GSPAC water movement in extremely dry area GSPAC water movement in extremely dry area

GSPAC water movement in extremely dry area

  • 期刊名字:干旱区科学
  • 文件大小:425kb
  • 论文作者:HongShou LI,WanFu WANG,GuoBin
  • 作者单位:The Conservation institute of Dunhuang Academy,Key Scientific Research Base of Conservation for Ancient Mural State Admi
  • 更新时间:2020-07-08
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论文简介

JOURNAL OF ARID LAND, 2011, VOL.3, NO.2, 141-149GSPAC water movement in extremely dry areaHongShou L1,2*, WanFu WANG1.2, GuoBin ZHANG1,2, ZhengMo ZHANG1,2, XiaoWei WANG1,21 The Conservation Institute of Dunhuang Academy, Dunhuang 736200, China;2 Key Scientific Research Base of Conservation for Ancient Mural State Administration for Cultural Heritage, Dunhuang 736200,ChinaAbstract: Under an extremely arid condition, a PVC greenhouse was built on the top of Mogao Grottoesin gobi area. The results of 235-day constant extraction of condensed water on the greenhouse film and soilwater content showed that 2.1 g/(m^.d) groundwater moved up and exported into the soil, and a phreaticwater evaporation existed in the extreme dry area where the groundwater is buried deeper than 200 m.After a prolonged export, the soil water content in the greenhouse was not lower but obviously higher thanthe original control ones. According to the monitored parameters including relative humidity and absolutehumidity of soil, and temperature outside and inside the greenhouse, it was found that there is the availablecondition and mechanism for the upward movement of groundwater, and also it can be sure that the ex-ported water was not from the soil and atmosphere outside the greenhouse. Phreatic water, an importantsource for soil water, interacts with atmosphere moisture via soil respiration. Soil salinity also has importanteffects on soil water movement and spatial-temporal heterogeneity. The extremely dry climate, terrestrial .heat and change of upper soil temperature are the fundamental driving forces of water transportation andphreatic water evaporation in the Groundwater-Soil-Plant Atmosphere Continuum (GSPAC) system.Keywords: greenhouse method; GSPAC system; extremely dry area; water movement1 Introductionrainfall once-in-a-decade in Mogao Grotteos within 20days (Li et al., 2010a). .Water circle is important to ecosystem. Vertical waterAccording to previous investigations, the soil watercircle is constituted by the water movement in the Gr-content was high in the proluvial clay layer at 1.4 mound water-Soil-Plant-Atmosphere Continuum (GSPAC)depth of the gobi land around the Grottoes (Li et al.,system (Wang et al., 2004; Zhou et al, 2005). It is2009), and it could reach 24% at 4 m depth (Yang etwell known that when groundwater level is shallow,al, 2009). Further, the experiments conducted inphreatic water is an important supplement to soil,closed system revealed that the annual precipitation inplant and atmosphere moisture through capillary acthis area (42.2 mm) is not enough to supply soil watertion (Yang, 1999; Chen et al., 2004; Ren et al., 2006). .content (Li et al., 2010a). Therefore, other water re-However, it remains unclear whether phreatic watersources supplying soil water indeed exist.can contribute to soil water, which is a key to under-The only possible resource of soil water except pre-stand whether there is a maximum depth of phreaticcipitation is phreatic water. The research work on thewater evaporation (Zhu and Qian, 2005).climate, geology and vegetation in this area proved theA common belief is that soil water in extremely drypossibility of vertical transportation of phreatic waterarea is the remain of last precipitation (Warner, 2008).(Li et al., 2009). However, as the phreatic water in thisHowever, Liu et al. (2006) found that precipitation isarea is buried deeper than 200 m, water could not beinvalid if its amount is less than or equal to 13.44 mm,transported upward due to capillary action. To furtherbecause water would be evaporated completely beforeverify the existence of phreatic water evaporation, apermeating into deep soil. In former simulated pre-PVC greenhouse was used to eliminate the influencecipitation experiments we found that a rainfall rangingfrom 5 mm to 10 mm could be evaporated entirelyReceived 2010- 10 28, accepted 2011-01-06doi: 10.3724/SPJ.1227.2011.00149within 8 days and 12 days respectively, and a 15 mm● Crresponding author: HongShou Lu (E-mail: dlbs69@ 163.com).