Rivers provide numerous benefits to man as avenues of commerce and sources of water supply. Flood plains have rich agricultural soils, and some of the earth’s most heavily populated areas occur along rivers.
Yet the riverine environment can be hazardous. Ancient civilizations struggled against floods while trying to earn a living from the fertile land adjacent to the Nile, Tigris, Euphrates, Indus, and Yellow Rivers. The worst geologic disaster known occurred in 1887 when about 800,000 Chinese lost their lives from the Yellow River flood (Costa and Baker, 1981). Another 100,000 Chinese died when the Yangtze River flooded in 1911. The great flood of 1927 extensively damaged the lower Mississippi River Valley and a flood-control plan was quickly adopted. The Arno River ripped through Florence, Italy, in 1966 and damaged one of the foremost art centers of the world.
Legget (1973, p. 66) has noted that in Central Europe the builders of medieval towns generally avoided the flood plains. They were rightly afraid of floods, and recognized the difficulty of construction on the wet ground adjacent to rivers. The early sectors of the older cities were usually located on the higher ground provided by river terraces. This wise practice was not based consciously on geological training, but utilized the same craft-lore demonstrated by the builders of the Pyramids and other early works (Chapter 1, this volume). Unfortunately, since the late 1800s, buildings on flood plains has steadily increased throughout the world with the growth of major cities to satisfy pressures for urban living.
In the United States, flood-related deaths continue, and annual flood damage is increasing (Rahn, 1986).
Figures & Tables
A review of milestones and changes in geological theory and practice from which modern engineering geology in North America has developed. Five chapters discuss historical events and the contributions of early scientists and engineers; nine chapters review the state of knowledge of dominant geologic processes, phenomena, and specialized principles critical to modern practice; and three chapters discuss geologic environs and the properties of construction materials. Four chapters are devoted to geoscience investigations and related techniques for: initial regional-areal evaluation of conceptual candidate sites (Phase I); selection of preferred-designated sites and design (Phase II); typical kinds of investigations used during project construction (Phase III); and as-built documentation and explorations of the operating or rehabilitation phases. Closing chapters focus on the geoscientist's responsibilities relative to engineering failures, errors of judgment that impact works, litigation, and forensic geoscience. The 34 contributors present extensive case histories applicable worldwide.