A water balance model to study the hydrological response to
A water balance model to study the
hydrological response to different scenarios of deforestation in Amazonia
Cassiano D’Almeida a,*,Charles J.Vo
¨ro ¨smarty a,b ,Jose ′A.Marengo c ,George C.Hurtt a ,https://www.sodocs.net/doc/3d12224940.html,wrence Dingman b ,Barry D.Keim d
a
Complex Systems Research Center,University of New Hampshire,Morse Hall,Durham,NH 03824,USA b
Department of Earth Sciences,University of New Hamsphire,James Hall,Durham,NH 03824,USA c
Centro de Previsa
?o do Tempo e Estudos Clima ′ticos,Instituto Nacional de Pesquisas Espaciais,Cachoeira Paulista,SP 12630-000,Brazil d
Department of Geography and Anthopology,Louisiana State University,Baton Rouge,LA 70803,USA
Received 6September 2005;received in revised form 2May 2006;accepted 9May 2006
Summary Amazonia encloses some of the largest watersheds in the world,experiencing sub-stantial amounts of rainfall annually and producing more runoff to the ocean than any other region.Amazonia experiences one of the highest rates of deforestation in the world and the hydrological effects of such a disturbance have already been investigated by several studies.Contrasting results exist,especially when different scales and degrees of heterogeneity are considered.This paper assesses the dependency of the hydrological impact of deforestation on these factors through application of a gridded water balance model.The model simulates different scenarios of deforestation based on straightforward water balance calculations.In all experiments performed,the scenarios conform to observations of decreased evapotranspi-ration within disturbed sites.Initially,by implying an uncoupling between small deforested a ′reas and circulation,the model suggests an increase in runoff locally.However,when the land-atmosphere coupling caused by intermediate levels of deforestation is reproduced through deviations on circulation,the model con?rms that the water cycle may or may not become regionally accelerated,depending on the degree of heterogeneity associated.Finally,by sim-ulating a scenario of complete deforestation,the model con?rms expectations of a less intense water cycle in Amazonia.Due to the broad range of numerical models and observation networks currently available,the importance of the proper representation of both scale and heterogene-ity of deforestation to the correct assessment of its hydrological effects is emphasized.
KEYWORDS
Deforestation;Amazonia;
Water balance model;Spatial scale;Heterogeneity
0022-1694/$-see front matter
c 2006Elsevier B.V.All rights reserved.doi:10.1016/j.jhydrol.2006.05.027
*Corresponding author.Tel.:+551231868572.E-mail address:cassiano@cnpq.br (C.D’Almeida).
Journal of Hydrology (2006)331,125–
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journal homepag e:www.elsevi e r.c o m /l o c a te /j h y d r o l
Despite our model results,there is need for more mechanistic studies on coupled land-sur-face and atmosphere interactions under varying conditions.
c2006Elsevier B.V.All rights reserved.
Introduction
The Amazon River represents the largest watershed in the world,with a drainage area of$7million km2(Sioli, 1984a).Including adjacent watersheds to the east(like Tocantins Basin),the region holds more than40%of all remaining tropical rainforests in the world(Laurance et al.,2001).Such an extensive vegetation cover maintains high levels of evapotranspiration(Franken and Leopoldo, 1984;Vo¨ro¨smarty et al.,1989;Salati and Nobre,1991;Vic-toria et al.,1991),which in turn,sustains a great portion of the local rainfall following the recycling of precipitation (Brubacker et al.,1993;Eltahir and Bras,1994;Trenberth, 1999;Bosilovich and Chern,2006).Through atmospheric teleconnections,the Amazonian rainforest is also critical to both regional and global climates(Eagleson,1978;Zeng et al.,1996;Marengo and Nobre,2001;Werth and Avissar, 2002).Currently,the region faces one of the highest defor-estation rates in the world(Fig.1;INPE,2004),following what has been taking place in the tropics for some time, where the rainforest is being replaced by soy bean planta-tion and pastures.The impact of land-cover changes on cli-mate and water cycle dynamics have been investigated (Charney et al.,1975;Eagleson,1982;Williams and Balling, 1996)and documented regionally in various parts of the globe(Calder et al.,1995;Hetzel and Gerold,1998;van Langenhove et al.,1998;Cherkauer et al.,2000;Yin and Li,2001;Goteti and Lettenmaier,2001;Yang et al.,2002).Particularly in Amazonia,the impact of deforestation on climate has been extensively studied over the last few decades.This impact has been evaluated under many differ-ent conditions,especially at different scales and under dif-ferent scenarios of deforestation.
Overall,results to date indicate that in all spatial scales, deforestation in Amazonia imposes a decrease in evapo-transpiration(Sioli,1984b;Shuttleworth,1988;Nepstad et al.,1994;Rocha et al.,1996,2004).At the local scale, deforestation also causes an increase in runoff(Gentry and Lopez-Parodi,1980;Williams and Melack,1997;Costa et al.,2003),which on the contrary,is generally expected to decrease following a complete deforestation scenario (Lean and Warrilow,1989;Lean and Rowntree,1993;Pol-cher and Laval,1994;Sud et al.,1996;Costa and Foley, 2000).Regarding the imposed effect on precipitation,it is also likely to decrease after extreme scenarios of deforesta-tion(Nobre et al.,1991;Henderson-Sellers et al.,1993;Manzi and Planton,1996;Lean et al.,1996;Lean and Rowntree, 1997;Hahmann and Dickinson,1997;Voldoire and Royer, 2004),although local disturbances do not seem to be large enough to signi?cantly affect its regime.Additionally,it has been noted that regional areas of clearing may or may not be able to increase cloud formation and potentially rain-fall(Pielke et al.,1991;Chen and Avissar,1994;Avissar and Liu,1996;Avissar and Schmidt,1998;Baidya Roy et al., 2003),depending on the degree of heterogeneity imposed on the land-cover.Therefore,apparently con?icting
results Figure1Spots(black dots)with the highest rates of deforestation in Brazil’s Legal Amazonia(main?gure)(INPE,2004),as observed by LANDSAT images(small squares).Geographic location(left?gure)of Legal Amazonia and of the area considered in our study with in South America,including Amazon and Tocantins Basins plus nearby watersheds to the northeast(thick lines).
126 C.D’Almeida et al.
exist.However,despite all the uncertainties involved,such contrasts are not necessarily or exclusively associated with the consistency of the numerical models employed,or with the accuracy of the observations performed.Rather,they seem to be related to intrinsic and interrelated scale and heterogeneity dependencies on the hydrological effects of deforestation.This paper investigates such dependencies in detail through application of a water balance model(see ‘‘A water balance model of deforestation’’).The application of a set of different scenarios of deforestation into the mod-el enables assessment of the importance of the size of the clearing area(see‘‘Effects of scale’’),as well as of its spa-tial con?guration(see‘‘Effects of heterogeneity’’),to the overall hydrological impact of deforestation in Amazonia.
A water balance model of deforestation
To assess the impact of deforestation at different scales and under different degrees of spatial heterogeneity,a model based on conservation of mass principles and on a scheme linking land-surface to atmosphere within a gridded domain was developed.The model is intended to represent consis-tency and tendency with respect to the hydrological impact of deforestation–and speci?cally to this effect alone.The analysis focus on steady-state solutions of the model,even though it has not been designed for quantitative applica-tions such as climate predictions.Its assumptions and parameterizations are kept straightforward,but in keeping with results from the literature(Nobre et al.,1991;Eltahir and Bras,1994;Williams and Melack,1997;Costa et al., 2003;Marengo,2004).
The model was designed to relate the main?uxes(precipi-tation(p),evapotranspiration(e),runoff(r),water vapor con-vergence(c),in mm yrà1)and stocks(atmosphere(w a),soil (w s),in mm)of water within a generic gridded domain.The model is based upon the following mass–balance equations:
d w a=d t?eetTàpetTtcetTe1Td w s=d t?petTàeetTàretTe2T
which are solved simultaneously for the water stock terms on each gridcell in the domain.The water?ux terms are cal-culated as linear functions of the water stock values:petT?k1w aetTe3TeetT?k2w setTe4TretT?k3w setTe5TEstimated values of w a and w s in Amazonia were used as the initial conditions for both stocks of water(Jipp et al.,1998; Kuznetsova,1990),while annual water budget estimates of p,e,r and c for this region(Roads,2002)were used to initialize the water?uxes.The constant factors k1,k2and k3were then set after the application of these amounts into Eqs.(3)–(5) (Table1).Therefore,these factors tend to stabilize the sys-tem throughout the experiments,making it converge to its long-term mean at steady-state–or,to a state only slightly away from such mean conditions in the disturbed scenarios.
