{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T15:37:44Z","timestamp":1770737864781,"version":"3.49.0"},"reference-count":53,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2017,12,7]],"date-time":"2017-12-07T00:00:00Z","timestamp":1512604800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The Sahelian region is characterized by significant variations in precipitation, impacting water quantity and quality. Suspended particulate matter (SPM) dynamics has a significant impact on inland water ecology and water resource management. In-situ data in this region are scarce and, consequently, the environmental factors triggering SPM variability are yet to be understood. This study addresses these issues using remote sensing optical data. Turbidity and SPM of the Agoufou Lake in Sahelian Mali were measured from October 2014 to present, providing a large range of `values (SPM ranging from 106 to 4178 mg\/L). These data are compared to satellite reflectance from Landsat (ETM+, OLI) and MODIS (MOD09GQ, MYD09GQ). For each of these sensors, a spectral band in the near infrared region is found to be well suited to retrieve turbidity and SPM, up to very high values (R2 = 0.70) seldom addressed by remote sensing studies. The satellite estimates are then employed to assess the SPM dynamics in the main lakes and ponds of the Gourma region and its links to environmental and anthropogenic factors. The main SPM seasonal peak is observed in the rainy season (June to September) in relation to precipitation and sediment transport. A second important peak occurs during the dry season, highlighting the importance of resuspension mechanisms in maintaining high values of SPM. Three different periods are observed: first, a relatively low winds period in the early dry season, when SPM decreases rapidly due to deposition; then, a period of wind-driven resuspension in January\u2012March; and lastly, an SPM deposition period in April\u2013May, when the monsoon replaces the winter trade wind. Overall, a significant increase of 27% in SPM values is observed between 2000 and 2016 in the Agoufou Lake. The significant spatio-temporal variability in SPM revealed by this study highlights the importance of high resolution optical sensors for continuous monitoring of water quality in these poorly instrumented regions.<\/jats:p>","DOI":"10.3390\/rs9121272","type":"journal-article","created":{"date-parts":[[2017,12,7]],"date-time":"2017-12-07T11:49:10Z","timestamp":1512647350000},"page":"1272","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["Analysis of Suspended Particulate Matter and Its Drivers in Sahelian Ponds and Lakes by Remote Sensing (Landsat and MODIS): Gourma Region, Mali"],"prefix":"10.3390","volume":"9","author":[{"given":"Elodie","family":"Robert","sequence":"first","affiliation":[{"name":"G\u00e9osciences Environnement Toulouse (CNRS, IRD, Universit\u00e9 de Toulouse 3, CNES), 31400 Toulouse, France"}]},{"given":"Laurent","family":"Kergoat","sequence":"additional","affiliation":[{"name":"G\u00e9osciences Environnement Toulouse (CNRS, IRD, Universit\u00e9 de Toulouse 3, CNES), 31400 Toulouse, France"}]},{"given":"Nogmana","family":"Soumaguel","sequence":"additional","affiliation":[{"name":"Institute of Research for Development (IRD), BP 2528 Bamako, Mali"}]},{"given":"S\u00e9bastien","family":"Merlet","sequence":"additional","affiliation":[{"name":"G\u00e9osciences Environnement Toulouse (CNRS, IRD, Universit\u00e9 de Toulouse 3, CNES), 31400 Toulouse, France"}]},{"given":"Jean-Michel","family":"Martinez","sequence":"additional","affiliation":[{"name":"G\u00e9osciences Environnement Toulouse (CNRS, IRD, Universit\u00e9 de Toulouse 3, CNES), 31400 Toulouse, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7958-4525","authenticated-orcid":false,"given":"Mamadou","family":"Diawara","sequence":"additional","affiliation":[{"name":"Universit\u00e9 de Bamako, BP 2528 Bamako, Mali"}]},{"given":"Manuela","family":"Grippa","sequence":"additional","affiliation":[{"name":"G\u00e9osciences Environnement Toulouse (CNRS, IRD, Universit\u00e9 de Toulouse 3, CNES), 31400 Toulouse, France"}]}],"member":"1968","published-online":{"date-parts":[[2017,12,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jhydrol.2008.12.012","article-title":"Spatio-temporal variability of hydrological regimes around the boundaries between Sahelian and Sudanian areas of West Africa: A synthesis","volume":"375","author":"Descroix","year":"2009","journal-title":"J. Hydrol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2007WR006785","article-title":"Land clearing, climate variability, and water resources increase in semiarid southwest Niger: A review","volume":"45","author":"Favreau","year":"2009","journal-title":"Water Resour. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.gloplacha.2007.08.011","article-title":"Land clearance and hydrological change in the Sahel: SW Niger","volume":"61","author":"Leblanc","year":"2008","journal-title":"Glob. Planet. Chang."