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第1篇

我科收治3例QT间期延长病人，均出现恶性心律失常，现报告如下。

1病例资料

病例1：女性，74岁，以“腹泻3天，发作性抽搐半天”为主诉入院，3天前因腹泻在当地医院治疗（未用延长QT间期药物），半天前出现阵发性抽搐，伴意识丧失、大小便失禁，数秒钟可缓解，反复发作，故转我院。既往有“冠心病”史5年，有发作性胸痛病史，无晕厥史，无既往心电图资料，直系亲属无类似病人，无猝死病人。入院时心电图显示：窦性心律，胸前导联T波深倒置，QT间期显著延长（附后图1）。急查血电解质钾、钠、氯、钙在正常值范围，心肌酶正常。入院后行吸氧，心电监护，对症治疗。入院后约半小时再次出现抽搐，意识丧失，心电监护显示室性心动过速，给以利多卡因静注缓解，后静滴门冬氨酸钾镁针，营养心肌，口服美托洛尔片等治疗，此后仍反复发作阿斯综合征，心电监护有时显示为尖端扭转型室速，后转上级医院，在上级医院未发作恶性心律失常，药物治疗3天出院。

病例2：女性，77岁，以“反复胸闷、心悸半月，抽搐2小时”为主诉入院，半月前因腹泻后出现胸闷、心悸，在当地按冠心病治疗（未应用延长QT间期药物），疗效差，于2小时前突然意识丧失，四肢抽搐，面色青紫，呼吸困难，约15分钟缓解，急来诊。既往“冠心病心肌缺血”史10余年，无晕厥史，入院时心电图显示：心房纤颤，不完全性右束支传导阻滞，QT间期大于600ms（附后图2）。急查血电解质、心肌酶正常。给以营养心肌，中成药活血化瘀等治疗。5小时后再次出现意识丧失，抽搐，心电图示：心室纤颤，行心肺复苏，复苏药物应用，心电图转为窦性心律。于第二天反复发作心室颤动、心室扑动（附后图3），转上级医院。

夜上海论坛 病例3：女性72岁，因头晕跌倒致额部裂伤，在外科住院治疗，既往身体健康。入院时心电图示：窦性心动过缓，心率每分钟45次左右，QT间期显著延长，T波直立、增宽（因时间较久，无当时心电图资料）。病人诉时有头晕，未引起重视，于入院第二天正输液时突然意识丧失，四肢抽搐，心音消失，大动脉搏动消失，立即行心肺复苏，查心电图示：尖端扭转型室速，后转为心室纤颤，持续心肺复苏，复苏药物应用，一小时左右，心电图显示为心房纤颤，随后病人出现自主呼吸，四肢活动，血压平稳，转上级医院。随访病人在上级医院诊断为急性心肌梗死，转院数小时后再次出现尖端扭转型室速，经治疗痊愈出院。

2讨论

3例病人心电图均有QT间期显著延长，均有恶性心律失常发作，可诊断为长QT综合征。长QT综合征可以是先天性，也可以是获得性的，先天性长QT间期在儿童或青春期最常见，表现为晕厥前兆或症状明显的晕厥反复发作。上述3例病人既往均无晕厥发作，考虑为获得性长QT综合征。获得性长QT综合征的常见诱因为：

2.1心源性心律失常（完全性传导阻滞、严重心动过缓性心律失常）、冠心病、心肌炎、低体温。

2.2代谢性酗酒、可卡因或有机磷化合物中毒、心肌缺血、神经性厌食症、电解质紊乱（低钾血症、低镁血症、低钙血症）、甲状腺功能低下等。

夜上海论坛 2.3神经源性脑血管意外、脑炎、创伤性脑损伤、自主神经系统疾病、人类免疫缺陷疾病等。

2.4药源性奎尼丁、胺碘酮、红霉素、阿司咪唑、酮康唑、左氧氟沙星等。基层医务人员对长QT综合征不熟悉，不易引起重视，治疗不规范，尤其是非心血管专业人员，处理不得当，可能导致严重后果。

3体会

夜上海论坛 3.1心电图显示长QT间期病人应查找原因，完善相关检查，去除诱因，避免恶性心律失常发生。

3.2基层医务人员加强业务学习，要掌握恶性心律失常的治疗原则。

第2篇

夜上海论坛 关键词：高尔夫场；果岭；根层基质；导水率；土壤淋洗

中图分类号：G 849.3；S 155 文献标识码：A 文章编号：1009-5500（2013）05-0072-07

夜上海论坛 收稿日期：2013-08-17； 修回日期：2013-10-09

作者简介：张华（1972-），男，广西柳州人。

E-mail：

Hydraulic conductivity of golf course putting green

root zones affected by sodium adsorption

ratio of leaching water

夜上海论坛 ZHANG Hua WANG Yi-chun LI De-ying

夜上海论坛 （1.School of Applied Chemistry and Biological Technology，Shenzhen Polytechnic，Shenzhen

