【作者】 张春敏；

【导师】 王根绪；

【作者基本信息】 兰州大学 ， 水文学及水资源， 2008， 硕士

【摘要】 长江源区是我国高寒生态系统典型区域,独特而脆弱的生态系统和特殊的水文特征,在寒区生态环境、水文循环及气候变化中起着极其重要的作用。生态系统植被净初生产力（NPP）和水分利用效率（WUE）是联系植被生态系统中水分循环和碳循环的重要变量,具有重要的水文学和生态学意义。论文以光能利用率模型为基础,结合MODIS高时间分辨率影像与地面气象资料,应用CASA模型估算长江源区植被净初生产力,根据植被净初生产力和潜在蒸散发,估算长江源区植被水分利用效率。从2000-2005年以时间和空间序列来分析长江源区植被水分利用效率、植被净初生产力,不同植被类型下的植被水分利用效率和植被净初生产力的分布情况,长江源区典型植被年际年内分布特征以及植被水分利用效率和净初生产力的影响因子分析。1、作为计算WUE的重要组成部分,在对长江源区潜在蒸散发模型的选择时,论文利用FAO Penman-Monteith、Priestley-Taylor、Hargreaves和FAO-Radiation模型进行拟合,得出FAO Penman-Monteith＞Hargreaves＞Priestley-Taylor＞FAO-Radiation,FAO Penman-Monteith模型对区域潜在蒸散发拟合效果最好,因此,选取FAO Penman-Monteith模型计算潜在蒸散发并进行了有效检验。2、论文分析了长江源区的生态系统植被净初生产力,研究结果表明:从2000-2005年,年NPP平均值在627.39-713.05 gC/m²·a,NPP总量总体上分布8.77×10¹³-9.96×10¹³gC/a。2005年最小,2003年最大,长江源区植被净初生产力变化趋势为2000-2002年和2003-2005两个阶段减少趋势。2002-2003年间年际变化最大,年NPP变化为41.42 gC/m²·a。NPP的年内分配,文中按照春季融化阶段、水分充分阶段、植被枯萎阶段和冬季冬季四阶段进行分析。空间分布上,长江源区通天河下游直门达水文站以上河沿（玉树县、称多县）、叶曲、莫曲、北麓河下游和沱沱河下游属于NPP高值区。NPP高值范围达到700gC/m²·a;NPP次高值出现在色吾曲流域、楚玛尔河下游流域及以东、沱沱河、通天河以南的大部分低海拔区域,NPP值在500-700gC/m²·a;NPP值最低值广泛分布在长江源区的高海拔地区和山脉地区:唐古拉山脉、祖尔肯乌拉山脉、乌兰乌拉山、可可西里山、各布里山、昆仑山、白日咀扎解依山和坑巴饿任山山区和楚玛尔河上游。这些地区NPP值很小,高海拔地区接近0值。长江源区陆地年均NPP的空间分布格局与植被类型和植被群落关系密切,以高寒草甸植被为主的当曲流域、以高寒草原为主的沱沱河、通天河流域和亚高山阔叶落叶灌丛的德曲流域是NPP值分布的高值区,在高海拔地区的无植被地段属于NPP值分布低值区。不同的植被类型的NPP值,以高寒草甸最高,其NPP值年均在682.36gC/m²·a左右;其次为高寒草原,为679.31 gC/m²·a;亚高山常绿阔叶灌丛,为606.79gC/m²·a;依次为亚热带山地针叶林,为601.13gC/m²·a;亚高山落叶阔叶灌丛,为597.78 gC/m²·a;高寒稀疏植被,为577.77 gC/m²·a;高寒垫状植被,为561.98 gC/m²·a;在影响因子方面,NPP值与NDVI、太阳辐射、温度、降雨和地温关系明显。3.分析了长江源区的植被水分利用效率,研究结果表明:2000-2005年长江源区的年WUE的平均值在0.83-1.00gC/mm.m²,2000年最小,2001年最大。2000-2005年6年间年WUE增加了0.10gC/mm.m²,总体变化趋势为小幅度波动增加的态势。2002-2003年间年际变化最大,年WUE变化为0.1gC/mm.m²,在2003-2005年WUE呈下降趋势,年WUE变化率均为-0.04gC/mm.m²。空间分布来看,WUE值分布与NPP值分布相似,只是高值区和低值区更明显分布。通天河下游直门达水文站以上河沿（玉树县、称多县）、叶曲、属于WUE高值区。WUE高值范围大于1gC/mm·m²;WUE次高值分布色吾曲、楚玛尔河下游、北麓河、沱沱河下游、沱沱河、通天河以南的大部分低海拔地区。WUE值在0.7-1.0gC/mm·m²;在沱沱河、通天河河沿以北,色吾河以西地区WUE值小于0.7gC/mm·m²;WUE最低值广泛分布在长江源区的高海拔地区和山脉:唐古拉山脉、祖尔肯乌拉山、可可西里山、昆仑山、坑巴饿任山山区和楚玛尔河上游。WUE接近0值。不同的植被类型的WUE来看,以高寒草甸最高,其WUE值年均在0.95 gC/mm.m²左右,其次为亚高山常绿阔叶灌丛,为0.91 gC/mm.m²;依次为高寒稀疏植被,为0.88gC/mm.m²;亚热带山地针叶林,为0.86 gC/mm.m²;高寒草原为0.86 gC/mm.m²;亚高山落叶阔叶灌丛,为0.85 gC/mm.m²;高寒垫状植被,为0.76 gC/mm.m²。更多还原

