Distribusi spasial konsentrasi Pb dalam tanah di sekitar jalan lingkar barat Yogyakarta=Spatial distribution of lead concentration in the soil around the West ringroad of Yogyakarta

The increase of emission resulted by motor-vehicles may create problem in some locations. This happens because the emission contains lead of special tolerance, resulting contamination to the environment, especially soil. The purpose of this research is to know the spatial distribution of lead concentration in the soil as the impact of emission resulted by premium fuel from motor-vehicles, the distribution of which differe between settlement and non-settlement area, and the correlation between lead concentration in the soil with variable of horizontal distance, soil depth, organic matter, pH, texture, vegetation, and land use. The research was conducted around the west ringroad, from Demak Ijo intersection in the North to the Pelem Gurih intersection in the South. The samples were collected with purposive sampling method in the rainy season, on wet and dry soils, on the west-side and the east-side of that road section. The samples consisted of high and low density settlement on wet and dry non settlement. The samples were cathegorized from the road-side based on the micro-relief of soil and the depth of soil (0 - 5 c