All model integrations were initialized with a one-year spin-up period.During this period,no deforestation is em-ployed by the model and the system converges to its primary steady-state.Following initialization,deforestation is then induced through the application of a factor(d)determining the fractional disturbance over the entire domain for each scenario as:absent(d=0),complete(d=1)or partial (0 F?Ne1àdTe6TD?Nde7T After application of the disturbance,the system moves to-ward a different state of equilibrium for each scenario.Ini-tially,the only perturbation imposed on deforested gridcells is a reduction in the corresponding evapotranspiration?ux (e d)–in agreement with various observations in Amazonia (Hodnett et al.,1995;Jipp et al.,1998): e d?k4ee8Twhere k4(0 f gridcells. Table1Variables and parameters used by our water balance model Symbol Variables and parameters Initial value Unit Reference w a Water in the atmosphere40.mm Kuznetsova(1990) w s Water in the soil440.mm Jipp et al.(1998) p a Precipitation1930.mm yrà1Roads(2002) r a Runoff760.mm yrà1Roads(2002) e a Evapotranspiration1430.mm yrà1Roads(2002) c a Water vapor convergence630.mm yrà1Roads(2002) k1Precipitation factor48.2yrà1– k2Evapotranspiration factor28.8yrà1– k3Runoff factor12.7yrà1– k4Evapotranspiration factor0.1–– n Number of bordering gridcells––– k5Attenuation factor0.46yrà1– a When displayed with the subscript f,it refers to mean?ux over forested gridcells,and with the subscript d,it refers to mean?ux over deforested gridcells;with no subscripts,it refers to the mean?ux over the entire domain. A water balance model to study the hydrological response to different scenarios of deforestation127 Several parameters involved with the dynamics of defor-estation,e.g.albedo,in?ltration and interception,were not explicitly considered by the model.It was assumed that the hydrological impact of deforestation induced by these parameters were implicitly and qualitatively incorporated through the changes imposed in evapotranspiration–since the energy available for the latent heat?ux in the surface goes down as albedo goes up with deforestation–and through the local increase in runoff obtained by the model (see‘‘Model experiments’’)–in accordance to the impact of decreased in?ltration and interception that occurs along with deforestation. Model experiments Modeling experiments were performed to test the hydrolog-ical impact of deforestation under different scenarios of deforestation within an idealized gridded domain.To be comparable in size to Amazonia($7million km2),the do-main was set to have N=280,000(25km2in area)gridcells. The scenarios employed differed in two respects:the extent (or,domain fraction)of deforestation,and the degree of heterogeneity.Model results were evaluated and compared in terms of mean changes to:precipitation,evapotranspira-tion and runoff,over both disturbed and undisturbed grid-cells,and also averaged over the entire domain. Effects of scale The hydrological response to deforestation is controlled by several factors,which are not simultaneously dominant at particular spatial scales.Different extents of deforestation are therefore,expected to induce distinct,possibly con-trasting effects.While local disturbances are expected to affect the water cycle exclusively within the disturbed area –by decreasing evapotranspiration and increasing runoff–scenarios of regional and complete deforestation are ex-pected to generate a wider impact,potentially signi?cant even on climate.Due to its size,Amazonia is likely to even-tually exhibit all of these responses at different stages of deforestation.In our model,the direct comparison between water?ux changes predicted for individual disturbed and undisturbed gridcells offers an estimation of direct,local-ized impacts of deforestation,while changes averaged across the entire domain reveals its aggregated,regional-ized impact.Furthermore,each particular scenario repre-senting a different extent of deforestation leads to a particular state of equilibrium,thus enabling the evaluation of the scale dependency in the response to each scenario considered.At this point,scenarios with the same extent of deforestation were all linked to the same degree of heterogeneity. Constant precipitation(constant P) The?rst analysis performed with the model was aimed on reproducing the effects of deforestation when a noticeable effect on circulation is not enabled,resembling the impact of local areas(<102km2)of clearing.To do so,both precip-itation and water vapor convergence terms were assumed constant throughout the integrations.Despite being repre-sentative of only the initial stages of deforestation,these conditions were repeatedly applied to all levels of clearing in the domain.Naturally,negative anomalies of mean do-Figure2Changes on mean(a)domain?uxes,(b)evapotranspiration,and(c)runoff for scenarios with different fractions of deforestation,calculated as the difference(in mm yrà1)between steady-state values for each scenarios and the corresponding value for the control simulation.Changes on(a)mean domain?uxes of evapotranspiration and runoff were respectively marked with squares and balloons,while corresponding changes in precipitation refer to the unmarked line.Mean changes on(b and c)forested and deforested gridcells were respectively marked with triangles and circles,while the mean domain changes refer to the unmarked lines. 128 C.D’Almeida et al. main evapotranspiration,in comparison to the control sim-ulation(Fig.2a),were suggested by the model(following Eq.(8)).The opposite occurred to the mean domain runoff, in agreement with?ndings from one of the few,if not the only,observational study that compiled runoff measures in a small catchment in Amazonia,both before and after clear-ing(Williams and Melack,1997).Regarding the mean grid-cell values of both evapotranspiration and runoff,they varied by the same amount for all levels of deforestation (Figs.2b and c,respectively)and therefore,changes in mean domain values were only due to the number of for-ested and deforested gridcells at each scenario.It then fol-lows that by assuming an absolute uncoupling between local land-surface disturbances and precipitation,the changes in mean domain?uxes of evapotranspiration and runoff are expected to be linearly and spatially aggregated as the ex-tent of deforestation increases. Uniform precipitation(uniform P) A scenario allowing deforestation to slightly and progres-sively in?uence the local pattern of precipitation was also simulated by the model,aiming to take into account the importance of the recycling of moisture in Amazonia(Bru-backer et al.,1993;Eltahir and Bras,1994;Trenberth, 1999).Precipitation was allowed to vary according to the mean basin stock of water in the atmosphere(Eq.