CAJ | 학술논문

NDVI-Ts特征空间方法结合了卫星遥感地表反射率和热红外特性,能较好地反映一定时空尺度的地表干旱状况,该文基于Terra-MODIS归一化植被指数(NDVI)和地表温度(LST)产品,构建NDVI-Ts三角形特征空间,采用植被温度状态指数结合MODIS地表分类产品IGBP对黑龙江省2007年夏季于旱进行监测和分析.结果显示:此次夏季干旱的空间分布广,持续时间长,干旱程度重,西部松嫩平原和东部三江平原等地主要农作物产区普遍发牛干旱,且旱情严重.结合同期地面气象观测的月降水量数据对监测结果进行验证和评估表明:植被温度状态指数是一项近实时的干旱监测指标,不仅与当地最近的降水事件有关,而且与前期一段时间内的总体降水事件相关,可以较真实地反映当地与地干旱发生、发展的动态过程.
NDVI-Ts특정공간방법결합료위성요감지표반사솔화열홍외특성,능교호지반영일정시공척도적지표간한상황,해문기우Terra-MODIS귀일화식피지수(NDVI)화지표온도(LST)산품,구건NDVI-Ts삼각형특정공간,채용식피온도상태지수결합MODIS지표분류산품IGBP대흑룡강성2007년하계우한진행감측화분석.결과현시:차차하계간한적공간분포엄,지속시간장,간한정도중,서부송눈평원화동부삼강평원등지주요농작물산구보편발우간한,차한정엄중.결합동기지면기상관측적월강수량수거대감측결과진행험증화평고표명:식피온도상태지수시일항근실시적간한감측지표,불부여당지최근적강수사건유관,이차여전기일단시간내적총체강수사건상관,가이교진실지반영당지여지간한발생、발전적동태과정.
Combining the spectral vegetation index with thermal infrared information, the triangular space of NDVI-Ts based on satellite remote sensing data provides an effective method for monitoring surface dry-ness at large spatial scales. Vegetation-Temperature Condition Index (VTCI) based on the triangular space of MODIS NDVI-Ts is applied to monitoring summer drought in Heilongjiang Province in 2007. The VTCI is based on satellite derived information only, and therefore the index is potential for operational applica-tion. The Terra-MODIS NDVI (MOD13A2) V005, LST (MOD11A2) V005 and the land cover product (MOD12Q1) V004 products, at 1-kilometer spatial resolution, are used as the indicators for the monito-ring and analysis. The monitoring period is from 10 June to 12 August 2007. It's found that the space of NDVI-Ts for the whole study area is typically triangular because the monitored area is large enough to make the value of NDVI and soil moisture vary in a very large scope. Then, a linear regression analysis is conducted to get the equations of the dry and wet line from the triangular space for the whole area, and the VTCI for the Heilongjiang Province is extracted. Combined with MODIS land cover product IGBP and fre-quency distribution of the VTCI, the spatial pattern and temporal evolution of the drought are also ana-lyzed. At last, the ground-measured precipitation data at the same periods are used to validate the drought monitoring measurements.The result shows that the drought widely distributed in spatial scale and is very serious. It is more se-rious in main crop-producing areas, especially in the western Songnen Plain and the west of eastern San-jiang Plain. From 10 June to 25 June the drought is heavier than the other 3 monitoring periods. Some fluctuations occur in July, then the drought weakens in most areas in August, except the Daxinganling Mountains in northwest where the drought enhances to some extent. The correlation analysis between VT-CI and ground-based measured precipitation indicates that there is a significant linear correlation between VTCI and total monthly precipitation. The VTCI and cumulative total monthly precipitation are also line-arly correlated from the monitoring month to the previous months. Obvious correlation is also found be-tween VTCI and the percentage of departure from normal monthly precipitation in the monitoring month,and between VTCI and the cumulative percentage of departure from normal monthly precipitation from the monitoring month to the previous months. The result suggests that VTCI is not only correlated with re-cent rainfall but also correlated with past cumulative rainfall. So it is a reasonable simplification of the ND-VI-Ts space and can monitor drought instantly, which is proved adaptive in Heilongjiang Province.