地球科学进展

地球科学进展 ›› 2004, Vol. 19 ›› Issue (3): 422 -428. doi: 10.11867/j.issn.1001-8166.2004.03.0422

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Impact of Vegetation on Main Hydrological Processes：A Field Study and Its Implication for Water Quality
ZHANGYou-kuan 1;KeithSchilling 2   
  1. University of Iowa，Iowa City，IA，USA；Iowa Geological Survey，Iowa City，IA，USA
  • 收稿日期:2004-04-09 出版日期:2004-12-20
  • 通讯作者: Zhang You-kuan,Ph.D.Main interest: Modeling flow and tcansport in beterogeneous soil and aquifers, temporal and spatial scaling of hydrological variables and parameters.E-mail:you-kuan-zhang@uiowa.edu E-mail:E-mail:you-kuan-zhang@uiowa.edu

Impact of Vegetation on Main Hydrological Processes：A Field Study and Its Implication for Water Quality

ZHANGYou-kuan 1;KeithSchilling 2   

  1. University of Iowa，Iowa City，IA，USA；Iowa Geological Survey，Iowa City，IA，USA
  • Received:2004-04-09 Online:2004-12-20 Published:2004-06-01

The impact of vegetation cover on groundwater table was assessed with the observed water level fluctuations at two monitored wells in stalled on a bare ground and a vegetated land，respectively．Substantial differences in water table behavior were observed under two land cover scenarios．Ingeneral，the water level in the east grass (EG） well was lower and had much less response to rainfall events than the WNG well mainly due to the difference in the land cover．The effect of vegetation was to lower the water level in the EG well through ET and thus reduce groundwater recharge，which in turn reduced the chemical loads to the creek．The daily and accumulative ET values were estimated with both the Penman-Monteith method and a water table recession model．It is suggested that while the Penman-Monteith method closely modeled hourly ET cycles during the day，it underestimated actual ET during an intensive mid-summer growing period，and especially underestimated actual ET when the water table was close to the landsurface．With the water table recession model，the amount of ET was estimated at its maximum ET of 7．6 mm when the water table was near the groundsurface and then decreases exponentially to zero around day 33 during a dry period with the accumulative ET of 93．9 mm，or 2．84 mm／day．The results from this study clearly demonstrate that landuse and vegetation coverage have significant effects on ET，groundwater recharge and implications for a basin-scale water cycle and chemical loads to rivers and streams．

关键词: Groundwater, Evapotranspiration, Vegetation cover

The impact of vegetation cover on groundwater table was assessed with the observed water level fluctuations at two monitored wells in stalled on a bare ground and a vegetated land，respectively．Substantial differences in water table behavior were observed under two land cover scenarios．Ingeneral，the water level in the east grass (EG） well was lower and had much less response to rainfall events than the WNG well mainly due to the difference in the land cover．The effect of vegetation was to lower the water level in the EG well through ET and thus reduce groundwater recharge，which in turn reduced the chemical loads to the creek．The daily and accumulative ET values were estimated with both the Penman-Monteith method and a water table recession model．It is suggested that while the Penman-Monteith method closely modeled hourly ET cycles during the day，it underestimated actual ET during an intensive mid-summer growing period，and especially underestimated actual ET when the water table was close to the landsurface．With the water table recession model，the amount of ET was estimated at its maximum ET of 7．6 mm when the water table was near the groundsurface and then decreases exponentially to zero around day 33 during a dry period with the accumulative ET of 93．9 mm，or 2．84 mm／day．The results from this study clearly demonstrate that landuse and vegetation coverage have significant effects on ET，groundwater recharge and implications for a basin-scale water cycle and chemical loads to rivers and streams．

Key words: Groundwater, Evapotranspiration, Vegetation cover

中图分类号: 

