Evaluation and analysis of land suitability based on matter element analysis and GIS technology: An case study at Dongbeigou small watershed of Pingquan county in the water resource area of Beijing and Tianjin

Focusing on the problems of fragile ecological environment and increasing soil erosion in the water resource area of Beijing and Tianjin, land suitability evaluation is badly needed, which is also can be the guide for land development uses and modern agriculture construction. Taking the Dongbeigou small watershed in Pingquan county of Hebei province as the study area, matter element analysis method and GIS technology are carried out to appraise suitability evaluation for agriculture, forestry, and pasture. Results showed that the areas of land which was the most suitable for agriculture were 44.202 hm
²
, while the better suitable were 85.95 hm
²
; The areas of land which was suitable for forestry were 1099.12 hm
²
, accounting for 20.08% of the total areas; the areas which was suitable for pasture amounted for 24.84%; The areas of land which was difficult to use accounted for 15.5%. Per capita arable land was 1.775 mu in the Dongbeigou small watershed, and per capita grain possession was 424.33 kg in 2009. The cultivated land and food production were relatively abundant. The results agreeed with the actual fact, and it could support for environment construction and land development uses in Dongbeigou small watershed.