518055，China；2.Department of Plant Sciences，North Dakota

夜上海论坛 State University，Fargo，ND 58108，USA）

夜上海论坛 Abstract：Soil salinization is a major problem threatening turfgrass management.Alternative water sources such as recycled water （RW） usually have elevated salt content.With high exchangeable sodium in soil，rain or irrigation with fresh water can cause soil dispersion，and thus reduce water infiltration and permeability.The objective of this study was to determine the effect of salt composition in irrigation water on saturated water conductivity （Ksat） of putting green root zone materials and constructions.Three root zone materials，clay （Fargo，North Dakota，USA），clay loam （Garick Corp.，Cleveland，OH），and sand/peat mixture （Dakota Peat，North Dakota，USA） （90/10 v/v） were tested alone，as well as tested in different root zone construction，i.e.soil pushup green （40 cm deep），sand/peat mixtures in USGA-putting green style （30 cm of root zone over 10 cm gravel） and California putting green style （40 cm deep）.Saturated water conductivity was determined after the root zone materials and construction were leached with water of five levels of SARw （0，2.5，5.0，15.0，and ∞）.All except the SARw 0 had an ECw of 11.0 dS/m.The results showed severe soil dispersion may happen when SARw of leaching water is greater 5 for clay and clay loam.A laboratory test may predict the severity of dispersion but further study is needed to quantify the effect of soil organic matter （OM） and clay mineralogy.Generally，sand/peat mixtures used in root zones of either California or USGA putting green style is not vulnerable to dispersion by salt in irrigation water.

Key words： golf course；putting green；root zone；saturated water conductivity；salinity；leaching.

夜上海论坛 INTRODUCTION

Soil salinization is a major problem threatening crop production in arid and semi arid pared to agriculture turfgrass management is facing a greater challenge because turfgrass irrigation is often viewed as a low priority when water shortage happens.Recycled water （RW） is a practical alternative for turfgrass irrigation as it is the only water source with increasing availability （Harivandi，2007；Qian and Harivandi，2008）.The National Golf Course Owners Association reported that 12% of the golf courses have adopted RW solely or partially for irrigation （NGCOA，2005）.Recycled water usually contains significant amounts of salt，and repeated use for turfgrass irrigation may result in soil salinization （Mancino and Pepper，1992；Thomas et al.，2006）.Excessive salts adversely impact turfgrass growth by inducing osmotic stress and toxicity （Munns and Tester，2008）.Leaching is an important means of removing excess salts out of the root zones.Once exchangeable sodium in soil is too high，rain or irrigation with fresh water can cause soil dispersion，surface crusting and compaction，and thus reduce water infiltration and permeability （Carrow and Duncan，1998）.The efficiency of leaching practice is affected by many factors，such as water quality，soil types，irrigation，and climate.For non-sodic saline soils，leaching can be achieved using water with electrical conductivity （EC） below the targeted soil EC.Nevertheless，larger leaching fractions （LF） are required as EC of leaching water increases.Once soil becomes sodic，leaching will not be effective because soil hydraulic conductivity decreases with decreasing electrolyte concentration and increasing sodium adsorption ratio （SARw） of the leaching water，especially for soils high in 2∶1 layer-silicates （McNeal and Coleman，1966；McNeal et al.，1966）.

夜上海论坛 The widely used guidelines of SAR and EC thresholds for water infiltration in salt management were established by Ayers and Westcot （1985） based on the research by Oster and Schroer （1979） and Rhoades （1977）.A more recent guideline was developed to include soil texture information （Steppuhn and Curtin，1993）.An evaluation of those guidelines using different soils and leaching water was conducted by Buckland et al.（2002） and the results indicated that soil texture is important in the selection of leaching water.

Currently，LF in turfgrass management is mostly based on the measurement of water EC and soil EC （Carrow and Duncan，1998；Rhoades and Loveday，1990）.However，different leaching strategies are recommended for sand and soil root zones.On sand-based systems，large amounts of water can be applied at one time，while for soils with lower infiltration rates，a leaching fraction slightly above the evapotranspiration （ET） can be applied （Soldat，2007）.Water permeability （infiltration and percolation） through different turfgrass root zones such as the United States Golf Association （USGA） style and California style is usually different （Aragao，et al.，1997；McCoy and McCoy，2006）.A small amount of silt and clay fraction is allowed in the USGA specifications （USGA Green Section Staff，1993），whether such a small amount has any influence on leaching practice in salinity management of sand-based root zones is not well understood.

The objective of this study was to determine the effect of salt composition in irrigation water on saturated water conductivity （Ksat） of four putting green root zone materials.The result will provide better understanding of interactions between root zone media and water quality and quantity in leaching process so that turfgrass managers can make decisions accordingly.

MATERIAL AND METHODS

Three root zone materials，clay （Fargo series，fine，smectitic，frigid Typic Epiaquerts），clay loam （topsoil，Garick Corp.，Cleveland，OH），and sand/peat mixture （Reed sedge peat，Dakota Peat，North Dakota，USA） （90/10，v/v） were packed into brass cylinders （6 cm diam. 5.4 cm i.d.） with two layers of cheese cloth attached at the paction was kept consistent by 5 drops of a 1.36 kg hammer from a 305 mm height （USGA Green Section Staff，1993）.Each soil type had four replicates.The compacted soil cores were treated in a laboratory for 10 saturation/drying cycles with salt solutions at five levels of SARw.Saturation was achieved by introducing the salt solutions from the bottom of the samples and drying process was conducted at room temperatures.The five levels of SARw were 0，2.5，5.0，15.0，and ∞，all except the SARw 0 had an EC of 11.0 dS/m.The EC for SARw 0 was 0.2 dS m-1 from distilled water.A target SARw level was achieved by mixing appropriate amounts of NaCl，CaCl2・2H2O，and MgCl2・6H2O，respectively，with Ca2+ and Mg2+ in 1∶1 ratio where they were needed，following the equation of SARw = [Na+]/（Ca2++Mg2+）/2，with concentration expressed in meq/L.After the wet/dry cycles，Ksat of those samples were measured using distilled water by a constant head method following Klute and Dirksen （1986）.Organic matter content was tested by the loss on ignition method （Nelson and Sommers，1996）.Soil EC was determined following the method of Whitney （1998） with miner modifications.Briefly，to a 10 g of soil sample deionized water was added in 1∶5 soil to water gravimetrical ratio and agitated on a shaker （Model 6010；Eberbach Corp.，Ann Arbor，MI） at 180 osc/min for 10 min.Then，following a 15-min equilibration，the EC from the supernatant was measured with an EC meter （model 1054；VWR Scientific，Phoenix，AZ）.Soil pH was determined with a pH meter （model 420；Thermo Fisher Scientific Inc.，Waltham，MA） following the method of Watson and Brown （1998） using a 1∶1 soil to water gravimetric ratio.Cation exchange capacity was measured using ammonium acetate extraction method at pH = 7 （Hendershot et al.，1993）.The chemical properties of soil materials used in the study are shown in Table 1.

