Abstract
Understanding the relationship between land use and surface water quality is necessary for effective water management. We estimated the impacts of catchment-wide land use on water quality during the dry and rainy seasons in the Dongjiang River basin, using remote sensing, geographic information systems and multivariate statistical techniques. The results showed that the 83 sites can be divided into three groups representing different land use types: forest, agriculture and urban. Water quality parameters exhibited significant variations between the urban-dominated and forest-dominated sites. The proportion of forested land was positively associated with dissolved oxygen concentration but negatively associated with water temperature, electrical conductivity, permanganate index, total phosphorus, total nitrogen, ammonia nitrogen, nitrate nitrogen and chlorophyll-a. The proportion of urban land was strongly positively associated with total nitrogen and ammonia nitrogen concentrations. Forested and urban land use had stronger impacts on water quality in the dry season than in the rainy season. However, agricultural land use did not have a significant impact on water quality. Our study indicates that urban land use was the key factor affecting water quality change, and limiting point-source waste discharge in urban areas during the dry season would be critical for improving water quality in the study area.
Highlights
Rivers are vulnerable to land use change and ubiquitous exploitation [1,2]
We investigated the spatial and seasonal variability of land use impacts on water quality to address the following questions: (1) What are the impacts of land use on water quality in the Dongjiang River basin? What is the key land use that impacts water quality? (2) Are there seasonal differences in the impacts of land use on water quality? (3) What are the implications of our findings for managing and mitigating pollutant loadings?
We used the Dongjiang River basin as a subtropical case study to investigate the relationships between land use and water quality in the dry and rainy seasons based on data from 83 sites
Summary
Rivers are vulnerable to land use change and ubiquitous exploitation [1,2]. Comparative studies have found that land use has significant impacts on river water quality and that the mechanisms are complex [6,7]. Despite the many studies that have described the general relationships between land use and water quality, those relationships are not fully understood [14]. There are still uncertainties regarding whether urban or agricultural land use is more important in influencing water quality on the scale of catchments. Donohue et al [15] identified that urban, arable and pasture lands were the principal factors affecting water quality in Irish rivers. Lee et al [11] found urbanization, rather than agricultural land use, was a major factor in water quality degradation in South
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
