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<br />" <br /> <br />OOOG6~ <br /> <br />. <br /> <br />. <br /> <br />" <br /> <br />3. III C:nl",.,,,k,. tlie illcr~<I',cd water yieJd appeal's ;ilmost entirely in the <br />SnO\A.1nt~ \ t pc r i (ld. <br /> <br />4. In ,',eller,ll, the magnitude ,md se::Isoll<l1 distrihution of runoff res- <br />pOl!se to vc,~"l;rl.inll treatment, in n previously untested region, is difficult <br />to predict. <br /> <br />C.01lrl ictinl! ()piniol!:; ejl! Lilrger Basins: <br /> <br />"llJere I~, Illtlc controversy on the results from small onsins, ho".evl:r, <br />tlie luge '-"lsil.S arc different. Results from USSI< (Rakhnranov, 36) have <br />c13im0.d to dell'<)''''tr~te thClt the gre3ter the degree of deforestation, the Less <br />is the water yiuld. Rodda (37) concludes that the infl,rence of forests on the <br />runoff mny sli II be a matter of del1ate. He implies that alleged negative <br />results of cle;Jring may be due to greater exposure of snow to wind and sun. <br /> <br />The author points out that the recent experimental studies have focused <br />on strip or patchcutting, appilrently in recognition that large scale clearcuts <br />may reduce water yield in certain conditions. <br /> <br />The author concludes in this study that the increase in "..ater yield due <br />to patchcuttinp. from Oldman Basin, Canada, may amount to no more than a few <br />percent, which would be extremely difficult to prove. It is the aut:lOr's <br />opinion that the idea of reducing forest cover to increase water yield is <br />controversial nmong people and its benefits are highly questionable. <br /> <br />(3) Hvdr?logr of Patchcut~ in Lodgepol~ Pine,. br ~ames R. Meiman and Thomas <br />L.DIetrlCh, ASCE IrngatIOn & Dramage DIVIsIOn, ~larch 1975. <br /> <br />In this study, patchcutting (1ess than one acre) in the lodgepole pine <br />zone was studied to determine its effects on (1) evapotranspiration, (2) snow <br />accumulation, (3) potential water yield. <br /> <br />The major conclusions from this study are as fo110\6: <br /> <br />1. Thcre was a greater amount of soil water in the cut areas and 110 <br />change in uncut areas. <br /> <br />2. On the cut areas the snowfall W<lS less during the low snol\fall year <br />and more during the high sno"fall year. Increases were associated with drift <br />areas and decreases "ith areas of greater ~xl'osllre to solar radiation. <br /> <br />3. llJe incrc:Jsc in water yield on cut areas averaged 4.6 inches. Large <br />pnrt of jncre:J~e in the \.;ater :vicld is <l result or reduced evapotranspiration <br />hllich would diminish ,;ith the re-establishllJent or lodgepole [li.ne ,}r other <br />vegetation. <br /> <br />2 <br />