by Peter E Rijtema (DLO Winand Staring Centre for Integrated Land, The Netherlands), Piet Groenendijk (DLO Winand Staring Centre for Integrated Land, The Netherlands), & Joop G Kroes (DLO Winand Staring Centre for Integrated Land, The Netherlands)

Peter Emile Rijtema has been involved in environmental research since 1972 and is a specialist in the field of the transport, fate and behaviour of agrochemicals in soils. A leading figure in the development of models on both the field and on the regional scale, which describe the leaching of nutrients and pesticides into groundwater and surface water, he also specialises in scenario analysis for the evaluation of the effects of different regulations in agricultural practice in the reduction of environmental pollution.

Pieter Groenendijk was responsible for the development and application of deterministic simulation models in relation to water management, hydrological systems analysis, ecology, groundwater chemistry, emission of nutrients to groundwater and surface water systems. An expert in the modelling of hydrological, chemical and biological processes for various levels of integration, he has lately been involved in research on agricultural pollution, as well as in the initiation and supervision of a number of applied research projects on the emission of nutrients and pesticides from agricultural soils to groundwater and surface water systems.

Johannes Gerardus Kroes was involved in the development and application of water quality simulation models, the pesticide model TRANSOL and the nutrient model ANIMO. He is an expert in the modelling of solute flow for various levels of integration and his publications have dealt largely with aspects of solute modelling, including developments in information technology. He is currently working on various projects on solute transport.

The concern over groundwater contamination has focused attention on the processes that influence the fate of chemicals in soil water systems. A major concern of groundwater contamination is the passage of these chemcials through the unsaturated zone and the relatively thin cover layers overlying the aquifers. Pollution due to diffuse sources is probably the most difficult to model. This is because the loads are usually non-homogeneous and they are also governed by spatially and temporally non-homogeneous, but dynamic, processes of chemical and biochemical phenomena.

In this book, the estimation techniques and transfer functions of required input data from existing databases in geographic information systems are provided. Spatially variable input data, such as the type of soil, hydrological conditions, intensity of land use and atmospheric deposit of pollutants, are derived from basic land and climate characteristics. A model for the evaluation of land use and water management is also described. In addition, examples of field and regional studies on water management and policy analysis are provided.

• Water Transport in Soils
• Transport of Solutes
• Physical-Chemical Processes
• Bio-Chemical Processes
• Environmental Influences on Processes
• Water, Nutrient Uptake and Crop Production
• Model Validation at Field Scale
• Regional Model Applications