Mapping and Evaluation of Salinized Soil in an Irrigated Area Based on Geostatistics and GIS
Hongqi Wu · Arid Zone Research · 2010
After analyzing the soil samples from 3 layers ( 0 -30 cm,30 -60 cm and 60 -100 cm in depth) in the study area,the data of total soil salt content and different-sized soil particles were derived. The distribution maps of soil salt content ( 0 -60 cm in depth) and different-sized soil particles ( 0 -30 cm,30 -60 cm and 60 -100 cm) were charted using GS + and GIS. A spatial distribution map of soil texture groups was charted with the raster calculator function of GIS. Based on the soil properties in arid region,the soil texture and its combination as well as total salt content were selected as the classification indexes of saline soil in arid region. The saline soil classification and digital soil mapping technology were researched by integrating the logarithmic ratio data converting process,geostatistics,GIS and field investigation and soil sampling. A GIS-based map of regional digital soil clas-sification was charted to quantitatively assess the texture and conditions of saline soil in the study area. The analyzed results reveal that slightly-salinized soil was dominated in the study area,its area was 1 535. 7 km2 ( 64. 7%) ; the total area of other three saline soils ( clay slightly-salinized soil,surface slightly-salinized soil and middle clay slightly-salinized soil) was 1 517. 4 km2( 63. 9% ). In the study area,clay content in soil is an important factor affecting soil salinization. The basic data can be derived from the digital map of saline soil for improving soil and land use.