PRESSURE OF WATER SHORTAGE ON AGRICULTURE IN ARID REGION OF CHINA

CHINFSE, GF0GRAPHICAL SCIENCEVolume 13. Number 2, pp. 124 - 129, 2003Science Press Beijing, ChinaPRESSURE OF WATER SHORTAGE ON AGRICULTUREIN ARID REGION OF CHINALI Xin( Universily of Science and Technology of Suzhou, Suzhou 215011, P. R. China)ABSTRACT: The arid ares in China are mainly locaed in North China and Northwest China. The North China is themain region for food production. There is 31. 19% of the total frmland and 26. 01% of the totl population, but only6. 14% of the avilable water resources of China. Groundwate is over pumped (6. 53 x 10°m' every year) in the regionsof Beiing, Tianjin, and Hebei Province, 50 waler supply could not meet the waler demand there. The distribution of wa-ter in Northwest China is uneven, some inland rivers and lakes are dried up, and desertification has expanded since riverwater in the upper and middle reaches is diverted for irigation. Up to 2050，population will be up to 1. 6x 10% in Chi-na, and industy will be devcloped fast, therefore 50% of the waler supply will be used by industy and resident, andwater for egriculure will be decreased year by year. In the comning 50 years, water demand for agriculure will be in-creased by 5.6x10*m' in the Huanghe (ellow) River valley, and by 1.7 x 10*m' in the Northwest China. It will beimpossible for the Huanghe River to meet the water demand, because it always dried up in the cold half year since 1984.To avoid water shortage of agriculture in the arid regions, it is necessary to divert water from the Changjiang (Yangtze)River in the south of China, and I0 use waler eficintly. It is the best way to use drip irigaion in agiculture, reyclewalter in industry and resident use, and control water pllution. Otherwise waler shortage in the arid regions wil restrietthe developmnent of egricuture in China.KEY WORDS: water shortage; water demnand; agriculure; arid region of ChinaCLC Number: TV213, S157. 1Document code: AArticle ID: 1002-0063 (2003 )02-0124-061 INTRODUCTION .China，annual runoff depth is less than 150mm becauseof lttle precipitation, and the diversion of the most riverWith the development of the world, water demand iswater for imigation has caused water shortage out ofincreasing, especially with the growth of population inoasis, so desertified area has expanded, and agricul-he last 50 years， water demand for irrigation has ture, even the existence of oasis is imperiled (QIAN,greatly increased for food production. In the arid and1991).semi-arid areas, water shortage becomes a heavierWater for irrigation has been increased 4 times, forproblem to restrict food production, local economy andindutry 22 times, and for urban resident 8. 5 times,environmental protection. China, with 22% of the totalbut population has been up only 1. 8 times during thepopulation in the world, has only 8% of fresh water in last 50 years. Up to 2050， China's population willthe globe; water shortage has afected agriculture andreach 1.6x 109 from 1. 28 x 10" in 2000; irigated arearesident's life in the northern China. Some scientists will grow from 54. 35 x 10*ha in 2000 to 64. 50 x 10haindicated that China's water shortage could shake worldin 2050. Water demand for imigation will be increasedfood security (BROWN and HALWEIL, 1998).by 10% -20% in the next 50 years, and total waterChina's per capita water resources (2200m') is less demand for irigation will be 450 x 10*m' - 500 x 10*m'than 1/4 of world average; in the northern China, it isin 2050.only 998m' per capita; extremely in North China, oneChina depends on imigation to produce 70 percent ofof the water-shortage regions in the world, per capita the g中国煤化工itisdrawingmorewater resources is only 150 - 300m'. In Northwest and_of its fast-growingYHCNMHG'Received date: 2002-03-01Biography: u Xin(1955 -), male, a native of Anhui Provinee, poesor, epecilized in water reources.Pressure of Water Shortage on Agriculture in Arid Region of China25eities and industries. As rivers run dry and aqifers are 2. 2 Some Problems on W ater Use in Agriculturedepleled, the emerging water shortage becomes heavierand heavier in the arid regions in the nothern China.In 1996, effective irigated area had reached 49. 