(3)),thus still being spatially uniform throughout the entire domain–following the assumption of a‘‘well-mixed’’atmosphere. As a result of the overall decline in the atmospheric stock of water following the decrease in evapotranspiration on deforested gridcells,the mean domain precipitation at equilibrium decreased as the level of deforestation in-creased(Fig.2d).At the same time,the mean basin evapo-transpiration stabilized at lower values in comparison to the previous experiment as deforestation progressed,also showing a higher decrease over deforested gridcells (Fig.4e).Regarding runoff,the model predicted opposite changes over different gridcell types.It showed enhanced runoff over deforested gridcells and diminished runoff over forested gridcells,even though both values decreased as deforestation progressed,while the mean basin runoff sta-bilized at its initial value for all levels of deforestation (Fig.2f).According to Eqs.(1)and(2),such invariance in the mean basin runoff follows directly from the imposed invariance in the mean basin water vapor convergence, since it equals the equilibrium value that runoff must converge to at steady-state.The invariance in runoff also explains why both mean basin precipitation and evapotrans-piration decreased at the same proportional rate as defores-tation,while the simultaneous occurrence of such reductions indicate that the precipitation recycling contrib-utes to the weakening of the water cycle as the impact of local disturbances gets linearly accumulated. Variable water vapor convergence(variable C) Compared to the scenarios above,regional areas of defores-tation(102–105km2)are expected to induce a stronger, potentially signi?cant land–atmosphere interaction(Silva-Dias and Regnier,1996;Dolman et al.,1999;Wang et al., 2000;Baidya Roy and Avissar,2002).To reproduce the ef-fects of such interactions,our model aimed on incorporat-ing anomalies on circulation induced by the spatial heterogeneities associated to fragmented areas of clearing. To do so,the water vapor convergence?eld was then forced to change.These changes were included in the model by increasing the water vapor convergence term(c d)over deforested gridcells and decreasing its analogous term(c f) over forested gridcells.The deviation in the mean conver-gence?eld over a gridded domain was then derived based on the scheme represented by Fig.3,which illustrates the expected in?uence of the boundaries between forested(in gray)and deforested(in white)gridcells on circulation. The arrows correspond to the enhanced horizontal diffusion of water vapor into deforested areas–as a result of the gra-dients of temperature and pressure generated–and there-fore,they are inversely dependent on the number of arrows departing from the same source cell.For simplicity,the ar-rows departing from each?rst-order gridcell(labeled with 1)are assumed to be twice as intense as the arrows depart-ing from each second-order gridcell(labeled with2),three times as intense as the arrows departing from each third-order gridcell(labeled with3),and so on.It then gives that each one of the n gridcells located along the borders be-tween forested and deforested areas contribute equally to the change imposed in circulation.Additionally,the conver-gence change over forested and deforested gridcells is as-sumed to be directly proportional to the water vapor stock(w af)over the source(forested)gridcells,giving that: c f?càk5nw af=Fe9Tc d?ctk5nw af=De10TThe k5factor[Tà1]is an adjusted parameter(k5=0.46)that delays the imposed effect on circulation in such a way that evapotranspiration over deforested gridcells never gets increased as a result of deforestation,in keeping with Eq. Figure3Scheme representing the impact of different spatial distributions of forested(in gray)and deforested(in white) gridcells on circulation,as simulated by our model for variable C and decaying C experiments.The arrows represent the anomalous horizontal diffusions of water vapor imposed for(a) 0.04,(b)0.20,(c)0.36and(d)0.96fractions of deforestation, while the numbers refer to the quantity of arrows departing from each forested(source)gridcell. A water balance model to study the hydrological response to different scenarios of deforestation129 (8).The response to the changes imposed in water vapor convergence(Eqs.(9)and(10))as simulated by our model in this scenario were then summarized as follows. Similarly to both previous analyses,evapotranspiration decreased for all levels of deforestation(Fig.4b).At the same time,runoff was predicted to increase on deforested gridcells and decrease on the forested ones,while its mean domain value still did not display any changes,regardless of the deforestation level applied(Fig.4c).Compared to re-sults above,the greatest change was noted in the impact on precipitation,which showed a slight increase over defor-ested gridcells at low levels of deforestation,while both forested and mean basin values decreased for all levels (Fig.4a).Despite the general tendency for deforestation to ultimately weaken all water?uxes in Amazonia,the re-sults presented here agree with indications that the land-atmosphere coupling induced by regional,fragmented areas of clearing may induce a noticeable ampli?cation of the cy-cle.Furthermore,since such ampli?cation is restricted to moderate levels of clearing,the predictions at high levels are in reasonable agreement with the impact of deforesta-tion expected at the large scale. Decaying water vapor convergence(decaying C) In this experiment,along with the?uctuations expressed above,the convergence term was progressively and linearly reduced as a function of the size of the clearing,in agree-ment with?ndings of some modeling studies that predict a decrease in mean water vapor convergence under scenar-ios of extensive deforestation(Shukla et al.,1990;Dickinson and Kennedy,1992;Polcher and Laval,1994b;McGuf?e et al.,1995).The tendency for a decay in the mean domain water vapor convergence term could be associated not only to the local impact of land-surface disturbances,but also to low-frequency oscillations in the atmosphere induced by re-mote forcings(Chu et al.,1994;Marengo,2004,2005).Our model suggests both decreasing precipitation(Fig.4d)and evapotranspiration(Fig.4e)as a response to a complete scenario of deforestation,while following moderate scenar-ios of deforestation it suggests an increase in precipitation. Due to the decreasing pattern on water vapor convergence, this time the mean basin runoff also decreased,forcing the mean runoff over deforested gridcells to decrease as well, as deforestation moved to levels nearing completion (Fig.4f),in agreement with previous modeling results(No-bre et al.,1991;Lean et al.,1996;Costa and Foley, 2000).In addition,the decrease in convergence caused a further decrease in both evapotranspiration and precipita-tion in comparison to results above. Effects of heterogeneity Land-surface heterogeneity–or,simply fragmentation–is an intuitive concept that can be understood in several dif-ferent ways according to the context in which it is consid-ered.Due to its close association with the impoverishment of forest ecosystems(Bierregaard et al.,2001)and with the increase in?re vulnerability around areas of clearing (Alvarado et al.,2003),land-surface heterogeneity has been typically de?ned and evaluated under an ecological frame-work.The quanti?cation method proposed by Rudel and Ro-per(1997),for example,suggests that fragmentation in any disturbed domain should be calculated as the ratio of the forest–nonforest boundary extent and the intact area,link-ing patchiness and clumpiness with high and low levels of heterogeneity,respectively.Therefore,according to this and other similar methods(Olff and Ritchie,2000;Ritters et al.,2000),an almost entirely disturbed domain contain-Figure4Same as in Fig.2,but for variable C and decaying C experiments.Mean changes(a–c)on forested and deforested gridcells were marked with triangles and circles,while the mean domain changes refer to the unmarked lines. 