Abstract: Apparatus and method for flood control. The apparatus comprises at least one expandible compartment that may conform to surfaces against which it rests. The compartment comprises a filler material capable of taking up liquid and expandible upon liquid take-up; an outer skin, at least a part of which is liquid permeable; and means for sealing said skin to contain said filler material therein. The compartments may be dried or purged of liquid after use and retained for subsequent re-use.

Abstract: A passive reflective device provides a warning or message visible when the intensity of light incident on the device exceeds a preselected minimum intensity or threshold value. The device includes a display, in the form of statements, pictographs, or images, with an appearance which is altered in color or pattern when impinged upon by light with an intensity greater than the threshold value and viewed by a viewer in front of the device. The device can be used as a sign or stationary display, such as a road sign, or it can be mounted on or in a front vehicle facing behind the vehicle such that the display is visible from behind the vehicle by someone who is within a preselected range of angles.