Landsat Data, Its Use in a Soil Survey Program

Abstract

AbstractThis study's three objectives were: first, to investigate the unique characteristics of LANDSAT imagery as they aid in recognizing soil survey boundaries; second, to explore the use of LANDSAT imagery for low intensity soil surveys; and third, to investigate LANDSAT imagery as a base map for publishing thematic soils maps.As an aid in recognizing soil boundaries, the following characteristics of LANDSAT imagery have a bearing on its use in a soil survey program: the synoptic view of 3.5 million ha on which the condition of the soils and stage of vegetative growth are recorded at nearly the same moment; the near‐orthographic character of the scenes, allowing for the construction of mosaics; the temporal feature, permitting study of soils and vegetation as they change with time and the multispectral capabilities which increase the possibilities of unique signatures for vegetation and soils.Using many of the characteristics of LANDSAT imagery, a low intensity soil survey of Pennington County, South Dakota was completed in 1974. The purpose of this survey was to determine the feasibility of preparing an inexpensive soil map which could be used in the Great Plains areas of South Dakota which presently lack a detailed soil survey. The LANDSAT survey cost 2¢/ha and took about 5 weeks.The first step using LANDSAT imagery as a base map for publishing thematic soil maps is to prepare a mosaic. Twenty LANDSAT scenes from several late spring passes in 1973 were selected and made into a mosaic of scale 1:1,000,000. Two LANDSAT mosaics of South Dakota containing soils information have now been published. On the first, the soil associations are keyed to information on land sale prices from 1967–1972. The result is a land value map on a LANDSAT mosaic. On the second, the soil associations are keyed to soil test results in South Dakota of the last 25 years for organic matter, P2O5, K2O and pH. Also given for each soil association is relief and texture. Each of these publications cost about $400 for 5000 copies.