This book is written for all those involved in measurement of soil water phenomena, whether they be environmental scientists, field technicians, agronomists, meteorologists, hydrogeologists, foresters, physical geographers, civil or water engineers or students in these subjects. It contains a comprehensive description of all the major methods used for measurement of soil water content and potential, solute concentration, transport and balance of water and solutes, including recharge to groundwater aquifers. The emphasis is firmly on techniques which can be applied in the field or on samples obtained from the field. The theory and practice of the workings of the main instruments and methods available is described, along with practical tips on surmounting some of the main difficulties and explanations of many commonly encountered jargon words.

Laboratory tests were conducted with radar sensors to detect the presence of and measure the depth to subsurface interfaces when the surface was bare, and to determine the influence of vegetation at various stages of growth on radar responses. A secondary purpose was to continue earlier studies to relate radar returns and the electrical constants that they provided to moisture content and density of samples. Large laboratory samples were prepared at various moisture contents and densities and with various depths to a subsurface metal plate. Standard pulsed radar sensors operating with frequencies of 297, 5870, 9375, and 34,543 megacycles/sec and directed at various angles of incidence to the surface were employed. The results of this laboratory study indicate that the standard pulsed radar sensors can provide information that will permit an estimate of the moisture content of deep, homogeneous soil samples and the detection of surface vegetation of various heights. Radar signatures of vegetation-covered soil were more significantly altered at Ka-, X-, and C-band frequencies than at P-band frequencies. However, standard pulsed radar sensors used monochromatically cannot provide information for predicting depth to subsurface interfaces or for directly indicating the presence of a subsurface interface.

Agriculture is strongly affected by changes in soil hydrology as well as changes in land use and management practices and the complex interactions between them. This book aims to develop an understanding of these interactions on a watershed scale, using soil hydrology models and addresses the consequences of land use and management changes on agriculture from a research perspective. It includes case studies that illustrate the impact of land use and management on various soil hydrological parameters under different climates and ecosystems. It is suitable for researchers and students in soil sc

This book describes the application of polarimetric synthetic aperture radar to earth remote sensing based on research at the NASA Jet Propulsion Laboratory (JPL). This book synthesizes all current research to provide practical information for both the newcomer and the expert in radar polarimetry. The text offers a concise description of the mathematical fundamentals illustrated with many examples using SAR data, with a main focus on remote sensing of the earth. The book begins with basics of synthetic aperture radar to provide the basis for understanding how polarimetric SAR images are formed and gives an introduction to the fundamentals of radar polarimetry. It goes on to discuss more advanced polarimetric concepts that allow one to infer more information about the terrain being imaged. In order to analyze data quantitatively, the signals must be calibrated carefully, which the book addresses in a chapter summarizing the basic calibration algorithms. The book concludes with examples of applying polarimetric analysis to scattering from rough surfaces, to infer soil moisture from radar signals.

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 108. Non-point source (NPS) pollution in the vadose zone (simply defined as the layer of soil extending from the soil surface to the groundwater table) is a global environmental problem. Characteristically, NPS pollutants are widespread and occasionally ubiquitous in extent, thus making remediation efforts difficult and complex; have the potential for maintaining a relatively long active presence in the global ecosystem; and may result in long?]term, chronic health effects in humans and other life forms. Similar to other global environmental issues, the knowledge and information required to address the problem of NPS pollutants in the vadose zone cross several technological and subdisciplinary lines: spatial statistics, geographic information systems (GIS), hydrology, soil science, and remote sensing. Cooperation between disciplines and scientific societies is essential to address the problem. Evidence of such cooperation was the jointly sponsored American Geophysical Union Chapman/Soil Science Society of America (SSSA) Outreach Conference that occurred in October 1997, entitled “Applications of GIS, Remote Sensing, Geostatistics, and Solute Transport Modeling to the Assessment of Non-Point Source Pollution in the Vadose Zone.” The objective of the conference and this book, which was developed from the conference, was to explore current multidisciplinary research for assessing NPS pollution in soil and groundwater resources.