Environmental issues and countermeasures in exploiting water resources of rivers

Vol.5 No. 2J Chongqing Univ.-Eng. Ed.June 2006Article ID: 1671-8224(2006)02- 0111-04Environmental issues and countermeasuresin exploiting water resources of riversZHOU Hou-gui aChina Gezhouba Group Corporation, Yichang 443002, Hubei, P.R. ChinaReceived 14 October 2005; Revised 27 March 2006Abstract: Based on afirming the tremendous benefits that water resources of rivers can provide in their exploitation, mainenvironmental problems and their countermeasures have been proposed and analyzed in this paper. It is argued that multiplemeasures should be applied to solving those problems by simultaneously carrying out engineering measures, scientific researchand also programs to cultivate the society's awareness, aimed at a sustainable development strategy for exploiting waterresources.Keywords: water resources exploitation; environment protection; measures; sustainable developmentCLC number: TV213.2Document code: A1 IntroductionSince 1960s, environmental problems and sedimentdeposition due to reservoir impoundment have attractedWater resource of rivers is a reusable and invaluablepeople's attention and they begin to investigate andnatural resource. Peddle irrigation wheel, water millanalyze the negative impacts on environment in theand man-made channel in ancient times, and water gate,process of water resources exploitation. Up to thereservoir, dam, and artificial waterways nowadaysbeginning of 70s in last century, papers, investigationshow that man has been exploiting the water resourcesreports, experience exchanges and internationalof rivers since the beginning of history. Byconferences in this domain have been augmentedconservancy works, water resources of rivers may brapidly, and the attentions of governments and theused for supplying water for living and industrialwhole society have been attracted. For this purpose, thepurposes, irrigation for farm land, water transportation,environmental problems arising from exploitation ofgeneration of electricity， fishery in reservoir andwater resources of rivers and their measures are studiedtourism.in this paper.Certainly, upon the completion of its construction, awater conservancy work can play a great and2 Major environmental problemscomprehensive role in flood prevention， powergeneration，water supply， irrigation, navigation,The exploitation of water resources of rivers incursaquiculture and tourism. This is the reason why peoplecomplicated, gradual, comprehensive, systematic andprefer to build water conservancy works to make fulllong- standing environmental problems, which includeuse of water resources of rivers. On the whole, watermainly water loss because of reservoir flling,resources exploitage gives a remarkable multi-benefit,deterioration of water quality down the reservoir,which has been proved by countless facts.weakening in self-purge ability for pollutants in water,Like everything in the world, exploitation of waterdamage to invertebrates, inundation of reservoir arearesources of rivers through construction of waterand relocation of inhabitants, and changes of climate inconservancy works has its second side, that is, itsreservoir area.negative influence. The negative influence is bound to2.1 Water loss cdue to storage of reservoire realized more and more clearly with man'sReservoir impoundment certainly reduces to adevelopment of water resources of river.degree the water volume inthe reaches.1) Remarkabl中国煤化工ed area aftera ZHOU Hou-gui (周厚贵): Male; Born 1962; PhD; Prof; Chiefreservoir impqfHC N M H Gincrease inEngineer; Research interest: water resources & hydropowerevaporation area of water and hence in evaporatedconstruction; E-mail: hougui@cggc.cn.Environmental Science & Engineering.112J Chongqing Univ.-Eng. Ed.Vol.5 No.2water volume, eventually in reduction of water volumeoriginal equilibrium of pollutants carried in a river,in the river.resulting in a deceased holding capacity of pollutants in2) Reservoir impoundment leads to raise in waterwater and weakened ability to mix and dilute pollutants.level and water head pressure, wetted area and amountSo，the pollution problem of water quality by theof leaked water underground, all contributing to waterpollution zones along the two banks of a river must beloss.stressed. Meanwhile, sharp reduction in the volume ofFig.1 ilustrates the factors contributing to waterdissolved oxygen in water on which aquatic animalsloss in the circulation of water resources.and plants live directly results in deterioration of waterquality.Water in air2) Reduction of discharge brings about reduction inPrecipitation| Evaporationthe capacity of silt transport on the other hand, the siltWater resources→[ReuReusable watercarrying capacity of river is reduced due to theSeepagePumped waterdecrease of the flow amount. The carried fin siltreduces the sorption capacity of metal particles andGroundwaterresults in sedimentation.Fig. 1 Chart of relations of water loss2.3 Influence on invertebrateWater loss affects ecology and environment itaspects of upstream water quality, water temperature,Reservoir impoundment has influences onclimate, and plant growing, and animal activities. Thisinvertebrates.has been proved by examples in some countries, such1) Reservoir impoundment results in variation ofas China. India, Egypt, former USRR and United Statesdischarge and flow regime. The invertebrate isof America. In the former USRR, the two inland river,unaccustomed to this change. Some kinds ofAM River and Sil River, have only 2/3 of the naturalinvertebrate, which lack of adaptability, go to reductionrunoff volume flowing into the Salt Sea due toin amount or extinction.reservoir flling. The Y ellow River in China has only2) A reservoir can regulate water temperature. Ione half of the natural runoff volume since 1980s afterchanges the cyclic law of life of some kinds of inthe construction of some water conservancy works onvertebrate and their living circumstance.this river such as the Sanmenxia Hydroelectric Station,3) Sand flushing into downstream section of the rivermuch less than the volume of water flowing into theand variation of riverbed load change the microbialsea in 1950s. Water reduced in amount has a smallerenvironment of invertebrates.silt transporting capability and is not as clear as it used4) Variation of water level and sand flushing ofto be. With the increase of sedimentation, the riverchannel enlarge the shallow water zone such as alluvialoften gets dried up. The Nile River in Egypt had aplain where bacterium, mosquitoes, flies, locusts,water volume of 32 