Spectral Water Indices in the Study of Estuaries

The studyof estuariesisof keyimportanceforagriculture,especiallyinaridregions,wherecontrolledfloodinghelpsto leachsaltsfromthe soilandcreatenaturalpastures.However, traditionalmethodsof monitoringwaterbodies are laboriousandinsufficientlyoperational,whichmakesremotesensingof the Earth(remote sensing)a promisingtoolforanalyzingwaterbodies.Thepaperanalyzesthe spectralcharacteristicsof waterinvariousranges(visible,nearandmediuminfrared),considersthe factorsaffectingtheaccuracyof detection(depth,turbidity,vegetation,atmosphericconditions).Theprinciplesof calculatingindicesbasedon normalizeddifferencesof spectralchannelsare investigated.TheeffectivenessofNDWI,MNDWI, andAWEIindifferentenvironmentalconditionshas been compared.Spectralindexesmake it possibleto automatemonitoringof waterbodies,however, the choiceof the optimalindexdependsonspecificconditions(typeof reservoir,presenceof interference).The combinationof severalindexesandcorrectionof atmosphericeffectsincreasethe accuracyof highlightingwatersurfaces.The accuracy and reliability of research results can be improved through the use of higher-resolution satellite imagery; however, their high cost increases expenses and limits widespread application. As an alternative, spectral images obtained from unmanned aerial vehicles can be used, but their spectral capabilities are technically constrained and depend on the quality of the cameras employed