地下水计算参数的测定与估计

Measurement and Estimation of the Parameters for Groundwater Resources Computation

  • 摘要: 叙述了浅层地下水资源评价中几个常用参数(给水度、降雨入渗补给系数和潜水蒸发系数)的测定和估计方法,并结合实例进行剖析.通过分析,得到几点新的认识:(1)给水度值同注水的方式有关,在实际情况中,由于农田表层土壤疏松,且有作物影响,因而其最大值会出现在地表附近;(2)用抽水试验法测定给水度,其值因孔而异;(3)降雨入渗补给系数与土壤结构和给水度的关系密切,一般随着埋深的增加,该系数随之减小;(4)不同季节和不同作物,潜水蒸发系数不同,表现在计算公式上的参数也不相同.

     

    Abstract: In this eater,the measuring and estimating methods of frequently used param eters(such as specific yield,coefficient of recharge from precipitation and coefficient of phreatic evapaolration) in shallow groundwater resources assessment are described and it is dissected by practical examples.Through analysis,weobtain some new knowledge,that is:(1)The value of specific yield is related to the conditions of injected and released water.In the practical situation,the maximum value of specific yield may occur around the ground surface since the surface soil of farm land is loo se and is effected by cro ps.(2) By using the pumping test technique to measure the specific yield,its value is varied from well to well,we adopt the mean value of it in the domain of mainly affected radius and this is a new attempt;(3) The coefficient of recharge from precipitation is not only related to the construction of soil but also related intimately to specific yield and its regular pattern of distribution is decided by the size of specific yield.Generally,there is a tendency that the coefficient decreases with increasing depth from ground surface to water level;(4) The coefficient of phreatic evaporation varies according to different seasons and croes and the parameters in the calculating formula varied as well.

     

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