1.3.3 Organizations and institutions of the basin

It is said that it had administrators special for water management as early as in the dynasties of Xia, Shang and Zhou. At that time the management of the Yellow River had become an important matter of the state. Since Qin and Han Dynasty, governments at all levels along the river all had the responsibility of river management. In the Cheng Emperor reign of Han Dynasty, it had full-time officers for river management and established river management units at city and county levels that were located along the river since Song Dynasty. In Jin and Yuan Dynasty, the river engineering works in the lower reaches were protected together by the army and people. It had channel premier in Ming Dynasty and had channel governor in Qing Dynasty. In 1933, the government of the Republic of China established Yellow River Conservancy Commission (YRCC), being responsible for the management of the river, except the river engineering works of Shanxi, Henan and Shandong were still managed directly by each province because of big floods occurred in the Yellow River and heavy disasters in the lower reaches.

In 1946, YRCC established Hebei Repairing Division in the north suburbs of Zhengzhou, beginning to unify river managing organizations but which was not the institution for the whole river basin management. On Jan. 25^th 1950, the State Council of the Central Government decided to make YRCC as a basin-wide organization, being responsible for the management and development of the whole basin and all the institutions for river harnessing in Shandong, Henan and Pingyuan (Shanxi) provinces were under the leadership of YRCC.

In 1989, YRCC has been upgraded from a department level to a vice-ministry level, which was approved by the State Council via the Ministry of Personnel. It is a basin-wide organization under the leadership of the Ministry of Water Resources (MWR), an agency of MWR for the management of the Yellow River basin and inland river areas of Xinjiang and Inner Monggolia Autonomous Region. It is authorized by the state to conduct the duty of water resources management in the above-mentioned regions. It unifies the management of the water resources and channel of the basin according to the principle of unified management and management by each level. It is responsible for a comprehensive management of the basin, key and important engineering works, conducting planning, management, coordination, monitoring and service, promoting river management and water resources development, utilization and protection.

The headquarter of YRCC is situated in Zhengzhou, Henan Province and its branch institutions are scattered in each province along the Yellow River. By 1996, the Yellow River basin has formed a completed system on management and development of the Yellow River taking YRCC as a unified unit (see Fig. 1.4). The staff member has been increased from 3,041 in 1951 to 30,420 in 1996, increasing 10 times. The professional engineers are 9,347, making up 30.7% of the total number, among which, senior engineers 717, engineers 2,952 and technicians 5,678. YRCC has done a great deal of work on the aspects of flood control, survey, planning, development and utilization of water resources, hydrology, hydro-electric power, water and soil conservation, etc. achieving no dyke breaches during summer and autumn floods for 52 years running and making a great contribution to the social and economic development of China.

2. Management and achievement of the Yellow River

2.1 Construction of engineering works system on the lower reaches

2.1.1 Historical evolution of river harnessing

The Yellow River has a long history on river management due to frequent flood disasters happened in history. As early as in primitive society, it had popular legend of Yu The Great who controlled the river. In the period of Warring States, it had started to build dykes on the lower reaches. Jia Rang, a person lived in West Han Dynasty of 2000 years ago had put forward ¡°Three Measures on River Management¡±, which was the earliest document on river management policies in China. Wang Jing of East Han Dynasty led hundreds of thousands people to build about 500 km long canals and dykes through creatively adopting a measure of a gate in every 5 km.  Pan Jixun, a famous expert on river management, adhered to the principle of ¡°control water by building dykes and solve sediment problem by water¡± and conducted practice in a large scale, making the channel in the lower reach stable for a certain period. The lessons and experiences of those experts had made profound historic significant to the later generations.

The breach in the lower Yellow River was blocked in 1946. After returning back to the original course, YRCC had adopted the policy of ¡°keeping wide river sections and strengthening embankments¡±, built flood detention basins and conducted protection both by the army and people by using the historic experiences. Thus, it had greatly increased the capability of flood control and conquered the extraordinary flood in 1958. Along with the construction and development of soil conservation work in the upper and middle reaches and reservoirs built on the main and tributaries, a system of flood control engineering works of ¡°retaining water at the upper stream, discharging at the downstream and retarding at detention basins on the both banks¡± has been formed. This had finished the passive situation of only relying on the dykes and conquered floods for years, including 6 severe ice run floods that were considered could not be managed by men in history and achieving a great success of no dyke breaches during summer and autumn floods for 52 years running.

