| 引用本文: | 程 杰,杨亮彦,黎雅楠.2000—2018年陕北地区NDVI时空变化及其对水热条件的响应[J].灌溉排水学报,2020,39(5):111-119. |
| CHENG Jie, YANG Liangyan*, LI Ya’nan,CHENG Jie, YANG Liangyan*, LI Ya’nan,CHENG Jie, YANG Liangyan*, LI Ya’nan.2000—2018年陕北地区NDVI时空变化及其对水热条件的响应[J].灌溉排水学报,2020,39(5):111-119. |
|
| 摘要: |
| 【目的】分析陕北地区NDVI时空变化，探究NDVI对水热条件的响应关系。【方法】基于MODIS遥感数据，利用差值法和线性回归斜率法对2000—2018年陕北地区的NDVI进行像元尺度的植被变化分析。【结果】在2000—2009年和2009—2018年，陕北地区的植被指数变化速度具有较大差异，前者平均斜率为0.013 0/10 a，后者为0.007 6/10 a。在空间分布上，2000—2009年退化的区域主要分布在西部山区和毛乌素沙地边缘地带，2009—2018年退化的区域主要分布在延安市区周边和其他城镇边缘地带；NDVI的年变化趋势与降雨量和气温基本一致，但NDVI与二者的相关性差距较大，NDVI与年降雨量存在显著正相关（R=0.63，P<0.01），与气温相关性较弱（R=0.23）。【结论】线性回归斜率法更适合长时间序列植被动态变化研究，陕北地区植被生长受降雨量和气温共同影响，降雨量较气温更能决定研究区植被生长状况，且植被指数与温度、降水之间存在一定的滞后关系。 |
| 关键词: NDVI；MODIS；时空变化；陕北地区；水热条件 |
| DOI：10.13522/j.cnki.ggps.2019268 |
| 分类号: |
| 基金项目: |
|
| Spatiotemporal Variation in NDVI and Its Response to Hydrothermal Change from 2000 to 2018 in Northern Shaanxi Province |
|
CHENG Jie, YANG Liangyan*, LI Ya’nan,CHENG Jie, YANG Liangyan*, LI Ya’nan,CHENG Jie, YANG Liangyan*, LI Ya’nan
|
|
1.Xi’an University of Technology, Xi’an 710048, China; 2. Shaanxi Provincial Land Engineering Construction Group Co., Ltd,Xi’an 710075, China; 3. Shaanxi land Engineering Technology Research Institute Co., Ltd., Xi’an 710021, China;4. Key Laboratory of Degraded and Unused Land Consolidation Engineering, the Ministry of Natural Resources, Xi’an 710021, China
|
| Abstract: |
| 【Background】Northern Shaanxi province is located at the center of the gully region in the Loess Plateau, characterized by dry climate with seasonally variable rainfall. It is in the transition zone from forest to grassland. Unsustainable economic structure and over-exploitation in early stage of development in this region had resulted in soil and water loss, which has made its ecosystem extremely fragile. As a key component in hydrological cycle, vegetation plays an important role in moving water from soil to atmosphere and balancing thermal energy of the planet. Spatial variation in vegetation is a result of the interplay of soil moisture, shallow groundwater and air temperature, and it is especially sensitive to climate change in arid and semi-arid region.【Objective】 The objective of this paper is to analyze the spatiotemporal variation in NDVI in northern Shaanxi province in attempts to provide baseline data for restoring functions of its ecosystems and sustaining economic development.【Method】The data were derived from the MODIS remote sensing from 2000 to 2018. Finite difference method and linear regression slope method were used to analyze the NDVI of each pixel in the remote sensing imageries.【Result】Vegetation change in 2000—2009 differed from that in 2009—2018, with the average vegetation changing rate in the former being 0.013/10a compared to the 0.0076/10a in the latter. In terms of spatial distribution, the degraded soils from 2000 to 2009 were mainly in the western mountainous area and at the edge of the Maowusu sandy land, while the degraded soils from 2009 to 2018 were mainly in the periphery of Yanan and at the edge of other cities and towns. The annual NDVI change was consistent with rainfall and temperature, but their correlations were different. NDVI was positively related to annual rainfall at significant level with R=0.63 (P<0.01), while there was only a weak correlation between NDVI and temperature with R=0.23.【Conclusion】Linear regression slope method is more suitable for studying temporal change in vegetation dynamics. Vegetation growth in northern Shaanxi province is affected by rainfall more than by temperature. There was a lag between the time when a change in temperature and precipitation happened and the associated shift in vegetation. |
| Key words: NDVI; MODIS; temporal-spatial variation; northern Shaanxi; hydrothermal condition |
