Tham khảo tài liệu 'sustainable natural resources management part 4', khoa học tự nhiên, công nghệ sinh học phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Upstream Landscape Dynamics of US National Parks with Implications for Water Quality and Watershed Management 31 Measure Source data Years Spatial resolution Reference Population US Census Bureau 2000 Census block groups US Census Bureau 2001 NPS 2010a Housing Spatially Explicit Regional Growth Model SERGoM 2010 100 m cells Theobald 2005 NPS 2010b Roads Environmental Systems Research Institute ESRI Varies up to 2005 Varies ESRI 2010 NPS 2010c Land cover National Land Cover Data NLCD 2006 30 m cells NPS 2010d Fry et al 2011 Conservation status Protected Areas Varies up Database of the US to 2010 Varies NPS 2011a USGS Gap Analysis Program 2011 PAD-US Table 1. NPScape data sources used to compute the landscape variables listed in Table 2 . Measure Variable Units Comments Population Population density count km2 Based on population totals Housing Housing density units km2 Based on mid-points of rural exurban suburban and urban Rural housing area 0-6 units km2 Exurban housing area 7-145 units km2 Suburban housing area 146-1 234 units km2 Urban housing area 1 234 units km2 Commercial industrial area Business - non-residential Roads Weighted road density km km2 Highway weighted by a factor of 3 interstates by 10 Land cover Impervious surface area weighted Anthropogenic sources only Developed area Anderson Level I Developed open space area Anderson Level II Low intensity development area Anderson Level II Medium intensity development area Anderson Level II High intensity development area Anderson Level II Agriculture area Anderson Level I Cultivated crops area Anderson Level II Hay pasture area Anderson Level II Conservation status Protected area Based on Gap Analysis Program GAP codes 1 and 2 Landowner density count km2 All owners of conservation lands including NGO private Table 2. NPScape variables used in the present analyses. 32 Sustainable Natural Resources Management In addition to NPScape variables we included the percentage of each watershed in private ownership .