925 x10*ha in China. There was 14. 881 x 10ha in North2 BASIC SITUATIONS AND UTILIZATION OF WA-China，which was 12. 266x 10*ha more than that inTER RESOURCES IN CHINA1950; and there was 5. 561 x 10'ha in Northwest Chi-na, which was 3. 502 x 10ha more than that in 1950.2.1 Distribution of Water ResourcesWater for imigation amounted to 416x10*m' in thewhole China in 1996 (LIU and HE, 1998).In China, 45% of precipitation transformns to surfaceIn the 1990s, the utilization ratio of surface water waswater or groundwater, and river water is about 5.8% of 66%， and the utilization ratio of gruundwater was overthe world's river water. Annual runoff depth is 284mm,90% in North China. Groundwater in the northernbeing 90% of the average in the world. But per capita China had been over pumped; 6. 53 X 10*m' of ground-water resources is 2200m'， which is less than 1/4 of water was over pumped every year, of which 4. 11 xthe average of the world. Most water resources 10m’ was deep groundwater; from 1985 to 1998,(80.9% ) of China are distributed in the southerm China 64. 9 X 10'm' of groundwater had been over pumped, of(the area to the south of the Changjiang River), thewhich 38. 8x 10°m2 was deep groundwater(CHEN,land area here, however, is only 36. 5% of the total 2000) . It was so difficult for deep groundwaler to bearea of China. The population in the northerm Chinareplenished, that around Tianjin, a funnel of ground-(the area to the north o[ the Changjiang River) is2/5of water with an area of 21 400km2 appeared in the deepthe total population of China, but water resources thereground; and around Beijing， a funnel of groundwateris less than 1/5 of the total of China. Per capita water with an area of 14 000km2 appeared in the deep ground.resources in 8 provinces (mainly in the northerm China) Because of the continuous drop of water table, thereare less than 1000m', among which Beijing and Tianjinhave been some environmental problems in the northernare less than 380m2 (Table 1). Farmland in the south- China, such as the drying of watercourses and lakes,em China is about 3/5 of the total in China; in Northsubsidence of ground, infall of sea water, and so on.China, though only 16. 2%of the land is cultivated,On the other hand, with the development of industry and70% of water resources is used by irrigation (LIU and urbanization, waste water has increased to pollute riversHE, 1998).and lakes, and even groundwater somewhere (SUN,Table 1 Distribution of water resources, population and farmland in North China and Northwest China (LU, 1998)AreaProvinceWater regourcesPopulationPer capite waterFarmlandPer unit area water(x 10'm)(x10%)(m)(x 10fha)(m/ha)Bejing4.08357.70.4139885.0NorthTianjin1. 468.84 .165. 20. 4313384. oChinaHebei23. 6961. 59384. 66. 5563613. sInner Mongolia50.6721. 632342. 64.96610204. 5Shanxi14. 3528. 99495.03. 6933886. 5Shandong33. 5084.936.8534884.0Henan40.7786.49471.46.9335880.0。Sublotal (average)168. 52303. 33555. 629. 8455646. 0.Percent of China(% )6.1426.0131.19Shaanxi1332. 63.53312508. 5Norhtwest Gansu27.4322. ss .1216.43. 4767890.0ChinsNingia4. 70210.60. 7961243.5Xinjiang88.285773.73.08728600. sQinghai62.6213977.70.578108414.0223.5180.182787.611. 47019486. 5Perent of China(% )7.03中国煤化工-1993; WEN and XUE, 1991).utMYHC N M H Gtains in XinjangIn Northwest China, the driest region of China, an-Autonomous Region and Gansu Province. Irrigationnual precipitation in the steppe area is less than 100mm water depends on the river water and groundwater that126L Xincomes from rainfall, glacier and snowmelt in mountainTable 2 Prediction o[ Chinu's unnul wuler demandareas. Nrarly 60% of the surface water was used for00 urban reaident in the first half of the 2|st centuryagriculture, industry and resident; in the Hexi region ofYearResident: Per capila waller demuanl Annual wauter demandGansu, 80% of the surface water was diverted for imi-(x10)[L/d)_ (x 10°m')gation; and in Xinjang, 55% of il was diverted. Not200028018518. 9too much of groundwater was used over there, but in 201021026.8203050250someinland basins， groundwater has been over205080073. 