California Landslide Inventory and Deep Landslide Susceptiblity

<div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial' size='4'><b><u>California Landslide Inventory</u></b></font></div><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial' size='4'><b><br /></b></font></div><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><span style='line-height: 17.12px;'><font face='Arial'>The statewide landslide map database shows many of the landslides mapped by CGS and others over the past 50 years. Each feature includes a database record showing at least the source of the original mapping. Landslide areas shown in color have more information available (see explanation button). The source maps for this database have focused on deep-seated landslides, mapping of debris flows is generally much less complete. Updates to the database are continuing, both to include more existing maps and to add current landslides as they occur. To contribute to the CGS landslide database, send original reports, maps, or photographs (not copies of newspaper articles or other generally available reports) to <a href='mailto:rghmp@consrv.ca.gov'><span style='line-height: 17.12px; color: rgb(42, 100, 150); background-image: initial; background-attachment: initial; background-color: white; background-size: initial; background-origin: initial; background-clip: initial; background-position: initial; background-repeat: initial;'>rghmp@consrv.ca.gov</span></a></font></span><br /></div><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial' size='4'><b><u><br /></u></b></font></div><font face='Arial' size='4' style='color: rgb(0, 0, 0); line-height: normal;'><b><u><div><font face='Arial' size='4'><b><u><br /></u></b></font></div>Deep-Seated Landslide Susceptibility</u></b></font><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial'><br /></font></div><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial'>Rock strength and slope are combined to create classes of landslide susceptibility. These classes express the generalization that on very low slopes, landslide susceptibility is low even in weak materials, and that landslide susceptibility increases with slope and in weaker rocks. Very high landslide susceptibility, classes VIII, IX, and X, includes very steep slopes in hard rocks, and moderate to very steep slopes in weak rocks.</font></div><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial'><br /></font></div><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial'>Mapped active landslides are assigned to susceptibility class X.</font></div><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial'><br /></font></div><div style='color: rgb(0, 0, 0); font-family: 'Times New Roman'; font-size: medium; line-height: normal;'><font face='Arial'>For more information on how the Deep Landslide Susceptibility data was prepared, please see: </font><a href='http://www.conservation.ca.gov/cgs/information/publications/ms/documents/ms58.pdf' target='_blank'><font face='Arial'>California Geological Survey, Map Sheet 58</font></a></div>