Maps showing land use within 500-m of the well and land-use change between cycles

The following maps (all in PDF format) show land-use characterization within 500 meters of wells sampled by the USGS National Water-Quality Assessment Program to study land-use effects on water quality. Cycle 1 (1991-2001) and/or cycle 2 (2002-2013) land use at each site is displayed along with an indication of land-use changes.

Land use/land cover is described and shown using detailed categories. In some cases land use was inconsistently mapped between cycle 1 and cycle 2.  Sometimes cycle 2 land use was characterized by someone who did not use the previous cycle 1 land-use characterization as a guide.  This resulted in apparent land-use changes when, in reality, land use did not change between cycles.  Sometimes inconsistencies appear in the identification of a land-use category (for example: identifying an area as 'mixed forest' in cycle 1 but as 'deciduous forest' in cycle 2;  or identifying an area as 'residential mixed housing' in cycle 1 but as 'farm residence/farm structures' in cycle 2) and other times inconsistencies are in the delineation of the land-use area (for example delineating a road as a separate category in one cycle but including it with adjacent land use in the next cycle). Other apparent land-use changes are because some of the spatial data from the different cycles do not align exactly due to spatial misalignment of DOQs which were used as a backdrop for digitizing. In order to display gross land-use changes over time and to compensate for some of the inconsitencies, the land use was aggregated to level 1 categories and is also shown on the maps.

The maps reflect data archived as of 01/09/2009. Contact Terri Arnold tlarnold@usgs.gov for more information or look at the USGS internal-use web page: http://water.usgs.gov/nawqa-only/luchar/

These maps were created by Kevin Jungk and Jacqueline Thomas under the direction of Terri Arnold during the Summer 2008.