简介:为了探明查干湖水文要素变化特征及规律,利用1981~2011年的气象、水文和遥感影像数据,通过遥感解译和库容曲线等技术方法,分析了查干湖的最高水位、最大蓄水量、湖面面积、湖面蒸散量和降水量等水文要素的变化。研究结果表明,自引松工程通水以来,除1986年和1998年这些发生了特大洪水的年份外,查干湖维持相对稳定的水文状况,其中,年最高水位为129.5~130.5m,年蓄水量为3.35×10。~6.47×10^8m3,水面面积为281.4-400.6km2。水量平衡模型估算结果证明,查干湖水体与地下水存在明显的水量交换关系,引松工程通水后,地下水为查干湖补给水量。1981~1985年期间,查干湖为地下水补给的水量为0.76x10-1113,但在1987年以后,地下水成为查干湖稳定的补给水源。1987-1997年期间,地下水为查干湖补给的水量为0.65×10。甜。1999-2011年期间,地下水为查干湖补给的水量持续在相同的水平(0.66x10^8m3)上。由本研究结果还可以推测,区域农业发展带来的地下水污染会对查干湖水质和生态环境造成较大影响。
简介:TheGurbantunggutDesertisthelargeststableandsemi-stablesanddesertinChina,yetfewdataexistonvegetationpatternandspecies-environmentrelationshipsforthesediversedesertlandscapes.Thesanddunesofthesurveyareaaremainlyofthelongitudinalformfromnorthtosouth,butcheckerboard-shapedandhoneycomb-shapedformsarealsopresent,withtheheightof10-50m.Wemeasuredvegetationandsoildataonnorth-southtransectsandcomparedthemwithvegetationandsoildataoneast-westtransects.Analysisrevealedthatthevaryingtrendandstrengthofthespeciesdiversity,dominanceandcoveroftheplantcommunitiesinthelongitudinalandtransversedirectionsacrossthelandscapearesignificantlydifferent.TheresultsofCCAordinationshowthatthemicro-habitatsofsoilorganicmatter(OM),soilsalts(TS),sortingindex(σ),topsoilwater-content(SM)andpHrelatetothedifferencesinvegetationobservedasdifferencesinspeciesassemblagefromsalt-intolerantephemerals,micro-subshrubsandsubshrubstosalt-tolerantshrubsandmicro-arbors.Theterrain(alt.)andsoiltexture(thecontentsofMzandφ1)affectthespatialdifferentiationofmanyspecies.However,thisspatialdifferentiationisnotsomarkedontransectsrunninglongitudinallywiththelandscape,inthesamedirectionasthedunes.Thespeciesofthedesertvegetationhaveformedthreeassemblagesundertheactionofhabitatgradients,relatingtothreesectionsrunningtransverselyacrossthelandscape,atrightanglestothedirectionofthedunecrests.Inthemid-eastsectionofthestudyareathetopographyishigher,withsand-landsordune-slopeswithcoarseparticles.HerethedominantvegetationcomprisesshrubsandsubshrubsofSeriphidiumsantoliumandEphedradistachya,withlargenumbersofephemeralandephemeroidplantsofSeneciosubdentatus,andCarexphysodesinspringandsummer.Onthesoilofthedune-slopesinthemidwestofthestudyarea,withcoarseparticlesandabundantTK,theplantassemblageofHaloxylonpersicu