中国煤化工YHCNMH G.142JOURNAL OF ARID LANdVol. 3of precipitation and atmosphere (Li et al, 2010a), andloose gravel sand, and the lower layer is gravel. Thethe amount of phreatic water evaporation by measur-gobi land is formed by Pleistocene diluvia conglomer-ing condensed water on film and soil water contentate, mid-Pleidiluvial alluvial Jiuquan conglomerate (Liwere calculated (Li et al, 2010b). Additionally, small 2005). The geology and water structure of study areamonitors were buried in soil to directly gauge theare shown in Fig. 1.temperature and relative/absolute humidity. TheThe upper 0- -50 cm soil is abundant in salts. Theanalysis work on the movement of GSPAC systemconstitution and contents of dissolved salts are shownwould provide scientific grounds for the effective in Table 1. The soil porosity is 20% to 30%. The aridityutilization of phreatic water in this extremely arid re-index is 32, indicating an extremely arid climate, andgion.the relative humidity is 31%. The radiation intensity is .Mogao Grottoes, with nearly 45,000 m2 frescos, is .1.1 KW/m2 and the percent of sunshine is 71%. Thethe biggest and most completed Buddhism relic in theannual average temperature is 11.23°C, wind speed 4.1world. The frescos are confronted with a series ofm/s (in 2005) and annual precipitation 42.2 mm. Inquestions concerning soil water, but it is still unclear2007, 19 times of rainfall were recorded and the pre-where the water comes from (Li, 2005). Consequently,cipitation totaled 64 mm. From the beginning to thethe understanding of the water movement in theend of experiments there were only 5 times of rainfallGSPAC system on the top of Mogao Grottoes will bewith a total precipitation of 8.2 mm. Conducted in thebeneficial to explain water resource in the surroundingyear with notably less rainfall, this research on GSPACrocks of the Grottoes and to protect the precious cul-water would make it more clear that the prelatic watertural relic.is a resource of soil water.2 Study area3 MethodsThe greenhouse experiment was carried out in the gobiA hemisphere greenhouse was built at the gobi landland, 1 km to the grottes, from June 6, 2008 to Feb- above Mogao Grottoes on the 119h day after a 2 mmruary 18, 2009. The upper 4 m layer of the gobi isprecipitation in 2008. The greenhouse is 1 .8 m high个SoilzoneDA A Unsaturated aeration zone 0 ) 9AAAeration IntermediateSaturated aeration zoneCapillarySaturated↑↑↑↑↑↑GroundwaterPhreatic waterFig. 1 Sketch of geology and groundwater structure of Mogao Grottoes中国煤化工MHCNMH G.No.2HongShou LI et al.: GSPAC water movement in extremely dry area143Table 1 Salinity contents in diftrent gobi soil depths at Mogao GrottoesDepthTotal saltNa2SO4CaSO4Ca(HCO3)2MgSO4CaCO3(cm)%)0-10 8.549.187 .5.3621.3701.9690.0480.1030.0570.00910-30 8.654.4620.8502.2981.1300.0530.0410.01630-50 8.522.2300.5921.0190.0230.0100.01250-70 8.601.7750.3130.2941.2180.0550.0150.0080.012 .with a radius of3.1 m, an area of 30 m2 and a volumecondensedwater and constantly upward movementof 30 m3 (Fig. 2). A plastic belt was bonded to the wa- and evaporation of ground water. The daily condensedter-proof film near the ground surface to make a“V”water amount from July 7 to October 31, 2008 isshape groove to collect condensed water. In order toshown in Fig. 3 with an average daily amount of 84 g,monitor the exportation of soil water inside theequal to 2.8 g/(m*.d) soil water exportation. Fromgreenhouse, an injector was used to extract the con-November 1, 2008 to February 18, 2009, water wasdensed water every day at 8 a.m. to 9 a.m. As soil wa-freezing and daily monitoring was not available; weter content is very low in this dry area and moisture iscollected 2,339 g water and ice at several times, equalan important form of soil water movement, weto 0.71 g/(m2-.d) soil water exportation. During theadopted HOBO mini-monitors to monitor the tem-235-day measurement, 15,081 g condensed water wasperature, relative and absolute humidity at 5, 10, 20,got in total, equal to 2.1 g/(m^.d) soil water exporta-30, 50, 70, 100 cm soil layers beneath and 0, 5, 10, 50,tion. Condensed water amount is highly related to100 cm above ground surface