GeographyAlabama
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Physiographic RegionsAlabama Physiographic RegionsAlabama |
Physical Features.
The surfaceAlabama inN.N.E., embracing about two-fifthsits area,diversifiedpicturesque;remaining portionoccupied bygently undulating plain havinggeneral incline south-westward towardMississippi River andGulfMexico.
Extending entirely acrossstateAlabamaabout 20 m. S.its N. boundary,inmiddle stretching 60 m. farther S., isCumberland Plateau, or Tennessee Valley region, broken into broad table-lands bydissectionrivers. InN. partthis plateau, W.Jackson county, thereabout 1000 sq. m.level highlands from 700800 ft. abovesea. Souththese highlands, occupyingnarrow strip on each side ofTennessee River, iscountrygentle rolling lowlands varyingelevation from 500800 ft. ToN.E.these highlandslowlands isrugged sectionsteep mountain-sides, deep narrow covesvalleys,flat mountain-tops. Its elevations range from 4001800 ft. Inremainderthis region,S. portion,most prominent featureLittle Mountain, extending about 80 m. from E.W. between two valleys,Asing precipitouslyonN. side 500 ft. above them or 1000ft. abovesea.
AdjoiningCumberland Plateau region onS.E. isAppalachian Valley (locally known as Coosa Valley) region, which isS. extremity ofgreat Appalachian Mountains,occupies an area withinstateabout 8000 sq. m. This islimestone beltparallel hard rock ridges left standing by erosionform mountains. Althoughgeneral direction ofmountains, ridgesvalleysN.E.S.W., irregularityone ofmost prominent characteristics. InN.E.several flat-topped mountains,which RaccoonLookout aremost prominent, havingmaximum elevation nearGeorgia linelittle more than 1800 ft.gradually decreasingheight towardS.W., where Sand Mountain iscontinuationRaccoon. Souththesemountainsmarked by steep N.W. sides, sharp crestsgently sloping S.E. sides.
South-east ofAppalachian Valley region,Piedmont Plateau also crossesAlabama border fromN.E.occupiessmall triangular-shaped sectionwhich RandolphClay counties, together withN. partTallapoosaChambers, formprincipal portion. Its surfacegently undulatinghas an elevationabout 1000 ft. abovesea. The Piedmont Plateau islowland worn down by erosion on hard crystalline rocks, then upliftedformplateau.
The remainder ofstateoccupied byCoastal Plain. Thiscrossed by foot-hillsrolling prairies incentral part ofstate, wherehasmean elevationabout 600 ft., becomes lowermore level towardS.W.,inextreme S.flatbut slightly elevated abovesea.
The Cumberland Plateau regiondrained toW.N.W. byTennessee Riverits tributaries; all other parts ofstatedrained toS.W. InAppalachian Valley regionCoosa isprincipal river;inPiedmont Plateau,Tallapoosa. InCoastal Plain areTombigbee inW.,Alabama (formed byCoosaTallapoosa) inW. central,inE.Chattahoochee, which forms almost half ofGeorgia boundary. The TombigbeeAlabama unite nearS.W. corner ofstate, their waters discharging into Mobile Bay byMobileTensas rivers. The Black Warrior isconsiderable stream which joinsTombigbee fromE.
The valleys inN.N.E.usually deepnarrow, but inCoastal Plain theybroadin most cases risethree successive terraces abovestream. The harbourMobile was formed bydrowning oflower part ofvalley ofAlabamaTombigbee rivers asresult ofsinking ofland here, such sinking having occurred on other parts ofGulf coast.
The faunafloraAlabamasimilarthose ofGulf statesgeneralhave no distinctive characteristics.
ClimateSoil.
The climateAlabamatemperatefairly uniform.
The heatsummertempered inS. bywinds fromGulfMexico,inN. byelevation abovesea. The average annual temperaturehighest inS.W. alongcoast,lowest inN.E. amonghighlands. Thus at Mobileannual mean67 degrees F.,mean forsummer 81 degrees,forwinter 52 degrees ;at Valley Head,De Kalb county,annual mean59 degrees,mean forsummer 75 degrees,forwinter 41 degrees . At Montgomery, incentral region,average annual temperature66 degrees, withwinter average49 degrees, andsummer average81 degrees . The average winter minimum forentire state35 degrees,therean average35 dayseach yearwhichthermometer falls belowfreezing-point. At extremely rare intervalsthermometer has fallen below zero, as wascase inremarkable cold wave of12th-13thFebruary 1899, when an absolute minimum17 degrees was registered at Valley Head. The highest temperature ever recorded was 109 degrees Talladega county1902.
The amountprecipitationgreatest alongcoast (62 in.)evenly distributed throughrest ofstate (about 52 in.). During each winter thereusually one fallsnow inS.two inN.; butsnow quickly disappears,sometimes, during' an entire winter,groundnot coveredsnow. Hail-storms occur inspringsummer, butseldom destructive. Heavy fogsrare, andconfined chiefly tocoast. Thunderstorms occur throughoutyear, butmost common insummer. The prevailing windsfromS.
As regards its soil, Alabama may be divided into four regions. Extending fromGulf northwardone hundredfifty miles isouter belt ofCoastal Plain, also called``Timber Belt, whose soilsandypoor, but responds wellfertilization. Norththis isinner lowland ofCoastal Plain, or``Black Prairie, which includes some 13,000 sq. m.seventeen counties. It receives its name from its soil (weathered fromweak underlying limestone), whichblackcolour, almost destitutesandloam,richlimestonemarl formations, especially adapted toproductioncotton; henceregionalso called``Cotton Belt. Between``Cotton Belt andTennessee Valley ismineral region,``Old Land area---``a regionresistant rocks--whose soils, also derived from weatheringsilu,of varied fertility,best coming fromgranites, sandstoneslimestones,poorest fromgneisses, schistsslates. North ofmineral region is``Cereal Belt,'' embracingTennessee Valley andcounties beyond, whose richest soils arered claysdark loams ofriver valley; northwhichless fertile soils, produced by siliceoussandstone formations.
