生态环境学报
生態環境學報
생태배경학보
ECOLOGY AND ENVIRONMENT
2013年
11期
1763-1768
,共6页
程红霞%林粤江%汪权方%梁凤超%武鹏飞
程紅霞%林粵江%汪權方%樑鳳超%武鵬飛
정홍하%림월강%왕권방%량봉초%무붕비
风沙灾害%NDVI%植被类型%空间自相关%南疆西部
風沙災害%NDVI%植被類型%空間自相關%南疆西部
풍사재해%NDVI%식피류형%공간자상관%남강서부
aeolian sand disaster%NDVI%vegetation types%spatial autocorrelation%West of Southern Xinjiang
不同植被类型对风沙灾害的响应研究有助于风沙灾害的遥感监测评估和防灾减灾工作。采用传统统计学和空间自相关方法,利用MODIS的每日反射率和土地类型产品,分析了风沙灾害后南疆西部不同植被类型NDVI的变化规律及其空间分布特征。结果表明:风沙灾害后,研究区不同植被类型NDVI的差异在增大,NDVI变化值在-0.3865~0.4148之间,NDVI 减小的面积占整个研究区面积的54.98%,变异系数增大值在2.44%~36.75%之间;受到风沙灾害的影响,研究区植被 NDVI 全局Moran’s I系数从0.7982减小到0.6786,但在空间上仍存在显著的正相关性,具有显著的空间集聚特征;由NDVI 差值的局部空间自相关指标集聚图以及不同植被类型NDVI差值的空间关联区域面积百分比,可以发现落叶针叶林和裸地或低植被覆盖地受风沙灾害的影响较小,郁闭灌丛和作物受风沙灾害的影响较大。上述关于风沙灾害后南疆西部不同植被类型的变化及其空间格局的研究结果,不仅证明了防护林的风沙阻挡作用,也可以为风沙灾害的防治工作提供参考依据。
不同植被類型對風沙災害的響應研究有助于風沙災害的遙感鑑測評估和防災減災工作。採用傳統統計學和空間自相關方法,利用MODIS的每日反射率和土地類型產品,分析瞭風沙災害後南疆西部不同植被類型NDVI的變化規律及其空間分佈特徵。結果錶明:風沙災害後,研究區不同植被類型NDVI的差異在增大,NDVI變化值在-0.3865~0.4148之間,NDVI 減小的麵積佔整箇研究區麵積的54.98%,變異繫數增大值在2.44%~36.75%之間;受到風沙災害的影響,研究區植被 NDVI 全跼Moran’s I繫數從0.7982減小到0.6786,但在空間上仍存在顯著的正相關性,具有顯著的空間集聚特徵;由NDVI 差值的跼部空間自相關指標集聚圖以及不同植被類型NDVI差值的空間關聯區域麵積百分比,可以髮現落葉針葉林和裸地或低植被覆蓋地受風沙災害的影響較小,鬱閉灌叢和作物受風沙災害的影響較大。上述關于風沙災害後南疆西部不同植被類型的變化及其空間格跼的研究結果,不僅證明瞭防護林的風沙阻擋作用,也可以為風沙災害的防治工作提供參攷依據。
불동식피류형대풍사재해적향응연구유조우풍사재해적요감감측평고화방재감재공작。채용전통통계학화공간자상관방법,이용MODIS적매일반사솔화토지류형산품,분석료풍사재해후남강서부불동식피류형NDVI적변화규률급기공간분포특정。결과표명:풍사재해후,연구구불동식피류형NDVI적차이재증대,NDVI변화치재-0.3865~0.4148지간,NDVI 감소적면적점정개연구구면적적54.98%,변이계수증대치재2.44%~36.75%지간;수도풍사재해적영향,연구구식피 NDVI 전국Moran’s I계수종0.7982감소도0.6786,단재공간상잉존재현저적정상관성,구유현저적공간집취특정;유NDVI 차치적국부공간자상관지표집취도이급불동식피류형NDVI차치적공간관련구역면적백분비,가이발현락협침협림화라지혹저식피복개지수풍사재해적영향교소,욱폐관총화작물수풍사재해적영향교대。상술관우풍사재해후남강서부불동식피류형적변화급기공간격국적연구결과,불부증명료방호림적풍사조당작용,야가이위풍사재해적방치공작제공삼고의거。
The west of South Xinjiang lies in the aeolian sand disaster zone. Normalized difference vegetation index (NDVI) is widely used as an effective indicator for monitoring changes of vegetation and ecological environment. Research on response of NDVI of different vegetation types to aeolian sand disaster is helpful for monitoring and evaluating the effect of the aeolian sand disaster using remote sensing as well as combating and reducing disaster. Base on MODIS land surface reflectance products and land cover type product, this paper analyzed the changes and spatial distribution characteristic of NDVI index of different vegetation types after aeolian sand disaster in the west of South Xinjiang. The results showed that the numerical value of NDVI varied remarkably in space, the NDVI difference ranged from 0.05 to 0.31, the area of NDVI decreases accouted for 54.98%, the variation coefficients of NDVI were from 2.44% to 36.75%. Under influence of the aeolian sand disasters, the global Moran's I coefficient of NDVI decreased from 0.798 2 to 0.678 6, but there were still a significant positive correlation and spatial agglomeration pattern. Based on local Moran's I indicators of NDVI difference of different vegetation types, NDVI difference among vegetation types has significant spatial dependence and spatial heterogeneity. Synthesizes the above analysis and the cluster type area percentage of NDVI difference of different vegetation types, the results also revealed that deciduous coniferous forests and barren were less affected, dense shrub and croplands were greatly affected by the aeolian sand disaster. All of these findings theoretically proved that protection forest around croplands was a natural barrier to prevent the wind and sand and provided a scientific basis for preventing the aeolian sand disaster.