both inside and outsideweather condition. When solar radiation tends to begreenhouse as well as on the inner film surface in anstronger and temperature becomes higher and dailyinterval of 10 minutes. These parameters were utilizedtemperature difference is bigger, the condensed waterto analyze whether water upward movement exists oramount will be higher.not. The soil water contents were measured by ovendry method after long-term water exportation. If thel.2 Dynamic analysis of temperature-humiditymeasured values are not less than original control ones,condition and soil water movementit could indicate water resource from deep soil layer 4.2. 1 Temperatureindeed exists.Temperature imain environmental factor influenc-ing soil water evaporation and moisture change. Thetemperature changes inside and outside greenhouse ontypical days during the experimental period are shownin Fig. 4. Within the upper 50 cm layer, soil tempera-ture changed with solar radiation, and the closer to soilsurface, the bigger the varying amplitude of the soiltemperature was. No obvious change was shown be-neath 50 cm soil layer. The result indicates that thedepth of soil temperature change was lower than 60Fig.2 The PVC greenhousecm even in summer, much lower than the ones of1-1.5 m in other regions Liu and Cai, 2000). The4 Results and discussionmaximum temperature inside the greenhouse was15°C higher in the day and only 1°C higher in th4.1 Condensed water in the greenhousenight than that of outside. In autumn, the averageThe results of this experiment proved the existence of temperatures at 10, 20, 30, and 50 cm soil layers中国煤化工MHCNMH G.144JOURNAL OF ARID LANDVol. 3回50040030200A人100DateFig. 3 The daily water condensing amount in the greenhouse(a)Ouside←+10cm0cm ---- 10 cmincrease of humidity strongly restricted water evapo-35----20 cm-30cm-50 cmration on account of the impact of closed environmentr 30-after three days, which resulted in the decline of cor-25relation between temperature and soil humidity. The20correlation between relative humidity and temperature豆15at 20 cm depth is 0.499 (P=0.01) in the control soil but10sonly -0.283 inside greenhouse. Therefore, the actualevaporation capacity of gobi soil may be significant ins0 r () lnsidethe arid air environment.巳4As soil water content is always very low in ex-tremely dry area, soil water usually exists as bound22water. The decomposition and combination of water三1coexist in a way of a bi-dynamical balance. Whentemperature is high, the decomposition amount is big-2ger than the combination one, reflecting that the in-crease of soil relative humidity and evaporation. Oth-erwise, bound water in soil is formed because mois-ture is adsorbed by soil, which leads to the reductionDate and timeof vapour pressure and the upward movement OFig. 4 Temperatures profiles inside and outside the grenhousesub-layer soil moisture.The daily change of soil water content in gobi landin the greenhouse were 5.2°C, 4.8°C, 4.4°C, and 3.3°C under a typical dry weather condition is shown in Fig.higher than that at control ones outside respectively, 5. Due to the daily change of solar radiation and delaywhile in summer the difference became bigger up toof heat conduction in soil, the temperature in one layer5- -8°C. The“heat island" of the closed environment inmay intersect with that in other layers, which results ingreenhouse greatly impacted the evaporation and the heterogeneous distribution of soil water contenthorizontal movement of soil water.with the temperature change. For instance, in Fig. 4In the early days after the construction of thethe temperature at 20 cm depth might be higher orgreenhouse, the inner temperature increased whereaslower than those at any other layers, and the soil waterthe relative humidity declined, thus causing the incontent could show a doublet distribution driven by acrease of unsaturated vapour pressure difference anchigher temperature (e.g. Fig. 5, 17:00). A warming upsoil water evaporation. According to the daily changeprogress is accompanied with decomposition of boundof moisture density in this time, the evaporation inten- water, increase of soil humidity and decrease of soilsity was estimated at most 0.02 mm/d. However, thewater content, and vice versa.