2.1.2 Engineering works for flood-control

The short-term mission of flood-control is: to guarantee that the main dyke should not be breached under the flood peak of 22,000 m³/s observed at Huayuankou Station and try all efforts to reduce hazard as much as it could in all cases under extraordinary flood.

Since 50¡¯s, a flood-control engineering system of ¡°Holding water upstream, discharging downstream and detention by both banks¡± has been initially formed under the guidance of ¡°Stabilizing the flow by widening river channel ¡±.

2.1.2.1 Reservoirs regulation system

Key reservoirs as: (1) Sanmenxia Reservoir on the main stream with basin control area 688,000 km², constituting 91.4% of the total basin; (2) Luhun Reservoir on the key Yihe trubutary with basin control area 3,492 km², constituting 57.9% of the total basin of itself and total storage 1.32 billion m³. This reservoir mostly serves as a supportive role for Sanmenxia reservoir in reduction of the flow peak from Sanmenxia to Huayuankou and mitigating the burden of flood-control on the Lower Yellow River. (3)Guxian reservoir on the Luohe river with control area 5,370 km², 45% of its watershed, design total storage 1.175 billion m³, mainly serving as supportive role for Sanmenxia, Xiaolangdi and Luhun reservoirs in mitigating the threat of the flood on the Lower Yellow River and raising the flood-control standard for Luoyang city. (4)The Xiaolangdi Reservoir under construction,when it is completed, will control 694,000 km² area of the whole river basin, occupying 92% of the total, reservoir storage 12.65 billion m³, 7.55 billion m³ storage left for sediment deposition, long-term effective reservoir storage 5.1 billion m³, is a multi-purpose hydro-structure with main functions of flood-control, ice-run control and sediment mitigation and considerable functions like water supply, irrigation and power generation etc. It will effectively control the Yellow River floodwater and mitigate and slow the silt up of the river channel of the Lower Yellow River. ( As shown in table 2.1.2)

Table 2.1.2  Main Design Indexes of the Regulation Structures for the Flood on the Lower Yellow River

2.1.2.2 Release works on the lower reach

•Protective dykes

Downstream dykes are main defense to fight against flood. Since people¡¯s harnessing the Yellow River, the downstream dykes have been rehabilitated for three times in a large scale, the first time was from 1950 to 1959, the second time from 1962 to 1965, and third time from 1974 to 1985. Through three times reinforcement and re-heighten of dykes, it greatly increases capability of flood control. Normally, the downstream dykes are 7m-10m high, the maximum height is about 14m, and 3m-5m higher than backside ground, the maximum up to 10m. The crest width of cross- section of dyke is 7m-15m. And slope of backside above Aishan is 1:3, and slope of riverside below Aishan is 1:2.5, slope of backside is 1:3. The total length of downstream dykes is 2,285.1km, out of which, the length of dykes near the river is 1368.3km, 312.8km dykes for retention area, 199,3km dykes for tributaries, and 247.3 km dykes for others, 157.2km dyke below Yuwa.

•Vulnerable spots and control works

The river training works on the lower reach of the Yellow River mainly includes two types: vulnerable spot and control works. Vulnerable spot attaches itself to main dykes in the form of dam, buttress and revetment to control river regime and to protect main dykes. Control works and floodplain protection works have been constructed in the front edge of floodplain in the form of dam, buttress and revetment and has function of controlling river regime and protecting floodplain and dykes. At present, 207 vulnerable spots and 6,259 dams, buttress and revetments have been constructed with total length of 394km. And 204 control works and flood plain protection works, and 3,793 dams and buttresses with the total length of 346km, 94 protection works for rolling river, 301 protection dams have been constructed on the lower reach of the Yellow River.

•Floodplain area on the lower reach of the Yellow River

The downstream river channel is from Tiexie of Mengjin county in Henan province to Kenli county in Shandong province and empties into the sea, the total length is 878km. The river channel is wide on the upper part and narrow on the lower part, and slope becomes flatter from up to down. The width between both banks on the wide section above Taochengpu, Shandong province ranges from 1.4 km to 20 km, from 0.5km to 5.0 km below Taochengpu. Normally, river channel is double channel, and plane external form appears type of joints of lotus root mixing wide section and narrow section together. For the wide section, there is wide floodplain in between. The floodplain has the good function of retention and alleviation of peak flood when the flood occurs. The total area of river channel is 4,647 km², out of which, floodplain occupies 3,956 km², taking 85% of the total.