简介:LakesinTibetPlateauwithlittleeffectsofhumanactivitiesserveasimportantindicatorsofclimatechange.ThisstudyanalysedremotesensingdataandlongtermclimatevariablestoexaminethehydrologicalresponseoflakesinNamCoBasin.TheareachangesoflakeswereextractedbyLandsatTM/ETM+andanalysedbySRTM3DEM.AndtheICESatelevationdatabetween2003and2009wereusedtoobservethelakeleveloftheNamCoLake.Theresultsshowthatthenumberofnewformedglacierlakesincreasedby36%andtheareaofglacierlakesincreasedby36.7%(0.97km~2)from1991to2011.Atthesametime,thesurfaceareaoftheNamCoLakeexpandedby3.71%(72.64km~2)oftheoriginalsizein1991,withatendencyvalueof3.63km~2peryear.ThelakeleveloftheNamCoLakeshowsanincreasetendencyof0.24mperyearduring2003–2009.Thesevariationsappeartoberelatedtoanincreaseinmeanannualtemperatureof0.06oCperyear,andanincreaseinannualprecipitationof2.1mmperyearinsummerinthelasttwodecades.Theincreasednumberoflakesandincreasedareaofglaciallakesreachedapeakatanaltitudeof5500–5600ma.s.l..Thenumberofnewformedglacierlakesandtheareaofglacierlakestendtohigheraltitudes.ClimatechangehasanimportantimpactonthevariationoftheglacierlakesandtheNamCoLake.
简介:巢湖地区下志留统高家边组页岩XRD衍射分析表明,页岩主要由伊利石,绿泥石和石英组成。根据沉降法获得石英等脆性矿物平均含量约为67.8%,黏土矿物平均含量约为25.12%。场发射环境扫描电镜对样品进行微观孔隙结构观察,发现页岩的孔隙主要有4种类型,即粒间孔隙、粒内孔隙、裂缝孔隙和溶蚀孔隙。其中粒间孔隙和溶蚀孔隙大量发育,它们是页岩气的重要的储集空间;裂缝孔隙发育良好,是页岩气运移的主要通道。页岩成分和结构之间关系进一步分析表明,页岩中石英等大量脆性矿物的存在,有利于页岩中裂缝的形成;而黏土矿物的存在,不仅能增加有机质含量,并且有利于页岩气的储集。综合分析认为,巢湖地区下志留统高家边组页岩具有较好的储集性能。