

  • To Reduce the terrestrial input of nutrients, and reduce the risks of algal blooms

  • Increase the sustainability potential of reservoir drawdown area (WBSR)

  • Meet the needs of stakeholders, optimize the social-economic system for long-term management


  • Stakeholders

  • Local residence

  • Local government

  • Upstream community

  • The China Three Gorges Corporation

  • Central government

  • Catchment Sociological sub-system

    Activities

    • Restore shoreline community, increase the capability of nutrients removal and upgrade landscape

    • Limit and optimize anthropogenic activities, in particular farming practice in reservoir drawdown area

    • Optimize reservoir operation strategy


    Expected Outcomes

    • Reduce nutrients input and increase the water quality


    • Reduce the frequency of algal blooms in the demo sites


    • Optimized agriculture activity



    Latest Results

    • In-situ development of NbS ecological engineering approach are constructed in the bay for restoration

    • Wastewater treatment plant and low impact infrastructure are constructed in the upstream watershed


    Contacts

    Zhe LI

    • lizhe@cigit.ac.cn
    • Key Laboratory of Reservoir Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences

    Overview

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