夜上海论坛 The three root zone materials also were used to fill in clear polyethylene tubes （5.4 cm diam.，40 cm height） to simulate root zones.Clay and clay loam were packed to 40 cm depth.Sand/peat mixtures were packed in USGA putting green style （30 cm of root zone over 10 cm gravel） and California putting green style，respectively.Therefore，four different root zones were created.Each tube was supported within a 7.5 cm diameter opaque polyvinyl chloride （PVC） pipe capped on the bottom.Holes were drilled on PVC cap and plastic tubing to allow for drainage.Sea-

Table 1 Properties of three soil materials used in the construction of putting green root zones

prior to the leaching experiment with different levels of sodium adsorption ratio （SARw）

夜上海论坛 1：Electrical conductivity measured in a 1：5 soil to water gravimetric ratio.2：Cation exchange capacity.3：Organic matter. side II' creeping bentgrass was seeded at a rate of 49 kg/ha in the four root zone mixtures.

Irrigation was applied with an automated mist system to maintain moisture during germination and then hand watered every other day four weeks after germination.Milorganite （5.0 N-0.9 P-0.0 K） was applied at 24.5 kg N/ha at the time of seeding and 13.0 N-0.0 P-22.0 K was applied every two weeks at 49 kg N/ha in the following two months.The grass was hand cut at 2 cm height twice a week following the germination.Average day/night air temperature was 28/18 ℃ and supplemental light with metal halite lamps were provided to have a minimum PAR of 375 mol/m・s and photo period of 12 h/d.

夜上海论坛 The experiment was set up as a split-plot with root zone mixtures being the whole-plot factor arranged in a randomized complete block design with three replicates.The sub-plots were assigned to a combination of five SARw levels as used above.A micronutrient fertilizer （0.84% B，1.80% Cu，15.25 % Fe，5.55% Mn，0.09% Mo，5.25% Zn，and 8.45% S） （EnP Inc.，Mendota，IL） was applied at 91.5 kg product per ha when the leaching treatments were initiated to avoid potential micronutrient deficiency.

夜上海论坛 Six months after the initiation of the study，all soil profiles were removed from the plastic tubes and air dried prior to crushing into particles and aggregates smaller than 3 mm.The soil samples from the top 0 to 10 cm depth were repacked into brass cylinders （5.4 cm diam.，6 cm height） and their Ksat values were determined using same methods described above.

Data were subjected to analysis of variance （ANOVA） using the general linear model procedure with the Ksat data transformed with the natural logarithm prior to the ANOVA analysis （SAS Institute Inc，2008）.Means of soil Ksat were compared using the Duncan's multiple range tests at 0.05 probability level.

RESULTS AND DISCUSSION

There was significant soil type，SARw level，and interaction effects on Ksat after the saturation/dry cycles （Table 2）.Saturated water conductivity of clay and clay loam was affected by SARw level in the salt solutions，whereas sand/peat mixture was not.For clay soil，significant reduction of Ksat from the control occurred as SARw became higher than 2.5，with the lowest Ksat occurred in the treatment that had no CaCl2

Table 2 Analysis of variance for the saturated water conductivity of the root zone materials （clay，clay loam，

夜上海论坛 sand/peat） after 10 cycles of saturation/drying cycles using salt solutions with

SARw at 0，2.5，5.0，15.0，and ∞. added （SARw = ∞） （Fig.1）.For the clay loam soil，significant reduction of Ksat from the control occurred only in salt solution without CaCl2 addition （SARw = ∞）.Therefore，the clay soil was more prone to dispersion than clay loam as a result of exposure to salt solutions with high SARw values.Sand/peat mixtures were most labile in response to different EC and SARw in irrigation water followed by leaching with distilled water.

夜上海论坛 Fig.1 Saturated water conductivity of root zone materials affected by 10 cycles of saturation/drying using salt solutions with sodium adsorption ratio （SARw） at 0，2.5，5.0，15.0，and ∞.Bars with a same letter are not significantly different at the 0.05 probability level.

Results from the greenhouse study were similar to that from the laboratory，with significant root zone material/construction effects，SARw effects and interactions （Table 3）.The Ksat of sand/peat mixtures was not affected by different levels of SARw in leaching water when used in California and USGA root zones （Fig.2）.There were no differences between California and USGA root zones despite the higher water holding potential in the USGA style root zone （Li et al.，2005）.All salt solutions resulted in reduction of Ksat from the control in clay soil，with the most reduction occurred in the treatment that had no addition of CaCl2 （SARw = ∞） （Fig.2）.A 25% reduction of Ksat occurred when SARw was greater than 2.5 with no difference for SARw levels of 2.5 to 15.For clay loam，significant reduction of Ksat showed as SARw was higher than 2.5，with the lowest Ksat occurred in the treatment that had no addition of CaCl2 （SARw = ∞） （Fig.2）.A 25% reduction of Ksat occurred when SARw was greater than 5 but there was Ksat difference between SARw levels of 5 and 15.