0punmped. For instance, water table around Urumqi inXinjiang wus 17m lower than that 20 years ago; watertalble in the lower reaches of the Shiyang River in Cansu 3. 2 Shortage of Water Demand from Industry and E-Province was 30m lower than thal 30 years ago (TANG cologyet al, 1992).Xinjiang was the region with most irigated area in China's production value of industry will inerease 6%Northwest China ('Table 1), annual waler demand for every year from 2000 to 2020, and will increase 5%irrigation was 45. 35x 10*m', of which 42. 39 x 10m'every year lrom 2020 to 2050 according to the predic-was surface water and 2. 96x 10*m' was groundwaler.tion(LU and HE, 1998); water demand on industry inImigated area has increased for 1.8 times during the 2000 was 66.5x 10*m'，and it will reach to 343. 6xlast 50 years, over 50% of the river waler was diverted 10'm' in 2050 (Table 3), which will be 5.17 times offor irigation, of which more than 70% was inlandthat in 2000.rivers (LI el ul, 2000; MA and LI, 2001).Somne environmental problems were the results of'Table 3 Prediction of China's annual water demandwater migrating to oasis in the inland river basins, manyfor industry in the first half of the 21st centuryrivers and lakes were dried up at the lower reaches,Production valur Water demund Wnter demand fordesertification was expanded. Deserifed lands in theof industry( x 10"m2)100y1:28n oflower reaches of the Tarim River in Xinjiang and the( x 10'syuan)industry produc:t(m/ 100yusn)southeaslem Qaidarn Basin in Qinghai expanded 4% or2122 I66. 5more every year. There were 150 lakes in Xinjiang in20105918. I92.9.15.7the 1950s， with an area of 9000km?, Tens of lakes in18085.8189. 910. sXinjiang were dried up during the last 50 years, and the49077. 8343. 67. 0surface area of lakes reduced 4395kn?.The increment of water demand for industry and 1rs-3 PRESSURE OF W ATER SHORTAGE IN THE 2IST ident (from 15% of China's total water demand in 2000CENTURYto 50% in 2050) will share the water resources for出griculture. In the Huanghe (Yellow) River valley, the3. ! Water Demands from Urban ResidentsHuaihe River valley and the Haihe River valley in theNorth China Plain, there is about 1/3 of the tofalPopulation in China was nearly 1.3x 10 in 2000, andpopulation and 40% of the total agricultural productionthe annual increasing rale was 1. 29% in the 1990s.in China. Water shortage for agriculture is inevitable inAccording to the calculation of Chinese government,the future, which will probably shake the food securilyChina's population will be 1.5x109 in 2020 with the and economic of China.annual inereasing rate of 0. 721%Juring 2000-Northwest China will be the important region of Chi-2020，and population will reach 1.6x 10° with the na's economic and agricultural development in the 2Istannual increasing rate of 0. 22% up to 2050 D. Incentury, and population there will increase fuster than2000, the urban residents were 280 x 10，and annualother regions in China. Irrigated area will expand anndwaler demand for resident was 18. 9 x 10*m'(LIU andwater demand for agriculture will be 80% or more of theHE，1998); in 2050, urban residents will be 800 xotal water demand in 2030. Now, more than 50% of10*， and annual waler demand will be 3. 86 times as the 8中国煤化iation and the eur.much as that in 2000, being about 73 x 10%m’(Tablelogicecause of the lark2).of wal:MYHC N M H Guffered from deser-①The whie lonk of population and developmnent of China in the 21st century, People Daily, 2002. 12-19Pressure of Water Stbvrtage on Agriculure in Arid Region of Chinaifeation. Water demand for ecolugy will be the table with an ara of 300km2 were formed inside ofllimpurant in Northwest China. Xinjiang has mostMinqin Oasis. Desertification land was expanded alferarea with deteriorated ecological environment, bul with 49. 3ha o[ lree was dead and 26. 7ha of farmland wasa maximum increase of irigaion area in Northwest abandoned (QU and MA, 1998). Much water is 心China. Up to 2030, water demand for ecology will be quired to balance grundwater for combating desertii8. 01 x 10"m'，waler demand for industry and resident cation.will be 4. 95 x 10°m', and for agriculture will be 56. 16x 10°n'，the total demand will be increased by 40% as 3. 