7be示踪土壤侵蚀的基础问题研究

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1、摘要活度为1．45Bq／L。沉降通量与次降雨量的关系为：沉降通量(Bq／m2)：0．7183x降雨量(mm)+10．632(R2=0．9593)。通过对2010年南京地区月沉降通量的观测，得出南京地区7Be沉降最大月为4月：434．81Bq／m2，最小月为1月：33．06Bq／m2。。7Be总沉降量季节排序为：春季(913．64Bq／m2)>夏季(506．7Bq／m2)>冬季(287．42Bq／m2)>秋季(267．34Bq／m2)。日平均沉降通量分别为：9．93Bq／m2d(春季)，5．50Bq／m2d(夏季)，2．93Bq／

2、m2d(秋季)，3．19Bq／m2d(冬季)。最大的季节沉降量出现在春季。4．地表径流中7Be含量无地表植物覆盖情况下的地表径流中平均7Be比活度为3．04Bq／L，地表植被覆盖度为50％情况下的地表径流中‘7Be比活度为1．61Bq／L，地表植被覆盖度为90％情况下的地表径流中7Be比活度为1．28Bq／L。地表植被覆盖度为90％的情况下的地表径流中7Be比活度为无地表植被覆盖情况下的地表径流中7Be比活度的52％，即地表植被能有效降低地表径流中7Be比活度。关键词：土壤侵蚀；高纯锗丫谱仪；探测效率；7Be沉降通量lIAbst

3、ractSoilerosionisseriousinChina，andcausesaseriesofecologicalproblemssuchassoildegradation，nutrientloss，waterpollution，riverjalns．Ithasnegativelyimpactedonsustainableagnculturaldevelopment．Theissuehasarousedwidespreadconcerns．However,soilerosionisamorecomplexprocess，w

4、hichreliesontheimprovementsofresearchmethodsandtechnology．Inpresentthereareanumberofmethodsforsoilerosionsuchasrunoffplotmethod,surveymethod，three—dimensionalphotographicmethod，andsimulatedrainfallmethodandSOon．however，thesemethodsgenerallyonlyresearchthelasterosiona

5、lresults．ItiSdifficulttomakequantitativedescriptionforerosionalphysicalprocesses．Theradionuclidetracermethodasanecessarycomplementforsoil-erosionmethodshasbeenpaidcloseattentionsinceMenzelstudiedtherelationshipofsoilerosionandradionuclidemigrationinthe1960’S．Currentl

6、y，theradionuclidetracerforsoilerosionmainlyusesradioactive1引Cs，210Pbex，226Ra，232ThandSOontotracefromdecadestocenturiestheannualaverageerosionrate，however，theshort-termsoilerosionisdifficulttodetect．7Behasashorthalflife，withcontinuoussedimentationandwidedistributionSO

7、thatitcannotonlystudythesoilerosionundertheconditionsoftheshorttimeorevryrainfallevent，spatialerosionaldistribution，andevaluateerosionalintensitywithdifferentlandcondition，butalsocanmoreaccurateresearchtheprocessandrateofsoilerosioninthecombinationoflonghalf-liferadi

8、onuclide．Thispapermainlystudiesthekeybasicissuesof7Befortracingsoilerosion．Bysampling，layingtest，laboratoryanalysismethods．Theconcl