Analysis of Sustainable Utilization of Yi River Water Resources
Analysis of Sustainable Utilization of Yi R iver Water Resources
Qu Pu , Shen Wanhe
(The Management Bureau of Yi-shu-si Water Resources, Xuzhou, PR China,221009)
Abstract: The finite quantity of the water resources carrying capacity in the basin determines the existence of the limit of its development and utilization. The water reservoir problem of Yi river is very typical in Yi-shu-si river system. It is quite important for the sustainable economic development of this region to analyze the exploitation and utilization of Yi-shu-si water resources problem. It provides a decision-making basis for water resources development in the basin.
Key words: Yi river, water resources,Sustainable Utilization
1Brief Feature of River Basin
Yi river is located in the huai river valley and is the largest mountain torrents river in Yi-shu-si region and winds it’s way from south lushan in Shandong province and flows into Luoma lake in Jiangsu. It is 333 km long and 11820 km2 area in total. The river is 110 km between Linyi and Luoma lake. The area up Linyi hydrological station is 87.3% of the whole valley that equals 10315 km2. Mountain and plain area there account for about 70% and 30% respectively.
Upper reaches system of Yi river Linyi has a fan-like feature. Flood gathers here and fluctuation feature is in a sudden rise and fall. Most of soil in midstream and downstream is loam and well covered by vegetation. But upstream mountain area has thin overburden by sandy loam or soil denudation and poor vegetation that is not benefit for conserving water. Ground water runoff shares a little proportional. Most part of river is dry in dry season. This characteristic as overflow in wet season and dry in dry season is not good for utilization of water resource. That it becomes drought and waterlogging region easily causes a lower development rate of economy in this area. It was listed as the important area to get rid of poor condition by Station Department in 1984.
2.Introduction of Reservoir Project
There is almost not any project in Yi river basin before 1958. Between 1958 and 1960, 5 large and many mini to middle scale reservoirs were set up here. Many mini to middle scale reservoirs were also built up between 1961 and 1975 as well as some barrage. After 1975 few reservoir projects were built up.
Table 1. Reservoir Works in Yihe River
Type Number Catchment
area /Km2
Total area of
reservoir /108m3
Total area of
reservoir /108m3
Large
reservoir
21 4739 18.24 10.65
Middle
480 708 4.4 2.6 reservoir
Dams 12 1260 2.85 1.82
total 518 0.56 0.56
26.1 15.63
Yi river reservoir project has 26.1×108m3 volume of reservoir and 15.63×108m3 active storage. However, there are some quality problems because most large and middle reservoirs were built up in Great Leap Forward period. Recently maintenance and reinforce work is carrying. Some reservoirs can’t work according to design, so present water supply capacity don’t reach design level. All barrage were constructed on trunk stream and main branch rivers with very short cycle of adjust capacity, annual water supply capacity is only 3~5 times of active reservoir volume.
Figure 1 relation-ship between precipitation and runoff
3. Water Resource Characteristic and Usage Situation
(1). Water Resources Feature
According to hydrologic data from Linyi station from 1951 to 2000, long-term average stream flow upper Linyi section is 29.5×108m3 (including 20.2×108m3 surface water resource and 9.3×108m3 ground water resource). Surface water resource is 17.3×108m3 in dry years while only 6.5×108m3 in driest year.
Yi river water resource distribution is very asymmetry annually and inter-annually. Long-term average precipitation is 830mm. 1998 saw the driest condition with 487.5 mm precipitation while 1964 is the wettest year with 1212.8mm that is 2.5 times of driest year. Flood period (from June to September) has a precipitation of 616mm which is about 75% of rainfall a whole year; and 50% rainfall is distributes in July and August. Actually 1999 saw Linyi’s driest year with only 1.38×108m3 runoff; most rainy year 1963 with 62.08×108m3 runoff which is 45 times of 1999.
Another characteristic of Yi river water resource is that surface water has a most proportionality. Stream flow of Huai river drainage area accounts for 75% of total water resource. Almost all of Yi-river’s water resource is from stream flow.
