利用净初级生产力模型C-FIX,陆面过程模型CoLM以及高时空分辨率的遥感数据集,定量估算了2002年西部地区1 km分辨率的水分利用效率(WUE)时空格局分布.模型估算2002年西部地区净初级生产力总量约为0.96 PgC,蒸散发总量约为2 098 km3,整个西部地区平均单位面积上年均WUE约为0.32 gC·mm-1.西部地区WUE时空分布格局具有显著的异质性:WUE最高值区主要分布在新疆西北部的天山和阿尔泰山区域,年均WUE最高可达4 gC·mm-1·m-2;其次为西藏东南隅以及陕西和甘肃南部山区,年均WUE约在1~2 gC·mm-1·m-2之间.WUE最低值广泛分布在青藏高原地区和西北沙漠地区,年均WUE基本在0.4 gC·mm-1·m-2以下.研究发现,西北干旱区内陆河流域荒漠植被呈现出相对高的WUE水平,反映出适度水分亏缺地区的天然植被生态系统可能具有较水分充足地区植被生态系统更高的水分利用效率功能.通过定量分析比较不同植被生态系统WUE特征及其季节变化廓线,得到西部地区主要植被生态系统的年均WUE大小为山区森林>荒漠乔灌丛>灌溉农田>高寒草地>寒漠和戈壁.
Water use efficiency(WUE) is the ratio between the net amount of carbon absorbed by the plant(NPP) and the amount of water lost through evapotranspiration(ET).West China includes large arid and semi-arid regions and has suffered water shortage and ecosystem degradation in recent decades.Therefore,investigating the spatio-temporal characteristics of WUE for different vegetation ecosystems and identifying their distribution with low WUE and high WUE are important for the conservation and management of water and land resources in West China(73°~112°,26°~50°).In this paper,the Monteith type carbon model-C-FZX driven by temperature,radiation and fAPAR retrieved from remote sensing was used to estimate NPP in West China in 2002.Meanwhile,the Common Land Model(CoLM) was also applied to estimate actual ET in the same year.The input data mainly included the NCAR 6-hour and 0.9(metrological datasets,1 km IGBP land cover data,1 km USGS soil data,the global 0.25(monthly MODIS LAI data and the 1 km VGT-S10 NDVI data.Then the WUE values were estimated by the ratio of NPP to ET in each 1 km pixel.Some field measurements of WUE for different plants in West China were used for validation.The study represented the preliminary overview of WUE in West China.The total annual NPP and actual ET in West China in 2002 were estimated about 0.96 PgC and 2 098 km3,respectively.The mean annual WUE per square meter was about 0.32 gC·mm-1·m-2.Meanwhile,the annual and seasonal spatial patterns of WUE in the region were pronounced.The high WUE level mainly distributed in the northwest part of Xinjiang Region with the highest WUE reaching to 4 gC·mm-1·m-2,followed by the south corners of Tibet Region and Shaanxi province with WUE ranged from 1 gC·mm-1·m-2 to 2 gC·mm-1·m-2.The low WUE level was showed in the sandy deserts and the most part of the Tibetan Plateau with WUE ranged from 0.4 gC·mm-1·m-2 to zero.On the other hand,some arid inland river basins in West China including the Tarim River Basin,the Heihe River Basin and the Shule River Basin showed in relatively high WUE patterns,especially in the summer,indicating that some particular ecosystems living in the arid basins might have predominant function in water use efficiency.In addition,it is also investigated that the WUE properties of different ecosystems and their seasonal profiles in West China.In general,the annual WUE of the main ecosystems in West China was ranked in the order as: mountain forest>desert shrub and woodland>irrigated farmland>alpine meadow>cold desert and Gobi.
- 卢玲, 李新, 黄春林, Frank Veroustraete. 中国西部植被水分利用效率的时空特征分析[J]. 冰川冻土, 2007, 29(5): 777-784.
- LU Ling, LI Xin, HUANG Chun-lin, Frank Veroustraete. Analysis of the Spatio-Temporal Characteristics of Water Use Efficiency of Vegetation in West China[J]. JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY, 2007, 29(5): 777-784.