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对极粗质地的森林土壤一次施用500t/hm~2干污泥15年后的土壤剖面样品,分析了pH值、ECE、全N、P、K、S、Ca、Mg、Cd、Cu、Ni、Pb和Zn等,并同对照土进行比较。表层(0～17cm)中全N、P、S、CEC、Cd、Cu、Ni、Pb和Zn的含量明显高于对照区;由于这种风化不完全的土壤含K、Mg、Ca较丰富,处理区与对照区差异不大;土壤pH值处理区要低;Mg移到较深层次;Ni和Zn稍有移动;Pb、Cd、Cu、移至17～27cm,但未再向下层移动。 相似文献
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Chuck Young Wesley Wallender Gerrit Schoups Graham Fogg Blaine Hanson Thomas Harter Jan Hopmans Richard Howitt Ted Hsiao Sorab Panday Ken Tanji Susan Ustin Kristen Ward 《Irrigation and Drainage Systems》2007,21(2):119-132
Groundwater discharge through evaporation due to a shallow water table can be an important component of a regional scale water
balance. Modeling this phenomenon in irrigated regions where soil moisture varies on short time scales is most accurately
accomplished using variably saturated modeling codes. However, the computational demands of these models limit their application
to field scale problems. The MODFLOW groundwater modeling code is applicable to regional scale problems and it has an evapotranspiration
package that can be used to estimate this form of discharge, however, the use of time-invariant parameters in this module
result in evaporation rates that are a function of water table depth only. This paper presents a calibration and validation
of the previously developed MOD-HMS model code using lysimeter data. The model is then used to illustrate the dependence of
bare soil evaporation rates on water table depth and soil moisture conditions. Finally, an approach for estimating the time
varying parameters for the MODFLOW evapotranspiration package using a 1-D variably saturated MOD-HMS model is presented. 相似文献
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