简介:Land-usechangeisanimportantaspectofglobalenvironmentchange.Itis,inasense,thedirectresultofhumanactivitiesinfluencingourphysicalenvironment.Thispaperanalyzedtheland-usechangeinNortheastChinaduring1985-2000basedonLandsatTMimages.ItdividesNortheastChinaintofiveland-usezonesbasedonthedynamicdegreemodelofland-use:woodland/grassland-arablelandconversionzone,dryland-paddyfieldconversionzone;urbanexpansionzone,interlockedzoneoffarmingandpasturingandreclamationandabandonzone.Thefindingsincludetheobviousincreaseofcroplandarea,paddyfieldanddrylandincreasedby75and276thousandhm2respectively;urbanareasexpandedrapidly,areasoftownandruralresidenceincreasedby76.8thousandhm2;areasofforestsandgrasslanddecreasedsharplywiththeamountsof1399and1521thousandhm2respectively;areasofwaterbodyandunusedlandincreasedby148and514thousandhm2respectively.Thispaperalsodiscussesthedriving
简介:这个秋天响古箐有一件急人的事情——有几头牛生病死了。于是整个山谷的牛都被拉去打针了,还好,没有更多的牛生病。
简介:通过水文地质调查、采样分析并结合地下水流动系统理论,对鄂尔多斯某一典型砂质基底排矸场煤矸石淋滤液对地下水环境的影响进行研究.结果表明,煤矸石的堆放改变了地下水流动系统的原有特征,矸石场由地下水的排泄区转变为地下水的径流区,矸石场底部煤矸石长期浸泡在地下水中,有毒有害物质大量析出并随地下水的径流向下游扩散.矸石场下游地下水及附近出露的地表水中铬、砷、氟、硝酸根、铜、锌、镍、锰等污染因子远远高出背景值.其中水源地附近地下水中砷浓度为1.013mg/l,高出背景值148倍,硫酸根浓度为602mg/l,高出背景值14倍.图4,表1,参8.