中文摘要：

土壤是人类赖以生存的根本,也是全球碳循环的重要环节。遥感技术的发展为土壤监测提供了高时空分辨率的数据,这有助于提高土壤有机碳储量估算的精度。本文利用遥感数据测量和评价土壤固碳价值,为区域碳核算及改善生态环境提供科学参考。基于遥感数据和碳循环过程模型估算2000、2005、2010和2014年关中-天水经济区内土壤有机碳储量（0~30 cm）,使用净现值法计算2014年固碳量的经济价值。2000-2014年关中-天水经济区土壤碳储量增加了2.4×107t,在预设的6个固碳收益情景（不同碳价格和贴现率）中,2014年土壤固碳净现值分别为44.958×10^8元、45.359×10^8元、62.186×10^8元、63.443×10^8元、85.156×10^8元、87.555×10^8元。林地的单位面积土壤固碳价值最大,而耕地的固碳总价值最高。除土壤理化性质,单位面积土壤固碳价值还受降水量、温度等气候因子影响。此外,合理的碳价格及贴现率可有效调控土壤固碳收益。

英文摘要：

Soil is fundamental to the survival of human,providing food,water and other resources. It is also an indispensable part of global carbon cycle. The estimation of soil organic carbon（SOC）is an important issue in regional carbon accounting. The development of remote sensing technology makes it possible to obtain high spatial resolution and short cycle of large area synchronized ground observation data,which contributes to improve the accuracy of soil organic carbon estimation. This paper measured and evaluated the value of soil sequestration,using remote sensing and a carbon cycle process model,providing references for regional carbon accounting.Based on the CASA model and ecosystem process model,the SOC stocks（top 0-30 cm）of the GuanzhongTianshui Economic Region in Shaanxi and Gansu Province,China,was estimated. Using the results,the region＇s2014 carbon sequestration value was evaluated using net present value（NPV）. The paper also presented the temporal changes and spatial distribution of soil organic carbon sequestration in the study area. Carbon sequestration in the top 30 cm soil in the Guanzhong-Tianshui Economic Region increased by approximately 2.4×10~7t between2000 and 2014（levels in 2000,2005,2010,and 2014 were 24.19×10~7t,24.86×10~7t,23.72×10~7t and 26.59×10~7t,respectively）. The paper examined 6 different carbon sequestration payoff scenarios with different carbon prices and discount rates. From the perspective of carbon sequestration across different land use types,it was found that the average NPV of forestland was greater than grassland,which was greater than other land types and cultivated land. The total value of cultivated land,however,was greater than grassland,forest land,and other land types. In addition to physical and chemical properties,the unit area sequestration values of soil are also affected by the climate factors such as precipitation and temperature.Besides,setting up reasonable carbon price and discount rate will be a effective way to adjust the earning of soil