Geoscience Reference
In-Depth Information
Introduction
1.1 OVERVIEW OF RIVER ENGINEERING
The origin of river engineering dates back to ancient times. According to historical
records, the Chinese began building levees along the Yellow River about six thou-
sand years ago. Approximately around the same period, irrigation systems and flood
control structures were constructed in Mesopotamia, and also some ten centuries
later in Egypt. During the Renaissance period, the observation of water flow and
sediment transport was carried out by the Italian artist and engineer Leonardo da
Vinci (1452-1519). Since then, scientists and engineers have performed a great num-
ber of studies on rivers, and constructed dams, levees, dikes, bridges, river training
works, navigation facilities, and water supply facilities along rivers. This section briefly
highlights the key issues in river engineering.
River dynamics
The study on the flow, sediment transport, and channel evolution processes in rivers
began centuries ago, but river dynamics emerged as a distinct discipline of science
and technology only after M. P. DuBoys established a bed-load formula in 1879 and
H. Rouse proposed a function for the vertical distribution of suspended sediment in
1937. River dynamics deals with river flow and sediment problems, such as turbu-
lent flow in alluvial channels, movable bed roughness, sediment settling, incipient
motion, transport, deposition, and erosion. River dynamics also incorporates the
study of fluvial processes, including river pattern classification, channel evolution
laws, and regime theory. It provides physical principles and analysis methods for river
engineering.
Flood control and mitigation
Flood is one of the biggest disasters rivers can cause. A river system is usually in
balance - to a certain degree - with the hydrological and geological conditions of its
basin. When the amount of runoff generated from uplands due to overwhelming rain-
fall exceeds the transport and storage capacity of the river system, the flowwill overtop
or break banks and flood neighboring areas. Owing to thousands of years' struggling
against flood threats, humans have developed many flood control technologies, such
as levees, river training works, storage areas, and diversion structures. Levees are one