中国煤化工MHCNMH G.No.2HongShou LI et al.: GSPAC water movement in extremely dry area145to the maximum and minimum absolute humidity (the- 13:00daily range of vapour density in summer is about 20- 17:00。21:00g/m’and 15 g/m' in autumn), only 20% of evaporatedo 05:00water condensed on film and 80% was re-absorbed bysoil with the decrease of temperature. The absorbingeffect of soil moisture from air is so strong that therewas no condensed water in the greenhouse in the first20 30 4(506019 days after building it. .Depth (cm)4.2.2 HumidityFig. 5 The daily change of soil water content in the gobi landFigure 6 shows the relative and absolute humidity at(2007-06-12)different heights above ground surface and depths ofsoil layers in the greenhouse. Closed to underlyingWhen soil temperature is high, the decomposedsurface (50 cm) the humidity was impacted by mois-water in upper soil layer could be absorbed bture of soil absorbing and the relative humidity wassub-layer soil where temperature is lower, and the restlower than that at upper layer (100 cm) of ground sur-small amount water evaporates into the air. On theace. Both the relative and absolute humidity in thecontrary, upper soil layer absorbs water from warmersoil increased with soil depths. Relative humidity ofand wetter sub-layer soil when the temperature issoil at 20 cm depth increased with temperature (r =low,and the absorbed amount is farther bigger than0.286, P = 0.01), while at 50 cm above surface it wasthat from surface soil and air. Under this thermo-dy-opposite (r = 0.969, P = 0.01). Soil bound water de-namical circumstance of soil water moving upward,composed when the temperature increased and re-the change of vapour pressure plays a critical rolesulted in high soil humidity. Otherwise, it would be(Zhu and Qian, 2005). As shown in Fig. 5, the dailychange of the soil water content could amount to 3.8二. -100 cm-..+50 cm ....+100 cm - - _ Film Surfacemm, over 1,000 times compared with the condensedamount in the greenhouse. As a result, the condensed2water amount could be only recognized as an evidenceof the existence of phreatic soil water evaporation. Theorupward migration of water needed to be highlighted tofurther confirm the amount of phreatic water evapora-tion.The unsaturated soil water moves from the position2 10with higher temperature/humidity to that with lowerones. The coexistence of higher temperature and hu-midity is sufficient but not essential to the outer mi-gration of soil water in sub-layer ( Zhu and Qian, 2005;Warner, 2008). In summer, even if the temperature atthe top soil is higher, the soil humidity still increasesfrom top to bottom which supports the upward migra-Date and timetion of soil water. The condensed water amount inFig. 6 Relative humidity and absolute humidity in the green-summer is significant when air temperature is high.house at different heights above ground surface and depths ofThe decline of condensed water amount in Fig. 3 isoildue to the decrease of air temperature. Although thesoil temperatures at different layers were intersected,absorbed by soil when the temperature declines (Fig.the soil water remained upward movement. According 4). This phenomenon reflects the typical characteristic中国煤化工YHCNMH G.146JOURNAL OF ARID LANDVol. 3of bound water in extremely arid area. At the deeperWhen the soil temperature increased, the soil watersoil layer in which the daily fluctuation of temperatureevaporation led to an evident increase of vapour den-is small, and the soil humidity is stable.sity in the greenhouse; while the temperatures of airFigure 7 shows that the relative and absolute hu-and top-soil decrease, water would be absorbed by soilmidity of outside soil were apparently lower than thatparticle and salt, and the vapour density declines too.in the greenhouse (Fig. 6), which indicated the green-The soil evaporates water in warming process and ab-house could not only increase temperature but also soil sorbs water in cooling process in afternoon, whichhumidity. According to the humidity/temperature conforms the“respiration" of soil (Zhang and Wei, 2003). .dition for water migration (Zhu and Qian, 2005; War-4.3 The influence of phreatic water, salt and geo-ner, 2008), the soil water in the greenhouse can movethermy on soil wateroutward and the water inside is not from outside soilThe random monitoring results