Table 3 Analysis of variance of saturated water conductivity affected by four root zone constructions and materials （clay

夜上海论坛 pushup，clay loam pushup，sand/peat California，sand/peat USGA） after 6 months of irrigation using sodium

adsorption ratio （SARw） levels at 0，2.5，5.0，15.0，and ∞

夜上海论坛 Results from this study are in agreement with McNeal and Coleman （1966） in that hydraulic conductivity decreases with decreasing electrical conductivity and increasing SARw of the leaching solution and the responses vary with different clay mineralogy，with montmorillonite being most sensitive.This study also supports the maximum SARw of 5 as the guideline for leaching fine textured soil as reported by Steppuhn and Curtin （1993）.In addition to the clay content，soil samples used in this study had a great difference in OM content （Table 1）.Therefore，OM content may also influence the levels of soil dispersion caused by high SARw in the leaching water.

In conclusion，a severe soil dispersion hazard may happen when irrigating with salt water with SARw value greater than 5 as shown in the reduction of Ksat.A laboratory test could be used to predict the severity of dispersion but further study is needed to quantify the effect of soil OM and clay mineralogy.Generally，sand/peat mixtures used in either California or USGA style root zones are not vulnerable to dispersion from the salt in irrigation water，although the threshold of clay or OM content in sand-based root zones requires further investigation for saline water irrigation.

夜上海论坛 Fig.2 Saturated water conductivity of four root zone constructions and materials （clay pushup，clay loam pushup，sand/peat California，sand/peat USGA） affected by 6 months of irrigation with different sodium adsorption ratio （SARw） levels in the water.Bars with a same letter are not significantly different at the 0.05 probability level.

REFERENCES

夜上海论坛 Aragao，S.，H.J.Geering，M.G.Wallis，C.J.Pearson，and P.M.Martin.1997.Hydrological properties of three greens with different construction profiles.Int.Turfgrass Soc.Res.J.8：1136-1149.

Ayers，R.S.and D.W.Westcot.1985.Water quality for agriculture.FAO Irrig.Drain.Paper 29，Revision 1.FAO，Rome，Italy.174 pp.

Carrow，R.N.，and R.R.Duncan.1998.Salt-affected turfgrass sites：Assessment and management.Ann Arbor Press.Chelsea，MI.

Harivandi，A.2007.Using recycled water on golf courses：As more restrictions are placed on water use，it becomes increasingly important for superintendents to learn the ins and outs of irrigating with recycled water.Golf Course Manage.75：98-108.

夜上海论坛 Hendershot，W.H.，H.Lalande，and M.Duquette.1993.Ion exchange and exchangeable cations.P.167-176.In M.R.Carter （ed.） Soil sampling and methods of analysis.CRC Press，Boca Raton，FL.

Klute，A.and C.Dirksen.1986.Hydraulic conductivity and diffusivity：Laboratory methods.687-734.in：A.Klute （ed） Methods of soil analysis.Part 1.Agronomy 9.ASA and ASSSA.Madison，WI.

夜上海论坛 Li，D.，D.D.Minner，N.E.Christians，and S.Logsdon.2005.Evaluating the Impact of Variable Root Zone Depth on the Hydraulic Properties of Sand-Based Turf Systems.Inter.Turfgrass Soc.Res.J.10：1100-1107.

Mancino，C.F.，and I.L.Pepper.1992.Irrigation of turfgrass with secondary sewage effluent：Soil quality.Agron.J.84：650 654.

夜上海论坛 McCoy，E.，and K.McCoy.2006.Dynamics of water flow in putting greens via computer simulation.USGA Turfgras and Enviro.Res.Online.5（17）：1-15.

McNeal，B.L.and N.T.Coleman.1966.Effect of solution composition on soil hydraulic conductivity.Soil Sci.Soc.Amer.Proc.30：308-312.

夜上海论坛 McNeal，B.L.，W.A.Norvell，and N.T.Coleman.1966.Effect of solution composition on the swelling of extracted soil clays.Soil Sci.Soc.Mer.Proc.30-313-317.

夜上海论坛 Munns，R.，and M.Tester.2008.Mechanisms of salinity tolerance.Annu.Rev.Plant Biol.59：651-681.

Nelson D.W.and L.E.Sommers.1996.Total carbon，organic carbon，and organic matter.961-1000.in：D.L.Sparks （ed） Methods of soil analysis.Part 3-Chemical methids.SSSA book series 5.ASA and ASSSA.Madison，WI.

NGCOA （National Golf Course Owners Association）.2005.Golf's environmental impact fact sheet.Available at http：///pdf/advocacy/Environmental%20Impact%20-Fact%20Sheet.pdf.（verified 27 Dec.2010）.NGCOA，Charleston，SC.

Oster，J.D.and F.W.Schroer.1979.Infiltration as influenced by irrigation water quality.Soil Sci.Soc.Amer.J.43：444-447.

夜上海论坛 Qian，Y.and A.Harivandi.2008.Salinity issues associated with recycled wastewater irrigation of turfgrass landscapes，p.419 429.In Pessarakli，M.（ed.）.Handbook of turfgrass management and physiology.CRC Press，Boca Raton，FL.

