河南省淮河流域不同土地利用方式近地表层的水文效应

对河南境内淮河流域不同土地利用方式下近地表层的凋落物与表层土壤的水文特性及其保水蓄水性能进行测定与分析,结果表明：1）各土地利用方式下的凋落物具有相同特性的吸水过程,4h后吸水速率逐渐下降,24 h可达饱和状态,饱和吸水量差异不大;初始吸水速率以草丛或灌丛的较大,但阔叶林或针阔混交林以及灌丛具有较高的有效拦蓄水量,针叶林通常较小.2）刺槐林（褐土）总蓄水量最大,所有农田土壤的总蓄水量均较小;同一土壤中农田与草丛土壤的水文效应较小,森林与灌丛土壤的相对较大.农田土壤的渗透速率35 min时达稳渗状态且稳渗率较低,其他的在45 min时达稳渗且稳渗率较高;初渗率与稳渗率均表现为森林土壤高于灌丛、灌丛高于草丛,阔叶林比针叶林的稍高.3）不同土地利用方式下土壤的水文效应基本可划分为农田与草丛、森林与灌丛2大类,后者的水文效应相对较大.研究结果可为水土保持对策的制订、营养物质对水体冲击负荷的深入研究提供依据与参考.

Hydrological effect of near surface soil under different landuse types in Huaihe River Reaches in Henan Province

The hydrological characteristics and water-holding capacity of litter and near surface soil under different landuse types were determined in the Huaihe River Reaches in Henan Province.The results are shown as follows.1） All litter under different landuse types had similar water absorbing process,in which the water absorbing rate gradually declined after 4 h and reached saturation at 24 h,and the saturation absorbing amount was similar also.The initial absorbing rate was larger in herb or shrub communities; however,as for the modified interception,it was larger in broadleaf forest,broadleaf and conifer mixed forest and shrub community,and smaller in conifer forest.2） The water storage capacity of Robinia pseudoacacia forest soil was the largest,while that of farmland soil was smaller.The infiltration rate of farmland soil reached stable at 35 min with a smaller final infiltration rate,and as for others,at 45 min and with a larger rate.The order of initial and final infiltration rate of soil from high to low was forest,shrub and herb; while in forest,it was broadleaf forest and conifer forest.3） The hydrological effect of soil under different landuse types could be divided into two clusters that are farmland and herb community,forest and shrub community,respectively; the later one had a higher hydrological effect.The result could provide a base and reference for the policy determination of water and soil conservation,and further study of nutrient material load into water body.