of soil water contentsor air when the air temperature, relative and absolutein 2007 and 2008 are shown in Fig. 8. The averagehumidity inside and outside greenhouse were similar,contents of soil water are nearly the same. However,which meets the condition of the upper migration ofthe soil water content at 20 cm depth is higher thanwater. Because vapour migration flux is correlative tothat at other depths. This implies that although soilthe gradient of air humidity, the dry air outside green-water contents were fluctuated with climate and dailyhouse determines outward movement of soil water.temperature, they were stable as a whole and did notThis illustrates that evaporation is not limited in thedecrease unlimitedly due to continuing evaporation,“heat island" greenhouse but exists widely. Our former which indicated the existence of deep water.weighing experiment of the soil samples outsidegreenhouse conformed this phenomenon (Li et al,_ ◆_ 2008-08-262008-07-282010a).2008-06-122008-05-06-70 cm2007-05-08: 3(2007-05-15信252007-05-22口2007-06-05号15-1(1020304(50。10Depth (cm)i 900-Fig. 8 The soil water distribution in representative days in theextremely dry area点s0t..The abundant salt content in top soil layer is an-豆20Fother proof to the existence of phreatic water. The pre-liminary monitoring results revealed that in the aera-?。tion zone at 2.9 m depth the relative humidity of soilwas saturated. An observation at 1.25 m depth of sur-rounding rocks at the Grottoes indicated that the hu-Date and timemidity in deep rock is perennially saturated (Guo et al.,Fig. 7 Relative humidity and absolute humidity at difterent2009). This shows that the aeration zone below 2.9 mdepths outside greenhousedepth is saturated. The formation of the saturated Va-The decomposition and combination of soil water ispour is caused by geothermy. Affected by geothermy,a dynamical process driven by varying temperature.the temperature of soil from bottom to top decreases中国煤化工MYHCNMH G.No.2HongShou LI et al.: GSPAC water movement in extremely dry area147with a rate of 2- 3°C per 100 m. Normally, the heat deep water. The high humidity and porositytransmitted by geothermy is 2x10' J/m2 (Liu and Cai,(20%- -30%) of deep soil are necessary to continued2000). In this area there is a fracture belt of Sanweivertical movement of vapour. Vapour and film waterMountain and the large quantity of geothermic energy are the two main forms of phreatic water movementhas been already found. Based on the temperature ofand the two phases coexist but also shift each otherhot well which is 50- -60°C at 1,100-1 ,500 m depth, when temperature changes.the temperature gradient in this area is around 3- _4°CSalt is a key factor that influences soil water content.per 100 m.Salts such as Na2SO4. 10H2O, MgSO47H2O,The saturated vapour in aeration zone could con-MgCl:6H2O and Na2CO;: 10H2O significantly en-dense and form film water on the surface of gravel hance the soil water content at upper layer (10- -40 cm).sand under a reducing gradient of temperature. DiNa2SO4 is abundant at 10- -30 cm soil depth and whensolved salt in the film water migrates upward slowlytemperature is lower than 32 5°C, Na2SO4 combinesand stays in an evaporating surface of soil at about 20with water and then forms Na2SO4 10H2O,whichcm depth (Zhu and Qian, 2005). After a long geologytriggers the notably increase of soil water content andduration a saline soil layer about 50 cm thickness wasvice versa ( Li, 2005; Angeli et al., 2007). In summer,formed and acicular crystals were found in soil profilethe soil temperature in the greenhouse was higher than(Li et al, 2009; Yang et al, 2009). The high soil water 32.5°C, thus the soil water content at 20 cm depth wascontent at the clay layer was the concentration of filmlower than that at the control sample outside (Fig. 9 awater for soil particles with strong absorbing ability.and b).The evaporation of vapour in unsaturated zone im-In summer, the soil water content at 20 cm depthproves the salt density gradient in film water and thevas 4% lower than that at the control one, and thewater potential difference, as well as the upward mi- decrement of soil water was similar to that of con-gration ability of film water. Dry climate helps to formdensed water amount. If the change of soil water wasa big humidity gradient in unsaturated belt; and alsonot caused by temperature and salt, the condensed wa-forms a dynamic factor for the upward migration ofter could only come from soil moisture and there was9p (b) 208-08-158 r (a) 2008-08-12+ Inside号621020304050600 2(10 50 600p (c) 208-11-21B (d) 2008-12-19号5系1(2(3(405020 3(Depth (cm)Fig. 9 Comparison of soil water contents inside and outside greenhouse中国煤化工MYHCNMH G.148JOURNAL OF ARID LANdVol. 