为明确延边朝鲜族自治州(以下简称延边州)植被指数变化规律及其对气候因子的响应机制,利用 2000-2022 年的MOD13Q1数据,结合降水量、气温等资料,通过一元线性回归法、Theil-Sen Median 趋势分析、Mann-Kendall检验法和相关系数分析法等,从时间和空间2个尺度分析延边州NDVI变化特征及其与气温和降水量的响应程度.结果表明:时间变化上来看,2000-2022年延边州植被ND-VI多年平均值为0.539,呈波动上升趋势,上升斜率为0.003 6/年.各县(市)植被NDVI存在差异,但总体均呈现相似的波动上升趋势.其中,和龙市年均NDVI最高,为0.560,延吉市最低,为0.515.图们市NDVI年均值上升趋势最为明显,为0.004 3/年,和龙市NDVI年均值上升趋势最慢,为0.003 1/年.空间分布上来看,延边州植被整体覆盖状况较好,植被NDVI年均值大于0.6 的区域面积占总面积的22.93%,NDVI年均值在0.4～0.6的占67.16%;植被NDVI年均值小于0.4 的面积仅占9.91%,主要分布在各县(市)中心及周边区域.植被NDVI呈上升趋势的面积占研究区总面积的94.23%,其中,呈极显著上升趋势的面积占71.80%,呈下降趋势的面积仅占研究区面积的2.48%,零星分布在部分耕地区域.植被NDVI对气候因子响应方面,延边州大部分地区NDVI与气温、降水量呈正相关,约有67.23%的地区与降水量呈显著正相关,大于与气温呈显著正相关区域(59.49%),表明全州范围内NDVI与降水量和气温均以正向促进为主,且与降水量的相关性强于气温.
The Spatiotemporal Variation Characteristics of NDVI in Yanbian Korean Autonomous Prefecture and Its Relationship with Climate Factors
In order to clarify the variation law of vegetation index in Yanbian Korean Autonomous Prefecture and its response mechanism to climate factors,MOD13Q1 data from 2000 to 2022 were used,combined with precipitation,temperature and other data.Through univariate line-ar regression,Theil Sen Median trend analysis,Mann-Kendall test and correlation coefficient analysis,the NDVI variation characteristics of Yan-bian Prefecture and their response degree to temperature and precipitation were analyzed from two scales of time and space.The results showed that in terms of temporal variation,the average NDVI of vegetation in Yanbian Prefecture from 2000 to 2022 was 0.539,showing a fluctuating upward trend with an upward slope of 0.003 6 per year.There were differences in vegetation NDVI among various counties and cities,but over-all they showed a similar fluctuating upward trend.Among them,Helong City had the highest annual NDVI value at 0.560,while Yanji City had the lowest at 0.515.The annual average increase trend of NDVI in Tumen City was the most obvious,at 0.004 3/year,while the annual average increase trend of NDVI in Helong City was the slowest,at 0.003 1/year.In terms of spatial distribution,the overall vegetation coverage in Yan-bian area was good,with 22.93%of the total area having an annual average NDVI greater than 0.6,ranging from 0.4 to 0.6,accounting for 67.16%;the area with vegetation NDVI less than 0.4 accounted for only 9.91%,mainly distributed in the centers and surrounding areas of va-rious counties and cities.The area with vegetation NDVI showing an upward trend accounted for 94.23%of the total area of the study area,of which 71.8%showed a highly significant upward trend,and only 2.48%showed a downward trend,sporadically distributed in some cultivated land areas.In terms of the response of vegetation NDVI to climate factors,in most areas of Yanbian Prefecture,NDVI was positively correlated with temperature and precipitation,with about 67.23%of areas showing a significant positive correlation with precipitation,which was greater than the significant positive correlation with temperature(59.49%).This indicated that NDVI was mainly positively promoted with precipitati-on and temperature throughout the state,and the correlation with precipitation was stronger than that with temperature.
万方数据
维普
