Developing a Prototype Web-Based Application for Non-Point Source Pollution Assessment in the Songtao Watershed, Hainan, China
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Developing a Prototype Web-based Application for Non-Point Source Pollution Assessment in the Songtao Watershed, Hainan, China by Yunwei Dong A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master of Environmental Studies in Geography Waterloo, Ontario, Canada, 2009 ©Yunwei Dong 2009 AUTHOR'S DECLARATION I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract The Songtao reservoir, located in the center of Hainan province, is one of the ten biggest reservoirs in China. Since agriculture is the main industry in the watershed, non-point source (NPS) pollution is the primary pollutant source affecting water quality in the reservoir. A scientific approach is required to assess NPS pollution in the Songtao watershed in order to support planning and decision making process related to land use and water resource management. This study compared several commonly used NPS hydrological models in order to identify a suitable model for NPS pollution analysis in the Songtao reservoir. The Soil and Water Assessment Tool (SWAT) was selected as the model to be used in this research. In order to put the SWAT model to practical use, a prototype web-based application was developed to help officers in local government in China to use the SWAT model in their decision making process. In addition, spatial and non spatial data about the Songtao watershed area were collected for the SWAT model. Despite data limitations, ArcSWAT software was employed to develop relative scenarios to assess the NPS pollution in the reservoir. One land use scenario was developed to identify an environmentally sensitive basin in the Songtao watershed and the other was created to demonstrate the consequences of over-exploiting forest land in local area. The limitations of using SWAT model in Hainan province were discussed. Further research opportunities such as data collection and model calibration and validation were identified. In addition, possible improvements to the web-based application were presented. iii Acknowledgements Here I would like to express my thanks to all people who have helped, encouraged and assisted me during my master study. First of all, I would like to thank my supervisor Professor Peter Deadman and committee member Professor Douglas Dudycha for their guidance during my research and study at University of Waterloo. Their enthusiasm and inspiration had motivated me during the whole studying process. Starting from the thesis topic selection, throughout the methodology design and writing the thesis, they provided sound advice and lots of good ideas. I would never make it without them. Dr. David Wood and Professor Robert Feick deserve particular thanks as my thesis readers. Specially, I would like to express my sincere thanks to Dr. David Wood who introduced me into the geography program. Thank you for all government officers in Hainan province who participated in this research project. Without their fully incorporation and hard working, my field research could not be successful. Moreover, I would like to express my special thanks to Cuiping Zhang for her generous help in Hainan province to arrange and organize everything for me. Moreover, I would like to thank my lab-mates and friends especially Mingming Su who helped me in the thesis writing work. Finally, my deepest gratitude goes to my parents for their unflagging love and support throughout my life. Their understanding and encouragement helped me throughout the whole writing process. To them I dedicate this thesis. iv Table of Contents List of Figures .......................................................................................................................................... viii List of Tables .............................................................................................................................................. x Chapter 1 Introduction ................................................................................................................................ 1 1.1 Problem statement ............................................................................................................................. 1 1.2 Purpose of research ........................................................................................................................... 2 1.3 Study area .......................................................................................................................................... 3 1.4 Research questions ............................................................................................................................ 5 1.5 Thesis structure ................................................................................................................................. 5 Chapter 2 Literature review ........................................................................................................................ 7 2.1 Hydrological models and NPS pollution ........................................................................................... 7 2.1.1 Theory of NPS pollution research .............................................................................................. 7 2.1.2 Relationship between GIS and spatial analyzing model .......................................................... 10 2.1.3 Hydrological models and GIS .................................................................................................. 14 2.1.4 Hydrological and NPS pollution models .................................................................................. 15 2.1.5 SWAT model theory and applications ..................................................................................... 39 2.2 Decision Support System (DSS) ..................................................................................................... 45 2.2.1 Internet Technology .................................................................................................................. 47 2.2.2 Web-based decision support system ......................................................................................... 48 2.2.3 Structure of Internet GIS .......................................................................................................... 49 2.2.4 Technology behind Internet GIS .............................................................................................. 51 2.2.5 Hydrology web based DSS ....................................................................................................... 53 2.2.6 SWAT web-based hydrological tools ....................................................................................... 55 2.3 Gap in literature ............................................................................................................................... 56 2.4 Summary ......................................................................................................................................... 57 Chapter 3 Internet GIS Server .................................................................................................................. 58 3.1 Open source and commercial GIS server ........................................................................................ 58 3.1.1 Open source GIS server ............................................................................................................ 58 3.1.2 Commercial GIS server ............................................................................................................ 59 3.1.3 Comparison of open source and commercial GIS servers ........................................................ 60 3.2 ArcGIS Server ................................................................................................................................. 61 3.2.1 Architecture of ArcGIS Server ................................................................................................. 62 3.2.2 Technologies behind ArcGIS Server ........................................................................................ 64 3.2.3 Application Development Framework for .NET ...................................................................... 65 3.3 Summary ......................................................................................................................................... 66 v Chapter 4 Methodology- developing web-based application ................................................................... 68 4.1 Demand analysis ............................................................................................................................. 68 4.2 System architecture of ArcSWAT .................................................................................................. 69 4.3 Design of web-based application from ArcSWAT ......................................................................... 71 4.3.1 Conceptual data model of web-based application .................................................................... 72 4.3.2 Software component for transmitting data from PDB to SQL database .................................. 74 4.4 Web-based application design ......................................................................................................... 75 4.4.1 Software environment .............................................................................................................