4 Shortage of Water from W ater Pllutionmuch as thatl in 2000. Agriculture will face the pressureof water shortuge then”Tens billion tons of wastewater is discharged every yearin China, and 80% of them directly flows into rivers or3. 3 W ater Demand from Regional W ater Deficitlakes without decontamination. Groundwater aroundcitics is also polluted to varying degree due to the in-Since last mid-century， the population of China hasfitration of wastewalter of industry and domestic sewagegrown by 700x 10*. Twenty-five years ago, with more (Table 4).and more river water pumped out for national multipleuses,the Huanghe River began tw faler. In 1972, theTable 4 IPrediction of China's wastewater dischargewater level fell so low that it dried up for 15 days beforein the 21st century ( x 10*t)reaching the sea at the first time in China. It dried upYearFrom industryFrom residentTolaleach year with a progressively longer period. In 1996,200026. 019.045. 0it was dry for 133 days. From 1997 to 1998, due to201029.20.550.0203031.021. 052.0drought exacerbution, the river waler failed for 33053.0205031.21.5days, with 704km of the dry river course, and did notreach Shandong Province. Agriculural irigation in theHuanghe River valley was suffered from water shortageMuch chemical frilizer and pesticide lows into thepressure because the half of irigation water depends on rivers and lakes from farmland, even pollutes gound-the Huanghe River.vater. Salt is also transported to the lower reaches ofThe drying-up of the lower reaches of the Huangherivers or lakes by leaching water in inland watersheds.River is one of many such signs. The Huaihe River, aFor example, in the upper reaches of the Tarim River,small river situated between the Huanghe River and the the longest inland river in China, 3.7x10*r of siultChangjiang River, was also dry for 90 days in 1997.migrates to the river every year. The river water is get-Satllite inages show hundreds o{ lakes disappearing ting salty and fresh water is lack at the lower reachesand lovcal streams going dry recent years, 50 groundwater(Table 5)(FAN, 1998).tables fall and spring cease to flow.In the northerm China 6. 53 x 109m' of groundwater 3. 5 Prediction of W ater Demand from Irigationwas over pumped every year, and 64. 9x 109m’0groundwater had been over pumped from 1985 to 1998.According to the calculation, irigation area in ChinaAquifer would be exhausted after 9- 10 years if thewill increase from 54. 35 x 10°ha in 2000 to 64. 50xpumping does not stop, and it would need 150 - 20010ha in 2050, but water demand for imigation will de-years for aquifer restitution.crease from 485. 1 x10'"m' to415.7x10"m' due to theSome inland rivers were dry up because river walerdecreasing of water demand for per unit area. Anyway,was diverted for irigation, and water table beside of water demand for agriculture will be 49. 9% of the totalrivers had fllen down. For example, annual runoff ofdemand then, now water demand for agriculure isMinqin Oasis, located in the lower reaches of the 85% of the total (LIU and HE, 1998). However, waterShiyang River, had decreased from 500x 10°m’to lessdemand in the Huanghe River valley and Northweslthan 200x 10^m2 in the last 40 years, 200x 10m2 of China will be more than now, water demand for industrygroundwater was over pumped each year, and 4x 10*m3and中国煤化工Tle 6); bul supplyhad been over pumped to the 1990s. Groundwater tablewaterl water shortage onover there had dropped 10 - 30m, three funnels of water agricuMYHCNMHG①Xinjang Intiule of W ater Consrvaney and Eletrcily. 1998. The exlial ion and program of mobhbll wauter reoure in Xinjiang.128 .LI XinTable 5 Monthly change of mineralization of river water in Alar Hydrological Slation al theupper reaches of the Tarim River(g/L) (FAN, 1998YearJan.Feb.Mar.Apr.JuAug.Sep.___0et. Nov.Dec.__0. 895197619770.7510. 5402.5604.862 5. 4620. 4400. 6400. 5301. 44019841. 9724.1300. 05419850. 8481.216.016 5.1525.9641.2760.6641.5205. 028.I, 7601. 26619861. 3403.412.3.804I. 824.，9241.5801987(. 9760. 8633. 2084.560 6.640 4. 4801991!. 210 .1. 730 2. 2405.760 4.570 1.850 3. 400 1.120 5. 9901. 980.5.640 2.87019974.256 0.864 0.820 1. 6720.5481283. 46019983. 164 .1.564 6. 0888.424 10. 