Relationship of land use/cover on water quality in the Liao River basin, China

AbstractA total of 76 sampling sites were selected in the Liao River basin (21.9×104km2). During the period of 2009-2010, 58 water samples were collected in 2010 and 42 were collected in 2009, physical-chemical variables were analyzed to investigate their spatial-temporal variability in particular the relationship with land use /cover. The results indicated that physical and chemical properties showed obvious spatial heterogeneity in the Liao River basin. Taizi River and Hun River are located in the southeast of the basin, the water quality for two sub-basins: water quality in upstream is better than that in downstream, water quality level in downstream was classified into IV-V. There were no obvious features in the East Liao River basin, water quality in downstream was classified into III level. West Liao River run for many years, water quality was classified into IV. Big Liao River basin was located in middle and east of the Liao River basin. Water quality was classified into V. Correlation and regression analysis indicated that BOD5, COD, sediment, hardness and nitrate–nitrogen (NO3−–N), total dissolved particular (TDP) were significantly related to land use for forest and agriculture