Guest Editorial — God Didn’t Make Those Little DNAPLS Andrew W. Stone
Risk-Based Evaluation of Ground-Water Contamination by Agricultural Pesticides    P. Varshney, U. S. Tim & С. E. Anderson
Agrotechnically Induced Salinization in the Unsaturated Zone of Loessial Soils, N.W. Negev, Israel    M. Magaritz & A. Nadler
A Simple Analytical Approach for Predicting Nitrate Concentrations in Pumped Ground Water    D. N. Lerner & К. T Papatolios

Water is the basic requirement for the development of civilization. The primitive civilizations were developed along the surface water bodies to meet the demand of water for the society. With the progress of time, the population-led demand for water was increased in those civilizations and which ultimately led to conflicts. The Indus valley civilization was destroyed mainly because of issues related to water management.

The need for hydrological research, basic as well as applied, is substantial to help rationally manage the world’s water resources. To satisfy this need, and the interest of Member States, UNESCO, in 1975, launched a long-term intergovernmental programme, the International Hydrological Programme (IHP), to follow the first worldwide programme devoted to scientific study of the hydrological cycle, the International Hydrological Decade (1965–1974). Although the IHP is basically a scientific and educational programme, UNESCO endeavours to direct programme activities towards the practical solutions of the world’s very real water resource problems, while maintaining the IHP scientific concept <...>

To understand hydrochemistry and to analyze natural as well as man-made impacts on aquatic systems, hydrogeochemical models have been used since the 1960’s and more frequently in recent times.
Numerical groundwater flow, transport, and geochemical models are important tools besides classical deterministic and analytical approaches. Solving complex linear or non-linear systems of equations, commonly with hundreds of unknown parameters, is a routine task for a PC.