宁夏植被动态变化及其对降水的响应

摘要

Regional vegetation ecosystem change and its response to climate change was an important as-pect on evaluating regional ecological environment, and has get more attention by scholars. Dynamic change of vegetation NDVI and its response to precipitation was analyzed on the basis of 250 m resolution and composite image of 16d MODIS NDVI,and daily precipitation data in 9 meteorological stations from 2000 to 2014 . Result showed:①Vegetation growing season began in the late of April and ended in the late of September. The annual average NDVI value of vegetation growing season had a linear increasing trend with a rate of 0. 052/10 a,but over the past 4 years,vegetation NDVI continued to decline,whichneed to pay more attention to strengthen the monitoring of vegetation change and to keep abreast of re-gional ecological environment change.②Average NDVI value of vegetation growing season was mainly in increasing trend,accounting for 91. 62% of the total area of Ningxia,which distributed mainly in the central arid region and southern hilly area of Ningxia. Only 8. 38% of the total area had decreasing trend,which mainly in the northern irrigated area and central arid region of Ningxia.③The correlation coefficient between average NDVI value of vegetation growing season and precipitation had the linear in-creasing trend. Positive correlation coefficient and significant positive correlation coefficient were mainly distribute in the southern hilly area of Ningxia,while the negative correlation coefficient and significant negative correlation coefficient mainly distribute in the northern irrigated area of Ningxia,especially a-round Yinchuan city.%区域植被生态变化及其对气候的响应研究,是科学评价区域生态环境的重要内容,受到广泛关注.利用2000—2015年250 m分辨率、16 d合成的MODIS NDVI影像、以及9个气象站点2000—2014年逐日降水数据,分析了宁夏植被NDVI动态变化及其对降水的响应,结果表明:①宁夏植被生长季开始于4月下旬,结束于9月下旬;年际植被生长季NDVI平均值以0.052/10 a的速率呈线性增加趋势,但近4a持续减少,需加强植被监测,及时了解区域生态环境变化;②植被生长季NDVI平均值以增加趋势为主,占区域总面积的91.62%,主要分布在中部干旱区和南部丘陵山区;减少趋势仅占8.38%,主要分布在北部引黄灌区和中部干旱区西部部分区域;③植被生长季NDVI平均值与降水的相关系数呈线性增加趋势,相关系数正相关与显著正相关区域主要分布在南部丘陵山区,而负相关与显著负相关区域主要分布在北部引黄灌区尤其是银川等城市周围区域.