3no upward migration of phreatic water. Under this con-water is deeply buried, and soil water could enter at-dition, to confirm the existence of deep water migration, mosphere through aeration zone. The temperature,humidity in the soil of greenhouse should be equal torelative and absolute humidity at the deep soil layeror higher than the control one when temperature waswere higher than that of the upper soil layer, and thislower than the critical value of 32.5°C. Monitoring ofcondition is suitable to the upward migration ofsoil temperature in winter identified that soil waterphreatic water. Even in summer when the temperaturecontent was high when soil temperature was lower thanof the top-soil was higher, the humidity gradient at the32.5*C. The soil water content at 20 cm depth wassub-layer was enough to support the constant migra-higher than that at the control one and that at the earlyion and evaporation of phreatic water. In a warmingdays after building of greenhouse. This result confirms process soil bound water was decomposed and evapo-the existence of deep water migration, and denies the rated, and it was absorbed by soil when temperaturepossibility that the decrease of isolated soil water wasdecreased. The soil temperature change is a key to thecaused by soil structure damage. Another experiment fluctuation of soil water and exchange of air moisture.at the same period verified that condensed water in theThermo-dynamical effect is fundamental to the verti-greenhouse was not derived from outer air or precipi-cal movement of water in GSPAC system. Dry climate,tation (Li et al, 2010a). Therefore, the condensed wa-geothermy and soil salt all play important roles in the .ter in the greenhouse was surely from the deep soil.migration, spatial and temporal distribution of soilFurthermore, another greenhouse experiment fromwater.' The increasing of soil water content after a1 km distance demonstrates that continuous water long-term experiment reflects that phreatic watercondensed also existed in the sandy land (Li et al.,evaporation can occur at different burial depths. Im-2010b), indicating that our research setting is reason-pacted by the closed environment, the condensed wa-able. In addition, we did an experiment with an ter amount on the film was not the actual evaporationair-condition inside the greenhouse to restrain thof natural soil, and the transported phreatic water in“greenhouse effect” and the evaporation of phreatic this extremely arid area should be more than measuredwater reached up to 21.9 g/(m-.d) (10 times of thisone. The discovery of phreatic water evaporation inone), which further confirms our analysis (Li et al,extremely dry area and its related analysis provide2010c). In conclusion, the condition and mechanismnew possibility of ecological restoration using water infor the upward migration of phreatic water exist where the GSPAC system. Meanwhile, understanding thegroundwater level is deeply buried, and the ultimatewater resource in the surrounding rocks of Mogaoresource of deep soil water is no other than phreaticGrottoes at a large scale is of great importance to thewater. Phreatic water evaporation is widespread inconservation work of culture relics in the Grottoes.extremely arid area.Acknowledgements5 ConclusionsThis work was founded by the National Natural Science Foun-The results of the greenhouse experiment abovedation of China (40940005). The authors thank Mr. Fei QIU,HongTao ZHAN, ShuangHu LING and Rui LI for their sin-Mogao Grottoes at the gobi land under typical drycerely help in field work; we also thank our fellows in the en-climate condition showed that phreatic water evapora-vironmental research group for their support of meteorologicaltion exists in the extremely dry area where grounddata.ReferencesAngeli M, Bigas J P, Benavente D. 2007. Salt crystallization in pores:2108-2114.quantification and estimation of damage. Environmental Geology, 52: Guo Q L, Wang X D, Xue P.2009. Research on spatial distribution and205- -213.relations of salinity and moisture content inside rock mass ofChen M J, Wang H, Wang F 2004.Water-driver ecological evolutionlow-layer caves in Dunhuang Mogao Grottoes. Chinese Journal ofmechanism in inland arid region. Acta Ecological Sinica, 24 (10):Rock Mechanics and Engineering, 28 (Suppl. 