130 C.D’Almeida et al. ing only a small and localized forested area is regarded as highly fragmented.This outcome clearly indicates an eco-logically oriented approach,since it de?nes heterogeneity according to the disturbance upon the remaining forested area only,neglecting its impact on the surrounding areas al-ready disturbed.However,since the evaluation of the over-all hydrological impact of deforestation on any disturbed domain would necessarily include its entire area,the impor-tance of heterogeneity in such a context would not be ade-quately accounted for by this method.Hence,a similar method that estimates the degree of heterogeneity over any disturbed domain as the ratio of forest-nonforest boundary extent (or perimeter;pr )to the total area of the domain (A )is de?ned here,as spatial heterogeneity (h ):h ?pr =A e11T As suggested earlier,land-surface heterogeneities are expected to in?uence the local climate in Amazonia,espe-cially when associated with regional scenarios of deforesta-tion.Since any particular extent of deforestation may be linked to several different geospatial patterns,not all such scenarios of deforestation are necessarily able to induce a signi?cant effect in the atmosphere.In order to show that,our model was then aimed at comparing the hydrological ef-fects of not only different extents of deforestation,but also of different spatial distributions of the disturbance. Clearly,the perimeter of deforestation (which is equiva-lent to n ,in Eqs.(9)and (10))depends not only on the extent of deforestation,but also on the degree of heterogeneity associated with each scenario.Therefore,to test for the in?u-ence of deforestation scenarios with different degrees of het-erogeneity on circulation,our model evaluated the response to different relations between n and d (see ‘‘Varying spatial heterogeneity (varying H )’’).In the experiments above,a somewhat regular expansion of deforestation linking the dif-ferent fractions of deforestation considered was used (Fig.5).Such a relation shows that intermediate levels of deforesta-tion generates the longest border between the two distinct areas and therefore,tends to induce a greater effect on circu-lation.Similarly,it shows that for low and extreme levels of clearing,the perimeter of deforestation approaches zero,and so does the spatial heterogeneity associated. Varying spatial heterogeneity (varying H ) The method of quanti?cation proposed above was then ap-plied to a wide range of scenarios of deforestation (Fig.6)sorted according to the fraction of area disturbed (columns)and to an ‘‘intuitive’’degree of heterogeneity (rows).Such an ‘‘intuitive’’degree of heterogeneity can be understood as the smallest fractional (or,individual)disturbance present on each row of scenarios.The spatial heterogeneity index (h )associated with each one of these scenarios –calculated by Eq.(11)–appears in Fig.7a,while each curve in the graphic refers to a particular row of scenarios in Fig.6.In every row,the highest spatial heterogeneity value occurs at moderate levels of deforestation,while all scenarios approaching both absent and total clearing (where pr =0)are linked to its low-est values.Scenarios on Fig.6differ among each other only in terms of n ,which is exactly the quantity that reproduces the effect of land-surface heterogeneity on circulation as im-posed by our water balance model.The n ·d pro?les associ-ated with the curves in Fig.6are depicted in Fig.7b,which shows the manner in which the scenarios with contrasting levels of spatial heterogeneity affect the water vapor con-vergence ?eld.The top curves in Figs.7a and b indicate that the scenarios with the maximum spatial heterogeneity at each level of deforestation are responsible for the greatest impact on circulation.This reveals the importance of the spatial resolution employed (by gridded models,or observa-tions)to the potential impact of spatial heterogeneity on cir-culation.The gridcell area is equivalent to the smallest possible fractional area considered,thus making the magni-tude of such an impact inversely proportional to the spatial resolution of the grid.Our model was then used to simulate the hydrological effects of all the scenarios in Fig.6and to evaluate the impact of their contrasting degrees of spatial heterogeneity on these effects. According to results from previous studies (Wang et al.,2000;Baidya Roy and Avissar,2002;Baidya Roy et al.,2003),the most relevant impact of land-surface heterogene-ities on climate tend to occur on precipitation,which may or may not increase over disturbed areas due to the anomalous convection induced.The mean changes of precipitation over the deforested gridcells (p d )linked to the scenarios in Fig.6are shown in Fig.8a,which con?rms that the increase in the local rainfall caused by land-surface heterogeneities are most likely observed over moderate levels of deforestation –for instance,at d =0.16.However,it also shows that even at this particular level of clearing,the impact of fragmenta-tion may not be strong enough to compensate for the predic-tion of a general weakening of the water cycle.The average changes to precipitation over the forested area (p f )are pre-dicted to decrease for all degrees of spatial heterogeneity (Fig.8b),while the precipitation averaged over the entire domain decays linearly for all cases and at the same exact rate (Fig.8c).This last result is directly linked to the assumption that with no ?uctuations on the mean basin water vapor convergence,signi?cant changes induced at the regional scale may not be detected at the basin scale.Furthermore,it indicates that independent –and poten-tially remotely induced (Chen et al.,2001;Fu et al.,2001;Foley et al.,2002;Marengo,2004,2005)–?uctuations on the water vapor convergence ?eld would make it even harder to detect such changes. Figure 5Relation of the number of bordering gridcells [n ]to the fraction of deforestation as determined by Eq.