The zoning map is a composite of zoning designations adopted as resolutions by the Marin County Board of Supervisors. Data extend over Assessor parcel boundaries in the unincorporated area of Marin County, California. The Zoning map denotes the spatial extent of land use designations defined in the Countywide Plan.

The zoning map is a composite of zoning designations adopted as resolutions by the Marin County Board of Supervisors. Data extend over Assessor parcel boundaries in the unincorporated area of Marin County, California. The Zoning map denotes the spatial extent of land use designations defined in the Countywide Plan.

The General Plan map denotes the spatial extent of land use designations defined in the Town of Ross General Plan. Data extend over Assessor parcel boundaries in Town of Ross' Sphere of Influence.

The Zoning map denotes the spatial extent of land use designations defined in the City of Belvedere Zoning Ordinance/Development Code. Data extend over Assessor parcel boundaries in City of Belvedere.

This shapefile contains tax rate area (TRA) boundaries in Marin County for the specified assessment roll year. Boundary alignment is based on the 2014 county parcel map. A tax rate area (TRA) is a geographic area within the jurisdiction of a unique combination of cities, schools, and revenue districts that utilize the regular city or county assessment roll, per Government Code 54900. Each TRA is assigned a six-digit numeric identifier, referred to as a TRA number. TRA = tax rate area number

The Zoning map denotes the spatial extent of land use designations defined in the Town of San Anselmo Zoning Ordinance/Development Code. Data extend over Assessor parcel boundaries in Town of San Anselmo.

The General Plan map denotes the spatial extent of land use designations defined in the Town of San Anselmo General Plan. Data extend over Assessor parcel boundaries in Town of San Anselmo's Sphere of Influence.

The Zoning map denotes the spatial extent of land use designations defined in the Town of Corte Madera Zoning Ordinance/Development Code. Data extend over Assessor parcel boundaries in Town of Corte Madera's Sphere of Influence.

Dam Inundation maps for the State of California are required by California Government Code Section 8589.5(b). Inundation potential to cause damage to life and property is mapped for individual dams. Dam inundation maps show the maximum extent of damage of a flood wave emanating from a dam failure. The map does not indicate or infer the probability of such an event occurring. This data set represents a combined, statewide shapefile of all the dam inundation boundaries in the state. It serves as a quick index to locating all dam inundation boundaries in a particular area, or the geography of a particular inundation boundary, or group of boundaries. This shapefile is updated from time to time, and is currently located in New_CD\06_CD\Data\Arc\dam_inundation_digitizing_mrg_07.shp It has a polyline geometry structure, and dam-name attribution.

