长沙地区樟树林土壤水稳定同位素特征及其对土壤水分运动的指示
|
摘要
为研究长沙地区林地土壤水分运动规律,基于2017年3月—2018年2月长沙地区樟树林土壤水分及0～130 cm土壤水、地下水和降水中稳定同位素监测数据,分析了土壤水中稳定同位素特征及其与降水中稳定同位素的关系.结果表明:(1)土壤水分季节变化表现为丰水期(3—6月,土壤蓄水量大而稳定)、耗水期(7—10月,土壤水分以消耗为主)、补水期(11月—翌年2月,土壤水分以补给为主)3个阶段,土壤含水量由表层至深层呈增加趋势,稳定性增强,土壤含水量的垂向差异依次为耗水期>补水期>丰水期.(2)受到冠层截留和地表枯枝落叶吸持的影响,林地的有效降水为降水量(P)>3.3 mm,并且LMWL_(P>3.3 mm)(降水量>3.3 mm时的当地大气水线)较LMWL的斜率和截距显著增加,与各深度SWL(土壤水线)更接近.(3)由表层至深层,土壤水稳定同位素受降水入渗、新旧水混合和蒸发的影响减小,0～40 cm土壤水中δ~(18)O均表现为丰水期>补水期>耗水期,而40～130 cm土壤水中δ~(18)O的季节变化不显著.(4)观测期间不同水体中lc-excess(δD与LMWL的差值)的平均值依次为降水(0)>地下水(-2.80‰)>土壤水(-5.00‰),土壤水中lc-excess随深度的增加而增大.研究显示:土壤水下渗时新旧水混合是一个持续累积的过程,旧的土壤水逐渐被降水替代;受土壤结构、质地等性质的差异及不同降水事件的影响,土壤水分的补给在剖面上存在时滞.
Based on the soil water content and stable isotopes in 0-130 cm soil depth,groundwater and precipitation in a Cinnamomum camphora grove in Changsha from March 2017 to February 2018,the characteristics of stable isotopes in soil water and the relationship between isotopic composition of soil water and precipitation were analyzed in order to reveal the movement of soil water in this area. The results showed that:( 1) The seasonal variations of soil water content during the observation could be divided into three stages,i.e. waterrich period from March to June when soil water storage was large and kept stable,water consumption period from July to October and water replenishment period from November to following February. Soil water content increased from surface to deep soil,and its stability increased. The soil water content showed a larger vertical difference in water-consuming period than that in water-replenishing period and than that in water-rich period.( 2) The daily effective precipitation P at the survey site was larger than 3. 3 mm due to canopy interception and surface litter absorption. The slope and intercept of LMWLP>3. 3 mm( local meteoric water line under P>3. 3 mm),very close to SWL( soil water lines) at different depths,were significantly higher than those of LMWL.( 3) From surface to deep soil,the influences of water infiltration,mixing of old and new soil water and soil evaporation on the stable isotopes in soil water gradually decreased. The average δ18 O in 0-40 cm soil water showed greater values in water-rich period than that in water-replenishing period and than that in waterconsuming period,but insignificant seasonality in 40-130 cm soil water.( 4) The average lc-excess( δD deviations from the LMWL) in different water bodies during the observation period showed higher value in precipitation( 0) than that in groundwater(-2. 80‰) and than that in soil water(-5. 00‰). The lc-excess in soil water increased with depth. Because the mixing of old and new water was a continuous and cumulative process,and was impacted by different soil structures,soil textures and precipitation events,there appeared significant time delays with soil depth in supply of soil water.
Based on the soil water content and stable isotopes in 0-130 cm soil depth,groundwater and precipitation in a Cinnamomum camphora grove in Changsha from March 2017 to February 2018,the characteristics of stable isotopes in soil water and the relationship between isotopic composition of soil water and precipitation were analyzed in order to reveal the movement of soil water in this area. The results showed that:( 1) The seasonal variations of soil water content during the observation could be divided into three stages,i.e. waterrich period from March to June when soil water storage was large and kept stable,water consumption period from July to October and water replenishment period from November to following February. Soil water content increased from surface to deep soil,and its stability increased. The soil water content showed a larger vertical difference in water-consuming period than that in water-replenishing period and than that in water-rich period.( 2) The daily effective precipitation P at the survey site was larger than 3. 3 mm due to canopy interception and surface litter absorption. The slope and intercept of LMWLP>3. 3 mm( local meteoric water line under P>3. 3 mm),very close to SWL( soil water lines) at different depths,were significantly higher than those of LMWL.( 3) From surface to deep soil,the influences of water infiltration,mixing of old and new soil water and soil evaporation on the stable isotopes in soil water gradually decreased. The average δ18 O in 0-40 cm soil water showed greater values in water-rich period than that in water-replenishing period and than that in waterconsuming period,but insignificant seasonality in 40-130 cm soil water.( 4) The average lc-excess( δD deviations from the LMWL) in different water bodies during the observation period showed higher value in precipitation( 0) than that in groundwater(-2. 80‰) and than that in soil water(-5. 00‰). The lc-excess in soil water increased with depth. Because the mixing of old and new water was a continuous and cumulative process,and was impacted by different soil structures,soil textures and precipitation events,there appeared significant time delays with soil depth in supply of soil water.