(11),which speci?es the impact of land-surface gradients on the horizontal water vapor diffusion (as exempli?ed in Fig.2). A water balance model to study the hydrological response to different scenarios of deforestation 131 Discussion The hydrological effects of deforestation in Amazonia are subject to intrinsic and interrelated scale and heterogeneity dependencies.This implies that the size and fragmentation of the disturbed areas may determine whether the water cy-cle in the basin becomes intensi?ed or weakened under par-ticular deforestation scenarios.In this perspective,apparently con?icting results at different scales,or under different degrees of heterogeneity,are in fact part of the Figure 6Scenarios of deforestation with different distributions of forested (in gray)and deforested (in white)gridcells,as simulated by the model in varying H experiment.Scenarios within each column experience the same extent of deforestation,while the scenarios within each row have the same fractional area of clearing. Figure 7Number of bordering gridcells [n ](a)and spatial heterogeneity [h ](b)linked to the scenarios in Fig.6.Points marked with squares,circles,triangles,and ·-crosses refer to scenarios with minimum,low,high and maximum degrees of heterogeneity,respectively. 132 C.D’Almeida et al. same complex system in witch different factors prevail at different conditions.At local scales,the prevailing factor is the uncoupling between land-surface disturbances and circulation,which leads to an increase in runoff along with a decrease in evapotranspiration,without signi?cant changes in precipitation.At regional scales,depending on the degree of heterogeneity associated,the land–atmo-sphere coupling induced by fragmentation may or may not become a factor,potentially inducing an increase in cloud formation and rainfall.Following a complete deforestation in Amazonia,the weakening on the recycling of moisture is expected to be the dominant factor,ultimately contribut-ing to diminish all water ?uxes in the region.Such scenarios of deforestation were simulated in the present work by a water balance model,which follows basic mass balance equations.In general,our model agrees with commonly ex-pected hydrological responses to deforestation,con?rming the notion that potentially con?icting predictions and observations gathered by the literature do not necessarily imply inconsistency.However,because of its straightfor-wardness,it may be prudent to ?rst ask whether the model is too unsophisticated to accurately investigate such com-plex interactions. Regarding the linear relations employed in Eqs.(3)–(5),these are clearly approximations to the actual behaviour of the water cycle in Amazonia,which does not exhibit such a strict linear dependence between ?uxes and stocks of water.However,due to the application of the constant fac-tors k 1,k 2and k 3,these quantities converge to their long-term means at steady-state.Furthermore,when moderate deviations linked to the direct effect of deforestation are imposed upon such undisturbed state of equilibrium,the system converges only to a slightly different state.Conse-quently,neither the stocks nor the ?uxes of water are al-lowed to vary signi?cantly,preventing the model to generate inconsistencies potentially caused by the approxi-mation above.Therefore,it is expected that Eqs.(3)–(5)are able to represent the low-frequency proportionality be-tween stocks and ?uxes of water with suf?cient accuracy,similarly to previous studies (Vo ¨ro ¨smarty et al.,1989).The intentional overlook of a few variables linked to the hydro-logical effects of deforestation,e.g.albedo,in?ltration and interception,is another simpli?cation requiring caution.Nonetheless,the hydrological impact of deforestation due to changes on these variables is expected to be indirectly considered by the model.Albedo,for instance,has been ob-served to increase after deforestation (Bastable et al.,1993;Roberts and Cabral,1993).Consequently,cleared soils absorb less solar radiation and thus contain less energy available to be converted in latent heat ?ux,which then must decline.Such an effect is proportional to,and also partially reproduced by,the decrease in evapotranspiration imposed in the model on every scenario of deforestation.In a similar manner,the model is also expected to have indi-rectly considered the hydrological impact due to changes in in?ltration and interception.Both of these variables have been found to decrease with deforestation (Elsenbeer et al.,1999;Godsey and Elsenbeer,2002),thus contributing to increase runoff.Therefore,the application of such parameters in the model would have only intensi?ed the re-sults encountered,since the model has predicted an in-crease in runoff over deforested areas even without considering them.Finally,the model have not considered the regrowth of deforested areas and the corresponding ef-fect on the water cycle in Amazonia.It has been docu-mented,for example,that just a few years after cutting,regenerating forests are able to produce evapotranspiration ?uxes similar to the same ?uxes over undisturbed areas (Ho ¨lscher et al.,1997;Sommer et al.,2002).However,since the totality of modeling studies considered in the present work have not taken this effect in account,we have opted to follow the exact same approach,enabling a closer comparison between the results encountered. In any case,regardless of the acceptability of the assumptions above,it is true that our model is not able to predict the magnitude,timing,and certainly not the loca-tion of the changes with reasonable precision.However,due to its intended simplicity,it provides a fast,clear assessment of mean tendencies caused by deforestation un-der widely different scenarios,and at a reasonably ?ne spa-tial scale.More complex models,on the contrary,are capable of predicting the hydrological impact of deforesta-tion with much greater accuracy.However,due to the numerous factors and variables considered,to the coarse scale normally employed,to the uncertainties involved,and to the computational resources required,such a broad Figure 8Mean changes of precipitation over deforested (a)and forested (b)gridcells,as well as over the entire domain (c)as predicted by the model for the scenarios in Fig.6.Points marked with squares,circles,triangles,and ·-crosses refer to scenarios with minimum,low,high and maximum degrees of heterogeneity,respectively. A water balance model to study the hydrological response to different scenarios of deforestation 133 assessment is presently almost impossible to perform.Still, the use of complex models is essential to con?rm the consis-tency of the results presented here and to expand their applicability.Therefore,further efforts should be directed to the development of more?exible,but yet robust models, enabling the evaluation of a wide range of scenarios of deforestation with much better accuracy. In general,our model indicates the relevance of both scale and degree of heterogeneity of deforested areas to the overall hydrological impact generated,particularly with-in large domains such as Amazonia.It then follows that accu-rate and continuous observations of the land-cover are needed.Additionally,to facilitate the detection of the hydrological impact of deforestation in the region,the implementation