摘要
水资源短缺是黄土高原面临的最为关键的一个生态环境问题。研究黄土高原地区河川径流演变对土地利用与气候变化的响应是开展适应性流域管理的基础。该文以黄河流域中游山西省吉县境内的清水河流域(面积436km2)为研究对象,采用非参数统计秩检验法(Mann-Kendall)、滑动t检验和跃变参数分析法,对该流域1959-2005年的年径流量、降水量和潜在蒸发散量进行了趋势分析和突变点验证;用遥感数据判读和解译的结果分析了该流域不同时期土地利用变化;在此基础上根据水量平衡原理,分析了土地利用变化和气候变化对流域径流变化的贡献,并采用FDC曲线法分析了二者对高、中、低流量变化的影响。研究结果表明:该流域年径流量在1959-2005年的47年间呈显著下降趋势,突变点出现在1980年,但该流域降水量没有出现明显的趋势性变化,而以Hamon公式计算的流域年潜在蒸发散则呈显著上升趋势,其突变点出现在1997年。该流域气候变化和土地利用变化对年径流减少的贡献率分别为46.79%和53.21%。综合以上结果可以看出,潜在蒸发散增加和乔木林地面积增加是导致该流域径流减少的重要原因。
Aims Shortage of water resources is a key ecological problem facing the Loess Plateau.Therefore,it is critically important to understand and predict the coupling effects of landuse and climate variability on streamflow characteristics for integrated watershed management and ecological restoration.We used the typical meso-scale Qingshui River watershed located in middle reach of the Yellow River to examine the trend of annual streamflow and separate the effects of landuse change on streamflow from that of climate variability.Methods The trend of annual streamflow,precipitation and potential evapotranspiration and their inflection points were analyzed and examined using the nonparametric Mann-Kendall test,Moving t-test technique and analysis of hopped parameter.Three phases of landuse for the watershed were obtained representing the original and dramatic landuse changes due to the watershed ecological restoration.Landuse in 1959 （original） was interpreted from the aerial photo image taken that year.Landuses in 1986 （Three Norths Shelterbelt Program） and 2007 （Three Norths and Land Conversion Program） were extracted and merged from four-season Landsat TM images by deploying Geomatica V8.2.The stream flow response to landuse and climatic variability was separated following the approach Milly and Dunne （2002） developed on the basis of water balance.In addition,the landuse and climate variability effects on the high,normal and low flow were examined by flow duration curve （FDC） analysis.Important findings Streamflow decreased significantly during 1960 to 2005,with the inflection point in 1980.We estimated that streamflow reduction from 1980 to 2005 compared to 1960 to 1980 was attributable to landuse change （53.21%） and climate change （46.79%）.Because precipitation had no significant trend and potential evapotranspiration significantly increased from 1960 to 2005,we concluded that the streamflow reduction was mainly due to the temperature-induced increase in potential evapotranspiration and evapotranspiration increase by increased forest landuse.
出处
《植物生态学报》
CAS
CSCD
北大核心
2010年第7期800-810,共11页
Chinese Journal of Plant Ecology
基金
国家"十一五"科技支撑计划项目(2006BAD-03A0202)资助