引文
[1]田日昌,陈洪松,宋献方,等.湘西北红壤丘陵区土壤水运移的稳定性同位素特征[J].环境科学,2009,30(9):2747-2754.TIAN Richang, CHEN Hongsong, SONG Xianfang, et al.Characteristics of soil water movement using stable isotopes in red soil hilly region of northwest Hunan[J]. Environmental Science,2009,30(9):2747-2754.
[2]BUSARI M A,SALAKO F K,TUNIZ C,et al. Estimation of soil water evaporative loss after tillage operation using the stable isotope technique[J].International Agrophysics,2013,27(3):257-264.
[3]MUELLERA M H,ALAOUI A,KUELLS C,et al. Tracking water pathways in steep hillslopes byδ18O depth profiles of soil water[J].Journal of Hydrology,2014,519:340-352.
[4]GAZIS C,FENG X H.A stable isotope study of soil water:evidence for mixing and preferential flow paths[J]. Geoderma,2004,119(1):97-111.
[5]LEE K S,KIM J M,LEE D R,et al.Analysis of water movement through an unsaturated soil zone in Jeju Island,Korea using stable oxygen and hydrogen isotopes[J]. Journal of Hydrology,2007,345(3/4):199-211.
[6]DANSGAARD W. Stable isotopes in precipitation[J]. Tellus A,1964,16(4):436-468.
[7]BRINKMANN N,SEEGER S,WEILER M,et al.Employing stable isotopes to determine the residence times of soil water and the temporal origin of water taken up by Fagus sylvatica and Picea abies in a temperate forest[J]. New Phytologist,2018,219(4):1300-1313.
[8]侯士彬,宋献方,于静洁,等.太行山区典型植被下降水入渗的稳定同位素特征分析[J].资源科学,2008,30(1):86-92.HOU Shibin,SONG Xianfang,YU Jingjie,et al. Stable isotopes characters in the process of precipitation and infiltration in Taihang Mountainous region[J].Resources Science,2008,30(1):86-92.
[9]刘君,聂振龙,段宝谦,等.氢氧稳定同位素指示的呼和浩特地区土壤水的补给特征[J].干旱区资源与环境,2016,30(10):145-150.LIU Jun,NIE Zhenlong,DUAN Baoqian,et al. Characteristics of stable isotope(δ2H andδ18O)in soil water in Hohhot Area[J].Journal of Arid Land Resources and Environment,2016,30(10):145-150.
[10]马田田,柯浩成,李占斌,等.次降雨事件下雨养区典型小流域土壤水分运移规律[J].水土保持学报,2018,32(2):80-86.MA Tiantian,KE Haocheng,LI Zhanbin,et al. Soil moisture migration characteristics of typical small watershed in rain feed region under individual rainfall events[J]. Journal of Soil and Water Conservation,2018,32(2):80-86.
[11]HSIEH J C,CHADWICK O A,KELLY E F,et al.Oxygen isotopic composition of soil water:quantifying evaporation and transpiration[J].Geoderma,1998,82(1/2/3):269-293.
[12]SONG X F,WANG S Q,XIAO G Q,et al. A study of soil water movement combining soil water potential with stable isotopes at two sites of shallow groundwater areas in the North China Plain[J].Hydrological Processes,2009,23(9):1376-1388.
[13]ZHANG X,XIAO Y,WAN H,et al. Using stable hydrogen and oxygen isotopes to study water movement in soil-plant-atmosphere continuum at Poyang Lake wetland,China[J]. Wetlands Ecology and Management,2017,25(2):221-234.
[14]王婷,章新平,黎祖贤,等.近52年来洞庭湖流域气象干旱的时空分布特征[J].长江流域资源与环境,2016,25(3):514-522.WANG Ting,ZHANG Xinping,LI Zuxian,et al. Temporal and spatial distribution characteristics of meteorological drought for recent 52 years in Dongting Lake Basin[J]. Resources and Environment in the Yangtze Basin,2016,25(3):514-522.
