Liu Chunhua, Yang Lizhi

(Shandong Geological Survey, Jinan Shandong 250013)

Abstract: Shandong province has been short of water resource for its development. In the long term, only water-saving can not solve this problem. In this passage, the reasonable exploitation of groundwater in the next 30-50 years will be discussed , obtaining evidence from the analysis of population, economy and so on.

Key words: Shandong province, water-saving society, groundwater exploitation, population, economy

1 General situation of Water resources in Shandong Province

According to the hydrological data of 1956~1992 in Shandong province, the average annual rainfall has been 681 millimeters, and the aggregate water resources that composed by 22.6 billion cubic meters surface water and 15.36 billion cubic meters groundwater has been 30.58 billion cubic meters in quantity, being 1.2 percent of our whole country. However, Because of the population of Shandong province, the annual per-capita amount of water resource has been only 350 cubic meters, just 1/6 by the average of the whole country ^[1].Particularly , water flow of the biggest stream "Yellow River" in Shandong area has been descended in recent years ,which resulting in the decrease of surface water inflow and supplying of groundwater resources .In addition, the increasingly water has been polluted in streams which number has doubled in the past ten years, even salt-water intrusion has happened in the coastal regions about several thousand square kilometers. These actions have turned large quantities of water resources to be unavailable. Overall, the rigorous situation about water resources shortage will restrict the development of Shandong province. no solving of the problem about the water resources shortage, no development.

Strategically , building the water-saving society is the most realistic and valid measure to resolve the water resources shortage of Shandong province. However, only saving water could not satisfy the further development of our society in the long run for the premise of the stated gross amount of water resources. So it is a consensus that rational exploitation of water resource also has great strategical meaning. Chairmen Jiang Zeming had used to point out that it is required for society development to save water first ,and exploiting new water resource at the same time in Shandong province^[1].

Because of the huge water storage in the aquifers under surface, the research on reasonable exploitation of groundwater has been necessary recently. In this passage will discuss the reasonable exploitation of groundwater in Shandong province, and whether it is feasible to over exploit the groundwater somewhere in the future about 30-50 years in order to meet the water demand of our sustained development in society.

2 Tissue of the Reasonable Exploitation of Groundwater

The reasonable exploitation of groundwater resources has been an focus tissue for long time. Since the 1950's, many scholars have tried to clarify the quantity boundary of groundwater exploitation by dividing the groundwater resource into lots of sections such as allowable yield, safety yield , exploitable quantity of groundwater resource and so on, even by building an reasonable standard evaluation. Things going contrary to one's wishes, these sections have just be conceptual and many depletion that used for groundwater distinction have almost not been quantified .though the amount of groundwater exploitation and the groundwater level drop have been given, the quantity boundary of groundwater exploitation still could not be clarify correctly because of the neglects about the groundwater system wholeness and evolvement . Scientifically, the reasonable exploitation must be on basis of the coupling relation in our society which include lots of aspects such as population, economy, environment, groundwater resources etc. These factors must be the premise of the reasonable exploitation. In all, it is not accurate to describe the coupling relation of groundwater system and exploitation just depending on some evaluation index. Further speaking, the tissue on groundwater exploitation is too complex to be solved by resource clarification , it belongs to the study on groundwater resources plan and management scientifically ^[2].

According to the standpoint mentioned above, it is necessary to evaluate the groundwater resource comprehensively in Shandong province, basing on the analysis of society development condition and trends which emphasizing the water resource influence, then make a reasonable plan of water resources exploitation . Under some special situation, it is reasonable to break out the principles that it is prohibition against the exploitation of groundwater storage resources and over exploitation, even encourage the excessively groundwater exploitation that satisfying the water demand of sustainable development in our society.

3 Comprehensive Analysis of the Relation During Population, Socio-economic and Groundwater Exploitation

This passage will mainly discuss the relation during population, economy and groundwater exploitation , hoping to find some evidence as the proves that enlarging exploitation of groundwater in some area of Shandong province in the next 30~50 years is reasonable.

3.1 Relation of the population and groundwater exploitation in future ,in Shandong province

The accurate estimate of the population in future is the foundation of making population policy, being essential to the society economy development. So ,doing research on the future exploitation of groundwater in Shandong province is suggested predicting the population development first.

According to the 2003 report of National Population and Family Planning Commission of China ,which had predicted the nation population in 2004-2050 period (figure 1),China's population will attain tallest value 1,451,000,000 at 2028,2029,2030 and descend quickly later, and it can drop to the level of 2012 at 2050.in the other word , the most serious situation of population will be at 2030, Shandong population will also attain the top value and the number will reache 97.272milian. Provided that the annual per-capita amount of water resource keep the current level, the amount of water demand will reach highest at 2030 undoubtly. In the optimistic aspect, if we overcome the bottleneck of water supplying, the water resource shortage will be less restriction on the development of society in the future. In that, exploiting the "storage resource of groundwater " in some areas is viable which must be in premise that the water table of groundwater system could rebound after the decrease of pumping. In all, we could pump more water at present, and once the water resource fulfill the basic demand of society, keeping the groundwater system safe ,we could compensate to loss of the "storage resource of groundwater". These measures have been agreed with the sustained development in society.

