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r— .�--- <br /> :l�t <br /> caaur <br /> GROUMf WATER HYDROLOGY <br /> 152 canny <br /> ` s zs and others '''s� Although evaluating the effects is loves <br /> liantush= Sider:. <br /> complicated except fcr the simplest cases,common Meld situations t Tal <br /> often seduce the practicalimportance. <br /> well is located morertial penetration.* one th,ri 15 t 2 times <br /> occurs where an ob well;in this situatiun may <br /> the saturated aquifer�hnetratioess n can be neglected for homogeneous i <br /> the effect of partial p. <br /> and isotropic aquifers. Another applies to :nany alluvial aqui,ers <br /> with pronounced anisotropy. Ht:re the vertical flow co oz mated when <br /> become small,therenLs <br /> zby enabli�.g a pumping well to be app condi <br /> e a fully penetrating well in a confined or leaky aquifer with a <br /> szturated thickness equal to the lea�gth of the well screen. <br /> Well Flow for Special Conditions 53 the <br /> A variety of solutions to well flow problems have been derived <br /> for special aquifer,pumping.and well conditions.`'78 Inasmuch as There' <br /> these are of less general application than those outlined heretofore the fc <br /> -maticatment <br /> and involve more extensive mathe howcver,lth tasolut ons have ey tbeen Car. <br /> emitted here. <br /> it is worth noting. betwe <br /> obtained for the following special conditions: can be <br /> 1. Constant well era%jown?23 22 41,1s. <br /> = ables <br /> e <br /> 2,varying,cyclic,and intermittent well dischargs. small. <br /> 3.Sloping aquifers?- <br /> 4.AquifeI <br /> rs of variable thic:-less23 <br /> e a2. ti t <br /> S.Two-layered aquifers.j zs.2s.Wat2 _ <br /> S.Antsotropic aquifers. with depth!lss _ <br /> y,Aquifer conditions varying <br /> 8.Large diameter wells. 8'45 <br /> --- <br /> 9.collect c_wells(see chapter S)2hµ. <br /> 10.Wells with multiple-sectioned well screens" Tz <br /> Characteristic Well Losses M~i <br /> The drawdown at a well includes not only that of the logarithmic <br /> d by flow <br /> drawdown curve <br /> at then alndace,but flaw inside of the wellauseto the puino <br /> througlr thewith <br /> intake.gecausg the well <br /> praporti nPOto an nth powe of the discharge, <br /> be indicated a g rester than ane•Jacobs'suggested that _ <br /> as Q where n is a constant g ss pointed <br /> a value n e 2 might be reasonably assumed,but Rorabaugh <br /> Gut that n can deviate significantly from 2. An exact value for n <br /> •!t should be netrd than any well with e5 percent of more open or screened hole <br /> in the saturated tht�Loess may be considered as fully pcxctrattng• _At. <br />