水保所知识产出(1956---)知识库

植被是影响土壤侵蚀过程的重要因素。论文基于 MODIS 遥感数据和同期降水数据，用相关和回归分析方法从不同时间
尺度揭示了内蒙古草甸草原、典型草原和荒漠草原 2002—2016 年光合植被覆盖度(Fractional Photosynthetic Vegetation，f PV )的变
化规律及其对降水变化的响应。结果表明:(1)2002—2016 年间多年平均 f PV 草甸草原为 46．5%，典型草原和荒漠草原分别为
36．3%和 22．4%;草甸草原 f PV 随时间变化呈不显著增长趋势(线性变化斜率为 0．29%/a)，典型草原和荒漠草原 f PV 呈不显著下降
趋势(线性变化斜率分别为 －0．04%/a 和 －0．21%/a);相应时期年降水量随时间变化都呈现不显著波动上升趋势。(2)内蒙古
草原的月植被覆盖度对月降水量存在明显的 1—2 个月滞后效应和显著的累积效应，且表现出草原类型越干旱，滞后效应越明
显的特征;相比草甸草原和典型草原，荒漠草原植被对降水量变化更加敏感。(3)内蒙古 3 类草原年平均植被覆盖度对降水量
的响应，均表现出年、季、月尺度上分别受当年降水量、生长季降水量以及 6、7、8 月份降水量的显著影响的特征;3 类草原年植
被覆盖度与生长季降水线性拟合结果都较好，内蒙古 3 种草原类型的年植被覆盖度与降水量具有的强相关性，可为区域土壤侵
蚀动态评价提供科学依据。

 Vegetation cover is an important factor in the process of soil erosion． This paper revealed the changes of
photosynthetic vegetation coverage (f PV ) for meadow steppe，typical steppe and desert steppe in Inner Mongolia from 2002
to 2016 and their responses to precipitation in the annual，seasonal，and monthly scales． The MODIS derived data and
corresponding precipitation data were used in the analysis． The results showed that: (1) from 2002 to 2016，the annual
average f PV of three steppe types was 46．5%，36．3%，and 22．4%，respectively． The trend of f PV over time for all three
steppe types was not significant． For meadow steppe the annual change was positive with a rate of 0．29% per year，while for
typical steppe and desert steppe it was negative with the rate of －0．04% / a and －0．21% / a，respectively． The annual
precipitation for the three steppe types all showed an increasing trend without statistical significance． (2) The monthly
vegetation coverage was clearly affected by the prior one to two month precipitation，and the cumulative effect was also
evident． The more arid the steppe type，the more obvious of the lag effect． The coverage of dessert steppe was comparatively
more sensitive to the change of precipitation． (3) The annual vegetation coverage of three steppe types in Inner Mongolia
was significantly affected by the annual precipitation，growth season precipitation，and the precipitation in June，July，andAugust． The linear regression between the annual vegetation coverage and the precipitation in the growth season showed a
good fit． The significant correlation between annual vegetation coverage and precipitation of three steppe types in Inner
Mongolia provides a scientific basis for dynamic，regional soil erosion assessment．