The minimum slope, measured in blank" >target="_blank" >degrees from the blank" >target="_blank" >glossary/horizontal/" class="glossaryLink" data-cmtooltip="95a209856a013f60a40560d5e339204d" blank" >target="_blank" >horizontal, at which loose solidblank" >target="_blank" >material will begin toslideorflow. (Ching, 1995)