GIS空间分析技术在棉花叶面积测定中的应用

为了快速准确的获得棉花叶面积信息，通过扫面仪获取棉花叶片和准图形的数字图像，利用GIS空间分析技术对长方形、等腰三角形、正方形和直角三角形进行面积和周长计算。结果表明，GIS法提取的面积、周长信息与准图形面积、周长之间的平均相对误差分别为0.021和0.01，远小于叶面积仪器的测量误差，说明GIS空间分析技术应用于棉花叶面积测定是切实可行的。这种方法不受叶片形状、大小、厚薄、叶片幼嫩等因素的影响，对于叶面积不大的植物，利用GIS强大的数据处理功能，可以进行批量处理。因此和其他叶面积测定方法相比，GIS空间分析技术测定叶面积具有准确、快速、数据处理量大等优点，适用于科研和生产推广使用。

Application of GIS Spatial Analysis to Measuring Leaf Area of Cotton

In order to measure leaf area of cotton,a new method for measuring leaf area of cotton was developed by using scanner and GIS.Firstly,the digital images of the cotton leaves and standard graphics were gotten through the scanner.Secondly,the digital images were vectored,and then the data of area and perimeter of rectangle,isosceles triangle,square and right triangle were extracted by using the GIS spatial analysis.The results showed that,compared to actual values of standard graphics,average relative error of area and perimeter extracted were 0.021 and 0.01,respectively,which was less than the measurement error gained by leaf area meter.Therefore,it was feasible to measure leaf area of cotton by means of GIS spatial analysis.Moreover,the GIS spatial analysis was not affected by the factors of leaf shape,size,thickness and tender leaves.For the plant with small leaf area,it could automatically output abundant data by using GIS batch data processing function.Compared with other methods of measuring leaf area,the GIS spatial analysis had the merits of precision,fast and abundance data,and it could be extended in the fields of production and scientific research.