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利用1980-2010年4期Landsat遥感影像,获取相应年份的土地利用图,并提取NDVI,在此基础上利用CASA模型计算关天经济区植被NPP,计算分析土地利用变化对NPP的影响。结果表明:1)林地NPP均值最大(383.38gC·m-2·a-1),其次是草地、耕地,建设用地NPP最低(271.66gC·m-2·a-1)。2)关天经济区近30年NPP呈现先降低后增加再小幅降低的趋势,1980年的植被NPP为2.3×107gC·m-2·a-1,2000年为1.7×107gC·m-2·a-1,2005年为3.2×107gC·m-2·a-1,2010年2.2×107gC·m-2·a-1。3)关天经济区植被NPP在空间上分布不均衡。秦岭山区以及宝鸡与天水交界处的山区植被NPP高,秦岭山区植被NPP高达631.15gC·m-2·a-1,而低值区(53.85gC·m-2·a-1)位于经济发达的关中平原。4)土地利用变化区域,土地利用类型变化对区域植被NPP的影响显著,耕地转变为建设用地使NPP降低,关中平原与天水地区人口居住区与开垦区植被NPP明显下降,土地开发利用导致了植被NPP的降低。所以,关天经济区在维持经济发展的同时,要控制建设用地的无序增长,维持好区域的植被覆盖,保障区域生态平衡。
Using Landsat remote sensing image from 1980 to 2010, the land use maps of the corresponding years were obtained and NDVI was extracted. Based on this, the CASA model was used to calculate the NPP of vegetation in the Guantian Economic Zone, and the impact of land use change on NPP was calculated and analyzed. The results showed that: 1) NPP of forest land was the highest (383.38gC · m-2 · a-1), followed by grassland and arable land, and the lowest NPP of construction land was 271.66gC · m -2 · a-1. 2) In the recent 30 years, the NPP of the Kuantian Economic Zone tended to decrease and then decrease slightly. The NPP of vegetation in 1980 was 2.3 × 107gC · m-2 · a-1 and 1.7 × 107gC · m-2 · in 2000 a-1,2005 to 3.2 × 107gC · m-2 · a-1, and 2010 to 2.2 × 107gC · m-2 · a-1.3). The NPP in the Guanzhong Economic Zone was not evenly distributed in space. The NPP of mountainous areas in the Qinling Mountains and at the junction of Baoji and Tianshui is very high. The NPP in the Qinling Mountains is as high as 631.15gC · m-2 · a-1 while the low-value area (53.85gC · m-2 · a-1) Guanzhong Plain. 4) In the land use change area, the change of land use types has a significant impact on the NPP of the area vegetation. The conversion of cultivated land into construction land reduces the NPP, while the vegetation NPP in the population and reclamation area in the Guanzhong plain and Tianshui area obviously decreases. The land development and utilization lead to vegetation NPP reduction. Therefore, while maintaining economic development, Guantian Economic Zone must control the disorderly growth of construction land, maintain the vegetation coverage in the region and ensure the ecological balance of the region.