This is the new World Water Quality Portal by the International Initiative of Water Quality IIWQ, UNESCO-IHP International Hydrological Programme.

The IIWQ Water Quality Portal is a free visualiser of satellite derived water quality information for worldwide lakes and rivers.

A global set of parameters in 90m spatial resolution is provided on a continental base for each of the UNESCO Regions. Access to time series products in 30m spatial resolution is available for pilot regions, one per continent, covering the year 2016.

This application allows you to interactively browse water quality products. You can use the features on the right hand side to select your region of interest, select various water quality parameters, set any desired virtual sampling stations, gather values and time series information.

To find more information, please use the Training Materials button.

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IIWQ World Water Quality Information and Capacity Building Portal
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Time Series Plot


Welcome to UNESCO WaterQualityApp, a free online visualiser for global water quality products of all inland and coastal waters worldwide.

The online platform provides you with water quality based information for all continents including a merged global set of parameters in 90m resolution. You can also access time series products in 30m sampling resolution, for selected regions in each continent, covering the year 2016.

This application allows you to interactively browse the water quality products. Use the features on the right hand side to select your region of interest, select various water quality parameters, set any desired virtual sampling stations, gather values and time series information. A quick information guide gives a summary of how to use this portal, see also below.

To download an information booklet on these products, click Information Booklet Water Quality Monitoring

To download a training handbook covering main practical questions of using satellite based information products, click Training handbook

How to use this Portal

Basic map tools for interacting with the map are provided on the right hand side of the top bar. Basic map tools include zooming and placing a virtual measuring station. A computer mouse can be used for panning and zooming or alternatively, interact on the touch screen of a mobile device. Virtual stations are created with a tap on the map and map sections can be moved by dragging the fingers across the screen.

The blue function bar includes the following:

  • Select regions to explore individual dates and time series in 2016 or full world mosaic layers.
  • Select water quality parameters (turbidity, chlorophyll-a, the harmfull algae bloom indicator HAB, organic absorption or surface temperature).
  • Once virtual station is set, a parameter value is shown in the value section. If you have selected the World Mosaic layer, you can view also the record date below the parameter value.
  • Generate a time series plot of the selected parameter value at your virtual measuring station.
    After placing the pin for the virtual measuring station please wait few seconds before clicking the button as the time series data is generated on the fly from the available data layers.
  • Generate a report including statistical measures for the selected year. Once a parameter is visualized in the time series plot you can find the button for generating the report on the lower right part of the time series plot.
  • The blue function bar can be minimized by clicking on the ">" character on the upper right of the blue panel. This may be of help if you are using mobile devices.

What this Portal shows

Turbidity: measures the degree to which light is being backscattered by particles in the water. Tracking changes in turbidity is useful when monitoring sediment plumes from dredging and dumping activities. The measurement unit is Earth Observation Turbidity Unit (ETU) and directly related to backscattering of particles, very similar in magnitude to Nephelometric and Formazine Turbidity Units (NTU and FTU). It is linearly related to Total Suspended Matter (TSM) at low to moderate turbidity values.

Chlorophyll-a: Chlorophyll-a is an essential pigment included in phytoplankton cells and therefore a measure of phytoplankton. The displayed Chlorophyll-a CHL is calculated from total scattering and total organic absorption of water constituents. Unit is [µg/l]

HAB Indicator: Harmful Algae Blooms (HAB) indicator shows possible areas affected by harmful algae blooms formed by cyanobacteria containing phycocyanin.

Please read the information booklet for further information on the water quality products and to learn more about the validity range of the products. Products are generated independent on any form of ground truth data, and inter-comparable over the various resolutions provided. The Chlorophyll and HAB indicator may have site-specific limitations e.g. for extremely humid, calcareous, or ferruginous waters, and can be improved with local adaptations. General restrictions are caused by clouds, optical shallow waters, or undetected artefacts from e.g. cloud shadows.


Q: How can I learn more about these satellite-derived map and data water quality products, uncertainties and methodological differences between satellite based and in-situ or laboratory measurements
A: For a first overview, please download our information booklet. For further details on WQ monitoring…please refer to links provided in the booklet.
Information Booklet Water Quality Monitoring
Validation Examples Water Quality

Q: I have technical problems using the portal, or wish to access water quality data for other dates or resolutions. Who can help me?
A: Please contact the support team at, or the support team of EOMAP at

Q: I am interested in a location outside the polygon areas that you feature here. How can I view water quality maps for my location?
A: In the blue function bar on the right hand side, you can select the full world mosaic layer. As soon as you have set a virtual station, you can see the date of the data record for that point. Or you can select in the same tab other available demo regions with time series data of 2016 in 30m resolution.



7 place Fontenoy
75007 Paris

phone: +33 (0)1 4568 1000

This application is provided by the: International Hydrological Programme (IHP)


The information presented through this interface is provided "as is" and users bear all responsibility and liability for their use of the data. UNESCO does not warrant that the information, documents and materials contained in its website is complete and correct and shall not be liable whatsoever for any damages incurred as a result of its use.


AM/AZ - Caucasus highlands

One of the largest freshwater high-altitude lakes of Eurasia, Lake Sevan in Armenia at 1900m above sea level, the recently completed Semkir Reservoir in the Caucasus region of Azerbaijan and the associated river systems including the Kur river are covered in this focus region. The waterbodies in this region have been intensively used for irrigation in the past century, resulting in severe ecological impacts for Lake Sevan.

The Caucasus region around the Semkir reservoir is characterized by semiarid subtropical steppe climate, mild winters, hot summers and an annual precipitation of 250nm. At Lake Sevan the winters are very cold due to the high-altitude semiarid continental climate, with an slightly higher annual precipitation of 300nm.

