Exercises in Soil Physics

This book is designed to complement available soil physics and vadose zone hydrology texts (e.g. Hartge/Horn: Essential Soil Physics, Kutliek/Nielsen: Soil Hydrology or Bohne's Introduction to Applied Soil Hydrology) by providing more than 200 additional practice exercises with detailed answers. The material presented in this book is suitable for beginning to graduate level students and may be studied either independently or in conjunction with formal classes. The main features for the book arose from discussions while Lazarovitch was a postdoctoral student at Arizona. At that time, we recognized the desirability of additional exercises to accompany available books which understandably must concentrate on presenting subjects and explaining concepts. Inclusion of detailed solutions presents sufficient detail for discussion as well as to clarify concepts, both for students and teachers. The topics of soil physics are explored in nine categories: solid phase, soil water relations, saturated water flow, unsaturated flow, field water processes, chemical fate and transport, heat and energy transport, soil gases and transport and soil variability. Experts in these topics were chosen to complete the corresponding chapter including the questions and the solutions. We worked with the chapter authors in order to provide some commonality of layout and style as well as provide feedback in terms of appropriateness and validity. After the reader selects a problem of interest, we encourage first solving independently and then to compare results with the given detailed answer. Many questions require short answers, but some require a spreadsheet or program. Liberal references are made to EXCEL of which familiarity is assumed although the reader can use other programs if preferred. Several problems are also logically solved using HYDRUS-1D, STANMOD, ROSETTA and RETC which are available in the public domain. In Chapter 9, use can be made of WINASTSA, also available in the public domain, although some of the presented results were performed with ISATIS, a proprietary program. The appendix of the book summarizes various file names with the associated problems. These files are available in the CD provided with the book and also will be available for downloading in the WebPage of the first editor: http://cmsprod.bqu.ac.il/Enq/Units/bidr/Faculty_Members/Lazarovitch.html As most students soon find out, notations and conventions in soil physics take on a variety of forms. Here, each chapter has its own symbol list although, insofar as practical, we encouraged consistent notations across the entire book. Generally soil water potential expressed as energy per unit weight is favored and results expressed in appropriate length units. Soil water content, 6 without extra subscripts or adjectives refer to water content on a volumetric basis. Ultimately, notation and rounding of numbers have been left primarily to the chapter authors. We have striven to be rigorous with respect to signs regarding flow, whether dealing with water, energy, solutes or gases. In order to differentiate between positive and negative flow, careful attention to the coordinate system is required. The cartoons in the beginning of each chapter and the Albert Einstein quotes at the end of each chapter are added mostly for entertainment. It probably is a surprise to many readers that one of Einstein's early papers dealt with soil erosion (Einstein, A., 1926. The cause of the formation of meanders in the courses of rivers and of the so-called Baer's Law. Read before the Prussian Academy, January 7, 1926).