Public Alert Grids

Public Alert Grids are 1/4-mile rectangles (grids) used when targeting public alert messages to specific areas in Clark County and southern Cowlitz County. When needed, grids are selected to represent the full area that requires the message. Using the grid codes, field commanders can easily communicate the extent of the needed alert area to CRESA and mapping (GIS) staff. For example, a wildfire that requires an evacuation zone can be delineated in the field and the grid codes (making up the evacuation zone) can be used to communicate the extent to CRESA. The grids are loosely based on Public Land Survey System (PLSS) quarter sections. However, they should not be used as a survey or legal description reference. See Clark County Metadata Data source: ..\FGDB\dw_PubSafety.gdb\PublicAlertGrids公共警报网格（Public Alert Grids）是1/4英里见方的矩形网格，用于向克拉克县（Clark County）及考利茨县南部的特定区域推送公共警报信息。必要时，可选取对应网格覆盖需发布警报的完整区域。借助网格编码，现场指挥官可便捷地向CRESA及地理信息系统（GIS）工作人员传达所需警报区域的范围。例如，针对需划定疏散区域的野火事件，可在现场完成疏散区域的网格划定，再通过组成该疏散区域的网格编码向CRESA传达其范围。此类网格大致基于公共土地测量系统（Public Land Survey System, PLSS）的四分地块，但不可用作测量或法律权属描述的参考依据。详见克拉克县元数据，数据源路径：..FGDBdw_PubSafety.gdbPublicAlertGrids