Rhoades J.D.1977.Potential for using saline agricultural drainage waters for irrigation.Proc.Water Management for Irrigation and Drainage.ASCE，Reno，Nevada.20 22 July 1977.pp.85116.

Rhoades，J.D.and J.Loveday.1990.Salinity in irrigated agriculture.In Stewart，B.A.and D.R.Nielson （Eds.）.Irrigation of Agricultural Crops.Agronomy Monograph No.30.Amer.Soc.Of Agron.，Madison，WI.

SAS Institute Inc.2008.SAS 9.1.3.SAS user's guide.Copyright 2002-2003.Cary，NC.

夜上海论坛 Soldat，D.2007.Managing salts on sand putting greens in Wisconsin.The Grass Roots.36（4）：7-9，11，13.

Steppuhn，H.and Curtin，D.1993.Sodicity hazard of sodium and bicarbonate containing irrigation waters on the long-term productivity of irrigated soils.Agriculture and Agri-Food Canada，Swift Current，SK.174 pp.

夜上海论坛 Thomas，J.C.，R.H.White，J.T.Vorheis，H.G.Harris，and K.Diehl.2006.Environmental impact of irrigation turf with type I recycled water.Agron.J.98：951 961.

第3篇

分析得出：在剖面上，土壤饱和导水率由大到小的排列顺序为 0~10cm、20~30cm、10~20cm 和 30~40cm；土壤饱和导水率与植被盖度相关性显著，植被盖度越高土壤入渗能力越强，土 壤饱和导水率越大；温度是影响高寒草甸土壤水分分布的重要因素，随着地温的升高，土壤 的饱和导水率也相应增大。植被和地温是影响高寒草甸的土壤入渗能力的重要因素。

关键词：入渗，饱和导水率，植被盖度，

Abstract

Infiltration is an important process in hydrologic cycle， in the source region of Yangtze River， infiltration of soil moisture has impact in runoff and plateau ecology. Basing on the measured data in

infiltration， ground temperature and vegetation during three years， the results are as follows: in profile，

the sequence of saturation conductivity coefficient was soil layers 0～10cm， 20～30cm， 10～20cm and

30～40cm below the surface from max. to min.; There is positive and significant correlation between

夜上海论坛 the saturation conductivity coefficient and vegetation cover; when the ground temperature increased， the saturation conductivity coefficient too. So， the vegetation cover and ground temperature have important influence to the soil infiltration in alpine meadow.

Keywords：Infiltration; saturation conductivity coefficient; vegetation cover; the source region of Yangtze River

夜上海论坛 长江源区土壤入渗是指降雨落到地面上的雨水从土壤表面渗入土壤形成土壤水的过程，它是水在土体内运行的初级阶段，也是降水、地表水、土壤水和地下水相互转化过程中的一个重要环 节[1]。

土壤入渗是分析模拟土壤侵蚀过程的重要参数，同时也是实施水土保持规划时需要认真 考虑的因素。总结各因子下的土壤入渗的变化规律，将有助于研究地表产流的机理及其规律[2]，揭示水量转化关系及“五水”(大气降水、地表水、地下水、土壤水、植物水)转化机理， 以从更深层次上弄清水量转化规律。这对土壤侵蚀的预测和防治、洪水的预报、各种水土保 持措施的最优化配置及其效益评价都具有极为重要的指导意义，同时为增加土壤蓄水、土壤 水分最优化调控、合理有效地利用土壤“水库”的调节功能，提高土壤水分生产力等方面具有 重要的理论和现实意义。

土壤的入渗性能受制于许多内在因素的影响，诸如:土壤剖面特征、土壤含水量、导水 率及土壤表面特征等[3~6]。特别是土壤导水率又取决于土壤孔隙的几何特征(总孔隙度、孔隙 大小分布及弯曲度)、流体密度和黏滞度、温度等因子[2，7]。不同林地、草地、地形地貌、土 地利用方式等外界条件对土壤内在理化性质均有显著的影响，从而形成不同外界条件下土壤 入渗的特异规律。本文用土壤饱和入渗仪（2800K1）对不同植被盖度、不同地温、不同土 层深度的土壤进行观测，得出饱和导水率，并进行统计分析，弄清长江源区高寒草甸植被覆 盖与地温变化对土壤饱和导水率的影响，找出高寒草甸生态环境下的土壤入渗规律。

1. 研究区概况

长江源区位于青藏公路以西的昆仑山和唐古拉山之间，平均海拔高度 4500m，生态环境 极为复杂、生物多样性最集中的地区，该区域独特的地理位置及其生态环境特点、特有的水 源涵养生态功能、丰富的自然资源与生物多样性，以及对整个流域环境的深刻影响等，使该 区域近年来成为全社会所广泛关注的热点地区之一。

本文所选择的研究区位于长江源区多年冻土和高寒草甸比较典型的小流域北麓河一级 支流——左冒西孔曲流域，地理位置9249′48～93°0′40E，34°39′36～34°46′50N，流域面 积为134km2。该区域深居内陆，属高原寒带半湿润～半干旱区气候。年均气温为-5.2 ℃，多

