Soil sampling The first step in soil sampling

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Soil sampling • The first step in soil sampling is to divide the area

Soil sampling • The first step in soil sampling is to divide the area to be sampled into homogeneous units. • These homogeneous units, where one sample will be representative of the whole area

Soil sampling • The soil sample from each uniform area is composed of many

Soil sampling • The soil sample from each uniform area is composed of many subsamples. In other words, the soil sample is a composite sample, made up of many subsamples taken from throughout the uniform area. • Subsamples are taken to minimize any local non-uniformity present within the sampling area.

Sampling material • Common tools used to sample soils for routine analysis include: spade,

Sampling material • Common tools used to sample soils for routine analysis include: spade, hand probe, hand auger, bucket auger

Soil sampling • The first step in soil sampling is to divide the area

Soil sampling • The first step in soil sampling is to divide the area to be sampled into homogeneous units. • These homogeneous units, where one sample will be representative of the whole area

From point data to areas: spatial interpolation • Thiessen polygons • trend surfaces •

From point data to areas: spatial interpolation • Thiessen polygons • trend surfaces • inverse distance (or power of distance) • geostatistics

Lead concentration estimation Pb 230 ppm Pb 180 ppm ? Pb 580 ppm

Lead concentration estimation Pb 230 ppm Pb 180 ppm ? Pb 580 ppm

Geostatistics: origin • Krige (1950): application of spatial variability analysis to mining activity •

Geostatistics: origin • Krige (1950): application of spatial variability analysis to mining activity • Matheron (1955): first studies on “theory of regionalised variable” • Journel (1978): Mining geostatistcs

Geostatistics: objectives • Qualitative and quantitative analyisis of spatial variability • Estimate of unknown

Geostatistics: objectives • Qualitative and quantitative analyisis of spatial variability • Estimate of unknown value via interpolation • Simulation

Geostatistics: fields of application • Geology and mining sciences • Environmental sciences • Soil

Geostatistics: fields of application • Geology and mining sciences • Environmental sciences • Soil science • Agronomy and precision farming • Meteorology • GIS and remote sensing

From point data to areas: spatial interpolation • Thiessen polygons • trend surfaces •

From point data to areas: spatial interpolation • Thiessen polygons • trend surfaces • inverse distance (or power of distance) • geostatistics

From point data to areas: spatial interpolation • Thiessen polygons • trend surfaces •

From point data to areas: spatial interpolation • Thiessen polygons • trend surfaces • inverse distance (or power of distance) • geostatistics