3.2 Relation of the socio-economic development and groundwater exploitation in future ,in Shandong province

In the last few years, comparing with the economic desolate in other countries, China has kept its good momentum of development. Chinese modernization has been in a brand period. Doctor Su, the deputy director of Research Institute for Fiscal Science, Ministry of Finance, P.R. China ,reclaimed that the Chinese economy could maintain the quick speed of increase in the next30~50 years. Economist Li also believe that Chinese economy increases still have a big potential in the long run. Even the." the father of euro" Robert. A.Mundell has predicted that China will keep the considerable economy increases in the next 10 years.

In the other side, the technique and people's cultural awareness of water-saving will be up to a higher degree accompanying with our society development.

These favorable terms will permit the implementation of water-saving in industry ,agriculture and domestics in the next 30 years. So does it in Shandong province.

But we had to face to the unreasonable management of water resource in Shandong province at present. The situation is that irrigation water efficiency is only 0.4, the industrial water demand per ten thousand yuan output as high as over 100 million cubic meters which repeating utilization of industrial water is only 30%~40%, the loss of urban domestic water is not less than 20% because of the water drip from pipes. The work of water-saving has just begun and isn't effective yet, the reason involves lots of aspects, such as the water-saving science not being recognized as a Well Organized System, water-saving technology falling behind the practice, the lack of water-saving system ideas because of inadequate coordination between different administration, poor management of water-saving, the lack of standards for water management, imperfect water policies and regulations, the investment system is incomplete, weak enforcement of water-saving and so on^[3].

Speaking from the opposite perspective ,we have taken the arduous task in the next 30 years. First we must promote the scientific progress of water-saving in order to rise the irrigation water efficiency to 0.7~0.8 and decrease the industrial water demand per ten thousand yuan output to 20~40 cubic meters. Second, spreading the mind of water-saving will play an important role also ,for the construction of new water-saving society.

In all, beyond the trends of population and socio-economic, it is necessary and impossible to increase the exploitation of groundwater resources for the demand of the rapid economic development in Shandong. Corresponding, the plan of groundwater exploitation must make some change, such as pumping more groundwater than the "allowable withdrawal" ,which has been regarded as incorrect at present. Actually, the recent "excessive pumping" which must cause unserious export mutations such as groundwater resources and ecol-environment problems has been the normal fluctuations of exploitation from the average.

4 Method of Reasonable Exploitation of Groundwater in Shandong Province

In order to keep the rational exploitation of groundwater in the next 30 years, we must first make some accurate predicts of the population ,economic, water resources and groundwater resources carrying capacity in the future in Shandong province.

At present, there have been lots of approaches to the accurate quantitative predict of population, including one-variable linear regression equation, self-function regression method, exponential function method, multivariate regression function method, grey system GM(1;1)method and dynamics system method. These methods have their own characters and applicable domains. So the approach to Dezhou or Heze city may be different from that of in Qindao or Weihai or Yantai.

The quantitative predict of economy must be on the basis on regional strategic programming .In particular, attentions need to be put on the water-saving polices and their promotion ^[5-7].it is no doubt that the effect of economic programming in urban will be further great than in rural areas.

The content of quantitative predict of water situation include the total amount of future water resource, the total amount of water resource at present and the per-capita demand of water resource for the development of agriculture, industry and domesticity.

Comprehensive evaluation on regional groundwater resources carrying capacity is also indispensable, calculating the largest amount of groundwater resources which can satisfy the demand of industry, agriculture , domesticity and the protection of the ecol-environment, in different time scales, basing on a techno-economic levels and social conditions . Generally, the content of regional groundwater resources carrying capacity include : ① the evaluation of regional groundwater resources carrying capacity has been necessary to take into account the impact of four factors such as society, economy, technology and ecology; ② the carrying capacity has been with the threshold, and the threshold depends on the technological capabilities, economic level and the restriction of ecol-environment; ③ the value of regional groundwater resources carrying capacity has dynamic changed in different periods ^[2],for example, it could be higher accompanying with the technological advances which will result in gradually increasing proportion of the allowable groundwater resources, but such growth is the threshold, also with the advance of water-saving technology and water-saving awareness which may increase the efficiency of water use. By contrary, if overexploitation of groundwater resources or serious water pollution take place, which may cause the degradation of freshwater resources, regional groundwater resources carrying capacity will be reduced.

The method of Comprehensive evaluation on regional groundwater resources carrying capacity has been proved to be feasible, the steps of the method include: obtaining the relevant groundwater data of next years at first ,then setting some classification standards, or making up some corresponding assessment models, finally districting the area into different levels in Shandong province. The level of some area has been indicated the potential of groundwater there ^[8].

5 Conclusion and Suggestion

Although the water resource is in shortage seriously at present, it will be alleviated in the next 30~50 years by the reasonable enlargement of exploiting groundwater in some areas of Shandong province, which must base on the forecasting of potential groundwater and be in the principle of reasonable groundwater exploitation. At the same time, quickly economic expansion in water-saving and establishing the water-saving society, will be benefit to solve the problem of water supply in Shandong province, promoting the economic further development.