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"309","DOI":"10.5194\/hess-14-309-2010","article-title":"Less rain, more water in ponds\u202f: A remote sensing study of the dynamics of surface waters from 1950 to present in pastoral Sahel (Gourma region, Mali)","volume":"14","author":"Gardelle","year":"2010","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1176","DOI":"10.1016\/j.jhydrol.2016.07.035","article-title":"Changes in lakes water volume and runoff over ungauged Sahelian watersheds","volume":"540","author":"Gal","year":"2016","journal-title":"J. Hydrol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3390\/rs6043446","article-title":"Rain-Use-Efficiency: What it Tells about the Conflicting Sahel Greening and Sahelian Paradox","volume":"6","author":"Dardel","year":"2014","journal-title":"Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"4591","DOI":"10.5194\/hess-21-4591-2017","article-title":"Modeling the paradoxical evolution of runoff in pastoral Sahel. The case of the Agoufou watershed, Mali","volume":"21","author":"Gal","year":"2017","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1016\/j.jhydrol.2009.03.007","article-title":"Rainfall regime across the Sahel band in the Gourma region, Mali","volume":"375","author":"Frappart","year":"2009","journal-title":"J. Hydrol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3998","DOI":"10.1002\/joc.3984","article-title":"Recent trends in the regime of extreme rainfall in the Central Sahel","volume":"34","author":"Panthou","year":"2014","journal-title":"Int. J. Climatol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"475","DOI":"10.1038\/nature22069","article-title":"Frequency of extreme Sahelian storms tripled since 1982 in satellite observations","volume":"544","author":"Taylor","year":"2017","journal-title":"Nature"},{"key":"ref_11","first-page":"1","article-title":"A short review of fecal indicator bacteria in tropical aquatic ecosystem: Knowledge gaps and future directions","volume":"6","author":"Nguyen","year":"2015","journal-title":"Front. Microbiol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Troeger, C., Forouzanfar, M., Rao, P.C., Khalil, I., Brown, A., Reiner, R.C., Fullman, N., Thompson, R.L., Abajobir, A., and Ahmed, M. (2017). Estimates of global, regional, and national morbidity, mortality, and aetiologies of diarrhoeal diseases: A systematic analysis for the Global Burden of Disease Study 2015. Lancet Infect. Dis.","DOI":"10.1016\/S1473-3099(17)30276-1"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"39","DOI":"10.3917\/autr.055.0039","article-title":"Des pompes et des hommes. \u00c9tat des lieux des pompes \u00e0 motricit\u00e9 humaine d\u2019une commune du Gourma malien","volume":"3","author":"Gangneron","year":"2010","journal-title":"Autrepart"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"109","DOI":"10.3917\/rtm.204.0109","article-title":"L\u2019\u00e9tonnante diversit\u00e9 des ressources en eau \u00e0 Hombori. Entre contrastes environnementaux, pratiques locales et technologies ext\u00e9rieures","volume":"4","author":"Gangneron","year":"2010","journal-title":"Revue Tiers Monde"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1257","DOI":"10.4319\/lo.2009.54.4.1257","article-title":"Spectral variations of light scattering by marine particles in coastal waters, from visible to near infrared","volume":"54","author":"Doxaran","year":"2009","journal-title":"Limnol. Oceanogr."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1016\/j.csr.2009.12.007","article-title":"Estimating turbidity and total suspended matter in the Adour River plume (South Bay of Biscay) using MODIS 250-m imagery","volume":"30","author":"Petus","year":"2010","journal-title":"Cont. Shelf Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"843","DOI":"10.4319\/lo.2003.48.2.0843","article-title":"Light scattering properties of marine particles in coastal and open ocean waters as related to the particle mass concentration","volume":"48","author":"Babin","year":"2003","journal-title":"Limnol. Oceanogr."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/j.rse.2014.09.020","article-title":"A single algorithm to retrieve turbidity from remotely-sensed data in all coastal and estuarine waters","volume":"156","author":"Dogliotti","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1080\/02626668009491950","article-title":"Satellite remote sensing of water turbidity\/Sonde de t\u00e9l\u00e9mesure par satellite de la turbidit\u00e9 de l\u2019eau","volume":"25","author":"Moore","year":"1980","journal-title":"Hydrol. Sci. Bull."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"709","DOI":"10.4319\/lo.1977.22.4.0709","article-title":"Analysis of variation in ocean color","volume":"22","author":"Morel","year":"1977","journal-title":"Lymnol. Oceanogr."