Crop monitoring and yield estimation using synthetic methods in arid land
干旱区农作物长势综合监测

It is difficult to monitor growing crops in a large scale. There isn't, up to now, a satisfied method to know what the way a crop is growing and how can get accurate yield estimations of the growing crops, which scientists have been intending to probe into. Remote sensing was used to monitor growing crops in North China and Northeast China. However, in arid land of Xinjiang in Northwest China, this method has not been used because of special geographical environment. In this paper, the researched subject is the winter wheat planted on the northern slope of Tianshan Mountains. A new method to monitor growing crops was experimented supported by modern spatial technology which integrated remote sensing, geographic information system, global positioning system, and other measures such as intensive ground surveys and the analysis for the situation in its history, in order to obtain more exact results. Geographic information system and global positioning system were properly integrated by GVG sampling system for the purpose of monitoring crop growth with the support of GVG system. Field investigations for the growth of winter wheat has been carried out and the database for yield evaluation has been built, which will be not only used to analyse the growth of crops, but also used to estimate the crop yieldmore exactly by contrasting the result from remote sensing imageries with information from intensive ground surveys. Three methods were used in estimating crop yield: remote sensing aided by GIS, field investigation and analysis for historic yield. It was showed that crop growth monitoring and yield estimation using this integratied method is practical, which should be extensively applied in arid land in Northwest China.