[15]李广,章新平,张立峰,等.长沙地区不同水体稳定同位素特征及其水循环指示意义[J].环境科学,2015,36(6):2094-2101.LI Guang,ZHANG Xinping,ZHANG Lifeng,et al. Stable isotope characteristics in different water bodies in Changsha and implications for the water cycle[J]. Environmental Science,2015,36(6):2094-2101.
[16]刘珊,颜智勇.湘江流域长沙段水资源问题分析[J].湖南农业大学学报(自然科学版),2009,35(1):64-66.LIU Shan,YAN Zhiyong.Problems of the exploration and utilization of water resources in Xiangjiang River Changsha[J]. Journal of Hunan Agricultural University(Natural Sciences),2009,35(1):64-66.
[17]CRAIG H.Isotopic variations in meteoric water[J].Science,1961,133(3465):1702-1703.
[18]LANDWEHR J M,COPLEN T B. Line-conditioned excess:a new method for characterizing stable hydrogen and oxygen isotope ratios in hydrologic systems[C]//International Atomic Energy Agency.Isotopes in Environmental Studies. Vienna:International Atomic Energy Agency,2006:132-135.
[19]HERVé-FERNáNDEZ P,OYARZU'N C,BRUMBT C,et al.Assessing the‘two water worlds’hypothesis and water sources for native and exotic evergreen species in south-central Chile[J].Hydrological Processes,2016,30(23):4227-4241.
[20]HASSELQUIST N J,BENEGAS L,ROUPSARD O,et al. Canopy cover effects on local soil water dynamics in a tropical agroforestry system:evaporation drives soil water isotopic enrichment[J].Hydrological Processes,2018,32(8):994-1004.
[21]SPRENGER M,TETZLAFF D,SOULSBY C. Soil water stable isotopes reveal evaporation dynamics at the soil-plant-atmosphere interface of the critical zone[J]. Hydrology and Earth System Sciences,2017,21(7):3839-3858.
[22]LANDWEHR J M,COPLEN T B,STEWART D W. Spatial,seasonal,and source variability in the stable oxygen and hydrogen isotopic composition of tap waters throughout the USA[J].Hydrological Processes,2014,28(21):5382-5422.
[23]张川,陈洪松,聂云鹏,等.喀斯特地区洼地剖面土壤含水率的动态变化规律[J].中国生态农业学报,2013,21(10):1225-1232.ZHANG Chuan,CHEN Hongsong,NIE Yunpeng,et al.Dynamics of soil profile water content in peak-cluster depression areas in Karst Region[J]. Chinese Journal of Eco-Agriculture,2013,21(10):1225-1232.
[24]王晓燕,陈洪松,王克林,等.不同利用方式下红壤坡地土壤水分时空动态变化规律研究[J].水土保持学报,2006,20(2):110-113.WANG Xiaoyan,CHEN Hongsong,WANG Kelin,et al. Spatiotemporal dynamic change of soil water in sloping land with different use modes in red soil region[J]. Journal of Soil and Water Conservation,2006,20(2):110-113.
[25]赵玮,张铜会,刘新平,等.差巴嘎蒿灌丛土壤和根系含水量对降雨的响应[J].生态学杂志,2008,27(2):151-156.ZHAO Wei,ZHANG Tonghui,LIU Xinping,et al. Spatiotemporal variation of soil moisture and its relations with Artemisia halodendron root water content as affected by rainfall[J]. Chinese Journal of Ecology,2008,27(2):151-156.
[26]HEISLER-WHITE J L,KNAPP A K,KELLY E F. Increasing precipitation event size increases aboveground net primary productivity in a semi-arid grassland[J].Oecologia,2008,158(1):129-140.
[27]黄一民,章新平,唐方雨,等.长沙大气降水中稳定同位素变化及过量氘指示水汽来源[J].自然资源学报,2013,28(11):1945-1954.HUANG Yimin,ZHANG Xinping,TANG Fangyu,et al. Variations of precipitation stable isotope and vapor origins revealed by deuterium excess in Changsha[J]. Journal of Natural Resource,2013,28(11):1945-1954.
[28]WU H W,ZHANG X P,LI X Y,et al. Seasonal variations of deuterium and oxygen-18 isotopes and their response to moisture source for precipitation events in the subtropical monsoon region[J].Hydrological Processes,2015,29(1):90-102.