夜上海论坛 年平均降雨量290.9mm，多年平均蒸发量1316.9mm，相对湿度平均为57%，海拔4680～5360

m（王根绪等，1998）。 该区域植被类型主要有高寒草甸和高寒草原两大类。草甸植物以莎草科嵩草属占优势，

如西藏嵩草和嵩草等；草原植物以禾本科和菊科为主，如紫花针茅、羽柱针茅等。该区成土 母质多为第四纪沉积物及变质岩、中入岩等岩石风化的坡、残积物，砂砾石、碎石土基 亚粘土夹碎石（王根绪等，2001）。土壤发育很慢，处于原始的粗骨土形态。土壤类型基本 分为三大类：高山草甸土、高山草原土和高山荒漠土。冻土和地下冰比较发育，河谷中存在 着潜水，常形成冰锥、冻胀丘；斜坡地带常有冰锥、冰丘、冻融泥流及冻融滑塌发育；连续 多年冻土地区的地温为-3.0～-1.0 ℃，天然冻土上限为0.8～2.5m。

2．研究方法

2.1 实验设置

夜上海论坛 在研究区小流域内，根据流域两侧的地形、植被类型与植被覆盖状况布置观测试验点， 在每个观测实验点上进行以下试验与观测内容：地温、植被类型与盖度、土壤含水量、土壤 根系层深度、土壤容重、土壤饱和导水率及土壤取样等。按植被盖度分为 10%、40%、70%、

夜上海论坛 90%四个实验点，每个实验点重复实验四次。

2.2 土壤饱和导水率的测定

夜上海论坛 土壤入渗采用 2800K1 土壤饱和入渗仪。在流域内选择 10%、40%、70%、90%四个不 同盖度的植被进行观测，在每个盖度下重复 4 次，求其平均值。数据读取以 2 分钟作为时间 间隔并记录各个数据，直到土壤入渗达到饱和稳定入渗，停止观测。求出液面下降速率，单 位为 cm/s。

设管中液面下降速率为 R（cm/s），测得 5cm 处入渗水头为 R1，10cm 处为 R2，由此， 标准饱和导水率（Kfs）由下列公式计算：

夜上海论坛 当使用外部储水管的时候使用以下公式：

夜上海论坛 Kfs=0.0041XR2-0.0054XR1； 当使用内部储水管的时候使用以下公式： Kfs=0.0041YR2-0.0054YR1；

夜上海论坛 式中，X，Y 分别为外管和内管的面积值，分别为 X=35.22cm2，Y=2.15cm2。

2.3 主要环境因子的测定

(1) 利用地温计对活动层5， 15， 25和35 cm的土壤温度进行观测， 每1 h 进行1 次； (2) 采用便携式TDR 对活动层5， 15， 25和35 cm 的土壤水分进行观测； (3)土壤的颗粒度通过取 样用激光粒度仪进行测定；（4）土壤容重采用环刀法进行测定。

3. 结果与讨论

夜上海论坛 3.1 土壤垂直剖面上的饱和导水率变化规律

夜上海论坛 土壤水分入渗过程受多种因素影响，在土壤水分入渗过程中，土壤剖面某一深度的土层 吸水过程或脱水过程往往相互交替或者同时并存，因此存在着滞后作用对入渗的影响[8]。当 有效降水进入土壤后，土壤水开始向下入渗并进行分配。在较大的时间尺度里，土壤水分的

动态变化实际上是一时间序列的变化，分析土壤的入渗特性，可以通过分析不同层次土壤饱和导水率来进行研究。

在青藏高原，土壤水分入渗对是高原生态环境变化影响显著。由于生态环境变化引起土

夜上海论坛 壤水分的运移、储存等过程严重变化。在垂直剖面上，土壤饱和导水率随土壤深度趋势有如 下特征（见图 1）：

夜上海论坛 （1）四种不同的植被盖度下（10%，40%，70%，90%）变化曲线有着共同的变化趋势： 随着土层深度的增加，土壤饱和导水率总体呈现下降趋势。产生这个影响的根本原因是随着 土层深度的增加土壤空隙度在减小，这是因为在青藏高原的这种特殊的高寒草甸生态条件下，

夜上海论坛 随着土层深度的增加植被的根系越来越少，也使得土壤空隙度减小，这势必影响到饱和导水

率的减小。

（2）在 20~30cm 土层的时候，变化趋势出现了一个拐点。这是因为在长江源区这个特 殊的高寒草甸区，主要植被就是藏嵩草和小嵩草，而嵩草的须根层主要分布在 20~30cm 的 土层，经过对土壤剖面的观察，这个土层根系吸收水分很明显，这就使得 20~30cm 土层的 土壤空隙度 10~20cm 土层的大，因此 20~30cm 土层的饱和导水率相应就大于 10~20cm 土层 的饱和导水率。

3.2 植被盖度对入渗的影响

夜上海论坛 植被变化对区域水平衡的影响是目前国际水文科学最具活力的研究领域，尤其是大量研 究表明大尺度土地覆盖与土地利用变化是导致区域气候变化的重要因素，其中以水分、热量 传输变化为改变气候的主要方式[9]，因此 IGBP 将水循环的生物圈作用研究(BAHC)一直作为 其核心计划[9，10].在描述土壤-植被-大气相互作用关系时，降水入渗不仅依赖于随机的降水事 件，而且受制于土壤水分状况[10，11].同时，不同植被类型的土壤具有不同的水分平衡关系，土壤 湿度依赖于植被类型和土壤特性，但反过来是决定不同植被蒸散量的关键因素[12].土壤水分 是连接气候变化和植被覆盖动态的关键因子，对不同地区的不同植被类型土壤水分平衡要素 的确定，是一个研究较早但始终未能解决的水文科学问题，也是新生边缘学科———生态水文 学的主要研究内容之一[13].

