Sự cố giọt nước trên bề mặt đất chỉ có hai lựa chọn: nó có thể xâm nhập vào đất hoặc nó có thể chạy. Quá trình này phân vùng là rất quan trọng. Xâm nhập, và bổ sung cho dòng chảy của nó, quan tâm cho hydrologists những người nghiên cứu thế hệ dòng chảy, dòng chảy sông, và nước ngầm. Sự tham gia của nước qua bề mặt liên quan đến các nhà khoa học đất, xâm nhập bổ sung dưỡng chất lưu trữ của đất nước. Quá trình phân vùng là cực kỳ quan phụ thuộc của. | 6 Infiltration Brent E. Clothier HortResearch Palmerston North New Zealand 1. INTRODUCTION A water droplet incident at the soil surface has just two options it can infiltrate the soil or it can run off. This partitioning process is critical. Infiltration and its complement runoff are of interest to hydrologists who study runoff generation river flow and groundwater recharge. The entry of water through the surface concerns soil scientists for infiltration replenishes the soil s store of water. The partitioning process is critically dependent of the physical state of the surface. Furthermore infiltrating water acts as the vehicle for both nutrients and chemical contaminants. Infiltration because it is both a key soil process and an important hydrological mechanism has been twice studied once by soil physicists and again by hydrologists. Historically their approaches have been quite different. In the former case infiltration was the prime focus of detailed study of small-scale soil processes and in the latter infiltration was just one mechanism in a complicated cascade of processes operating across the scale of a catchment. Latterly access to powerful computers has meant that hydrologists have been able to incorporate the soil physicists detailed mechanistic descriptions of infiltration into their hydrological models of watershed functioning. This has increased the need to measure the parameters that control infiltration. To the memory of John Philip 1927-1999 for without his endeavors this would have been a very short chapter. 239 Copyright 2000 Marcel Dekker Inc. In this chapter I first describe the development of one-dimensional ponded infiltration theory discussing both analytical and quasi-analytical solutions. In passing I mention empirical descriptions of infiltration before discussing the key development of a simple algebraic expression for infiltration that employs physically based parameters. Emphasis is placed on theoretical approaches for they can predict