2): 3769- -3776.中国煤化工MHCNMH G.No.2HongShou LI et al.: GSPAC water movement in extremely dry area149Li H S, Wang W F, Guo Q L.2009. Mechanism analysis on water cohe-tion, 25 (3): 23- 26.sion in arid area of Dunhuang Mogao Grottoes. Acta EcologicaWang X s, Yue W F, Yang J Z.2004. Analysis on water cycling inSinica, 29 (6): 3198- -3205.GSPAC system of Teta-irigation dstrict, in Inner Mongolia, China.LiH s, Wang W F, Zhan H T.2010a. New judgement on the source of soilJournal of Irigation and Drainage, 23(2): 30- 33.water in extremely dry zone. Acta Ecologica Sinica, 30(1): 1-7.Warner T T. 2008. Desert Meteorology. Beijing: China MeteorologyLi H S, Wang W F, Zhang G B. 2010b. Qualitative analysis on the waterPress, 136-153.source of dune by coved canopy method in the extreme dry area. Yang J F, 1999. A review on water exchange through interface betweenJournal of Desert Research, 30 (1): 97- 103.groundwater, soil moisture or atmospheric water. Advance in WaterLiH s, Wang w F, Zhang G B. 2010c. Measurement of deep buriedScience, 10(2): 184- 190.phreatic water evaporation in extremely arid area. Acta EcologicaYang S L, Wang X D, Guo Q L.2009. Preliminary analysis of moistureSinica, 30(4): 6798- -6803.distribution in cliff rocks of the Mogao Grottoes in Dunhuang.Li Z X.2005. Conservation of the Wall Paintings and Colored Statues ofHydrogeology and Engineering Geology, 5: 94- 97.the Grottoes on the Silk Road. Beijing: Science Press, 360- 371.Zhang Q, Wei G A. 2003. Analysis of inverse humidity respirationLiu B P, Cai Y L. 2000. An Introduction to Earth Science. Beijing:process of surface soil in desert near oasis. Journal of Desert Re-Higher Education Press, 4, 79.search, 23 (4): 379- -384.Liu X P, Zhang T H, Zhao H L. 2006. Infiltration and redistribution Zhou A G Ma R, Zhang C.2005. Vertical water cycle and its ecologicalprocess of rainfall in desert mobile sand dune. Journal of Hydrauliceffect in inland basins, Nowthwest China. Advances in Water Sci-Engineering, 37 (2): 166-171.ence, 16(1): 127-133.Ren J, Shi H B,Li H P. 2006. Study on water dynamics of GSPACZhu X Y, Qian X X. 2005. Groudwater Hydrology. Biing: Chinasystem over Maowusu sandland in Etuoke Banner. Journal of Irriga-Environmental Sciences Press, 83.Journal ofArid Land was included in Abstract Journal, All-Russian Institute ofScientific and Technical Information (VINITI) DatabaseOn December 22, 2010, an E-mail by Dr. Elena Raevskaya, the manager of Asia and Africa Section, All _RussianInstitute of Scientific and Technical Information (VINITI), was sent to Journal Publishing Center, Xinjiang Insti-tute of Ecology and Geography, CAS and said “Here is some new information about the Chinese jourmals evalu-ated by our experts. Ten journals have been found informative and useful in our work and have been included inVINITI database for regular abstraction (some of these journals were reexamined by expertise).”The VINIT publishes Abstract Journal, which has been issued since 1953. Abstract Journal is divided into 3types, integration, single-volume and fascicule, embodying total 220,000 journals and over 6,000 serials in 66languages from 130 countries and regions, and over 10,000 books, and 150,000 monographs and scientific andtechnologic reports each year, which cover all fields of natural and applied sciences. AJ is an authentic abstractingdatabase with the most numbers of citing publication and reporting.AJ asssment to journals is very strict. In 2007, AJ published a list of Chinese jourmals which was excluded,and 28 Chinese scientific journals were in the list. In this time, 6 Chinese journals were excluded.Journal of Arid Land applied the assessment to AJ since the Joumal was launched at the end of 2009 and wasincluded in the database after the Journal was strictly evaluated.中国煤化工MHCNMH G.

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