Global Environmental Flow Information System

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Global Environmental Flow System
This web-based interactive application provides information related to Environmental Flows for the current condition and for the different Environmental Management Classes (EMCs) of a river system. The estimated current condition of all rivers is based on the river health indicators developed by Vorosmarty et al., 2010. EMC define the state of the river ecosystem at different levels of river health which may be different to the current condition. They are defined in four classes (from A to D) with "A" being "natural" to "D" being "significantly modified" (Smakhtin and Eriyagama, 2008)
All the maps in this application are displayed on top of a world satellite base-map from ESRI.
The maps presented in the application are:
  1. Natural Annual Runoff (Modelled)(mcm)*: Mean annual runoff for natural conditions as generated by global hydrological model PRC-GLOBWB (Wada et al., 2014).
  2. Current Probable EMC: Represents the current condition of the river.
    1. Environmental Flow Percentage: Percentage of natural flow required to maintain the current condition of river.
    2. Environmental Flow (mcm): Flow in mcm required to maintain the current condition of river.
    3. Sustainable Groundwater Abstraction (mcm): Groundwater that can be abstracted without impacting the EFs for the current condition of river.
  3. EMC: Environmental Management Class (select one out of "A","B","C","D")
    1. Environmental Flow Percentage: Percentage of natural flow required to maintain the EFs for the selected EMC.
    2. Environmental Flow (mcm): Flow (in mcm) required to maintain the EFs for the selected EMC.
    3. Groundwater contribution to Environmental Flow (mcm): Contribution of groundwater (in mcm) in the EFs for the selected EMC.
    4. Sustainable Groundwater Abstraction (mcm): Groundwater that can be abstracted without impacting the EFs for the selected EMC.
2. Statistics
Calculating statistics from the maps
The application allows the user to download the data either as grid-data or as aggregated values at continent, country, basin level, or using a user defined polygon or an uploaded shapefile.
Once the AOI and data processing options are set, statistics are calculated at the server using defined geospatial models and the calculated values are returned to the client. The calculated statistics are presented in graphical and tabular formats.
Calculation of statistics
There are three main steps for the user to follow at the statistic calculation.

Step1 (set class for calculation)
User get the option of processing for Class A, Class B, Class C or Class D.
processing options
Step2 (set AOI)
Country based OAI:
Country based selection allows to select the area of interest from the region level to District (Admin Level III) this AOI option is provided under "Country Based Selection" tab.
Fig. 1: country based selection
Polygon based OAI:
Click on "Summarize Area" button under "Polygon Based" tab and then draw a polygon on the map to select the area of interest. At the end of drawing the polygon it will start processing raster data for calculating the statistics.
Fig. 2: polygon based selection
Fig. 3: an AOI selected by user
Statistical Outputs
Statistical Outputs are presented based on the area of land selected for processing. The outputs are presented in a tabular form.
Tabular output: A table of area correspond to each class and environmental flow is given in million cubic meters.
Fig. 6: A summary table
Tool Guide
Symbol / AbbreviationDescription
Activates zoom in tool. Draw a rectangle on map to zoom in.
Activates zoom out tool. Draw a rectangle on map to zoom out.
Display the map in full extent.
Set the map to next extent.
Activates pan tool for paning the map.
Deactivate any other selection.
Legend button. Display map legend at the right hand coroner
Abount button. Open the about window which gives a brief introduction about the map.
Help button. Open the help content

AOI

Area of Interest.
References

Sood, A. Smakhtin, V. Eriyagama, N. Villholth, K. G. Liyanage, N. Wada, Y. Ebrahim, G. Dickens, C. 2017. Global environmental flow information for the sustainable development goals. Colombo, Sri Lanka: International Water Management Institute (IWMI). 37p. (IWMI Research Report 168). doi: 10.5337/2017.201

Smakhtin, V. and Eriyagama, N. (2008). Developing a software package for global desktop assessment of environmental flows. Environmental Modelling & Software, 23: 1396-1406.

Vorosmarty CJ, McIntyre PB, Gessner MO, Dudgeon D, Prusevich A, Green P, Glidden S, Bunn SE, Sullivan CA, Liermann CR, Davies PM.(2010). Global threats to human water security and river biodiversity. Nature, 467(7315):555-61.

Wada, Y., D. Wisser, and M. F. P. Bierkens (2014). Global modeling of withdrawal, allocation and consumptive use of surface water and groundwater resources, Earth System Dynamics, 5: 15-40.

Maps

Natural Annual Runoff
High : 987.1
Low : 0
Present Day EMC
Environmental Flow (%)
<20
20 - 40
40 - 60
60 - 80
80 - 100
Environmental Flow (mcm)
High : 853.15
Low : 0
Sustainable Groundwater Abstraction (*10-3mcm)
0 - 50
50 - 100
100 - 150
150 - 200
200 - 350
350 - 600
600 - 1,000
1,000 - 2,000
2,000 - 5,000
> 5,000
Classes
A
B
C
D

Environmental Flow (%) - Class A
< 20
20 - 40
40 - 60
60 - 80
80 - 100
Total Environmental Flow - Class A
High : 878.66
Low : 0
Total Base Flow Contribution (mcm) - Class A
High : 595.1
Low : 0
Sustainable Groundwater Abstraction (*10-3mcm) - Class A
0 - 50
50 - 100
100 - 150
150 - 200
200 - 350
350 - 600
600 - 1,000
1,000 - 2,000
2,000 - 5,000
> 5,000

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