AR/BR/PY - Itaipú/Paraná River

Located right at the border of Paraguay and Brazil, the Itaipú dam impounds the Paraná river over a distance of more than 170 km. Until the construction of the Chinese Three Groges Dam, it was the world’s biggest power plant, and in terms of annual energy produced, it still is. Its construction took eight years and did not only have direct impacts on the economy, but also on the ecology and geography of the area. Forest had to be cut down to make room for the gigantic project, thousands of indigene people were moved and vast areas of rainforest, together with their adjacent waterfalls, were flooded. One of them had been the world’s largest waterfall by volume and had separated the areas above and below him into different ecoregions.After the building of the dam, species, formerly restricted to of these ecoregions, were able to enter the other and caused the typical problems that come with such invasions. On the other hand, the dam produces 75% of Paraguay’s and nearly 20% of Brazil’s energy and is also considered one of the seven modern Wonders of the World. Due to its size, political and economic value and its location within an ecologically precious region, monitoring the state of the river and lake is crucial.

DE - Mecklenburg Lake Plateau

More than 2000 small and few larger lakes cover the MecklenburgischeSeenplatte in Northern Germany. The lakes have formed from a pro-glacial lake during last glacial period.In this target area, a large variety of meso- and eutrophic lakes is included, which are under anthropogenic pressures such as fertilizers from agriculture. An increasing number of Cyanobacteria blooms is of public interest, and currently investigated as possible side effect of global warning. The regular assessment of the ecological status as requested by the European Union’s Water Framework Directive WFDis a challenging task for environmental agencies in states like Mecklenburg-Vorpommern with avery high number of distributed lakes larger than 10ha. Remote Sensing can therefore efficiently support planning and fundamental monitoring tasks - also for smaller lakes which are not covered under the WFD. The climate in Northern Germany is characterized by moderate warm summers and mild cloudy winters, with an annual mean temperature of 10 degrees Celsius and 600mm annual precipitation.

The region is well suited as a reference area for extended validation exercises of satellite-derived water quality products, due to the high activity level of several leading environmental research institutions, universities and the water agencies themselves.

EG/SD - Nile & Assuan Reservoir

Lake Nasser in Egypt and its southern end Lake Nubia as called by the Sudanese was created as result of the construction of the Aswan High Dam in Egypt, and fed by the Nile, the world’s longest river. Lake Nasser is one of the largest men-made reservoirs and was constructed to control flooding, provide increased water storage for irrigation, and generate hydroelectricity . It improves the extremely vulnerable food and water security situation in Egypt. Still, the Nile River has a major impact on the interstate politics of the region, as it is the only reliable source for renewable water supplies in the area. As other dams, sediment trapping is causing changes in downstream water quality, with significant impacts on coastal erosion in the Nile delta , which reversed from growth to a shrinking process since the closing of the dam.For this study, we selected the inflow area of Lake Nasser between Sudan and Egypt, covering the highest sedimentation levels and water quality gradients in the reservoir.

The climate conditions are subtropical at the borderline to a tropical arid climate, with extremely dry and hot summers and an annual precipitation of almost 0 mm. The Nile highwater season is in August/September, following the rainfall season in the upstream area in Ethiopia.

KH/VN - Mekong delta

The Mekong delta represents by far Vietnams highest productive aqua- and agriculture environment, and is home for a population of around 17 million people. It is highly vulnerable to several climate change impacts, such as saltwater intrusion caused by sea level rise . Also massive human made disturbances to the river ecosystem from large dams create major threads to the fish and agriculture production, both to Cambodia and Vietnam. Half of the sediments are trapped in a cascade of upstream dams and water diversion schemes, resulting in a significant nutrient reduction and consequent halving of productivity . Satellite based water quality measurements can contribute with independent measurements of turbidity , sediment flows, assessments of the organic components. A sediment analysis for the entire delta and the cascade of upstream dams can quantify not only actual impacts, but also historic changes using satellite data up to 30 years back in time.

The Mekong delta has a tropical wet and dry climate within the drainage basin (monsoonal), a high annual precipitation of approx. 1500mm especially during the summer months from May to October, and a relative dry season from November to April.

US - Florida lakes

Located near the eastern shore of central Florida, this area is covered by numerous lakes, from small to vast, with a wide spectrum of characteristics. The climate can be classified as humid subtropical, with an annual precipitation of approx. 1200mm, resulting in warm winters and hot, humid summers. Therefore, the waterbodies and their water quality parameters are highly dynamic and might differ within small areas. While some lakes are very clear, others can become very turbid, sometimes even with high amounts of phytoplankton. Their classification ranges from eutrophic to hyper-eutrophic, with some lakes showing regular and significant blooms of cyanobacteria. Partly, the lakes can be covered by water lilies and surrounded by cattail plants or swamp cypresses. Due to these differences and dynamics, the area is specifically interesting to put water quality algorithms to a test. Additionally, there are large amounts of validation data available, especially from the Lake County Water Authority and the United States Environmental Protection Agency (EPA). Those institutions provide long-term in-situ measurements for a large number of lakes in this region, which makes them well suited for extended validation exercises of satellite-derived water quality products.

ZM/ZW - Zambesi River

Lake Kariba is one of the largest reservoirs worldwide, providing electricity to much of Zambia and Zimbabwe. Lake Kariba is fed by the Zambesi River. The selected area covers the eastern part of Lake Kariba and the Middle Zambesi river between the Lower Zambesi National park and the Mana Pools National park. As other dams, sediment trapping in the Lake Kariba and the subsequent Cahora Bassa dam is causing significant impacts on coastal erosion in the Sambesi delta, which nowadays is only half of its original size.

Lake Kariba and the Middle Zambesi river is located in a tropical semiarid climate with an annual precipitation of approx. 800mm, where the significant contributions are during the summer months from November to March. April to October is very dry.