影响土壤降水入渗的主要因素是土壤自身性质如土壤质地、容重、含水率、孔隙度、地 表结皮、水稳性团粒等因子[14]，而植被盖度的不同，改变了土壤质地，使土壤中各因子发生了较 大的变化，从而影响到土壤入渗速率之间有较大差异[2]。

植被盖度是影响土壤入渗的重要因素之一。文章初步分析了长江源区高寒草甸区植被 盖度和土壤饱和导水率关系。

夜上海论坛 在研究区小流域内，分别选取植被盖度 10%、40%、70%和 90%的样地。对 0~10cm，

10~20cm，20~30cm 和 30~40cm 土层进行试验。

图 2 土壤饱和导水率与植被盖度关系图

夜上海论坛 Fig2. The curve between hydraulic conductivity and vegetation cover

夜上海论坛 表 1 土壤导水率回归方程仅有相关系数，没有显著性检验，下面回归方程难以成立

夜上海论坛 Tab.1 Hydraulic conductivity equation of regression

研究结果表明：

夜上海论坛 1、0~10cm，10~20cm，20~30cm 三层土层的饱和导水率曲线都很好得表明了：随着植被盖 度的增大，土壤饱和导水率明显有规律地增大（见图 2）。这是因为植被的存在很好的增大 了土壤的空隙度，增大了土壤的饱和到水率。这对土壤水分的保持很水文循环有着很重要的 意义。这也是江源地区能够为长江涵养水源的一个重要条件。

2、30~40cm 土层的饱和导水率曲线表明了：在植被盖度 70%以下的区域，植被的不足以影 响到 40cm 的地层，而且饱和导水率很小。因为中低盖度的植被须根层很少达到 40cm，

20~30cm 是须根的主要存在层。而在 90%的植被盖度下在 30~40cm 的土层也有很大的饱和 导水率，这是因为在高盖度的区域，植被的须根层生长良好，须根层达了 40cm，甚至更深。 这也说明了，植被盖度越高越有利于水分的入渗和保持。

3、表 1 表明了在长江源区的高寒草甸生态环境下，植被盖度和饱和导水率之间的相关方程 为二次多项式。相关系数都在 0.98 以上。这对水文循环研究和高寒草甸下水文模型的建立 都是一个很大的帮助。

夜上海论坛 4、图 2 中的三条变化曲线的变化趋势，随着土层深度的增加，变化越来越缓慢，这也表明： 植被盖度对表层土壤饱和导水率影响最大，随着土层深度的增加，植被的影响越来越弱。

30~40cm 的变化曲线也表明了 30cm 以下的土层，高寒草甸的植被对土壤的入渗较小。

3.3 地温对土壤入渗的影响 土壤温度也称地温，是影响冻结土壤入渗能力大小的一个主要因素。在非冻结条件下，

土壤温度对土壤入渗能力的影响甚微，但是在冻结条件下，土壤温度是土壤水分发生相变的 两大条件之一，对土壤入神能力的影响显著。土壤温度的变化引起土壤中固、液相水分比例 的变化，进而引起土壤孔隙状况的变化，对土壤的入渗特性产生较大的影响[15]。

为了观测地温对土壤入渗的影响，本试验选取在 90%植被盖度下 10~20cm 深度的土层， 做连续的饱和导水率观测试验。为了避免每次试验对土壤结构和性质的破坏而引起的误差， 试验设计再 90%植被盖度下，选取 5 个点，在 1 天内的 5 个不同时间分别对 10~20cm 深度 的土层进行饱和入渗试验，测算出饱和导水率，别记下当时的 10~20cm 土层的地温。为了 更好的看出地温和饱和导水率的关系，把地温从低到高排列，并与饱和导水率对应，得到下 面的地温与饱和导水率关系图。

图 3 地温与饱和导水率关系图

Fig2. The curve between hydraulic conductivity and ground temperature

研究结果表明：长江源区高寒草甸生态环境下，土壤的入渗与地温关系密切。随着地温

夜上海论坛 的升高，饱和导水率随之升高，两者的关系是二次多项式。在地温 0℃以下的土层，为冻土 层。在冻土层上，土壤水分是不会下渗的。

3.4 次降雨入渗过程随植被覆盖的变化

在一次降雨后，土壤水分在垂直剖面上的变化过程是土壤水分变化的主要过程之一，是 研究降雨、地表径流、降雨入渗以及土壤水分变化的重要内容[16]。为了研究一次降水后， 土壤水分在不同植被盖度下的分布变化，选取典型的样地和地段，对不同植被盖度下

（10%，50%，90%）土壤剖面深度 0~10cm，10~20 cm，20~30cm 和 30~40cm 范围的土壤含水 量进行了观测和分析。

夜上海论坛 结果表明，高寒草地土壤含水量与植被盖度有密切的相关性。从 0～10cm 土壤含水量 变化可以发现，在 0～10cm 的土层范围内，盖度不同，土壤水分变化明显(图 4)，雨后在植 被盖度为 10%的草地的初始土壤含水量最高，90%盖度草地的初始含水量最低。在一次降雨 后，植被盖度较高的地表土层较疏松，空隙度相对较大，土壤的入渗能力较好，使水分很好 得下渗到深层土壤。所以，在雨后的初始阶段，植被盖度越高，0~10cm 土层的水分含量越 越低。随着时间的变化，含水量总体都有减少的趋势，这是水分不断向下入渗的原因。植被

