نوع مقاله : مقاله پژوهشی
1 دانشجوی کارشناسی ارشد آبیاری و زهکشی، گروه مهندسی آب دانشکده علوم کشاورزی دانشگاه گیلان
2 استادیار گروه مهندسی آب دانشکده علوم کشاورزی دانشگاه گیلان
3 استادیار پژوهش موسسه تحقیقات برنج کشور
عنوان مقاله [English]
VSM is a simple vegetative simulation model which in spite of needs to a few input data, its accuracy in field scale is acceptable. However due to high uncertainty in input data, its application in regional studies is very limited. In this study, the regional rice estimation was improved by combining VSM model with satellite data of short wave solar radiation and leaf area index. The spatial resolution of remotely sensed leaf area index from MODIS was improved using downscaling technique and high spatial satellite data of Landsat TM. Later its impact was investigated on validation process of regional rice estimation. Comparison of observed and estimated LAI with (or without) downscaling indicated that in case of applying down scaling technique accuracy of LAI maps will increase up to two times (from R2= 0.44 to R2= 0.87). The results indicated also in case of using downscaled LAI data in VSM model, the overall accuracy of regional rice yield estimation will increase dramatically (from R2= 0.64 to R2= 0.91).