摘要: |
为了解黄河三角洲地区植被盖度的时空动态,在利用遥感资料分析归一化植被指数(NDVI)空间分布格局及其年际变化规律的基础上,进一步探讨了影响NDVI时空变化的自然和人为因素。结果显示,黄河三角洲地区2002、2006、2008、2013年10月的NDVI均值分别为-0.04、0.06、0.10、0.16,NDVI>0的区域面积分别约1253、1733、1742、2175km2(分别占区域总面积的43.67%、60.01%、66.82%、81.77%)。在时间动态上,区域NDVI总体呈逐渐增加的良性发展态势,黄河入海口地区尤为突出;在空间格局上,NDVI可分为高植被覆盖区(NDVI>0.4)、中等植被覆盖区(NDVI为0.1-0.4)和稀疏植被覆盖区(NDVI<0.1),且按离海远近在区域内分别呈现斜“Y”、斑块和条带状。地形高度、地下水和土壤水盐条件(尤其是潜水氯离子浓度,二者之间R=0.737)等环境因素影响NDVI整体空间分布格局,区域降水和气温等气候条件造成NDVI年际动态变化,而黄河下游生态调度对过水区域特别是河口地区NDVI良性变化具有显著的促进作用。黄河三角洲地区应持续加强生态环境保护与修复,提高植被盖度及其综合效益。 |
关键词: 归一化植被指数(NDVI) 植被 调水调沙 生态调度 黄河三角洲 |
DOI:10.11693/hyhz20161100241 |
分类号: |
基金项目:中国地质调查局地质调查项目,1212010611402号;安徽省高校自然科学研究重点项目,KJ2016A424号。 |
附件 |
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TEMPORAL AND SPATIAL VARIATION CHARACTERISTICS OF NDVI AND ITS DRIVING FACTORS IN THE HUANGHE (YELLOW) RIVER DELTA |
AN Le-Sheng1,2, ZHAO Quan-Sheng3, ZHOU Bao-Hua1, LIU Guan-Qun2
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1.School of Resources and Environment, Anqing Normal University, Anqing 246133, China;2.Department of Environmental Engineering, Ocean University of China, Qingdao 266100, China;3.Department of Environmental Science, Qingdao University, Qingdao 266071, China
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Abstract: |
To understand the temporal and spatial dynamics of vegetation coverage in the Huanghe (Yellow) River Delta, the spatial distribution pattern of normalized difference vegetation index (NDVI) and its interannual variation were analyzed based on remote sensing data, and the natural and human factors that affect the spatial and temporal changes of NDVI were discussed. The results show that the average NDVI of the area in October 2002, 2006, 2008, 2013 increased from -0.04, 0.06, 0.10, to 0.16, respectively, showing a good trend of green coverage. The areas of NDVI> 0 has been increasing from 1 253, 1 733, 1 742, to 2175 km2 (accounting for 43.67%, 60.01%, 66.82% and 81.77% of the total area), respectively. Overall, NDVI reflects a good development in time and in space (especially the river estuary). NDVI could be divided into high (NDVI>4.0), medium (NDVI between 0.1-4.0), and sparse (NDVI<0.1) vegetation patterns, showing oblique Y-shaped, patch, and strip zones, respectively, depending on the distance from the sea. The terrain height, groundwater, soil, and water-salt conditions (such as the concentration of chlorine ion in groundwater) affect the overall spatial distribution pattern of NDVI. The NDVI changed dynamically with the changes in precipitation and air temperature. Meanwhile, artificial involvement by water allocation in the lower reaches of the river promoted significantly with a good effect on the NDVI in the region, especially in the estuary area. Therefore, we shall continue to strengthen the protection and restoration of the ecological environment and to promote the improvement of vegetation coverage for comprehensive benefits to the study areas. |
Key words: normalized difference vegetation index (NDVI) vegetation water and sediment regulation ecological regulation the Huanghe (Yellow) River Delta |