图 4 不用植被盖度相同土层深度的水分变化

Fig4.ange of the soil moisture for different coveragein the same soil depth

盖度越高的草地，土壤含水量变化越慢。90 分钟后 90%盖度草地的含水量远远高于低

盖度的草地，这也表明了高植被盖度的草地良好的持水能力。这主要是植物的地上部分吸收 太阳辐射，减少了辐射到地面的热量，降低了土壤表层的蒸发量.植物根系有很好的亲水性，由 于表面张力作用使根系对土壤中的水分起阻滞作用[16]。10~20cm 和 20~30cm 土层的雨后土 壤含水量变化曲线图呈现出和 0~10cm 土层相同的变化趋势。

30~40cm 的土壤水分变化与 30cm 以上的土层含水量变化曲线不同。雨后初始含水量不 再是 10%盖度的草地，而是 50%盖度的草地，而 10%盖度的草地含水量最低。这说明了在

30~40cm 土层，10%盖度的草地土壤空隙度小，水分不利于下渗到 40cm 的深层土壤，而 90% 盖度的草地持水能力比较强，这也使 30~40cm 的土层的含水量小于 50%盖度的草地。随着 时间的变化，含水量总体仍然是减少趋势。90 分钟后 30~40cm 土层的土壤含水量仍然和初 始含水量关系一样：50%盖度草地的最高，10%盖度草地的最低。

以上关系充分说明植被盖度对土壤水分入渗的影响。土壤的入渗能力和持水能力的对比 都对土壤含水量有很大影响。随着植被盖度增大，土壤的入渗和持水能力都增加，入渗能力 变化得更明显。!

4.结论

综上所述，

1. 随着土层深度的增加土壤饱和导水率总体呈现下降趋势。30cm 的须根分布层增大了 土壤的入渗能力。土壤饱和导水率从大到小依次为在 0~10cm、20~30cm、10~20cm 和 30~40cm 土层；

2. 在 0~10cm，10~20cm，20~30cm 的 3 个土层剖面上，随着植被盖度的增大，土壤饱

和导水率明显有规律地增大，并呈现出二次多项式关系；

3. 在 30cm 以下的土层，植被影响较小，只有在 70%以上的高盖度植被覆盖下，影响 才比较明显，并呈现出 3 次多项式关系；

夜上海论坛 4. 长江源区高寒草甸生态环境下，土壤的入渗与地温关系密切。随着地温的升高，饱 和导水率随之升高，两者的关系是二次多项式。

5. 次降雨量的试验充分验证了植被和土壤饱和导水率的关系。植被是高寒草甸生态环 境下，影响水分循环的重要因素，好的植被有利于水分的入渗和保持，对长江源区生态水文 环境有重大意义。

参考文献

夜上海论坛 [1] 蒋定生.黄土高原水土流失与治理模式[M].北京:中国水利水电出版社，1997.

[2] 郭忠升，吴钦孝，任锁堂.森林植被对土壤入渗速率的影响[J].陕西林业科技，1996，(3):27-31.

[3] Helalia A M.The relation between soil infiltration and effective porosity in different soils[J].Agricultural Water

夜上海论坛 Management，1993，24:39-47.

[4] Philip J R.The theory of infiltration:5，the influence of the initial moisture content[J].Soil Sci，1958，84:329-339.

[5] Baunhards R L.Modeling infiltration into sealing soil [J].Water Resource Res，1990，26(1):2497-2505.

[6] Mein R G， Larson C L. Modeling infiltration during a steady rain[J]. Water Resource Res，1973，9(2):384-394.

夜上海论坛 [7] Duck H R. Water temperature fluctuations and effect irrigation infiltration[J].Trans. ASAE，1992，34(2):193-199.

[8] 刘贤赵 ， 康绍忠 ， 等 . 黄土区坡 地 降雨人渗 产 流中的滞 后 机制及其 模 型研究 [J]. 农 业工程 学

夜上海论坛 报，1999，15(4):95-99

[9] Hutjes R W A， Kabat P， Running S W，et al. Biospheric aspectsof the hydrological cycle [J]. Journal of

夜上海论坛 Hydrology， 1998， 212-213: 1-21.

夜上海论坛 [10] Zhang L， Dawas W R， Reece P H. Response of mean annual evapotranspiration to vegetation changes at catchment scale [J].Water Resour. Res.， 2001，37(3): 701-708.

夜上海论坛 [11] Dawson T E. Hydraulic lift and water parasitism by plants: implications for water balance， performance， and

plant-plant interaction [J]. Oecologia， 1993，95: 565-574.

[12] Rodriguez-Iturbe I. Ecohydrology: A hydrological perspective of climate-soil-vegetation dynamics [J]. Water Resour. Res.，2000，36(1): 3-9.

[13] Zhao Wenzhi， Cheng Guodong. Ecohydrology - a science for studying the hydrologic mechanisms of ecological patterns and processes [J]. Journal of Glaciology and Geocryology， 2001，23(4):450-457. [赵文智，程国 栋.生态水文学———揭示生态格局和生态过程水文学机制的科学[J].冰川冻土， 2001，23(4):450-457.

[14] 袁建平 ， 张素丽 ， 张春燕 ， 等 . 黄土 丘陵区小 流 域土壤稳 定 入渗速率 空 间变异 [J]. 土壤 学 报，2001，38(4):579-583.

[15] 陈军峰. 不同地表条件下季节性冻融土壤入渗特性的实验研究. 太原理工大学硕士研究生学位论 文，2006，5.