CAJ | 학술논문

叶面积指数（LAI）的快速估算对于及时了解作物长势、病虫害监测以及产量评估具有重要意义。利用2012年7月7日在黑河流域张掖市获取的CASI高光谱数据，精确提取出了不同作物的光谱反射率，同时结合地面实测数据，对比分析了宽波段和“红边”植被指数在估算作物 LAI方面的潜力，在此基础上，基于波段组合算法，筛选出作物LAI估算的敏感波段，并构建了两个新型光谱指数NDSI和RSI ，最后对研究区域作物LAI的空间分布进行了分析。结果表明，在植被覆盖度较低的情况下，宽波段植被指数 NDVI对LAI具有较好的估算效果，模型的精度 R2与RMSE分别为0.52，0.45（p＜0.01）；对于“红边”植被指数，由于CIred edge充分考虑了不同的作物类型，其对LAI的估算精度与NDVI一致；利用波段组合算法构建的光谱指数NDSI（569.00，654.80）和RSI（597.6，654.80）对LAI估算的效果要优于NDVI与CIred edge ，其中，NDSI（569.00，654.80）主要利用了植被光谱“绿峰”和“红谷”附近的波段，模型估算的精度 R2可达0.77（p＜0.0001）；根据LAI与NDSI（569.00，654.80）之间的函数关系，绘制作物LAI的空间分布图，经分析，研究区域的西北部LAI值偏低，需增施肥料。研究结果，可为农业管理部门及时掌握作物长势信息、制定施肥策略提供技术支持。
협면적지수（LAI）적쾌속고산대우급시료해작물장세、병충해감측이급산량평고구유중요의의。이용2012년7월7일재흑하류역장액시획취적CASI고광보수거，정학제취출료불동작물적광보반사솔，동시결합지면실측수거，대비분석료관파단화“홍변”식피지수재고산작물 LAI방면적잠력，재차기출상，기우파단조합산법，사선출작물LAI고산적민감파단，병구건료량개신형광보지수NDSI화RSI ，최후대연구구역작물LAI적공간분포진행료분석。결과표명，재식피복개도교저적정황하，관파단식피지수 NDVI대LAI구유교호적고산효과，모형적정도 R2여RMSE분별위0.52，0.45（p＜0.01）；대우“홍변”식피지수，유우CIred edge충분고필료불동적작물류형，기대LAI적고산정도여NDVI일치；이용파단조합산법구건적광보지수NDSI（569.00，654.80）화RSI（597.6，654.80）대LAI고산적효과요우우NDVI여CIred edge ，기중，NDSI（569.00，654.80）주요이용료식피광보“록봉”화“홍곡”부근적파단，모형고산적정도 R2가체0.77（p＜0.0001）；근거LAI여NDSI（569.00，654.80）지간적함수관계，회제작물LAI적공간분포도，경분석，연구구역적서북부LAI치편저，수증시비료。연구결과，가위농업관리부문급시장악작물장세신식、제정시비책략제공기술지지。
The fast estimation of leaf area index (LAI)is significant for learning the crops growth ,monitoring the disease and in-sect ,and assessing the yield of crops .This study used the hyperspectral compact airborne spectrographic imager (CASI) data of Zhangye city ,in Heihe River basin ,on July 7 ,2012 ,and extracted the spectral reflectance accurately .The potential of broad-band and red-edge vegetation index for estimating the LAI of crops was comparatively investigated by combined with the field measured data .On this basis ,the sensitive wavebands for estimating the LAI of crops were selected and two new spectral inde-xes (NDSI and RSI) were constructed ,subsequently ,the spatial distribution of LAI in study area was analyzed .The result showed that broadband vegetation index NDVI had good effect for estimating the LAI when the vegetation coverage is relatively lower ,the R2 and RMSE of estimation model were 0.52 ,0.45 (p<0.01) ,respectively .For red-edge vegetation index ,CIred edge took the different crop types into account fully ,thus it gained the same estimation accuracy with NDVI .NDSI(569.00 ,654.80) and RSI(597.60 ,654.80) were constructed by using waveband combination algorithm ,which has superior estimation results than NDVI and CIred edge .The R2 of estimation model used NDSI(569.00 ,654.80) was 0.77(p<0.000 1) ,it mainly used the wavebands near the green peak and red valley of vegetation spectrum .The spatial distribution map of LAI was made according to the functional rela-tionship between the NDSI(569.00 ,654.80) and LAI .After analyzing this map ,the LAI values were lower in the northwest of study area ,this indicated that more fertilizer should be increased in this area .This study can provide technical support for the agricul-tural administrative department to learn the grow th of crops quickly and make a suitable fertilization strategy .