billion m' flowing into theoncomelania propagate themselves, deteriorating theMediterranean sea. After the construction of Aswanecology and environment.Dam, the volume has reduced to 1.8 billion m' whichhas resulted in the refluence of sea water and decrease2.4 Inundation and relocation due to reservoirof fish species.impoundment2.2 Downstream water quality influencedReservoir impoundment surely causes inundation inthe upstream reaches of the river. The inundated areaWhen a water conservancy construction is erected,depends on the water level in the reservoir. Obviously,the original runoff flow hydrograph will be changed.the area inundated by rivers in plain places is largerThe larger the regulatory capacity of the reservoir is,than that in mountain places. Due to inundation, thethe larger the variation of the runoff flow hydrograph is.residents livinglated have to中国煤化工Reservoir impoundment affects downstream waterremove, cultivatloned, properquality in the following ways.measures haveYHCNMH(:istorical and1) The decrease in discharge volume will change thecultural sites in the reservoir area, and the ecology andEnvironmental Science & EngineeingVol.5 No.2 ZHOU Hou-gui/ Environmental issues and countermeasures in exploiting water resources of rivers113environment in the inundated area will be changed tothe ecological problem has been solved satisfactorily.some degree.3.2 Seeking new ways to solve environment problems2.5 Influence on the climate of the reservoir areaby scientific researchformed after thFirst of all, a scientifically prefect model for theimpoundment of a reservoir will change the climate inecological environment of one catch area or a model ofthe reservoir area to some degree through heatthe reservoir ecological environment of the waterabsorption and temperature regulation.Thoseconservancy project itself shall be established. Invariations of climate include variations in temperature,establishing the model, a series of key research topicshumid, precipitation, and atomization of water vapor.shall be proposed. For example, how to furtherminimize the loss of flow volume, how to guarantee the3 Proposed measureswater quality of the river, how to establish thesimulated ecology of invertebrates and how to handle3.1 Effective engineering measures to protect watersettlement.resourcesSecondly, people can probe deeply step-by-step intothe essence of the environment problem in exploitationFor reducing water loss, measures to reduce volumeof the water resources of rivers by continuous andof conversion from water in rivers into water in the aireffective scientific research and open up new paths andmay be taken. These measures include planting trees infind out new ways in protection of the environment.the reservoir area, protecting vegetation, developingThirdly, scientific research results are to be turnedfishery in the reservoir, aquiculture of aquatic animalsinto productive force to produce economical benefits,and plants, developing water tourist points, etc. Andand the environment problems can be thoroughlymore trees and vegetation will also avail preventingsolved.soil from erosion in the reservoir banks and reducingseepage area, seepage coefficient and hence water loss3.3 Putting the environment protection strategy intodue to seepage. .effect to promote sustainable development of theAs for water quality protection and improvement,water resourcesfirstly, reservoir management and control must beoptimized. Discharge curve of the reservoir must beFirstly, qualified scientists and technicians in waterdesigned according to the basic requirement of theconservancy of high level must be trained and broughtwater quality so that appropriate discharge flow stateup knowing engineering actualities. They are inclinedand discharge process can be obtained to achieve ato work with scientists in nature, biology, ecology andgood water quality. Secondly, pollution zones andsociety to solve problems by theoretical analysis,outlets of used water must be strictly controlled. Noscientific experiment and numerical analysis. Theseused water can be discharged into river withoutscientists and technicians know how to combine thesatisfying the discharge standard of used water. Nosustainable development into engineering design,works, which may pollute the water quality of rivers,construction and management, and how to satisfyan be constructed without careful and detailed designrequirements of both customers and nature.and calculation and approval in anticipation by relevantSecondly, based on studies on the stability of a riverauthority.system and the sustainability of water resourcesAs to the protection of invertebrates, firstly,exploitage, a development and exploitation model ofmeasures like fish-pass can be taken to minimize thesustainable water resources shall be established. Aenvironment variation of the invertebrates. Secondly,complete series of procedures， requirements andthose invertebrates which are unaccustomed to thecountermeasures shall be proposed, from the point ofchanged environment may be bred artificially. Afterstrategy, startingcent problem, .completion of the construction of the Gezhouba Project,nd water re:中国煤化工:rs shall bCN MH Gntthe rare and precious Cines Sturgeon were bredbrought into thisJTYHarificially and then let return to the river. In this way,Thirdly, environmental education projects should beEnvironmental Science & Engineering.114J Chongqing Univ-Eng. Ed.Vol.5 No.2implemented to enhance the awareness of the residentspoint of sustainable development to solve environmenton the two banks of the river to protect the waterproblems in exploitation of water resources. Multipleenvironment and water resources. Movements shouldmeasures should be applied by simultaneously carryingbe launched to attract attentions of the whole society toout engineering measures， scientific research andthe environment problems in exploitation of waterstrengthening the whole people's awareness.resources.References4 Conclusions1Fei X J. Environment and sit problems in exploitation ofwater resources of river [M]. Beijing: Tsinghua University,W ater resources exploitage of rivers is a business of1997. (in Chinese).public interests with remarkable benefits. But it is2Li Y L. Recent development in study of pollution mixedfollowed by a series of environment problems. Thesezone [M]. Beijing: Tsinghua University， 1997. (inproblems will be realized deeply with the developmentChinese).of people's awareness and water resources exploitation.Measures shall be determined and taken from theEdited by LUO Min中国煤化工MHCNMH GEnvironmental Science & Engineering