**6. Acknowledgments**

290 International Perspectives on Global Environmental Change

relatively high in farmland, urban and village areas, but very little change in forest areas. Since urban areas are dramatically increasing from 2000 to 2008, their impacts on TN and TP are quite obvious. These results not only provide the linkages between land-use types and stream water quality, but also show the high correlation of land-use types and water quality variables. The results indicate that water quality improvement and ecological restoration have great effects on the regional sustainable development. Thus, if the sustainable development is pursued, land management should consider the potential impacts of land-

Land use-land cover (LULC) change is one of the major environmental changes occurring around the globe. Water quality is such one factor affected by LULC change. In this study, an integrated approach, involving remote sensing technology, geographic information system (GIS), statistical and spatial analysis, and hydrologic modeling, is used to conduct a comprehensive study on the relationship between land-use types and water quality in the Wenyu River watershed. Landsat TM data is used to extract the land-use information in the study area. The result suggests that this model is indeed an useful tool in hydrologic research and management. The results of water quality comparison with different land-use types show that land use types are significantly correlated to water quality variables. The Spearman's rank correlation analyses confirmed the change of water quality is impacted by land-use changes. Based on an exponential model, multiple regression models were applied to estimate the contributions of different land types on six stream water quality variables, including TN, NO3- N, TP, PO4- P, COD and DO, in Wenyu River watershed. The obtained results are identified well to explain the water quality variables using land-use types, with the reasonable satisfactory in the goodness-

The results can provide insight into the linkages between land-use types and stream water quality. The study offers the supporting evidence for the previous studies to serve as a reference to similar studies estimating the response of water quality to the land-use change. The models can help examine the relative sensitivity of water quality variables to alterations in land-use types within a watershed. The predicted values are close to the actual monitored values, which indicates that with little calibration and validation, the regression model can be applied in other watersheds under a different geographical scale in a different region

The results also indicate that with the integration of GIS and ecological modeling, a decision-making support system can be developed to manage land development and control non-point sources pollution at the watershed scales. This study also suggests that if a sustainable development is pursued, land management should consider the ipmacts of land-use types on water quality change in the area. The study provides a technical support for the water quality improvement and ecological restoration in the Wenyu River watershed, which has the great significance for the sustainable economic development of

However, in the study, only land-use related variables are considered in the models. In fact, there are other factors would be related to water quality levels in a sub-watershed, such as population characteristics, waste water treatment plants, soil types, average precipitation

use on water quality changes in the watershed scale.

**5. Conclusion** 

of-fit of the models.

with variable landscapes.

Beijing City.

The authors are extremely grateful to Prof. Liding Chen and Dr. Ranhao Sun for their support of the field work and data collection at the Research Center for Eco-Environmental Sciences (RCEES) under the Chinese Academy of Sciences (CAS), and Jinrong Hu and Xiaofei Chen from the Chinese University of Hong Kong (CUHK) for their help in data processing and discussion. The authors would like to thank the two anonymous reviewers who gave helpful and critical comments to improve the original manuscript. The research is jointly supported by the CUHK Direct Grants, GRF (CUHK454909 and CUHK459210), National Outstanding Youth Science Foundation of China (40925003) and the Open Fund of State Key Laboratory of Urban and Regional Ecology (SKLURE2010-2-3).