of a vaster and more re?ned gauging station network is desirable.However,certain strategies for improvements on the network may be more effective than others in making the hydrological signal of deforestation sig-ni?cantly detectable at different spatial scales.In light of that,speci?c recommendations on how such improvements on the network should be pursued may be achieved with an enhanced version of our model.This version would rely on the implementation of a river networking on its scheme, and on the consideration of the ongoing geospatial structure of deforestation in Amazonia–including perhaps,a third type of gridcell referring to areas of secondary vegetation. Such proposed model framework would then allow,for example,the concomitant simulation of idealized gauging networks and projected levels of deforestation,providing a strategy for maximizing the measured response to deforesta-tion with a minimal number of additional gauging stations. Conclusions The hydrological effects of deforestation in Amazonia seem to depend on the extent and spatial distribution of the land-surface disturbance associated.Such dependencies have been con?rmed by a few simulations performed with a grid-ded water balance model.The scenarios applied to the model follow assumptions regarding the impact of defores-tation on land–atmosphere dynamics.The only condition shared by all model experiments is a local decay(of about 10%)imposed on evapotranspiration,which is a well-known effect of deforestation. In general,the model have showed that all water?uxes tend to decline with the size of deforestation.In the initial experiment performed,however,the model have predicted a local increase in runoff following small(<102km2)land-surface disturbances.Simulations of a widespread defores-tation(>105km2)have con?rmed the tendency for the weakening of the water cycle in the basin,especially when the mean water vapor convergence term decays.In the case of mesoscale disturbances(102–105km2),the model sug-gests that precipitation may–or,may not–get increased for early stages of deforestation(in comparison to an undis-turbed scenario),even though it also decreases as the spa-tial disturbance expands.Such a potential increase in precipitation occurs due to the spatial heterogeneity associ-ated with deforestation.The model have showed that for high levels of fragmentation,the change in the water vapor convergence?eld that follows from the intensi?cation of the horizontal heat?ux gradient between disturbed and undisturbed areas may generate an anomalous convective circulation and consequently rainfall. 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Zeng,N.,Dickinson,E.,Zeng,X.,1996.Climatic impact of Amazon deforestation–a mechanistic model study.Journal of Climate 9,859–883. 136 C.D’Almeida et al. 1麦考瑞雅思 已具有近10年英语和雅思培训经验，全国唯一开设在复旦大学城的专业雅思培训机构，唯一雅思承诺保分班，唯一突破中国学生写作口语瘸腿的创新性教学，写作口语成绩普遍高出社会平均分70%左右，唯一每天13小时《雅思高分技巧课+训练课》复合式教学体系，大学氛围，省级重点高中的管理模式，坚持高强度、大容量、出高分，得到了复旦大学高校教师和复旦内部大学生及上海大学生的普遍认可，享有极高的声誉，尤其是在写作口语双7分方面极为擅长。适合零基础、高中生、大学生在短期内的快速突破雅思6—8分。 麦考瑞雅思06年即开始G类移民类雅思培训，对G类雅思5分—8分都有丰富的教学和应试经验，每年都有G类学员在麦考瑞雅思的帮助下，取得了雅思4个6分，4个7分，总分和7分等，成功技术移民或投资移民到澳洲、美国、加拿大、新西兰等国家。 麦考瑞雅思低调而务实，从不做广告，除了江浙沪皖，仍有北京、河北、湖南、四川、内蒙等全国各地学员慕名而来。2010年度，麦考瑞雅思在沪江网被万名（ielts）《2010年度学员最满意的雅思培训机构》，并被央视CCTV、新华网等权威媒体报道班级成功故事，成为上海8万考生雅思7分实战人气排名第一和教学质量最好的专业雅思培训。 2新东方雅思 新东方教育科技集团(New Oriental Education & Technology Group )成立于1993年11月16日。经过十多年的发展，新东方教育科技集团已发展成为一家以外语培训和基础教育为核心，拥有短期语言培训系统、基础教育系统、教育研发系统、出国咨询系统、文化产业系统、科技产业系统等多个发展平台，集教育培训、教育研发、图书杂志音响出版、出国留学服务、国际游学服务，新东方在线教育、教育软件研发等于一体的大型综合性教育科技集团。2006年9月7号，新东方教育科技集团在美国纽约证券交易所成功上市，成为中国第一家在美国上市的教育机构。 3环球雅思 1、 Blindness is a very serious disability. 失明是非常严重的残疾。 2、 Though he is disabled, he is a gifted artist. 尽管身残疾 (的 )，他是一个有天赋的艺术家。 3、 person with a hearing and eyesight disability misses many things. 一位听力和视力残疾的人会错过很多东西。 4、 Beware of the love syndrome.当心恋爱综合症。 5、 Rosalyn had been there frequently in past years for treatment for infantile paralysis. 罗莎琳在过去的几年中频频来这里治疗小儿麻痹。 6、 Harris went on top in the last lap. 哈里斯在最后一圈跑到了最前面。 7、 He had a high ambition to be a headmaster. 他的抱负是想成为一名校长。 8、 I will love the ambitious for they can inspire me!我爱雄心壮志的人，因为他们能激励我！ 9、 We will have dictation today.我们今天要听写了。 10、 I wrote the letter at Sally's dictation . 我照萨利的口述写信。 11、 The campus is noisy today.今天校园里很吵。 12、 Do believe there is no best man, only much suitable one. 要相信没有最好男人，只有更适合的。 13、 Trees hid the entry of the cave. 洞穴的入口被树丛遮掩。 14、 Fresh air is beneficial to people's health. 新鲜空气对人的健康有好处。 15、 In other words, a classic fudge. 总之一句话，一派胡言。 16、 Mother reproached me for being too clumsy. 母亲责备我笨手笨脚。 17、 He used to be quiet, but now he is very outgoing. 他以前性格沉默少言，但现在很外向。 18、 How do you adapt to this new environment? 你要怎样适应这种新环境呢?。 19、 The bench often does duty for a table. 这条长凳经常当桌子用。 20、 The doctor told me to cut out meat for my fat. 由于肥胖，大夫叫我停止吃肉 21、 He applied his eye to the microscope. 他把眼睛贴近显微镜。 22、 She was out of breath from climbing the stairs. 爬楼梯使她上气不接下气的。 23、 A servant is known by his master's absence.主人不在就可以看出仆人的品行来。 24、 You are a milk-livered fellow!你真是一个胆小的家伙！ 25、 Thank you, my fellow colleagues. 谢谢，同事们。 26、 No joy without annoy. 没有无烦恼之快乐。 27、 I am really very annoyed about it. 我对此事真是很生气。 28、 I felt annoyance at being teased.我恼恨“别人”取笑我。 29、 I let go of all annoyance. 我放下所有烦恼。 30、 He has his faults, but all in all , he is a good guy. 他有缺点，但总的来说，他是不错的人。 单词拼读举例:Di sa bi li ty di sa bled syn drome in fan tile pa ra ly sis am bi tion am bi tious ●中国培训机构排行榜 ● ●根据2013-2014年中国教育培训行业的发展，现在慢慢转向为在线教育，不 再是以前的传统式教育。现在大多数培训机构都是以面授加网授同步进行教学，满足学员需求。 ● ●在这么众多的培训机构里，有加盟的，有连锁的。中国大大小小的培训机构 上万家，到底哪些培训机构最好，最适合我们理想的学习环境。深圳爱培训网为大家整理出以下中国十个最为出色的培训机构！ ● ●一、新东方教育科技集团 ● ●培训项目：英语、厨师、出国留学、托福、雅思等。 ● ● ● ● ●中国培训机构排行榜---新东方教育集团 ● ●学校简介：新东方创办于1993年,20年专注教育培训,累积培训学员超过1600 万,从早教到成人,业务涵盖早教、学前、小学、中学、四六级、考研、出国考试、留学咨询、英语能力提升、国际游学、国际教育、图书、网络课堂等50多所学校,30000多名教职员工,旨在为学员提供一站式终身学习服务。 ● ●新东方教育科技集团已发展为一家以外语培训和基础教育为核心，拥有短期 语言培训系统、基础教育系统、职业教育系统、教育研发系统、出国咨询系统、文化产业系统、科技产业系统等多个发展平台，集教育培训、教育研发、图书杂志音响出版、出国留学服务、职业教育、新东方在线教育、教育软件研发等于一体的大型综合性教育科技集团。 ● ●学校优势：网授+面授同步进行、学校师资力量雄厚，中国老品牌教育培训 机构。 ● ●二、学而思教育 ● ●培训项目：小学奥数、英语、语文，初高中数学、物理、化学、英语、语文。● ● ● ●中国培训机构排行榜---学而思中小学教育 ● ●学校简介：2010年10月20日，学而思教育在纽约证券交易所正式挂牌交易， 成为国内首家在美国上市的中小幼课外教育培训机构。 ● ●学而思以“给孩子受益一生的教育”为使命，秉承“激发兴趣、培养习惯、 塑造品格”的教育理念，不仅关注学生学习成绩的提高，更关注学生学习兴趣的激发、学习习惯的培养和思维模式的塑造。为满足孩子多元的教育需求，学而思开展小班、1对1、网校等多种形式的教育服务，旗下拥有摩比思维馆、学而思培优、学而思网校、智康1对1、E度教育网五个子业务品牌，在各自细分领域都处于领先地位。 ● ●学而思还发展了国内布局完整的中小幼教育专业门户网站群——e度教育 网。e度网由育儿网、幼教网、奥数网、中考网、高考网、留学网等多个网 财务人员常用的Excel表格使用技巧 1、分数的输入 如果直接输入“1/5”，系统会将其变为“1月5日”，解决办法是：先输入“0”，然后输入空格，再输入分数“1/5”。 2、序列“001”的输入 如果直接输入“001”，系统会自动判断001为数据1，解决办法是：首先输入“'”（西文单引号），然后输入“001”。 3、日期的输入 如果要输入“4月5日”，直接输入“4/5”，再敲回车就行了。如果要输入当前日期，按一下“Ctrl+；”键。 4、填充条纹 如果想在工作簿中加入漂亮的横条纹，可以利用对齐方式中的填充功能。先在一单元格内填入“*”或“~”等符号，然后单击此单元格，向右拖动鼠标，选中横向若干单元格，单击“格式”菜单，选中“单元格”命令，在弹出的“单元格格式”菜单中，选择“对齐”选项卡，在水平对齐下拉列表中选择“填充”，单击“确定”按钮（如图1）。 5、多张工作表中输入相同的内容 几个工作表中同一位置填入同一数据时，可以选中一张工作表，然后按住Ctrl键，再单击窗口左下角的Sheet1、Sheet2......来直接选择需要输入相同内容的多个工作表，接着在其中的任意一个工作表中输入这些相同的数据，此时这些数据会自动出现在选中的其它工作表之中。