tailieunhanh - AGRICULTURAL NONPOINT SOURCE POLLUTION: Watershed Management and Hydrology - Chapter 9

Chất lượng tài nguyên nước của chúng tôi đã được cả hai mối quan tâm quốc gia và toàn cầu thập kỷ qua. Tương tự như vậy, vấn đề môi trường nhân tạo của nước ngọt và biển hiện tượng phú dưỡng và ô nhiễm nước ngầm đã tăng lên gần đây thập kỷ qua. Tác động tiêu cực tiềm tàng của các hóa chất nông nghiệp về chất lượng cả hai bề mặt và các nguồn tài nguyên nước ngầm đã được một mối quan tâm lớn của các nhà khoa học và kỹ sư trên thế giới cũng. Tác động có hại bao. | 9 Water Quality Models Adel Shirmohammadi Hubert J. Montas Lars Bergstrom and Walter G. Knisel Jr. CONTENTS Introduction Concept of Modeling Model Philosophy Model Classification Types of Water Quality Models Model Development Problem Identification and Algorithm Development Problem Definition Algorithm Development Database Requirement Sensitivity Analysis Model Validation and Verification Documentation Model Support and Maintenance Water Quality Models and the Role of GIS Use and Misuses of Water Quality Models References INTRODUCTION The quality of our water resources has been of both national and global concern for decades. Similarly the manmade environmental problems of freshwater and marine eutrophication and contamination of groundwater have increased over the last few decades. The potential negative impact of agricultural chemicals on the quality of both surface and groundwater resources has been a major concern of scientists and engineers worldwide as well. Such adverse effects include deteriorating surface water and groundwater quality by plant nutrients and pesticides1-6 and accumulation of agrochemicals in the soil to toxic levels Torstensson and Stenstrom7 . Agricultural chemicals can contaminate water resources by one or more of the following pathways Shirmohammadi and Knisel8 1 surface runoff to streams 2001 by CRC Press LLC and lakes 2 lateral movement of chemicals through unsaturated or saturated soil media to bodies of surface water or 3 vertical percolation of chemicals through unsaturated or saturated soil media to underlying groundwater. Climate soils geology land use and agricultural management practices influence the quantity of water and chemicals that move through each of the aforementioned pathways. Because of the complex nature of nonpoint source NPS pollution the development of detection and abatement techniques is not a simple process. Only two .