Preface

Recent advances in the interdisciplinary science of hydrology are facilitating a better understanding of the underlying physics associated with hydrologic cycle components, improved predictive capabilities of surface water numerical models, and enhanced strategic water management protocols. An effort is made in this book to present some of these advances. The book will be of interest to students who would like to advance their knowledge in hydrology and researchers in areas related to modeling, hydrometeorology, agronomy, water management policy decisionmakers, environmental science, and earth sciences. The contents of this book will supplement the material in standard hydrology textbooks. A brief overview of the book's chapters is summarized below.

The science of hydrometeorology, which focuses on studying the atmospheric and terrestrial components of the hydrologic cycle with emphasis on their interrelations, is fast maturing. Advances made in instrumentation and computational power are enabling researchers to better understand the underlying science. Valipour and his team (Chapter 1) extensively reviewed the evolution of observational hydrometeorology from 3500 BC to the present day and their combined role with modeling in assessing climate change. Curk and Glavan ( Chapter 2) reviewed the popular hydrologic models with a focus on their suitability and robustness for agronomy applications. The chosen model's strengths, weaknesses, and the importance of interpreting the model output were presented. Related studies in Slovenia have been summarized.

Legacy numerical models for hydrologic applications were originally written prior to 1990. These models were written in FORTRAN and are based on a strong theoretical foundation. However, owing to the lack of computational resources at that time, the coding techniques used are not optimal for the current computers. Additionally, the array limitations in the legacy codes might prevent their application over large domains. Rao and Hromadka (Chapter 3) reviewed the limitations in the USGS Diffusion Hydrodynamic Model (DHM) and enhanced certain components in the source code so that the model can be applied across large spatial domains. Zalewski (Chapter 4) detailed the underlying elements in ecohydrology, which is an interdisciplinary field that brings in hydrologists, hydrobiologists, botanists, and plant physiologists. The role of ecohydrology in achieving biosphere sustainability and the need to develop it as integrative sustainability science has been detailed.

Jeet and his colleagues, (Chapter 5) in their chapter, reviewed the effort that went in and the challenges associated with the linking of rivers in India. While linking of the rivers will address the water imbalance, addressing the associated infrastructure costs and potential opposition from landowners will require a significant commitment from the federal and state agencies. Some of the parameters that the authors have presented are very similar to other parts of the world, where discussion relating to interlinking rivers is in the infant stages. Shaban (Chapter 6) reviewed the characteristics of the rivers in Lebanon along with their watersheds.

The challenges associated with efficiently managing the nation's water resources coupled with the importance of developing an integrated management policy are detailed. Chakraborty and his colleagues (Chapter 7) detailed the statistical analysis of precipitation isotopes across gauge rainfall data from multiple stations in the Indian subcontinent. A potential application of this technique is in predicting the interannual variability of monsoon rainfall.
