scope:

Preface

The motivation for writing this book emanated from our firm belief that for sustainable development we need to conserve all our natural resources such as air, water etc. In addition, we need to emulate all the natural processes to the maximum possible extent in all our design endeavors aimed at achieving development through an improved infrastructure. Individuals and organizations at all levels should be made aware of the fact that water is a precious natural resource which is crucial to our survival. Water needs to be judiciously used in the context of an increasing population-not only to sustain essential requirements such as those for drinking and domestic usage but also for increased food production, industrial usage, power generation, navigational requirements, pisciculture, recreation, landscaping etc.

In view of the uncertainties associated with the global hydrological cycle over which human beings do not have any control, there is the problem of scarcity as well as excess of precipitation both spatially as well as temporally across the globe. Since precipitation is the primary source of water it is essential to harness/store this precious water resource for various usages at all the times as well as at all possible locations.

In the developed world, a large number of hydraulic structures have already been built to augment the water availability so that their overall water demand consistent with their industrial growth and their standard of living can be met. On the other hand, the developing/under-developed world consisting of low and medium income group of nations and accounting for about 85% of the global population have not been able to develop sufficient built-up capacity to augment/store their naturally available water resources. As a result of this most of their precipitation water flows into seas/oceans during peak flow season.

In view of the huge costs involved in major water resources projects as well as on account of their other associated operational, social and environmental problems, such as long gestation period, rehabilitation of project affected population, submergence of valuable forests, loss of rare plant/animal species and minerals, there is a strong international opinion against large scale water resource development. As an alternative to this, a greater emphasis is being given at all levels to small scale development and efficient use of water resources through appropriate technologies inclusive of revival of traditional technologies, water harvesting, low-cost and biological treatment/reuse of wastewater.

Already there are many books dealing with hydrology, hydraulics and hydraulic structures, which generally deal with larger problems of development, analysis, design and implementation of water resources. But there are not many books which deal with small-scale development of water resources consistent with the environmental concerns as well as application of relevant eco-friendly technologies.

Keeping all these factors into consideration, this book has been grouped into five chapters. Each of these chapters is briefly described here.

Chapter 1 provides the reader with a basic background of hydrology as well as all the hydrological processes. It also tries to establish the linkage between imbalance in these hydrological processes due to human intervention and its impact on ecology.

Chapter 2 deals with various uses of water in the order of importance to human civilization. Many relevant case studies from the developing as well as developed world are elaborated to describe water use for municipal requirement in urban/rural neighborhoods, agriculture, industries, hydropower generation, navigation, fisheries as well as recreation.

Chapter 3 explains the three fundamental conservation principles of hydraulics and their applications. Flow measuring instruments in conduits and open channels are also described prior to the listing of basic considerations for eco-friendly design of various water systems.

Chapter 4 discusses various types of qualitative/quantitative hazards arising out of water pollution, floods, landslides, collapse of dams and droughts. It also tabulates the information system requirement for mitigation of various disasters.

Chapter 5, the last among the Chapters, gives the details of traditional/ state-of-the-art water conservation/recharge practices in the developing/ developed world. Wastewater treatment/reuse by low-cost and localized biological processes are also described. Sustainable development through integrated water management practices (e.g., the construction of facilities which are almost self-sustaining in terms of their freshwater requirement and wastewater generation) are also explained.

The authors gratefully acknowledge the financial assistance by the Continuing Education Cell of IIT Kharagpur, in the preparation of this manuscript. The help provided by Sriyuts Mukesh Gupta, Abhinav Goel, Aditya, Tushar Ganvir, Ashwin and Lalit Jha in web searching as well as scanning is sincerely thanked. Likewise, the assistance by Sri Chinmoy Mukherji in the preparation of the figures is worth mentioning here. We thank them from the bottom of our heart. Lastly the authors are highly indebted to their family members Smt. Savita Desai and Dyuti Ghosh, Sriyuts Nachiket Desai and Archisman Ghosh, for their exemplary patience and cooperation shown during these years.