The Dying Dead Sea Assessing the decline of the Dead Sea area in relation to irrigated agriculture Noel Peterson and Zach Tagar FR 5262

Off basin Water diversion since 1960’s Israel’s National Water Carrier – one of several causes for the decline of the Dead Sea

Water level 1900 The dying of the Dead Sea

Measuring Surface Area Change Based on Landsat band 4 (near-IR) Examined histograms in ArcMap to determine cutoff for water: bimodal distributions.

Measuring Surface Area Change Using cutoff values determined by histograms, we created binary images using ArcMap’s Reclass tool. Output clipped to Dead Sea area to remove misclassified shadows.

Measuring Surface Area Change Converted rasters to polygons and removed the rest of the misclassified spots. By putting polygon features in a geodatabase, areas are calculated automatically.

Results YearFull Area (km^2)North Area (km^2) Note: 1900 values calculated by reclassifying SRTM DEM (90m spatial resolution) with an historical surface elevation measurement instead of satellite imagery and histogram values.

Results

Assessing extent of (irrigated) agriculture (Data: Landsat /2009)

Try 1: NDVI Band 4NDVI No variability between classes

Try 2: unsupervised classification (40 classes) Same class for agriculture and nature

Try 3: supervised classification Defining AOI’s across the country ( ) (Ag, natural vegetation/desert; water; urban)

Stats…

Try 3: supervised classification Sort of working!

Classification 1Classification 2

Accuracy Assessment - no reference map! 200 random points from ArcMap …

… to Google Earth (import shapefile in Google Earth Pro Trial version)

Manual inspection…

Results: classification 4Reference AgricultureNatural vegetationUrbanWater Agriculture Natural vegetation Urban Water % correct: 68.31% Error of Omission (ag): 33.33% Error of Comission (ag) 46.15% No. of pixels: 6,233, m resolution; 900 sq/m Total area ag: sq/Km