What Is Land Cover?

Although the terms land cover and land use are often used interchangeably, their actual meanings are quite distinct.

• Land cover is the natural landscape recorded as surface components: forest, water, vegetation (wetlands), soils, rocks, and urban infrastructure (constructed materials covering the land surface) physically present and visible. Land cover can be interpreted and documented by analyzing satellite and aerial imagery. This documentation of land cover based on spectral signatures is land cover mapping.
• Land use can be defined as economic and cultural activities that are practiced at a place, but these activities may or may not be manifested as visible land cover features. Land use is the documentation of human uses of the landscape: residential, commercial, agricultural, etc. This documentation of land use can be inferred but not explicitly derived from satellite and aerial imagery. There is no spectral basis for land use determination in satellite imagery.

For example, industrial or commercial land use may be visibly manifested as developed land cover, but recreational land use may occur in many different types of land cover, often without visible evidence of recreational use (Dobson and others, 1995).

Why Is Land Cover Mapping Important?

Identifying, delineating, and mapping land cover is important for resource management and planning programs. Land cover mapping is an essential tool used by natural resource managers as they struggle to protect habitat and plan against future loss and degradation. The challenge for resource managers is ever increasing as projected U.S. population growth in coastal regions accelerates losses of wetlands and adjacent habitats, and as waste loads and competition for limited space and resources increase (U.S. Congress, 1989). Coastal wetlands are being destroyed by erosion, dredge, fill, impoundments, toxic pollutants, and eutrophication (Dobson and others, 1995).

Identification of land cover determines the baseline from which monitoring activities (land cover change detection) can be performed. Land cover change is a direct measure of quantitative habitat loss or gain (Dobson and others, 1995). Data portraying the characteristics and locations of land cover are necessary to ascertain which land areas and corresponding water resources are in critical need of analysis and protection. Land cover and land cover change information can be used by resource managers in their decision-making processes to assess urban growth, determine changes to natural resources, and develop trend analyses.