[29]WENNINGER J,BEZA D T,UHLENBROOK S. Experimental investigations of water fluxes within the soil-vegetation-atmosphere system:stable isotope mass-balance approach to partition evaporation and transpiration[J]. Physics and Chemistry of the Earth,2010,35(13):565-570.
[30]田立德,姚檀栋,TSUJIMURA M,等.青藏高原中部土壤水中稳定同位素变化[J].土壤学报,2002,39(3):289-295.TIAN Lide,YAO Tandong,TSUJIMURA M,et al. Stable isotope in soil water in the middle of Tibetan Plateau[J]. Acta Pedologica Sinica,2002,39(3):289-295.
[2]BUSARI M A,SALAKO F K,TUNIZ C,et al. Estimation of soil water evaporative loss after tillage operation using the stable isotope technique[J].International Agrophysics,2013,27(3):257-264.
[3]MUELLERA M H,ALAOUI A,KUELLS C,et al. Tracking water pathways in steep hillslopes byδ18O depth profiles of soil water[J].Journal of Hydrology,2014,519:340-352.
[4]GAZIS C,FENG X H.A stable isotope study of soil water:evidence for mixing and preferential flow paths[J]. Geoderma,2004,119(1):97-111.
[5]LEE K S,KIM J M,LEE D R,et al.Analysis of water movement through an unsaturated soil zone in Jeju Island,Korea using stable oxygen and hydrogen isotopes[J]. Journal of Hydrology,2007,345(3/4):199-211.
[6]DANSGAARD W. Stable isotopes in precipitation[J]. Tellus A,1964,16(4):436-468.
[7]BRINKMANN N,SEEGER S,WEILER M,et al.Employing stable isotopes to determine the residence times of soil water and the temporal origin of water taken up by Fagus sylvatica and Picea abies in a temperate forest[J]. New Phytologist,2018,219(4):1300-1313.
[8]侯士彬,宋献方,于静洁,等.太行山区典型植被下降水入渗的稳定同位素特征分析[J].资源科学,2008,30(1):86-92.HOU Shibin,SONG Xianfang,YU Jingjie,et al. Stable isotopes characters in the process of precipitation and infiltration in Taihang Mountainous region[J].Resources Science,2008,30(1):86-92.
[9]刘君,聂振龙,段宝谦,等.氢氧稳定同位素指示的呼和浩特地区土壤水的补给特征[J].干旱区资源与环境,2016,30(10):145-150.LIU Jun,NIE Zhenlong,DUAN Baoqian,et al. Characteristics of stable isotope(δ2H andδ18O)in soil water in Hohhot Area[J].Journal of Arid Land Resources and Environment,2016,30(10):145-150.
[10]马田田,柯浩成,李占斌,等.次降雨事件下雨养区典型小流域土壤水分运移规律[J].水土保持学报,2018,32(2):80-86.MA Tiantian,KE Haocheng,LI Zhanbin,et al. Soil moisture migration characteristics of typical small watershed in rain feed region under individual rainfall events[J]. Journal of Soil and Water Conservation,2018,32(2):80-86.
[11]HSIEH J C,CHADWICK O A,KELLY E F,et al.Oxygen isotopic composition of soil water:quantifying evaporation and transpiration[J].Geoderma,1998,82(1/2/3):269-293.
[12]SONG X F,WANG S Q,XIAO G Q,et al. A study of soil water movement combining soil water potential with stable isotopes at two sites of shallow groundwater areas in the North China Plain[J].Hydrological Processes,2009,23(9):1376-1388.
[13]ZHANG X,XIAO Y,WAN H,et al. Using stable hydrogen and oxygen isotopes to study water movement in soil-plant-atmosphere continuum at Poyang Lake wetland,China[J]. Wetlands Ecology and Management,2017,25(2):221-234.
[14]王婷,章新平,黎祖贤,等.近52年来洞庭湖流域气象干旱的时空分布特征[J].长江流域资源与环境,2016,25(3):514-522.WANG Ting,ZHANG Xinping,LI Zuxian,et al. Temporal and spatial distribution characteristics of meteorological drought for recent 52 years in Dongting Lake Basin[J]. Resources and Environment in the Yangtze Basin,2016,25(3):514-522.
[15]李广,章新平,张立峰,等.长沙地区不同水体稳定同位素特征及其水循环指示意义[J].环境科学,2015,36(6):2094-2101.LI Guang,ZHANG Xinping,ZHANG Lifeng,et al. Stable isotope characteristics in different water bodies in Changsha and implications for the water cycle[J]. Environmental Science,2015,36(6):2094-2101.
