松嫩平原紅旗灌區(qū)水鹽運動規(guī)律與土壤次生鹽漬化.pdf

1、東北農(nóng)業(yè)大學碩士學位論文松嫩平原紅旗灌區(qū)水鹽運動規(guī)律與土壤次生鹽漬化姓名：劉杰申請學位級別：碩士專業(yè)：土壤學指導教師：周連仁2001.11.1顫l。學位論義挫嫩’F原紅旗灌區(qū)水鹽運動規(guī)律與七壤攻生鹽漬化東北農(nóng)業(yè)大學StudiesonthePrinciplesofWaterandSaltMovementandSecondarysalinizationinSongnenPlainAbstractBeingapartoftheNoaheast

2、GreatPlaintheSongnenPlaincovers497millionshectaresItisoneofthemainyieldingzonesofcommercialfoodstufrinChinaBecauseofspecialgeographical，climaticandhydrographicalconditions，secondarysalinizationhasbeenalwayshamperingthelo

3、calagriculturaldevelopment，especiallywhichhasbeenaggravatedbyirrigationcausedudngthepastdecadesAtpresent，theareaofsaline—soilhasaccountedto1116millionshectaresandtherearestill曲out533millionshectaresconfrontinghiddensalin

4、izationTheaimofprojectistoforecastandpredictsecondarysalinizationonthebasisofthestudiesontheprinciplesofwaterandsaltmovementTheresultsasfollows：1BystudyingthefeaturesofwaterandsaltmovementintheSongnenPlain，wecarlmakethef

5、ollowingconclusions：(1)Inthesoilprofilesalthedepthfrom0to30cm，saltcontent，Na，HC03’andpHarethehi曲estatthelayerof20～30cmAtendencythatsaltismovingtowardsthesol】surfacewiththeincreaseofcultivatedyearshasbeenproved(2)Theaccum

6、ulationofsaltisdecreasingfastwiththeincreaseofundergroundwaterlevelindespiteofcultivatedordeeperlayers(3)DifferentwaysofirrigationcausedifferenttypesofdynamicchangesofundergroundwaterUndergroundwatertablevariesfrom60to16

7、0cmundertheconditionofwellirrigationvariancebeing100cm；undergroundwatertablevariesfrom16to168cmvariancebeingLS0cmundertheconditionofcanalirrigation(4)Intermsofwaysofirrigationdrainage，thewayofcombinationofirrigationanddr

8、ainageisbeRerthanthewayofsingleirrigation2ThepredictionandforecastofsecondarysalinizationintheSongnenPlain，Undertheconditionofweltirrigation，saltcontentof11Omg／kgisaccumulatedincultivatedlayerannuallyandatthisrate，severe

9、secondarysalinizationwillbehappenedin4080yearSandmediumsecondarysalinizationin140yearsUndertheconditionofcanalirrigation，saltcontentof17Omg／kgisaccumulatedincultivatedlayerannuallyandseveresecondarysalinizationwillemerge

10、3060yearsandmediumsecondarysalinizationwillemerge1～30years3ItisfeasibletoestablishmodelofpredictingandforecastingsecondarysalinizationbyapplyingArtificialNeuralNetItiscomparativelyaccuratetodescribetheoccurrenceanddevelo