输入完毕之后，再次按下键盘上的Ctrl键，然后使用鼠标左键单击所选择的多个工作表，解除这些工作表的联系，否则在一张表单中输入的数据会接着出现在选中的其它工作表内。 6、不连续单元格填充同一数据 选中一个单元格，按住Ctrl键，用鼠标单击其他单元格，就将这些单元格全部都选中了。在编辑区中输入数据，然后按住Ctrl键，同时敲一下回车，在所有选中的单元格中都出现 了这一数据。 7、在单元格中显示公式 如果工作表中的数据多数是由公式生成的，想要快速知道每个单元格中的公式形式，以便编辑修改，可以这样做：用鼠标左键单击“工具”菜单，选取“选项”命令，出现“选项”对话框，单击“视图”选项卡，接着设置“窗口选项”栏下的“公式”项有效，单击“确定”按钮（如图2）。这时每个单元格中的分工就显示出来了。如果想恢复公式计算结果的显示，就再设置“窗口选项”栏下的“公式”项失效即可。 8、利用Ctrl＋*选取文本 如果一个工作表中有很多数据表格时，可以通过选定表格中某个单元格，然后按下Ctrl ＋*键可选定整个表格。Ctrl＋*选定的区域为：根据选定单元格向四周辐射所涉及到的有 数据单元格的最大区域。这样我们可以方便准确地选取数据表格，并能有效避免使用拖动鼠标方法选取较大单元格区域时屏幕的乱滚现象。 9、快速清除单元格的内容 如果要删除内容的单元格中的内容和它的格式和批注，就不能简单地应用选定该单元格，然后按Delete键的方法了。要彻底清除单元格,可用以下方法：选定想要清除的单元格或 单元格范围；单击“编辑”菜单中“清除”项中的“全部”命令，这些单元格就恢复了本来面目。 10、单元格内容的合并 根据需要，有时想把B列与C列的内容进行合并，如果行数较少，可以直接用“剪切” 和“粘贴”来完成操作，但如果有几万行，就不能这样办了。 解决办法是：在C行后插入一个空列（如果D列没有内容，就直接在D列操作），在Ｄ1中输入“=B1&C1”，D1列的内容就是B、C两列的和了。选中D1单元格，用鼠标指 哪个雅思培训机构最好？ 哪个雅思培训班好？哪个雅思培训机构最好这应该是广大考雅思们最关注的问题。每次看到都是感触良多，我想到大家选择雅思培训学校的心情的时候，就真的想借给每位雅思考生一双慧眼，让他们把这些培训学校都看的清清楚楚、明明白白。 雅思考试费用不菲，培训价格更高，简直可以说高的离谱，学费几千甚至上万的雅思培训学校比比皆是。那如何选择雅思培训学校呢？我总结了以下几点注意事项，希望对大家有帮助。 一、雅思培训机构的口碑 俗话说得好：金杯，银杯，不如老百姓的口碑！选择雅思培训机构之前一定要多听取周围参加过培训同学的意见，做到心中有数。而对于通过网络搜索学校好坏的同学，一定要谨慎，慎重选择，因为网络上的职业枪手无以计数。 二、学校的师资 目前国内有很多知名雅思培训机构，其中不乏连锁或者加盟的，多数培训学校的老师都是本土化，如果哪家学校的宣传上给老师的包装冠以“北京”，“著名”，“学者”之类的名师，大家可要留意了，很多都是假的。其次老师的稳定性，如果学校的授课老师不断变换，对培训效果就会无法保障，报培训班之前一定要了解授课老师情况，有 的学校虽然打出了什么外教或者是名师的招牌，其实这些老师甚至连从业资格都没有这样我们怎么期待他们能给我带来英语能力的提高！ 三、雅思学校课程设置 专业的雅思学校会根据学生不同英语基础开设课程，例如长期班、基础班、提高班、强化班等。这里建议大家最好选择一对一的雅思课程，在教学上会更有针对性，学习效果也显著。如果基础不同，采取一勺烩的做法，那你需要敬而远之。 四、能为学员提供相关服务 一个专业的雅思培训学校，会为学员提供很多的专业服务。例如：雅思写作批改，雅思口语交流机会，学前、学中、学后的模考等等。如果能提供这些服务并贯穿整个雅思学习的过程，那你可以优先选择了！ 作为中国在线英语培训的领先者，引入欧美授课新理念，一直以来都认真聆听学员的心声，专注于提高学员的英语口语能力，使之成为最高性价比抉择的首选出国前英语雅思培训机构。易格英语利用专门的音频视频软件，通过在线学习的形式为学员提供一对一的专业辅导。他们最大的特色就是英美专业外教，一对一辅导以及免费试听。因为是在线培训的方式，所以培训不受时间、地点的限制，因为省去了场地和往返的费用，真正做到为每位学员节省每一分钱。全国官 模块7各单元词汇和短语复习 Unit 1 Living Well Part One 根据首字母或汉语提示写出完整的单词: 1. An unexpected accident made Sang Lan a girl with a physical d____________, but she never gave up. 2. We often observe the tiny cells with m______________ in our biology classes. 3. The production of iron and steel is the most important i______________ of the city. 4. Taiwan is part of China and not an i_______________ state. 5. I have passed all the exams and I am waiting to get the graduation c_______________. 6. A place is a______________ if it is possible to reach it. 7. I was not alone on the journey. Instead, I had so many c________________. 8. You can refer to old people in general as the _______________. 9. When something can help people or improve their lives, we say it is ______________ to people. 10. When the disabled meet with difficulty, we should do what we can to give them a___________. 11. One of his ________________ (志向) is to become a world-wide famous pop singer. 12. He was _____________(笨拙的) with a tool. 13. The patient’s _______________(呼吸) grew stronger and stronger. 14. Who took his place and controlled the company during his ________________ (不在) ? 15. I’m going to give some suggestions to this famous ________________(建筑师). 16. A man’s _______________（尊严）doesn’t depends on his wealth but on his character. Part Two 一、词形变换（用所给词的适当形式填空） 1. The ______________ is good at ______________ TV plays from the stories he reads about or hears. (adapt) 2. The country used to be _____________ on Britain in many ways, but now it has become absolutely_______________. (depend) 3. We have ___________ a lot from the co-operation and I’m sure it will continue to be ________ to both of us. (benefit) 4. Her _____________ lecture ____________ all of us. We won’t forget her ____________. (encourage) 5. ______________ people should be treated equally in spite of their ______________. (disability) 6. You were _____________ yesterday, Tom. Can you tell me the reason for you _____________? (absent) 7. The ______________ serving the passengers on the train is of good_______________. (conduct) 8. ________________ countries pay much attention to the development of ________________. (industry) 二、翻译句子 1. 应该给残疾人尽可能多的鼓励和援助。 ______________________________________________________________________________ 2. 换句话说，这些措施对我们的工业发展是有益的。 ______________________________________________________________________________ 3. 总之，在学校寄宿(board)能帮助学生学会独立。 ______________________________________________________________________________ 财务人员必备的EXCEL 财务人员必备的EXCEL 我的天地2010-06-17 14:02:16 阅读54 评论0 字号：大中小订阅 也许你已经在Excel中完成过上百张财务报表，也许你已利用Excel函数实现过上千次的复杂运算，也许你认为Excel也不过如此，甚至了无新意。但我们平日里无数次重复的得心应手的使用方法只不过是Excel全部技巧的百分之一。本专题从Excel中的一些鲜为人知的技巧入手，领略一下关于Excel的别样风情。 一、建立分类下拉列表填充项 我们常常要将企业的名称输入到表格中，为了保持名称的一致性，利用“数据有效性”功能建了一个分类下拉列表填充项。 1.在Sheet2中，将企业名称按类别(如“工业企业”、“商业企业”、“个体企业”等)分别输入不同列中，建立一个企业名称数据库。 2.选中A列(“工业企业”名称所在列)，在“名称”栏内，输入“工业企业”字符后，按“回车”键进行确认。 仿照上面的操作，将B、C……列分别命名为“商业企业”、“个体企业”…… 3.切换到Sheet1中，选中需要输入“企业类别”的列(如C列)，执行“数据→有效性”命令，打开“数据有效性”对话框。在“设置”标签中，单击“允许”右侧的下拉按钮，选中“序列”选项，在下面的“来源”方框中，输入“工业企业”，“商业企业”，“个体企业”……序列(各元素之间用英文逗号隔开)，确定退出。 再选中需要输入企业名称的列(如D列)，再打开“数据有效性”对话框，选中“序列”选项后，在“来源”方框中输入公式：=INDIRECT(C1)，确定退出。 4.选中C列任意单元格(如C4)，单击右侧下拉按钮，选择相应的“企业类别”填入单元格中。然后选中该单元格对应的D列单元格(如D4)，单击下拉按钮，即可从相应类别的企业名称列表中选择需要的企业名称填入该单元格中。 提示：在以后打印报表时，如果不需要打印“企业类别”列，可以选中该列，右击鼠标，选“隐藏”选项，将该列隐藏起来即可。 二、建立“常用文档”新菜单 在菜单栏上新建一个“常用文档”菜单，将常用的工作簿文档添加到其中，方便随时调用。 1.在工具栏空白处右击鼠标，选“自定义”选项，打开“自定义”对话框。在“命令”标签中，选中“类别”下的“新菜单”项，再将“命令”下面的“新菜单”拖到菜单栏。 按“更改所选内容”按钮，在弹出菜单的“命名”框中输入一个名称(如“常用文档”)。 2.再在“类别”下面任选一项(如“插入”选项)，在右边“命令”下面任选一项(如“超链接”选项)，将它拖到新菜单(常用文档)中，并仿照上面的操作对它进行命名(如“工资表”等)，建立第一个工作簿文档列表名称。 重复上面的操作，多添加几个文档列表名称。 会计人必学必会的Excel表格技巧 从Excel中的一些鲜为人知的技巧入手，领略一下关于Excel的别样风情。也许你已经在Excel中完成过上百张财务报表，也许你已利用Excel函数实现过上千次的复杂运算，也许你认为Excel也不过如此，甚至了无新意。但我们平日里无数次重复的得心应手的使用方法只不过是Excel全部技巧的百分之一。 一、建立“常用文档”新菜单 在菜单栏上新建一个“常用文档”菜单，将常用的工作簿文档添加到其中，方便随时调用。 1.在工具栏空白处右击鼠标，选“自定义”选项，打开“自定义”对话框。在“命令”标签中，选中“类别”下的“新菜单”项，再将“命令”下面的“新菜单”拖到菜单栏。按“更改所选内容”按钮，在弹出菜单的“命名”框中输入一个名称(如“常用文档”)。 2.再在“类别”下面任选一项(如“插入”选项)，在右边“命令”下面任选一项(如“超链接”选项)，将它拖到新菜单(常用文档)中，并仿照上面的操作对它进行命名(如“工资表”等)，建立第一个工作簿文档列表名称。重复上面的操作，多添加几个文档列表名称。 3.选中“常用文档”菜单中某个菜单项(如“工资表”等)，右击鼠标，在弹出的快捷菜单中，选“分配超链接→打开”选项，打开“分配超链接”对话框。通过按“查找范围”右侧的下拉按钮，定位到相应的工作簿(如“工资.xls”等)文件夹，并选中该工作簿文档。重复上面的操作，将菜单项和与它对应的工作簿文档超链接起来。 4.以后需要打开“常用文档”菜单中的某个工作簿文档时，只要展开“常用文档”菜单，单击其中的相应选项即可。提示：尽管我们将“超链接”选项拖到了“常用文档”菜单中，但并不影响“插入”菜单中“超链接”菜单项和“常用”工具栏上的“插入超链接”按钮的功能。 二、建立分类下拉列表填充项 我们常常要将企业的名称输入到表格中，为了保持名称的一致性，利用“数据有效性”功能建了一个分类下拉列表填充项。 1.在Sheet2中，将企业名称按类别(如“工业企业”、“商业企业”、“个体企业”等)分别输入不同列中，建立一个企业名称数据库。 2.选中A列(“工业企业”名称所在列)，在“名称”栏内，输入“工业企业”字符后，按“回车”键进行确认。仿照上面的操作，将B、C……列分别命名为“商业企业”、“个体企业”…… 3.切换到Sheet1中，选中需要输入“企业类别”的列(如C列)，执行“数据→有效性”命令，打开“数据有效性”对话框。在“设置”标签中，单击“允许”右侧的下拉按钮，选中“序列”选项，在下面的“来源”方框中，输入“工业企业”，“商业企业”，“个体企业”……序列(各元素之间用英文逗号隔开)，确定退出。再选中需要输入 BOOK7 Unit1单词练习题 一．根据所给的首字母写出单词的正确形式。 1.What we choose and decide forms our life, but a_______ decides our choice and decision. 2.We should design more websites that are both technically a________ and also usable for people with disabilities. 3.As is known to all, Mo Yan was awarded the 2012 Nobel Prize for l_________. 4.The whole class c________ me on getting the first prize in the English competition. 5.Recently I watched a cartoon a________ from the famous drama by Shakespeare. 二．根据句意用括号内所给单词的适当形式填空。 