气候变化对青海湖流域牧草产量的影响

Impact of Pasture Production to Climate Change in Qinghai Lake Basin

基于青海湖流域3个气象站点1961~2017年气温、降水、日照时数和潜在蒸散量等气象数据,分析了1961年以来青海湖流域的气候变化特征;利用2003~2017年的牧草观测资料,通过相关性分析,评价了各气象要素对牧草产量的影响。结果表明:近57年青海湖流域的年和四季平均气温均呈显著上升趋势,冬季的升温幅度最大,年和四季降水量均增加,夏季降水量增加最多,年和四季日照时数呈下降趋势,夏季日照时数下降最为明显,海晏、刚察年潜在蒸散量呈微弱增加趋势,天峻呈微弱减小趋势,春季潜在蒸散量增加明显;青海湖流域天然牧草高度均呈下降趋势,海晏、天峻、刚察分别以每年0. 23、0. 4、0. 06cm的倾向率下降,牧草覆盖度海晏、天峻分别以每年0. 82、0. 5个百分点增加,刚察以每年0. 5个百分点减小,牧草产量海晏、天峻分别以每年178. 5、97. 5kg/hm2增加,刚察以每年45kg/hm2减少;各气象因素中,对牧草产量影响最大的是降水量,且均为正效应,其次是潜在蒸散量,牧草高度、覆盖度主要取决于降水和气温,因各站所处位置不同,气温的影响有正有负;建立的气象产量估算模型,经过验证,有较好的估测能力,可以满足应用需要。

Based on meteorological data such as temperature,precipitation sunshine hours and potential evapotranspiration of three meteorological stations in Qinghai Lake Basin from 1961 to 2017,and analysed the climate change characteristics of Qinghai Lake Basin since1961.The pasture observation data from 2003 to 2017 was used,through correlation analysis,the effects of meteorological elements on pasture production were evaluated.The results show that:Nearly 57 years,the annual and seasonal average temperatures in the Qinghai Lake Basin have showen a significant upward trend,with the largest temperature increase in winter;The annual and seasonal precipitation increase,and the summer precipitation increase the most;the annual and seasonal sunshine hours have showen a decrease trends,and the decline in summer sunshine hours is most pronounced;The potential evapotranspiration of Haiyan and Gangcha showed a slight increase trend,Tianjun showed a slight decrease trend,and the potential evapotranspiration increase significantly in spring.The height of natural pasture in Qinghai Lake Basin showed a downward trend.Haiyan,Tianjun and Gangcha decreased with the tendency of 0.23 cm/a、0.4 cm/a and 0.06 cm/a respectively;The pasture coverage in Haiyan and Tianjun increased by 0.82/a,0.5/a percentage point respectively,and Gangcha decreased by 0.5/a percentage point,The pasture production of Haiyan and Tianjun increased by 178.5 kg/hm2(a)1、97.5 kg/hm2(a)respectively,and Gangcha decreased by 45 kg/hm2(a).Among various meteorological factors,the most significant impact on pasture production is precipitation,and all have positive effects,followed by potential evapotranspiration.The height and coverage of pasure mainly depend on precipitation and temperature,due to the different locations of each station,the influence of temperature is positive and negative.The established meteorological production estimation model,through verification,and has good estimation ability to meet the needs of the application.