title: Long-term diffuse phosphorus pollution dynamics under the combined influence of land use and soil property variations.
abstract: Analyses of the spatial-temporal distribution of diffuse pollution in agricultural regions are essential to the sustained management of water resources. Although nutrients, such as phosphorus fertilizers, can promote crop growth while improving soil fertility, excessive nutrient inputs can produce diffuse pollution, which may results in water quality degradation. The objective of this paper is to employ the SWAT (Soil and Water Assessment Tool) to estimate diffuse P effects on temporal and spatial distributions for a typical agricultural watershed and to identify the conjunct and independent influences of long-term land use and soil properties variation on diffuse P. With the validated model, the four-period simulation results (from 1979 to 2009) indicate that land use changes from agricultural development increased diffuse P yields. However, regarding updated soil properties, no significant differences of P yield were found between 1979 and 2009, demonstrating that impact of the cropland expansion were naturalized with soil property variations. An F-test was employed to assess the essentiality of all of the variables examined during the simulation period, and the test results indicated that diffuse P loading was more sensitive to soil properties than to land use. Before the P pollution control project about the land use optimization planning, it is more effective to distinguish the impacts of land use and soil properties.
authors.affiliation: School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing 100875, China.
authors.forename: Haobo
authors.initials: H
authors.lastname: Huang
authors.affiliation: School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing 100875, China. Electronic address: wei@bnu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Ouyang
authors.affiliation: School of Environment, State Key Laboratory of Water Environment Simulation, Beijing Normal University, Beijing 100875, China.
authors.forename: Haotian
authors.initials: H
authors.lastname: Wu
authors.affiliation: Key Laboratory of Nonpoint Source Pollution Control, Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Environmental Sciences, Informatics and Statistics, University Ca' Foscari Venice, Venice 30123, Italy.
authors.forename: Critto
authors.initials: C
authors.lastname: Andrea
keywords: Combined influence; Diffuse phosphorus pollution; Land use; SWAT; Soil properties