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"4850","DOI":"10.1364\/AO.35.004850","article-title":"Diffuse reflectance of oceanic waters. III. Implication of bidirectionality for the remote-sensing problem","volume":"35","author":"Morel","year":"1996","journal-title":"Appl. Opt."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"854","DOI":"10.1016\/j.rse.2009.11.022","article-title":"Calibration and validation of a generic multisensor algorithm for mapping of total suspended matter in turbid waters","volume":"114","author":"Nechad","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Novoa, S., Doxaran, D., Ody, A., Vanhellemont, Q., Lafon, V., Lubac, B., and Gernez, P. (2017). Atmospheric corrections and multi-conditional algorithm for multi-sensor remote sensing of suspended particulate matter in low-to-high turbidity levels coastal waters. Remote Sens., 9.","DOI":"10.3390\/rs9010061"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.catena.2009.05.011","article-title":"Increase in suspended sediment discharge of the Amazon River assessed by monitoring network and satellite data","volume":"79","author":"Martinez","year":"2009","journal-title":"Catena"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1274","DOI":"10.1002\/2014JF003404","article-title":"The optical properties of river and floodplain waters in the Amazon River Basin: Implications for satellite-based measurements of suspended particulate matter","volume":"120","author":"Martinez","year":"2015","journal-title":"J. Geophys. Res."},{"key":"ref_26","first-page":"1","article-title":"Human induced turbidity changes in Poyang Lake between 2000 and 2010: Observations from MODIS","volume":"117","author":"Feng","year":"2012","journal-title":"J. Geophys. Res."},{"key":"ref_27","first-page":"286","article-title":"Evaluating suitability of MODIS-Terra images for reproducing historic sediment concentrations in water bodies: Lake Tana, Ethiopia","volume":"26","author":"Kaba","year":"2014","journal-title":"Int. J. Appl. Earth Obs. Geoinform."},{"key":"ref_28","first-page":"243","article-title":"Monitoring water turbidity and surface suspended sediment concentration of the Bagre Reservoir (Burkina Faso) using MODIS and field reflectance data","volume":"52","author":"Robert","year":"2016","journal-title":"Int. J. Appl. Earth Obs. Geoinform."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2569","DOI":"10.5194\/angeo-26-2569-2008","article-title":"Large-scale overview of the summer monsoon over West and Central Africa during the AMMA field experiment in 2006","volume":"26","author":"Janicot","year":"2008","journal-title":"Ann. Geophys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"9507","DOI":"10.3390\/rs70809507","article-title":"Toward sentinel-2 high resolution remote sensing of suspended particulate matter in very turbid waters: SPOT4 (Take5) experiment in the Loire and Gironde estuaries","volume":"7","author":"Gernez","year":"2015","journal-title":"Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1082","DOI":"10.1002\/esp.1795","article-title":"Retrieval of suspended sediment concentrations in large turbid rivers using Landsat ETM+: An example from the Yangtze River, China","volume":"34","author":"Wang","year":"2009","journal-title":"Earth Surface Process. Landf."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1449","DOI":"10.5194\/hess-14-1449-2010","article-title":"The potential for remote sensing and hydrologic modelling to assess the spatio-temporal dynamics of ponds in the Ferlo Region (Senegal)","volume":"14","author":"Soti","year":"2010","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.jhydrol.2009.02.052","article-title":"Time series analysis of optical remote sensing data for the mapping of temporary surface water bodies in sub-Saharan western Africa","volume":"370","author":"Haas","year":"2009","journal-title":"J. Hydrol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.jhydrol.2009.06.045","article-title":"The AMMA-CATCH Gourma observatory site in Mali: Relating climatic variations to changes in vegetation, surface hydrology, fluxes and natural resources","volume":"375","author":"Mougin","year":"2009","journal-title":"J. Hydrol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jhydrol.2009.03.020","article-title":"AMMA-CATCH studies in the Sahelian region of West-Africa: An overview","volume":"375","author":"Lebel","year":"2009","journal-title":"J. Hydrol."},{"key":"ref_36","unstructured":"Gal, L. (2016). Mod\u00e9lisation de L\u2019\u00e9volution Paradoxale de l\u2019hydrologie Sah\u00e9lienne: Application au Bassin d\u2019Agoufou (Mali). Interfaces Continentales, Environnement, Universit\u00e9 Paul Sabatier. Available online: https:\/\/tel.archives-ouvertes.fr\/tel-01484584v2\/document."},{"key":"ref_37","unstructured":"Diawara, M.O. (2015). Impact de la Variabilit\u00e9 Climatique au Nord Sahel (Gourma, Mali) sur la Dynamique des Ressources Pastorales, Cons\u00e9quences sur les Productions Animales. [Ph.D. Thesis, Universit\u00e9 Toulouse 3]."