tailieunhanh - AGRICULTURAL NONPOINT SOURCE POLLUTION: Watershed Management and Hydrology - Chapter 8

Quản lý nước cho các mục đích nông nghiệp có thể được truy nguồn từ Lưỡng Hà về 9000 năm Herodotus, một sử gia Hy Lạp của thế kỷ thứ năm trước Công nguyên, đã viết về thoát một công trình gần thành phố Memphis ở Ai Cập. Thoát nước đã được một phần của ngành nông nghiệp Mỹ kể từ thời thuộc địa. Nếu không có thoát nước, rất khó để tưởng tượng miền Trung Tây Hoa Kỳ như chúng ta biết trong thế kỷ 20, hình ảnh thu nhỏ của sản xuất nông nghiệp. Phần lớn của Ohio, Indiana, Illinois, và Iowa ban. | 8 Agricultural Drainage and Water Quality William F. Ritter and Adel Shirmohammadi CONTENTS Introduction History of Drainage in the United States Materials and Methods for Subsurface Drainge Types of Drainage Systems Surface Drainage Conventional Subsurface Drainage Water-Table Management Water-Table Management Design Preliminary Evaluation and Feasibility of Site Drainage Characteristics Topography Barrier Hydraulic Conductivity Drainage Outlet Water Supply Detailed Field Investigations Design Computations System Layout and Installation Operations and System Management Soil and Crop Management Aspects of Water-Table Management Water Quality Impacts Hydrology Conventional Drainage Controlled Drainage Nutrients Conventional Drainage Controlled Drainage Pesticides Conventional Drainage Controlled Drainage 2001 by CRC Press LLC Impact of Drainage of Surface Water Quality Institutional and Social Constraints Summary References INTRODUCTION Water management for agricultural purposes can be traced to Mesopotamia about 9000 years Herodotus a Greek historian of the fifth century . wrote about a drainage works near the city of Memphis in Egypt. Drainage has been part of American agriculture since colonial times. Without drainage it is hard to imagine the . Midwest as we know it in the 20th century the epitome of agricultural production. Much of Ohio Indiana Illinois and Iowa originally was swamp or at least too wet to farm. Without drainage irrigation development in the western United States would have failed because of waterlogging and salinity. In the 1960s and 1970s drainage was considered an honorable and viable soil and water conservation practice. Drainage technology developed rapidly during this era. In the 1990s drainage is greeted with angry response