1.It is known to all that fresh air is _____ to our health and the new park ______ us all, so we should keep it clean.( benefit ) 2.The little boy made up a tale for his ______ ( absent ) from school. 3.Praise acts as an _____ to the players, and therefore they will feel _____ and get the ______ to continue and improve their performance. ( encourage ) 4.The ______ girls swims well in spite of her ______. (disable ) 5.My brother ______ from a well—known American university. My parents attended his ______ ceremony yesterday. ( graduate ) 上海雅思培训行业分析报告 ——专业解读上海雅思培训怎么选？ 上海雅思培训行业分析报告 ——上海雅思培训机构怎么选？ 随着雅思考试的持续火热，各种线上线下培训也余温不减。市面上的雅思培训机构被“吹”得天花乱坠，考生也被弄得晕头转向。诚然，不同的考生选择雅思培训机构关注的重点不一样，但是有四点是必须要看的。另外，相对于这四个必看点，考生容易陷入的一些误区，在此也为大家列出，以供参考。 第一，看口碑不看品牌 品牌的响亮很大程度在于机构广告费用的投入，及公司宣传策略的选择。大家在衡量一个机构质量的同时，不要仅凭平日里的印象进行选择，最好能先咨询参加过相关机构培训的朋友或同学，由他们进行推荐或者听取他们的建议。 部分知名度较高的培训机构内部培训效果难以评判，据一些参加过相关机构培训的考生反应，其培训效果与预期落差很大。 2 / 22 3 / 22 第二，看试听不看吹捧 考生在决定报考哪个培训机构前，一定要预约一次免费试听课。不要只听顾问老师的“吹捧”。通过试听，可以了解到这个机构老师上课的大致水平，从而对机构的教学实力做出评估。但是老师的教学水平千差万别，大家还需要对机构老师的整体水平做了解。如有条件还可以对相应授课教师做进一步的打听。 师资力量是一个机构培训实力的根本保证。大家需要从老师的教育背景、教学经验两方面去考察。有海外留学背景和国内知名院校背景相关专业的最好。另外，需要有三年及以上教学经验，且多次参加雅思考试并有高分学员培养经典案例的老师。 第三，看课程不看高分 课程设置是否全面，即有没有适合自己的 课程非常重要，切忌只看高分学员。高分学员的产生是有其自身英语基础的。一般考生要获取高分必须在适合自 十大英语培训机构推荐 一、美联英语 美联英语，全球体验式英语培训领先品牌，是美联国际教育集团旗下最重要的产线品牌，一直提倡“会用，才算会英语”。从2006年开创至今，已覆盖14个省份、25个城市，拥有近100家教学中心。多年来，美联英语一直秉持体验式英语的教学理念，以轻松灵活的教学方式，每年为全球3万余名学员提供专业、高端的英语教育。美联英语更开创多种英语学习方法和课程，满足不同英语水平学员的切实需要，让学员能够在职场、学校、生活上真正运用英语。 特点：口语培训，独特的体验式英语培训的教学方法，教学中给学员力争还原真实的英语交流环境。欧美国家外教跟你面对面对话，教你最地道的口语。如果说把自己扔在国外是学英语的好方法，美联英语是把国外的语言环境搬到了美联英语的中心里。 二、新东方英语 简介：新东方学校成立于1993年，并于2006年成功在美国上市，语言培训一直是新东方的核心竞争力。 特点：学英语的都知道，新东方在应试方面的培训全国一流。托福雅思GRE，四级六级，专四专八，老师会教你各种考试方面的技巧。新东方解决了很多中国人应付考试的问题，很多考托福的学生都在新东方接受过培训 三、昂立英语 上海市昂立进修学院前身为交大昂立外语培训中心，1991年成立，是全国首家大学生发起的勤工助学组织，取名“ONLY”，长期的发展在培训行业积累了一定的口碑。 特点：价格、开课种类以及课时人数方面与新东方有些类似，但包含更多英语以外的培训班。 四、新航道 创始人是原新东方教师胡敏，与新东方培训有异曲同工之处，“雅思梦之队”、“托福国家队”、“考研英语梦之队”等为广大学子提供雅思、新托福、SAT、GRE、考研英语、四六级考试、英语口语、中学英语、综合英语等应试培训课程。 特点：明星老师口才比较好，上课气氛热烈，应试技巧比较有用。 五、李阳疯狂英语 简介：李阳疯狂英语是在中国本土土生土长的实用高效的英语学习方法，在广大校园有很大的影响力。 特点：多以训练营、夏令营等短期全封闭培训为主，作为一种交新朋友、集体生活的体验对于学生来说，参加一次这样的英语培训也很不错。 选修七 ?Unit 1Living well 语法填空 MARTY’S STORY I am Marty Fielding, 1. ____ have a muscle disease that makes me very weak and can’t run or climb stairs as quickly as other people. 2. _________ (fortune), the doctors don’t know how to make me better, 3.____ I am very outgoing and have learned to adapt to my disability. I used to climb trees, swim and so on. In fact, I used to dream 4._____ playing professional football and possibly 5. _______ (represent) my country in the World Cup. Then I started to get weaker and weaker. In the end I went into hospital for medical tests, 6. ____ I stayed 7. ____ nearly three months. One of my biggest problems is 8._____ I don’t look any different from other people. So sometimes when I got out of breath 9. _____ running a short way or had to stop and rest halfway up the stairs, some children in my primary school would laugh. Every time I returned after 10. ___ absence, I felt stupid 11. ______ I was behind the others. My life is a lot easier at high school as my fellow students have accepted me. The few 12. ____ cannot see the real person inside my body do not make me 13. ______(annoy), and I just ignore them. All in all I have a good life, finding many things I can do. My ambition is 14. ______ (work) for a firm 15. ____ develops computer software in the future. My life is busy, having no time to sit around 16. _____(feel) sorry for myself. As well as going to the movies and football matches with my friends, I spend a lot of time with my pets. To look after my pets properly takes me a lot of time but I find it worthwhile. In many ways my 17._______(disable) has helped me grow stronger 18. _____________ (psychology) and become more independent. If I had a chance to say one thing to healthy children, it would be this: having a disability does not mean your life is not 19. _________(satisfy), s o don’t feel sorry for the disabled or make fun of them, and don’t ignore them either. Just accept them for who they are, and give them 20. __________(encourage) to live as rich and full a life as you do. Ⅰ.单词荟萃 1．_________n．伤残；无力；无能→_________ adj.伤残的→_______v．使…残疾2．________ n．雄心；野心→________ adj.有雄心的；有野心的 →______________ adv.有野心地 3．__________ adj.有益的；受益的→________n．利益，好处；v. 有益于 4．________ n．缺席；不在某处→________adj.缺席的；不在的 →________ adj.出席的；到场的 5．________v．使……不悦；惹恼→________adj.颇为生气的 →________adj.令人生气的→__________n．烦恼 6．____________n．鼓励；奖励→__________ vt.鼓励→___________ adj.鼓舞人心的7．________ n．政治(学)→________adj.政治的；政治学的→________n．政治家8．________ n．协助；援助→________n．助手；助理→________v．帮助；援助9．___________ n．毕业；毕业典礼→________vi. 毕业→________adj.受教育的10．________n．(接近的)方法；通路；可接近性→___________adj.可接近的；可进入的；可使用的 11. ________ vt. vi 使适应→____________ adj. 可适应的→____________n. 适应 12. _________ n. 行为，品行→____________ vt. 指挥，管理 Ⅱ.短语检测 1．换句话说___________________ 2. 适合_________________ 3．切去；省略；停止(做某事) _______________________ 4．上气不接下气_______________ 5．总而言之__________________ 6．闲坐着______________________ 国内十大（ielts）雅思培训机构排名相关资讯讯息 1麦考瑞雅思 已具有近10年英语和雅思培训经验，全国唯一开设在复旦大学城的专业雅思培训机构，唯一雅思承诺保分班，唯一突破中国学生写作口语瘸腿的创新性教学，写作口语成绩普遍高出社会平均分70%左右，唯一每天13小时《雅思高分技巧课+训练课》复合式教学体系，大学氛围，省级重点高中的管理模式，坚持高强度、大容量、出高分，得到了复旦大学高校教师和复旦内部大学生及上海大学生的普遍认可，享有极高的声誉，尤其是在写作口语双7分方面极为擅长。适合零基础、高中生、大学生在短期内的快速突破雅思6—8分。 麦考瑞雅思06年即开始G类移民类雅思培训，对G类雅思5分—8分都有丰富的教学和应试经验，每年都有G类学员在麦考瑞雅思的帮助下，取得了雅思4个6分，4个7分，总分6.5和7分等，成功技术移民或投资移民到澳洲、美国、加拿大、新西兰等国家。 麦考瑞雅思低调而务实，从不做广告，除了江浙沪皖，仍有北京、河北、湖南、四川、内蒙等全国各地学员慕名而来。2010年度，麦考瑞雅思在沪江网被万名（ielts）《2010年度学员最满意的雅思培训机构》，并被央视CCTV、新华网等权威媒体报道班级成功故事，成为上海8万考生雅思7分实战人气排名第一和教学质量最好的专业雅思培训。 2新东方雅思 新东方教育科技集团(New Oriental Education & Technology Group )成立于1993年11月16日。经过十多年的发展，新东方教育科技集团已发展成为一家以外语培训和基础教育为核心，拥有短期语言培训系统、基础教育系统、教育研发系统、出国咨询系统、文化产业系统、科技产业系统等多个发展平台，集教育培训、教育研发、图书杂志音响出版、出国留学服务、国际游学服务，新东方在线教育、教育软件研发等于一体的大型综合性教育科技集团。2006年9月7号，新东方教育科技集团在美国纽约证券交易所成功上市，成为中国第一家在美国上市的教育机构。 3环球雅思 广州市环球精英培训中心作为国内规模最大并首家在美国上市的连锁外语培训机构之一，为中国民办教育创新做出巨大贡献。12年来以驰名独特的“环球实用应试教学模式”，迅速发展成为具有全国（ielts）雅思、托福、SAT、GRE、PTE、少儿英语、BETS、BEC商务英语、职称英语、国际预科课程、四六级、外教口语、中教听说、新概念英语、词汇语法发音、夏冬令营、法德西意多语种、留学文书写作中心、职业网校、英语网校、政府及企业团培、英美公派奖学金申请、大学国际课程委培、英语教材开发等项的综合性学校及大型网校，成为第一个中国教育行业旗舰连锁机构，被称为“中国人的英语学习强国”。 4新航道雅思 新航道国际教育集团（是由英语教育专家胡敏教授率领一批国内外语言培训界精英及专家、学者共同创办，美国国际数据集团（IDG）和全球著名的教育培训机构美国KAPLAN国际 十大英语培训机构排名 1、新东方 简介：新东方学校成立于1993年，并于2006年成功在美国上市，语言培训一直是新东方的核心竞争力。 影响力：闻名遐迩的应试培训，英语四六级、雅思、托福等考试技巧传授得不错，应试品牌效用很强大。 特点：明星老师口才比较好，上课气氛热烈，价钱相对实惠。 不足：应试技能传授多过语言的培训，上课人数较多。据说笑话每期一样，课件每期一样，不过对于应试来说很有效果。 师资：中教、外教 上课模式：课堂面授，大班上百人，小班十余人 面对对象：大学生出国考试 2、英孚教育 简介：1965年，一位名叫Bertil Hult的瑞典年轻人创办了EF 英孚教育。1994年进入中国市场的英孚教育，基于各大城市布点宣传较多，网络搜索排名第二。 影响力：老外开的公司，品牌宣传投入大，知名度、费用很高的英语培训“贵族”机构之一。 特点：局限于大城市，高档写字楼的教学环境，英语学习氛围较好。学习时间自由，要自制力较好和有品质要求的学员。 不足：价格较贵，学习期限多为一年以上，2万以上，课时数比较少单价较高。 师资：中教、外教 上课模式：面授为主，辅助在线预习等学习，一对4+大班课+在线学习 面对对象：成人商务人士 3、环球雅思 简介：雅思是最受语言培训网民关注的语言考试，市场上存在众多以雅思辅导起家的语言培训机构，市场竞争激烈。2001年成立的环球雅思则以3.9%的关注度排名第三。 影响力：一如期名字，在雅思考试这一块是绝对的权威，要移民出国的语言考试选择这错 不了。 特点：针对考试开设听力、口语、写作、阅读方面的针对性课程，适合专项突破。 不足：大班教学，更偏向应试，口语课时数较少。 师资：中教、外教国内十大雅思培训机构排名
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