},{"key":"ref_38","unstructured":"Pr\u00e9vost, Y. (1989). Analyse spatiale de la pression animale comme facteur de d\u00e9sertification dans le nord du S\u00e9n\u00e9gal. Apports de la T\u00e9l\u00e9d\u00e9tection \u00e0 la Lutte Contre La S\u00e9cheresse, Compte-rendu Des Journ\u00e9es Scientifiques de Thies."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"4173","DOI":"10.3390\/rs6054173","article-title":"Water Feature Extraction and Change Detection Using Multitemporal Landsat Imagery","volume":"6","author":"Rokni","year":"2014","journal-title":"Remote Sens."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"3025","DOI":"10.1080\/01431160600589179","article-title":"Modification of normalised difference water index (NDWI) to enhance open water features in remotely sensed imagery","volume":"27","author":"Xu","year":"2006","journal-title":"Int. J. Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1763","DOI":"10.1139\/f84-217","article-title":"Wind Resuspension of Sediments in a Prairie Lake","volume":"41","author":"Carper","year":"1984","journal-title":"J. Can. Sci. Halieut. Aquat."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"927","DOI":"10.4314\/ijbcs.v9i2.30","article-title":"Moteurs et cons\u00e9quences de la resuspension dans un lac sah\u00e9lien peu profond: Le lac de Guiers au S\u00e9n\u00e9gal","volume":"9","author":"Ba","year":"2015","journal-title":"Int. J. Biol. Chem. Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1007\/s00027-008-8047-8","article-title":"The role of non-prevailing wind direction on resuspension and redistribution of sediments in a shallow lake","volume":"70","author":"Bengtsson","year":"2008","journal-title":"Aquat. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1016\/j.jhydrol.2008.09.007","article-title":"Surface thermodynamics and radiative budget in the Sahelian Gourma: Seasonal and diurnal cycles","volume":"375","author":"Guichard","year":"2009","journal-title":"J. Hydrol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1002\/ldr.526","article-title":"Causes, consequences and control of wind erosion in Sahelian Africa: A review","volume":"14","author":"Sterk","year":"2003","journal-title":"Land. Degrad. Dev."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1002\/2013RG000437","article-title":"Review of wave-driven sediment resuspension and transport in estuaries","volume":"52","author":"Green","year":"2014","journal-title":"Rev. Geophys."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1016\/j.rse.2013.09.011","article-title":"Re-greening Sahel: 30 years of remote sensing data and field observations (Mali, Niger)","volume":"140","author":"Dardel","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"4520","DOI":"10.1109\/TGRS.2015.2400928","article-title":"The radiometric stability and scaling of collection 6 Terra-and Aqua-MODIS VIS, NIR, and SWIR spectral bands","volume":"53","author":"Doelling","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"993","DOI":"10.1002\/(SICI)1096-9837(199910)24:11<993::AID-ESP24>3.0.CO;2-P","article-title":"Evaluation of the simple settling theory for predicting sediment deposition by overland flow","volume":"24","author":"Beuselinck","year":"1999","journal-title":"Earth Surface Process. Landf."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1029\/TR034i003p00407","article-title":"Trap efficiency of reservoirs","volume":"34","author":"Brune","year":"1953","journal-title":"Trans. Am. Geophys. Union"},{"key":"ref_51","unstructured":"Pinet, S., Martinez, J.M., Gosset, C., Grippa, M., Robert, E., Ouillon, S., and Kergoat, L. Monitoring of suspended particulate matter concentration using sentinel-2, landsat-8 and spot-5 data over highly turbid waters in a West African reservoir, In preparation."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/S0034-4257(01)00341-8","article-title":"Spectral signature of highly turbid waters: Application with SPOT data to quantify suspended particulate matter concentrations","volume":"81","author":"Doxaran","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.rse.2015.06.022","article-title":"A SWIR based algorithm to retrieve total suspended matter in extremely turbid waters","volume":"168","author":"Knaeps","year":"2015","journal-title":"Remote Sens. Environ."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/9\/12\/1272\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:53:05Z","timestamp":1760208785000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/9\/12\/1272"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,12,7]]},"references-count":53,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2017,12]]}},"alternative-id":["rs9121272"],"URL":"https:\/\/doi.org\/10.3390\/rs9121272","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,12,7]]}}}