[16]刘珊,颜智勇.湘江流域长沙段水资源问题分析[J].湖南农业大学学报(自然科学版),2009,35(1):64-66.LIU Shan,YAN Zhiyong.Problems of the exploration and utilization of water resources in Xiangjiang River Changsha[J]. Journal of Hunan Agricultural University(Natural Sciences),2009,35(1):64-66.
[17]CRAIG H.Isotopic variations in meteoric water[J].Science,1961,133(3465):1702-1703.
[18]LANDWEHR J M,COPLEN T B. Line-conditioned excess:a new method for characterizing stable hydrogen and oxygen isotope ratios in hydrologic systems[C]//International Atomic Energy Agency.Isotopes in Environmental Studies. Vienna:International Atomic Energy Agency,2006:132-135.
[19]HERVé-FERNáNDEZ P,OYARZU'N C,BRUMBT C,et al.Assessing the‘two water worlds’hypothesis and water sources for native and exotic evergreen species in south-central Chile[J].Hydrological Processes,2016,30(23):4227-4241.
[20]HASSELQUIST N J,BENEGAS L,ROUPSARD O,et al. Canopy cover effects on local soil water dynamics in a tropical agroforestry system:evaporation drives soil water isotopic enrichment[J].Hydrological Processes,2018,32(8):994-1004.
[21]SPRENGER M,TETZLAFF D,SOULSBY C. Soil water stable isotopes reveal evaporation dynamics at the soil-plant-atmosphere interface of the critical zone[J]. Hydrology and Earth System Sciences,2017,21(7):3839-3858.
[22]LANDWEHR J M,COPLEN T B,STEWART D W. Spatial,seasonal,and source variability in the stable oxygen and hydrogen isotopic composition of tap waters throughout the USA[J].Hydrological Processes,2014,28(21):5382-5422.
[23]张川,陈洪松,聂云鹏,等.喀斯特地区洼地剖面土壤含水率的动态变化规律[J].中国生态农业学报,2013,21(10):1225-1232.ZHANG Chuan,CHEN Hongsong,NIE Yunpeng,et al.Dynamics of soil profile water content in peak-cluster depression areas in Karst Region[J]. Chinese Journal of Eco-Agriculture,2013,21(10):1225-1232.
[24]王晓燕,陈洪松,王克林,等.不同利用方式下红壤坡地土壤水分时空动态变化规律研究[J].水土保持学报,2006,20(2):110-113.WANG Xiaoyan,CHEN Hongsong,WANG Kelin,et al. Spatiotemporal dynamic change of soil water in sloping land with different use modes in red soil region[J]. Journal of Soil and Water Conservation,2006,20(2):110-113.
[25]赵玮,张铜会,刘新平,等.差巴嘎蒿灌丛土壤和根系含水量对降雨的响应[J].生态学杂志,2008,27(2):151-156.ZHAO Wei,ZHANG Tonghui,LIU Xinping,et al. Spatiotemporal variation of soil moisture and its relations with Artemisia halodendron root water content as affected by rainfall[J]. Chinese Journal of Ecology,2008,27(2):151-156.
[26]HEISLER-WHITE J L,KNAPP A K,KELLY E F. Increasing precipitation event size increases aboveground net primary productivity in a semi-arid grassland[J].Oecologia,2008,158(1):129-140.
[27]黄一民,章新平,唐方雨,等.长沙大气降水中稳定同位素变化及过量氘指示水汽来源[J].自然资源学报,2013,28(11):1945-1954.HUANG Yimin,ZHANG Xinping,TANG Fangyu,et al. Variations of precipitation stable isotope and vapor origins revealed by deuterium excess in Changsha[J]. Journal of Natural Resource,2013,28(11):1945-1954.
[28]WU H W,ZHANG X P,LI X Y,et al. Seasonal variations of deuterium and oxygen-18 isotopes and their response to moisture source for precipitation events in the subtropical monsoon region[J].Hydrological Processes,2015,29(1):90-102.
[29]WENNINGER J,BEZA D T,UHLENBROOK S. Experimental investigations of water fluxes within the soil-vegetation-atmosphere system:stable isotope mass-balance approach to partition evaporation and transpiration[J]. Physics and Chemistry of the Earth,2010,35(13):565-570.
[30]田立德,姚檀栋,TSUJIMURA M,等.青藏高原中部土壤水中稳定同位素变化[J].土壤学报,2002,39(3):289-295.TIAN Lide,YAO Tandong,TSUJIMURA M,et al. Stable isotope in soil water in the middle of Tibetan Plateau[J]. Acta Pedologica Sinica,2002,39(3):289-295.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |