1 / 18

Use of MODIS and MERIS data for the water quality monitoring

Use of MODIS and MERIS data for the water quality monitoring of Amazonian rivers and floodplain lakes Jean-Michel Martinez, L. Maurice-Bourgoin, P. Moreira-Turcq, J.L. Guyot Contact e-mail : martinez@ird.fr French Research Institute for the development (IRD)

Download Presentation

Use of MODIS and MERIS data for the water quality monitoring

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Use of MODIS and MERIS data for the water quality monitoring of Amazonian rivers and floodplain lakes Jean-Michel Martinez, L. Maurice-Bourgoin, P. Moreira-Turcq, J.L. Guyot Contact e-mail : martinez@ird.fr French Research Institute for the development (IRD) Hydrology and Geochemistry of the Amazon Basin project (HIBAM)

  2. Context • Satellite data are routinely used for monitoring of ocean waters (primary production) • Low resolution sensor specialized such as Sea-Wifs • Complex models developed for inversion (radiative transfer, NN) • Few works on inland waters by satellite, problems are : • Fast changing and complex water quality (Sediment, chlorophyll, organic matter) • Spatial resolution • Radiometric resolution • Time resolution New sensors such as MODIS (launched in 2000) & MERIS (launched in 2002) offer the trade off between space/radiometric/time resolutions

  3. Objective • To quantify how medium resolution sensors allow to monitor water quality in Amazonian rivers and floodplain lakes • Analysis of MODIS & MERIS images in conjunction with HIBAM field campaign and network station database giving main water quality parameters Methodology

  4. Remote sensing data • MODIS (Terra) MOD09_L2G products calibrated and atmospherically corrected • 250 & 500-meter resolution, 1 image / day, 2 & 5 bands • MERIS (ENVISAT) Full resolution mode (acquired trough an ESA Category-1 user project) • 300-meter resolution, 1 image / 3 days, 15 bands ETM + MODIS MERIS Spectral resolution : 400 500 600 700 800 900 l (nm)

  5. Amazonian waters • 3 kinds of waters : • White water rich in suspended sediments (SS) and major elements • Black water rich in DOC/POC and poor in suspended sediments • Clear waters moderately enriched in nutrients and poor in SS

  6. The 4 seasons of the floodplain lakes • Rising stage : River water entering (moderate to high TSS* : 50 to 150 mg/l) - Low biological activity • High waters: Deposition (low TSS < 30 mg/l) and increasingprimary production (phytoplanctonic blooms) • Decreasing stage : Deposition (low TSS 30 mg/l) and maximum biological activity • Low water stage : shallow depth & re-suspension process under wind effect (very high TSS : 100 - 1000 mg/l) - Low biological activity *TSS : Total Suspended Sediment (in mg/l)

  7. Sub-Catchment of 3500 km² Test site : the Várzea of Curuaí Óbidos Amazon river Santarém Tapajós river 0 100 km

  8. Pure Water Increasing TSS Spectral profile using MERIS of the floodplain water : rising stage TSS data from the HYBAM project database

  9. Increasing TSS Spectral profile using MERIS of the floodplain water : high waters

  10. Spectral profile using MERIS of the floodplain water : high waters

  11. Increasing TSS Spectral profile using MERIS of the floodplain water : low water stage

  12. Implications for water quality monitoring • Analysis • PCA shows that the reflectance is firstly affected by the TSS concentration • TSS & Chlorophyll both affect Green and Red bands for low TSS values • Black waters : the organic matter absorption predominates • TSS monitoring • Retrieving model : linear model fitted by least square method using the 705 nm band for low TSS and the 775 nm band for high TSS • Accuracy assessment (Parametric Bootstrap) : Season Bands used Unbiased Residual STD Relative error (/) (mg/l) (%) Rising water 2003 705 & 775 22 34 Rising water 2004 705 & 775 18 23 High water 681 & 775 5.5 32 Low water 705 & 775 53 21

  13. MODIS bands A glance of MODIS using MERIS

  14. MODIS view of the Amazon river Amazon river Tapajós river Madeira river 300 km

  15. Amazon Solimões Lower Madeira Upper Madeira Amazonian rivers : MODIS vs TSS TSS data from the ORE HYBAM-IRD measurement network

  16. Potential of MODIS images • MODIS spatial resolution (250 & 500-meter modes) is efficient for monitoring of suspended sediment fluxes in the rivers • Low sensitivity of the reflectance to the viewing geometry • MODIS temporal resolution is idealforthisclouded region • Poor spectral resolution is a drawback in productive waters • No saturation of the signal up to 1600 mg/l • Signal is moderatly dependent on the river and on time • Like MERIS, retrieval model using MODIS Red band for low TSS values & the NIR band for the high TSS

  17. Amazon Solimões Lower Madeira MODIS predicted TSS vs measured TSS data from the ORE HYBAM-IRD measurement network

  18. Conclusions/Perspectives • This study proves that MERIS & MODIS data are well adapted for river water quality monitoring • MERIS spectral resolution allows to monitor both TSS and primary production in the floodplain lakes • Accuracy and availability (low cost & temporal resolution) of MODIS data make them an operational tool for TSS retrieval • Insertion in existing monitoring network • Future works : • Refined assessment of the impact of water and sediment properties on the reflectance • Extension of field data to 2003 & 2004

More Related