(2) Usage Situation of water resource
Based on 27 rainfall station’s which sites uniformly upper Yi river Linyi section, rainfall data and runoff data of Linyi station from 1951 to 2000 are analyzed. Reservoir project practice can be divided into three periods. 1951-1959 is building period, accounting for natural precipitation-runoff relation; 1976-2000 accomplishing period, accounting for present precipitation-runoff relation; 1960-1975 is a transition period. Precipitation data and runoff data can also be divided into 3 series responsively. Figure 1 shows the relation of between annual rainfall of Linyi station and annual runoff.
Comparing with the 3 series, we can find that runoff takes on a jump reducing trend in the same rainfall because of impaction of reservoir project. 1951-1959’s point data accords to 1951-2000’s reduced point data. Presently, annual runoff in Linyi station in normal year(830mm precipitation)is only 50% in a natural state, about 16×108m3. Linyi station’s annual runoff is only natural year’s 50% in a natural state about 16×108m3 by conjecturing. The reduced volume is composed of 2 parts: utilized by reservoir project and increasing soil conserving capacity because of more vegetation covering in river basin.
The reservoir water uses mainly for generating electricity, aquiculture and water supply. Of that agriculture is about 80%, industry is 12%, people and domestic animal is 8%.
4. Sustainable Utilization of water resource
(1). Advantaged Condition
Large number of water conservancy projects have been set up. All these projects will play an important role in sustainable utilization of water resources and economic development.
Afforested area of upstream mountain is enlarging. The conservation of water and soil has achieved. Sluice project is filled up obviously because erosion loss area of this valley accounts for 60% of total area. After 1981, economic fruit trees and forest increased quickly because of the fixing of all kinds of waste mountain contract system. In recent 10 years, forest coverage has risen from 13% to 29%. Many dams and ponds have changed environment state of this region.
Flood consciousness is strengthened. Drought is one of the significant natural disasters here. Crop heated by drought is more than 50% of plantation in 2000. Drought in successive years and frequent water contaminated accidents help people to realize the importance of water resources.
(2). Problems
Firstly flood resources doesn’t been used sufficiently. In despite of the shortage of water, Yi river basin is a relative region of water resources in Shandong province. Fluctuation of water resources in different seasons is very big, and most of annual runoff pooled in several floods even one or two floods. Therefore, runoff is not easy to retain. Water that flows out this area and doesn’t use secondly, wastewater has been 71% of total runoff since 1951. In addition of preventing flood we should pay more attention to use flood resources. Barrage don’t need much cost, adjustability period and emigration and can’t cause other problems, therefore it is a successful project of water resources utilization in this area. It can be developed properly according to region plan.
Secondly, water resources is wasted seriously and people don’t pay attention to save water resources. Efficient using coefficient is only 0.3~0.4 with flooding because irrigation is still charged by unit of acre. Many mini to middle enterprises consume a great deal of water, the reusing of water is less than 20%. Potential of water resources utilization is save water. It is urgent to spread economical irrigation and alter those enterprises that consume much water.
Thirdly, most water has been polluted seriously. Very few large-scale wastewater treatment plants locate in Yi river valley. Most wastewater produced from enterprises drain directly into water. Surface water and ground water have been contaminated in different degree. Contradiction of water resources demand and supply is pricked up and environment is worsened owing to contamination.
Fourthly, there isn’t allocation capacity water resources management is not scientific and several departments deal with water resources issues simultaneously. There isn’t an organization to manage water resources uniformly. Water price is too low to meet the demand of market economy. We need constituting and perfecting law or regulation related to water, as well as ascertaining the burden, duty and right of water resources governors and users.
Finally, there is not allocation capacity inter valley drainage areas. A majority of Yi-shu-si river system in Jiangsu can use water from the Changjiang River. West area of Weishan, Zhaoyang, Qushan and Nanyan Lake resources from Yellow River. Yi river and Shu river area can’t get water from other river basin, so it is still shortage of water. Yi river and Shu river itself need much water resources, and the potential of follow-up development is limited. In the future, it should be brought into transport project from Changjiang river to north China, and set up reservoir project, superinduce water from the Changjiang River.
The water reservoir problem of Yi river is very typical in Yi-shu-si river system. It is quite important for the sustainable economic development of this region to
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