［1］US Environmental Protection Agency (USEPA).  Overview of Current Total Maximum Daily Load TMDLProgram and Regulations, USEPA Office of Water, EPA 841F00009.2000.
［2］Schilling K E, Wolter C F. Contribution of Baseflow to Nonpoint Source Pollution Loads in an Agricultural Watershed［J］. Ground Water,2001, 39:49-58.
［3］Pettyjohn W T, Correll D L. Nutrient dynamics in an agricultural watershed: Observations on the role of a riparian forest［J］. Ecology,1983, 65:1 466-1 475.
［4］Hill A R. Nitrate removal in stream riparian zones［J］. Journal of Environ mental Quality, 1996,25:743-755.
［5］Cay E E, Rudolph D L, Aravena R, et al.Role of the riparian zone in controlling the distribution and fate of agricultural nitrogen near a small stream in southern Ontario［J］. Journal of Cont Hydrology, 1999,37:45-67.
［6］Lee K H, Isenhart T M, Schultz R C. Sediment and nutrient removal in an established multispecies riparian buffer［J］. Journal of Soil Water Conservation,2003,58:1-8.
［7］Nassauer J L, Corry R C, Cruse R M. The Landscape in 2025 Alternative Future Scenarios: A Means to Consider Agricultural Policy［J］. Journal of Soil Water Conservation,2002,57: 44.
［8］Coiner C, Wu J J, Polasky S. Economic and environmental implications of alternative landscape designs in the Walnut Creek Watershed of Iowa［J］. Ecological Economics, 2001,38(1):119-139.
［9］Vach K B, Eilers J M, Santelmann M V. Water quality modeling of alternative agricultural scenarios in the US corn belt[J]. Journal of American Water Resource Assoceration,2002,38: 773-787.
［10］Schilling K E, Lutz D S. Relation of Nitrate Concentrations and Baseflow in the Raccoon River, Iowa［J］. Submitted to Journal of the American Water Resources Association,2003.
［11］Schilling K E, Boekhoff J L, Hubbard T,et al.Reports on the Walnut Creek Watershed Monitoring Project, Jasper County, Iowa: Water Years 19952000, Iowa Department of Natural Resources[C]. Geological Survey Bureau Technical Information Series 46,2002.
［12］Schilling K E, Libra R D. Increased Baseflow in Iowa over the Second Half of the 20th Century［J］. Journal of American Water Resource Association,2003,39:851-860.
［13］Iowa Geological Survey (IGS). Nitrate Nitrogen in Iowa Rivers: Long-Term Trends. Water Fact Sheet 2001-5, Iowa Department of Natural Resources, Geological Survey Bureau, Iowa City, Iowa, 2001.
［14］Iowa Agricultural Statistics. Crop and Land Use Tables and Charts, Iowa State University Agronomy Extension［EB/OL］ http://extension.agron.iastate.edu/soils/tables_charts.html.2001.
［16］Dinnes D L, Karlen D L, Jaynes D B, et al.Nitrogen Management Strategies to Reduce Nitrate Leaching in Tile-Drained Midwestern Soils［J］. Agron Journal,2002,94:153-171.
［17］Bosch J M, Hewlett J D. A Review of Catchment Experiments to Determine the Effect of Vegetation Changes on Water Yield and Evapotranspiration［J］. Journal of Hydrology,1982, 55:3-23.
［18］Dunn S M, Mackay R. Spatial Variation in Evapotranspiration and the Influence of Land Use on Catchment Hydrology［J］. Journal of Hydrology,1995, 171:49-73.
［19］Le Maitre D C, Scott D F, Colvin C. A review of information on interactions between vegetation and groundwater[J]. Water SA,1999, 25:137-150.
［20］Zhang L, Dawes W R, Wallace G R. Response of Mean Annual Evapotranspiration to Vegetation changes at Catchment Scale［J］. Water Resource Research, 2001,37:701-708.
［21］Peel M C, McMahon T M, Finlayson B L,et al.Implications of the Relationship Between Catchment Vegetation Type and the Variability of Annual Stormflow［J］. Hydrology Process,2002,16:2 995-3 002.
［22］Allison G B, Cook P G, Barnett S R,et al.Land clearance and river salinisation in the western Murray Basin, Austrailia[J]. Journal of Hydology,1990,119:1-20.
［23］Dunin F X, Williams J, Verburg K,et al.Can agricultural management emulate natural ecosystems in recharge control in south eastern Australia?［J］. Agroforestry Systems, 1999,45:343-364.
［24］Swank W T, Douglass J E. Streamflow greatly reduced by converting deciduous hardwood stands into pine［J］. Science, 1974,185:857-859.
［25］Peck A J, Williamson D R. Effects of forest clearing on groundwater［J］. Journal of Hydrology, 1987,94:47-66.
［26］Watson F G R, Vertessy R A, Grayson R B. Largescale modeling of forest hydrological processes and their longterm effect on water yield［J］. Hydrological Process,1999,13:689-700.
［27］Caissie D, Jolicoeur S, Bouchard M, et al. Comparison of streamflow between pre and post timber harvesting in Catamaran Brook (Canada)［J］. Journal of Hydrology,2002, 258:232-248.
［28］VanShaar J R, Haddeland I, Lettenmaier D P. Effects of land cover changes on the hydrological response of interior Columbia River basin forested catchments［J］. Hydrologicat Process,2002,16:2 499-2 520.
［29］Schilling K E, Zhang Y K. Contribution of Baseflow to NitrateNitrogen Export in a Large Agricultural Watershed, USA[J]. Submitted to Journal of Hydrology,2003.
［30］Schilling K E, Zhang Y K, Drobney P. Water Table Fluctuations Near an Incised Stream,Walnut Creek, Iowa[J]. Journal of Hydrology,2004, 286: 236-248.
［31］Schilling K E. Relation of Baseflow to Row Crop Intensity in Iowa. Submitted to Agriculture, Ecosystems & Environment,2003.
[1] SUNNe-zheng. Parameter Estimation and Experimental Design in Groundwater Modeling[J]. 地球科学进展, 2004, 19(3): 409-414.
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