Matt Fox at the Google Earth Library blog has been hard at work creating quite a few layers for Google Earth. One of the KML files he's created is a set of topographic maps of the United States. There are currently over 2,000 georeferenced USGS topographic maps, mostly of the western United States and especially California available in the layer. Some of these maps are the historic HISTOPO maps of the San Francisco Bay Area and California. From the Google Earth Library blog: "Over 2,000 historic USGS Topographic maps covering large areas of the United States. The maps are available in various scales and date back to the late 1800s in some areas."

After downloading the KML file and opening it in Google Earth, users can view individual maps draped over the terrain and other features in Google Earth. The software also allows users to add and save information to the layer. The Google Earth Library blog provides more specific instructions: "To view the maps, just click on one of the indexes, find the area you are interested in, click on the placemark in the center of the outlined area, then click on blue hyperlink for the map year you want to view. The maps will appear under Temporary Places. You can delete them from there when you’re done. If you’re computer doesn’t have a very good video card, you may not be able to open more than a few at a time."

A disclaimer from the Google Earth Library blog: "[The author is] not an employee of Google and this blog was not created by, or endorsed by Google."

The San Francisco Department of Public Health (SFDPH) is responsible for, among other health-related issues, environmental health in the City of San Francisco. A portion of the organization's environmental health program is to monitor and abate noise pollution. Various departments within the City are responsible for different aspects of noise pollution enforcement. From the SFDPH site:

To illustrate street noise levels, the DPH has created a city-wide noise map for San Francisco. The map is in pdf format and not georeferenced, but is a good place to start an investigation into environmental health and noise issues in San Francisco.

The Center for Sustainability and the Global Environment (SAGE), part of the Institute for Environmental Studies at the University of Wisconsin - Madison, has published the Atlas of the Biosphere online. The purpose of the Atlas is very simple to: "gather as much information about the environment as possible, and deliver it to as many people as possible."

To this end, the Atlas of the Biosphere makes its data available in two ways: maps and schematics. The map themes include human impacts, land use, ecosystems, and water resources.

From the Atlas' site: "The Maps section contains geographically explicit data broken down into four general categories: Humans, Land Use, Ecosystems, and Water Resources. Simply follow the menus to reach your dataset of interest. The Schematics section looks at the various resource flows and pools that make up individual Earth systems."

Data from the maps are made available through ESRI ArcView grid files.

A few government agencies and companies have released aerial and satellite imagery, as well as GIS data, of the devastation to the Texas and Louisiana coasts, Galveston, Texas, and the Bolivar Peninsula area as a result of hurricane Ike:

ESRI, as part of the World User Imagery collection, has released GIS layers of the aftermath of the hurricane. These layers can be viewed with ArcGIS Explorer or added to maps in other ESRI software. These layers focus on Galveston Channel and surrounding areas.

The United States Geological Survey (USGS) has a wealth of information, including before and after images of the town of Crystal Beach, Texas. From the USGS site: "Storm surges and waves crested Crystal Beach and swept sand inland, along with the remains of homes. The four sets of before-and-after photographs posted online show these extreme changes to the residential area."

The National Oceanic and Atmospheric Administration (NOAA) has posted over 4,000 images of damage to the coast. From the NOAA site:
This imagery was acquired by the NOAA Remote Sensing Division to support NOAA national security and emergency response requirements. In addition, it will be used for ongoing research efforts for testing and developing standards for airborne digital imagery.

Please note that these images are corrected and rotated. The approximate ground sample distance (GSD) for each pixel is 50 cm (1.64 feet). The images have 60% forward overlap, and sidelap unknown. Image file size is between 1 MB and 3 MB."

The City of San Francisco has made its zoning maps available online. These maps were most recently updated in May 2006, but subscriptions to updates are available.

From the City of San Francisco's Municipal Code site: "The reclassification ordinances normally list the address, the Assessor's block and lot numbers, and a metes and bounds description of the property being rezoned, making it possible to identify the property with precision. Subscribing to the map ordinance service will assure that you have the current information at all times as ordinances will be mailed to subscribers by the time new legislation takes effect."

The maps are organized by zoning designation. The zoning of individual parcels is created through compiling designation information from various maps. These maps include: "Use District Maps, numbered ZN01--ZN13, and Height and Bulk District Maps, numbered HT01--HT13, as well as checking to see if the parcel is in a Special Use District (numbered SU01--SU13), Preservation District (numbered PD01--PD08), Coastal Zone (numbered CZ04--CZ13), or Special Sign District (numbered SS01 and SS02)." The site provides a text index for the maps as well.