【Abstract】 The Yangtze River Source Region is the type region of the high-cold ecosystem in China.Where have Unique and fragile ecosystem and especial hydrological characteristics.So,those characters have play important roll in cold’ entironment, water cycle and climate system.The vegetation water use efficiency（WUE）and Net Primary Productivity（NPP）are important variables linking to the water cycle of ecosystem and carbon cycle.whose variables are important provided with signification in hydrology and ecology.The thesis is about retrieving WUE and NPP using CASA （Carnegie Ames Stanford Approach）and multi-spectral radiometric data（MODIS）.To obtain temporal and spatial distribution of NPP and WUE in the Yangtze River Source Region during 200-2005 and the relation factors.The main reseach results are as follow:Fristly,Potential evapotranspiration is a component of water use efficiency.Four models were tried to calculate potential evapotranspirtion for comparison purpose,i.e. FAO Penman-Monteith、Priestley-Taylor、Hargreaves and FAO-Radiation. FAO Penman-Monteith model was chosen over others.Secondly,in thesis,analyse the temporal and spatial distribution of NPP.The rusults as follow:During 2000-2005,the annual mean NPP value between 627.39 and 713.05 gC/m².a, the total annual mean NPP value between 8.77×10¹³gC/a and 9.96×10¹³gC/a in the Yangtze River Source;from 2000 to 2003,the NPP was incresed and from 2003 to 2005,the tendency was opposite;for the change of during years.The change maximum is 41.42 gC/m²·a（2002-2003）.For the spatial distribution,the high NPP value were main focus on the down stream of the Yangtze River Source Region,i.e. the area along river over Zhimenda station and the water net of Yequ,Moqu and Danqu,the value is above 700 gC/m²·a;the second-high NPP value were main focus on the southern region along Tuotuoriver and Tongtian river,the value is between 500 and 700 gC/m²·a;the low NPP value were main located in the regions of high-altitude and cordillera such as Tanggula mountain,Zuerkenwula mountain,Kekexili mountain and Kunlun mountain,the value is near zero.The sptial pattern of NPP distribution were relation with vegetation type,vegetaion community,altitude,climate and latitude,in Yangtze River Source Region,in the regions of high-cold meadow and high-cold grassland,the NPP value are more high than sub-alp broad-leaf and deciduous shurb and sub-tropic mountain conifruticeta.The low value’vegetaion type are focus on high-cold cushion vegetation,aparsity vegetation and non-vegetaion. About NPP value in vegetation type,the high-value type is high-cold meadow,the annual number is 682.36gC/m²·a,the second one is high-cold grassland,the value is 679.31 gC/m²·a,the value in sub-alp evergreen broad shrub is 606.79gC/m²·a,value in sub-tropic mountain conifruticeta is 601.13gC/m²·a,sub-alp broad-leaf and deciduous shurb is 597.78 gC/m²·a,high-cold aparsity vegetation is 577.77 gC/m²·a, high-cold cushion vegetation is 561.98 gC/m²·a.Thirdly,In this thesis,analyse the temporal and spatial distribution of WUE.The rusults as follow:During2000-2005,the annual mean WUE value between 0.83 and 1.00 gC/mm.m2, the minimum value is 0.83 gC/mm.m2（2000）,the maxmum is 1.00 gC/mm.m2（2005）, from 2000 to 2005,the tendency is incresingand the incresed value is 0.10gC/mm.m². For the spatial distribution,the high WUE value were main focus on the down stream of the Yangtze River Source Region,i.e.the area along river over Zhimenda station and the water net of Yequ,Moqu and Danqu,the value above 1gC/mm.m²;the second-high NPP value were main focus on the southem region along Tuotuoriver and Tongtian rever,the value between0.7and 1.0 gC/mm.m²;for the northern of river,the value below 0,7gC/mm.m²;the low WUE value were main located in regions of high-altitude and cordillera such as Tanggula mountain,Zuerkenwula mountain, Kekexili mountain and Kunlun mountain,the value is near zero.About WUE value in vegetation type,the high-value type is high-cold meadow,the annual number is 0.95 gC/mm.m²,the second one is sub-alp evergreen broad shrub,the value is 0.91 gC/mm.m²,high-cold aparsity vegetation is 0.88gC/mm.m²,sub-tropic mountain conifruticeta is 0.86 gC/mm.m²,high-cold grassland is 0.86 gC/mm.m²,sub-alp broad-leaf and deciduous shurb is 0.85 gC/mm.m²,high-cold cushion vegetation is 0.76 gC/mm.m².更多还原