Application of Cadastre Maps, Agricultural Database and MODIS Satellite Images for Monitoring Cultivated Areas

摘要

This study has combined the 16-day NDVI (250-m) of Moderate Resolution Imaging Spectroradiometer remote sensing data and cadastre maps for monitoring cultivated areas during 2000-2013 in downstream of Doroodzan dam agricultural lands, Fars province, Iran. There are three regions in dams' downstream including Marvdasht, Shiraz and Kharameh which were mainly irrigated by this reservoir. In the surveyed period, 300 artificial bounds of Normalized Difference Vegetation Index (NDVI) were used. Then, the cadastre maps of each region were crossed over the NDVI bounds and the fluctuation of NDVI time series in each farmland were determined. Also, based on the ground observations through the Fars Comprehensive Agricultural Database (FCADB), the NDVI more than 0.2 throughout the time series was specified as the cultivation area. Therefore, on each farmland the history of cultivation was achieved. Also, the relationships between NDVI fluctuation and monthly mean temperature, precipitation and its anomaly (standardized precipitation) in various lags were analyzed. Results exhibited two crop cultivations including in both winter (mainly wheat and barley crops) and summer season types (majority paddy and maize). However, during droughts and shortages, just winter cultivation was detected from 2008 to 2010 in Shiraz and Kharameh farmlands. Also, the summer crop cultivation areas in Marvdasht region decreased during these years. Moreover, Kharameh in 2009 had no crop cultivation. With regard to cultivation areas with temperature, the most correlations were found between temperature and cultivation area in the third lag months equal to 0.73, 0.68 and 0.44 for Shiraz, Marvdasht and Kharameh, respectively. For precipitation, the most correlation with cultivation area appeared in 9 lag months equal to 0.44, 0.43 and 0.28 for Shiraz, Marvdasht and Kharameh, respectively. Although temperature and precipitation play an exclusive role in the fluctuation of NDVI over the study area, the lack of exact data, mainly cadastre one, has been the main source of non-efficient water allocation systems over the farmlands. Based on the new data provided by FCADB based on the cadastre maps, the managers and decision makers can have a stronger irrigation planning over the agricultural lands.