{ "name":"Geoscientific/PrecipitationInstabilityPotential_Maryland_MDOTSHA", "title":"Geoscientific/PrecipitationInstabilityPotential_Maryland_MDOTSHA", "type":"Map Service", "typeKeywords":["ArcGIS Server","Service","Map Service"], "description":"
MDOT SHA
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Esri Portal for ArcGIS Map Image Layer for accessing the MDOT SHA Precipitation Sensitivity data product.
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MDOT SHA Precipitation Sensitivity data showcases the estimated inches of rainfall needed to cause surficial instability causing potential downward movement in areas along roadways (IS, MD, US) throughout the State of Maryland.  <\/span>MDOT SHA Precipitation Instability Potential data is owned & maintained by the MDOT SHA Office of Materials Technology (OMT).<\/div>

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MDOT SHA Precipitation Sensitivity data i<\/span>s in the units of estimated inches of rainfall needed to cause surficial instability causing potential downward movement.  The data is the result of slope stability calculations for each pixel using MD iMAP lidar-based elevation, derived slope and USDA SSURGO soil properties including soil bulk density, specific gravity, allowable water capacity, parent material, estimated USCS classification used to estimate friction angle and cohesion.  Calculations were developed in 2020 by GeoDecisions, a division of Gannett Fleming.  The results of the slope stability calculations represent the estimated amount of rainfall necessary in a 3-day storm event to begin overcoming friction and cohesion forces, allowing for movement of a 6-foot thick soil mass.  The dataset is useful for preliminary risk assessments to characterize the relative susceptibility of of slopes and embankments to slope failure.  In locations where no data was provided by USDA SSURGO, estimations were used to allow for calculations, based on a conservative bulk density in the vicinity of roadways and the predominant parent material for each county.  To minimize processing time and storage space, the dataset is limited to areas within 500 feet of the Maryland Roadway Centerline with a Route Prefix of IS (Interstate Route), MD (Maryland State Route), US (United States Route), and RP (Interchange Ramp).  <\/span>The end result, <\/span>MDOT SHA Precipitation Sensitivity data,<\/span> was created in October 2021.<\/span>
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MDOT SHA Precipitation Sensitivity data i<\/span>s symbolized based on the following information:<\/span><\/div>

≥ -15 inches (or ≥ 0% statewide)<\/b> \u2013 Dark Umber<\/p>

≥ 0 inches (or ≥ 5% statewide)<\/b> \u2013 Tuscan Red<\/p><\/i><\/div>

≥ 5 inches (or ≥ 10 % statewide)<\/b> \u2013 Flame Red<\/p>

≥ 10 inches (or ≥ 15% statewide)<\/b> \u2013 Solar Yellow @ 75% transparent<\/p>

≥ 15 inches (or ≥ 20% statewide)<\/b> \u2013  @ 100% transparent<\/p><\/i><\/div>