简介:Producinggoodsandservicesallneedswaterconsumption.Thewaterusedintheprocessofanagriculturalorindustrialproductiscalledthe"VirtualWater"containedinthisproduct.Throughinternationaltrade,water-scarcecountriesandregionscouldpurchasewater-intensiveproducts--especiallyfoods,fromwater-richcountriestobalancetheirwaterdeficitsandachievewatersafety.Chinaisoneofthe13mostwater-deficitcountrieswhosewatersafetyhavebeenseverelychallenged.Thispapergeneralizedtherecentglobalresearchdevelopmentandmadeabriefintroductionaboutthemethodscalculatingvirtualwatercontentinspecificproducts.Asacasestudy,wequalifiedChina'sannualvirtualwaterflowsfromyear2000to2002withtradeincrops,andendedwithsomepolicyadviceforapplicationandpracticeofvirtualwaterstrategy.
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简介:Althoughchemicalcontrolofpestsincreasescropproduction,itbringsalotofdamagetoenvironmentandhumanhealth.Thereexistanumberofalternativemethodsthatarenotsoharmfultoenvironmentandhumanhealth.However,whetherandhowmuchinextentthesetechnologiesadoptedareplausibledependsonthecomparisonofbenefit-costbetweenchemicalcontrolandthealternativecontrolmethods(suchasIntegratedPestManagement,IPM)andfarmers'willingness-to-pay(WTP)forenvirormentandhumanhealth.Usingcontingentvaluationmethod(CVM),theauthorinvestigatesfarmers'WTPforenvironmentandhumanhealth,recognizesthefactorsinfluencingWTP,andaccordinglypointsouttheimportanceofpestcontroltechnologyextensionandgovernmentregulationofpesticides.
简介:SinceChinasetthesustainabledevelopmentstrategy,positiveprogresshasbeenmadeinimplementingthestrategy,andactivecontributionshavebeenmadetothesustainabledevelopmentofmankind.Currently,profoundchangesaretakingplaceinChina'sinternalandexternalsituation.Anewerahasbegunintheimplementationofthesustainabledevelopmentstrategy.Weshouldtakefulladvantageofthisopportunityandmakeuseofallfavorableconditionsandchancestofurtherpromotetheimplementationofthesustainabledevelopmentstrategy.
简介:运用卫星遥感(RS)技术、地理信息系统(GXS)和全球定位系统(GPS),按国家、省、市、县4级模式,建立突发性危险废物污染事故预警系统。国家级预警系统主要对跨省界及跨国突发性污染事故进行应急处置,对省级应急事故处置进行指导;省级预警系统主要对跨市界突发性污染事故进行应急处置,并指导市级污染事故应急处置;市级预警系统主要负责跨县界突发性污染事故的应急处置并指导县级污染事故应急处置;县级预警系统主要负责本行政区内的突发性污染事故的应急处置。建立4级预警系统的主要目的是使各级政府突出重点,集中解决本行政区域内突发性环境污染事故的应急处置,从管理层面上在全国建立一个能对突发性污染事故实施统一指挥协调、现场快速监测和应急处理,又能对污染隐患进行监控和警告的应急响应系统。以辽宁省辽河为案例,通过3S技术的综合运用.构建省级流域突发性危险废物污染事故预警系统方案,为政府应急决策提供快速服务。
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简介:根据杨村煤矿17煤的水文地质条件,应用岩石破裂过程渗流与损伤耦合作用分析系统(F-RFPA2D),建立了薄煤层底板采动破坏的数值模型,模拟了采动条件下底板的破断失稳、裂隙扩展和突水过程,探讨了底板突水的机理,并对底板的易发生突水部位进行了预测.结果表明,当回采工作面推进到26.8m时,在隔水层的两个约束端产生拉剪破坏区.该破坏区和12灰贯通形成突水通道.突水后通道处的位移、流量都发生突变增加,并形成连锁反应,使12灰到13灰及其之间的隔水层依次发生破坏,最大破坏深度达13m,但未勾通和14灰、奥灰之间的水力联系,在底板没有断层的地段不会发生突水.两个工作面采前和采后压水试验结果表明,采动后底板破坏深度在9.96~12.35m,同数值模拟结果相吻合.