89Table 6 Prediction of water demand for irigation in 2000 and 2050 in North China and Northwest ChinaRegion2000_2050Irmigation area Imigation water Water demandImigation area Irrigation water W ater demand( x 10^ha)m'/ha)( x 10*m')( x 10'ha)Haihe River valley6.75525035.49.00375033.8Huaihe River vlley and Shandong 8. 87705062.511. 5060.4Huanghe River vlley4.33720031.27.0036.8Norhwest China2.20997521.93. s0675023. 6Whole Chine54.35892548S.164. 506445415. 7W ater demand for industry and resident will increase 4 COUNTERMEASURES T0 WATER SHORTAGE INquickly in the first half of 21 century in China, espe- THE ARID RECION OF CHINAcially water demand for industry will be up 5 times andtotal demand will be increased by 41.3% in 2050 4. 1 Diverting W ater from South to North(Table 7). It will share much water from water demandfor agriculture, irigated urea could not increase 2 mil- Per eapia water resources in the Huanghe River valley,lion ha per year if water demand could not be meet in the Huaihe River valley and the Haihe River valley wasthe future 50 years.637m3 in 1980, and 500m' in 1997， the available perTable 7 Water demand in the first half of the 21st centuryFor AgricultureFor IndustryFor ResidentTolalWater Inerease rate PercentWater Inecrease role Percent Water Increae rate Percent( x 10'm"')(x10*m)__ (%)__ (%)_ (x0m)___ (%)(%) (x10*m')__ (%)(%)4848-0.41 85. 06653.3411.71893.563.3570220104653-0.13 79.59293.6415. 92682. 694.6585020304530-0.43 65. 83. 0027. 64562.386885415749.9343641.7308. g83232050capita water is also dropped from 468m' lo 340m'; but diverted water from the lower reaches of Changjiangthe total water demand increased from 39. 6x 10"m' in River nearby Yangzhou South to Tianjin North.1987to 46.0x 10*m' in 1997, anyway, 6. 53 x l0*m'Investment of the project to divert water from south toof groundwater was over pumped every year in the north is about 200 x 10'yuan( RMB) based on the price1990s. Local water resources is too limited to meet the in 2000, 8x10°-9x 10*m' of water will be diverted,demand, diverting water from the south is the unavoid- in which 5x10*-6x10'm’ will be diverted to theable way to meet the demand (YOU, 1994).north of the Huanghe River. The price of diverted walerThree proposals have been made for diverting water is high enough to ensure efcient industrial use that isfrom South to North in China, the first, the so-called many times higher than that for imigation(CHEN andwestem" route, calls for diverting water from the up←MA， 1998).per reach of the Changjiang River to the upper reach of中国煤化工the Huanghe River; the second,“middle" route, would4.be diverted water from the northermmost point of theFYHCNMHGHanshui River, a tributary o[ the Changjiang River, di-Higher prices of water would encourage shifting to effi-rectly to Beiing; the third, or* eastern” roule, has being cient irigalion practices for farmers. For example, dripPresure: of w ater Shortage on Agriculure in Arid Region of China129imigation, which is not economical for use on grain, butfore, pereentage of water use for agriculture to the tolalon high-value fruit and vegelable crops, can save irri- used water in whole China will decreased, and muchgation water up to 70% (WANG, 2000).more water could be supplied for the demand of naturalAnother promising possibility is tu increase water useecology, industry and resident.efficiency for residents and industry. As new cities risethroughout China and older eities expand or are rebuilt,REFERENCESurban planner would do well to keep the streams of in-BROWN L R, HALWEIL B, 1998. China's water shortage coulddustrial and residential waslewater separation- as op-shake world food security|JI. World Wutch, July / August: 10 -posed to the W estern model that combines these flows.lndustrial pollution water, residential wastewater can beCHEN Chuamn-you, MA Ming, 1998. 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(in Chinese)future by systemaically research and apply the tech-YOU Mao-zheng, 1994. The‘ middle" route of diverting waterfromf agrivulture in thenology of saving water. The processes include the use ofnorth中国煤化I 312:22rainwater, storage of precipitation, prevention of waterYHCNMHGpollution, avoidance of excessive consumption. There-