This webmap is a collaboration between the National Park Service, California Native Plant Society (CNPS) and the California Dept of Fish and Game (CDFG).The CNPS Vegetation Program has worked for over 15 years to provide standards and tools for identifying and representing vegetation, as an important feature of California's natural heritage and biodiversity. Many knowledgeable ecologists and botanists support the program as volunteers and paid staff. Through grants, contracts, and grass-roots efforts, CNPS collects field data and compiles information into reports, manuals, and maps on California's vegetation, ecology and rare plants in order to better protect and manage them. We provide these services to governmental, non-governmental and other organizations, and we collaborate on vegetation resource assessment projects around the state. CNPS is also the publisher of the authoritative Manual of California Vegetation, you can purchase a copy HERE. To support the work of the CNPS, please JOIN NOW and become a member!The CDFG Vegetation Classification and Mapping Program develops and maintains California's expression of the National Vegetation Classification System. We implement its use through assessment and mapping projects in high-priority conservation and management areas, through training programs, and through working continuously on best management practices for field assessment, classification of vegetation data, and fine-scale vegetation mapping.HOW THE OVERLAY LAYERS WERE CREATED:Nserve and GapLC Sources: Early shortcomings in the NVC standard led to Natureserve's development of a mid-scale mapping-friendly "Ecological Systems" standard roughly corresponding to the "Group" level of the NVC, which facilitated NVC-based mapping of entire continents. Current scientific work is leading to the incorporation of Ecological Systems into the NVC as group and macrogroup concepts are revised. Natureserve and Gap Ecological Systems layers differ slightly even though both were created from 30m landsat data and both follow the NVC-related Ecological Systems Classification curated by Natureserve. In either case, the vector overlay was created by first enforcing a .3ha minimum mapping unit, that required deleting any classes consisting of fewer than 4 contiguous landsat cells either side-side or cornerwise. This got around the statistical problem of numerous single-cell classes with types that seemed improbable given their matrix, and would have been inaccurate to use as an n=1 sample compared to the weak but useable n=4 sample. A primary goal in this elimination was to best preserve riparian and road features that might only be one pixel wide, hence the use of cornerwise contiguous groupings. Eliminated cell groups were absorbed into whatever neighboring class they shared the longest boundary with. The remaining raster groups were vectorized with light simplification to smooth out the stairstep patterns of raster data and hopefully improve the fidelity of the boundaries with the landscape. The resultant vectors show a range of fidelity with the landscape, where there is less apparent fidelity it must be remembered that ecosystems are normally classified with a mixture of visible and non-visible characteristics including soil, elevation and slope. Boundaries can be assigned based on the difference between 10% shrub cover and 20% shrub cover. Often large landscape areas would create "godzilla" polygons of more than 50,000 vertices, which can affect performance. These were eliminated using SIMPLIFY POLYGONS to reduce vertex spacing from 30m down to 50-60m where possible. Where not possible DICE was used, which bisects all large polygons with arbitrary internal divisions until no polygon has more than 50,000 vertices. To create midscale layers, ecological systems were dissolved into the macrogroups that they belonged to and resymbolized on macrogroup. This was another frequent source for godzillas as larger landscape units were delineate, so simplify and dice were then run again. Where the base ecol system tiles could only be served up by individual partition tile, macrogroups typically exhibited a 10-1 or 20-1 reduction in feature count allowing them to be assembled into single integrated map services by region, ie NW, SW. CNPS / CDFW / National Park Service Sources: (see also base service definition page) Unlike the Landsat-based raster modelling of the Natureserve and Gap national ecological systems, the CNPS/CDFW/NPS data date back to the origin of the National Vegetation Classification effort to map the US national parks in the mid 1990's.
These mapping efforts are a hybrid of photo-interpretation, satellite and corollary data to create draft ecological land units, which are then sampled by field crews and traditional vegetation plot surveys to quantify and analyze vegetation composition and distribution into the final vector boundaries of the formal NVC classes identified and classified. As such these are much more accurate maps, but the tradeoff is they are only done on one field project area at a time so there is not yet a national or even statewide coverage of these detailed maps.
However, with almost 2/3d's of California already mapped, that time is approaching. The challenge in creating standard map layers for this wide diversity of projects over the 2 decades since NVC began is the extensive evolution in the NVC standard itself as well as evolution in the field techniques and tools. To create a consistent set of map layers, a master crosswalk table was built using every different classification known at the time each map was created and then crosswalking each as best as could be done into a master list of the currently-accepted classifications. This field is called the "NVC_NAME" in each of these layers, and it contains a mixture of scientific names and common names at many levels of the classification from association to division, whatever the ecologists were able to determine at the time. For further precision, this field is split out into scientific name equivalents and common name equivalents.MAP LAYER NAMING: The data sublayers in this webmap are all based on the US National Vegetation Classification, a partnership of the USGS GAP program, US Forest Service, Ecological Society of America and Natureserve, with adoption and support from many federal & state agencies and nonprofit conservation groups. The USNVC grew out of the US National Park Service Vegetation Mapping Program, a mid-1990's effort led by The Nature Conservancy, Esri and the University of California. The classification standard is now an international standard, with associated ecological mapping occurring around the world. NVC is a hierarchical taxonomy of 8 levels, from top down: Class, Subclass, Formation, Division, Macrogroup, Group, Alliance, Association. The layers in this webmap represent 4 distinct programs: 1. The California Native Plant Society/Calif Dept of Fish & Wildlife Vegetation Classification and Mapping Program (Full Description of these layers is at the CNPS MS10 Service Registration Page and Cnps MS10B Service Registration Page . 2. USGS Gap Protected Areas Database, full description at the PADUS registration page . 3. USGS Gap Landcover, full description below 4. Natureserve Ecological Systems, full description belowLAYER NAMING: All Layer names follow this pattern: Source - Program - Level - Scale - RegionSource - Program = who created the data: Nserve = Natureserve, GapLC = USGS Gap Program Landcover Data PADUS = USGS Gap Protected Areas of the USA program Cnps/Cdfw = California Native Plant Society/Calif Dept of Fish & Wildlife, often followed by the project name such as: SFhill = Sierra Foothills, Marin Open Space, MMWD = Marin Municipal Water District etc. National Parks are included and may be named by their standard 4-letter code ie YOSE = Yosemite, PORE = Point Reyes.Level: The level in the NVC Hierarchy which this layer is based on: Base = Alliances and Associations Mac = Macrogroups Sub = SubclassesScale: One of 3 basic scales at which this layer will appear: Base = base scale, approx 1:1k up to 1:36k Mid = 72k to about 500k Out = 1m to 10mRegion: The region that this layer covers, ie USA=USA, WEST= western USA,
Marin = Marin County. May not appear if redundant to the Source-Program text.LABEL & COLOR: These overlays utilize a separate labelling layer to make it easy to include or not include labels, as needed. These are named the same as the layer they label, with "LABEL" added, and often the color used for that label layer in order to help tell them apart on the map. Note there can be multiple different label layers for the same set of polygons, depending upon the attribute or naming style desired, ie scientific names or common names. Finally the order of these services in the sublayers of a map service is normally designed so that ALL of the label services appear above ANY/ALL of the vector services they refer to, to prevent a vector service writing on top of a label and obscuring it.MAP LAYER CATALOGThis map includes a test segment of Natureserve Ecological Systems in the US Southwest, with the following layers and sublayers:GapNsUSA BoundaryMasksALB2: A grid showing the boundaries that define each partition tile of the national vegetation map services, with regional and state boundaries in the USGS Gap US Albers projectionPadus Gap13 WM Base Scale plus Label: (Full PADUS FGDC Metadata here) Overlay vectors at 1k to 288k scale with separate 1k-288k Labelling services for one of 3 different attributes: --Landowner Name: Land owner and primary entity responsible for managing parcel when ‘Manager Name’ is not attributed (e.g.