| 引用本文: | 杨亮彦,程杰,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,0,():-. |
| yang liangyan,Cheng Ji,Li Yanan.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,0,():-. |
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| 摘要: |
| 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年间，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 0/10a，后者为0.007 6/10a。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；年NDVI的变化趋势与降雨量和气温基本一致，但NDVI与两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，可综合考虑变化的过程和结果，具有较好的适用性；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 |
| 关键词: NDVI;MODIS;时空变化;陕北地区;水热条件 |
| DOI： |
| 分类号:P |
| 基金项目:自然资源部公益性行业科研专项项目(201411008) |
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| Spatial and Temporal Variation of NDVI and Its Response to Hydrothermal Conditions in Northern Shaanxi from 2000 to 2018 |
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yang liangyan,Cheng Ji,Li Yanan
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1.Institute of Land Engineering Technology of Shaanxi Land Engineering Construction Group;2.Shaanxi Province Land Engineering Construction Group
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| Abstract: |
| Abstract:【Background】Northern Shaanxi is located in the central part of the Loess Plateau and belongs to the gully region of the Loess Plateau. Its climate is dry and rainfall varies greatly seasonally, so it is a transitional zone from forest to grassland. In the early stage, due to unreasonable economic structure and over-development for a long time, soil and water loss in northern Shaanxi was intensified, resulting in a vicious circle of ecological destruction and economic poverty, resulting in extremely fragile ecological environment in northern Shaanxi. As the link of energy exchange, water cycle and biological cycle between earth and atmosphere, vegetation plays an important role in water cycle and energy conversion. The spatial distribution of vegetation can reflect the regional temporal and spatial distribution of soil moisture, shallow groundwater depth and air temperature. And the vegetation ecosystem in arid areas is very sensitive to climate change, so exploring the process of vegetation change can provide an important basis for climate change research. 【Objective】Therefore, analyzing the temporal and spatial variation of NDVI in northern Shaanxi and exploring the response of NDVI to hydrothermal conditions can provide a basis for the restoration of ecological environment and sustainable economic development in this area.【Method】Based on MODIS remote sensing data, the difference method and linear regression slope method were used to analyze the vegetation change at pixel scale in NDVI of northern Shaanxi from 2000 to 2018.【Result】Between 2000 to 2009 and 2009 to 2018, the vegetation index change speed in northern Shaanxi is quite different. The average slope of the former is 0.013 0/10a, and the latter is 0.007 6/10a. In terms of spatial distribution, the degraded areas from 2000 to 2009 are mainly distributed in the western mountainous areas and the edge of Maowusu sandy land, while the degraded areas from 2009 to 2018 are mainly distributed in the periphery of Yan'an and the edge of other cities and towns. The trend of annual NDVI is basically consistent with rainfall and temperature, but the correlation between NDVI and them is quite different. There is a significant positive correlation between NDVI and annual rainfall (R = 0.63, P < 0.01), and a weak correlation between NDVI and temperature (R = 0.23).【Conclusion】Linear regression slope method is more suitable for the study of vegetation dynamic change in long time series, considering the process and results of change comprehensively, and has better applicability. The vegetation growth in northern Shaanxi is affected by both rainfall and temperature. Compared with temperature, rainfall can better determine vegetation growth in the study area. There is a lag relationship between vegetation index and temperature and precipitation.
Key words: NDVI; MODIS; temporal-spatial variation; northern Shaanxi; hydrothermal condition |
| Key words: NDVI; MODIS; temporal-spatial variation; northern Shaanxi; hydrothermal conditions |
