Preface III of My Book on Yellow River Research and Management Strategy (by Mr. Guoying Li, YRCC Commissioner)

An unbalanced relationship between water and sediment with less water but more sediment is the outstanding issue of the Yellow River. The main direction of harnessing the Yellow River should focus on developing a harmony relationship between water and sediment. With the implementation of Water and Soil Conservation Project of the Loss Plateau, sediment that comes into Yellow River can be reduced to the greatest extent. At the same time, how to make full use of the sediment transport characteristics of the hyperconcentrated flood, and the potential sediment transport capacity of the natural channel to transport as much sediment as possible to sea, becomes the key technical issue of dealing with the hyperconcentrated flood.

Focusing on the dynamic features, transport principles and processing technology of the hyperconcentrated flood, unremitting long term research and in-depth analysis have been carried out by domestic and foreign scholars throughout the years. Many breakthroughs in understandings were obtained, which provides solid scientific supports for the comprehensive sediment management strategies like “block, discharge, regulate, release and dredge”. For three decades on ends, the author of this book painstakingly devoted himself to the research of managing the Yellow River. From the fundamental characteristics of the hyperconcentrated flood, and the analysis on comparing the field data collected along the main stem and tributaries, he made an important conclusion that a narrow and deep channel is suitable for transporting hyperconcentrated flow. Furthermore, he proposed the necessity of developing the hyperconcentrated flood. With the research on the operation mode of Xiaolangdi Reservoir, he proposed “sediment should be regulated on a multi-year basis, and it should be released at the right time”, and he proved the feasibility of creating hyperconcentrated flood by combined reservoir operations. With the research on regulations of meandering reaches in the lower Yellow River, he proposed the two-bank training strategy to stabilize the main channel, and he studied on constructing an efficient flood discharge and sediment transport channel.

This book focuses on illustrating the following four key topics:

(1)   It introduces flood discharge/sediment transport characteristics and potentials of the narrow and deep channel. With the analysis on the mechanism and the condition of a phenomenon called “the more sediment comes in, the more sediment will be transported.”,  it also explains the dynamics and evolution rules of the hyperconcentrated flood, reasons for abrupt increase of flood peaks, friction characteristics of hyperconcentrated flow, influences of the change in sediment concentration and energy slope on sediment transport, erosion during rising and deposition during the falling of a flood event in an alluvial river, and reasons for the huge flood discharge and sediment transport capacity of narrow and deep channel.

(2)    It illustrates the principles of variation in the meandering reaches, and conditions of the river pattern transformation, and it provides methods to regulate the meandering reaches.

(3)    It explains the key technologies of flow and sediment regulation by the reservoir, application rules and control conditions of multi-year sediment regulations,   mechanical properties of reservoir sediment, possibilities that the hyperconcentrated flood can be created during reservoir emptying, flow and sediment regulation by combined reservoir operations, results of the reduced sediment deposition after multi-year sediment regulations, and the amount of water required for sediment transport that can be saved.

(4)    It explains the outstanding issues in harnessing meandering reaches, causes for the secondary suspended river, analysis on whether the production dikes should be demolished or not, comparisons of the pros and cons between various river training plans, and the necessities of two-bank training. It also provides theories and technologies of how to construct an efficient channel for flood discharge and sediment transport.

It cannot be denied that some views and opinions in this book are still in debates at the theoretical and practical level of studying the Yellow River issues. However, it should also be noted that due to the complex nature of the Yellow River, there are unavoidable disagreements in understandings and management strategies. Actually, some essential debates are very beneficial. The sparkles inspired by collisions between different opinions usually reflect the deep insights of the truth. Just like the Yellow River, which accepts numerous tributaries and flows into the ocean, for harnessing this river, we should allow different opinions, gather their intelligence, take new steps continuously, and march toward the new era. The author of this book, Prof. Pu Qi, has pursued his career of studying the Yellow River for several decades. Reading between the lines, the reader can reveal his assiduous efforts in exploiting the principles of managing the Yellow River, and also the genuine knowledge and profound opinions. I sincerely believe with the publication of this book, great references will be provided for the research on natural principles of the Yellow River, and then to the future developments of management strategies.

Mr. Guoying Li, Professor and Senior Engineer, Commissioner of the Yellow River Conservancy Commission (YRCC), Ministry of Water Resources, P.R. China

January 22, 2009