Preface for the report on Yellow River Groundwater Project

Abstract

As the groundwater literally means water in the ground, we cannot see it readily. However, digging wells and analyzing its hydrological characteristics enable us to understand the true face of groundwater. From many studies by many people in the past and from our own experiences we know that groundwater flows slowly in the ground and it has some relations with river and sea water as well as meteoric water in the atmosphere. The fact that groundwater is flowing suggests that it is recharged and discharged somewhere and it is connected with other types of water. Flowage and interaction of water on earth is called hydrologic cycle (water cycle), and the groundwater forms a part of hydrologic cycle. To know how the groundwater has existed is not only to improve our scientific knowledge but also is essential to predict its future and more efficient utilization of groundwater as one of the precious resources as well as to protect our environment. One of the four pre-historic civilizations of the world developed in this Yellow River basin (In recent years the fifth ancient civilization, in Changjiang, separated from the Yellow River basin is also recognized.). Other three, Egyptian, Mesopotamian, and Indus Valley, were all developed along large rivers. Overall, large rivers must have given rich bounties rather than hazards for the people of the time. Around the time of 21 centuries BC the fi rst dynasty of China, Xia, was established in the mid to downstream area of Yellow River followed by Shang (or Yin) dynasty in 18 centuries BC in present day Henan Province. Xia and Shang had been considered as mythical dynasties but proved to be real after excavations at Erlitou site for Xia and Yinxu site for Yin in recent years. Internet search reveals that Shang commerce was quite active and it is said that ‘man of Shang,’ meaning merchant in Chinese, has originated from there. Following Xia and Shang, most dynasties that ruled major parts of China were located in or around Yellow River basin as well. First emperor of China, the Emperor Shihuang of Qin, had his capital located in Xianyang (presently west of Xian, Shaanxi Province), and the next dynasty Qian Han had its capital in Changan (presently Xian) under Liubang. Xianyang and Changan are situated along Weihe, a branch of Yellow River. After those times, Han and other races established many nations in turn and sometimes small nations juxtaposed at the same period in the history, but always the nations ruled Yellow River dominated China. From ancient times, the Yellow River has been historically and economically the mother river of China, as all the Chinese people agree. The Yellow River is a big river; 5,464 km long, and according to Rika Nenpyo 2000 (Chronological Scientifi c Tables 2000 edited by National Astronomical Observatory in 1999) it is the sixth largest river in the world in terms of length. The Yellow River basin has a catchment area of 795,000 km including closed inland Ordos catchment, and the total area is twice as large as that of whole Japan. The headwater is in the high mountains of Qinghai Province flowing down to east, then to north, again to east, to south, and fi nally to east before reaching to Bohai Bay. It passes Gansu, Ninxia Hui Autonomous Region, Inner Mongolia Autonomous Region, Shanxi, Shaanxi, Henan, and Shandong Provinces. Compared to Tone River, one of the biggest rivers in Japan with a length of only 322 km, the size of the Yellow River is overwhelming. Several years ago in Tokyo, I had an opportunity to listen to expert members of China Yellow River Committee spoke. The summary of their talks was that the Yellow River is characterized by ‘scarce water rich sand, and uneven distribution in space and time.’ It means that the amount of water is not much but the amount of sand the river carries is large, and the water availability is uneven in time and space. The annual flow rate of the Yellow River is merely 58 billion m while that of the other big river in China, Changjiang, is estimated to be 1 trillion m, but it carries 1.6 billion m of sediments a year. About 60% of water is estimated to be fed from upstream areas of Lanzhou, Gansu