基于草地分类的草产量建模与数表编制方法研究

Study on grass yield modeling and table establish⁃ ment based on grassland classification

摘要:

草原资源外业调查数表的研制，对草原资源的经营和管理，编制草产量调查表具有实践意义。研究采用不同的备选模型和哑变量设置方法进行模型拟合，以相对等级法为例编制调查数表，并进行了落点检验。结果表明：Chapman 拟合决定系数平均值为 0. 62，拟合结果优于其他备选模型；以草地类型作为哑变量能显著提高模型的拟合效果，相较于其他哑变量设置方法，拟合决定系数提高了 0. 26。各草地类型草产量表落点检验值均大于 75%，基于草地分类的草产量数表编制方法能满足草原资源外业调查草产量的估计要求。

Abstract:

Grassland is the largest terrestrial ecosystem in China and one of the main battlefields of ecological civilization construction. Under the strategic background of carbon peak and carbon neutral，rapid and accurate survey and monitoring results can guide grassland protection and restoration more scientifically. The lack of inventory tables for grassland productivity has limited the management grassland resources for a long time. Therefore，it is of practical significance to establish survey tables for grass yield. In this paper，different alternative models and dummy variable setting methods were used for model fitting，and the ratio method was used to compile the inventory table，and the drop point test was carried out. The results show that the average determination coefficient of Chapman model fitting is 0. 62，and the fitting result is better than other alternative models. Taking grassland type as dummy variable can sig‐ nificantly improve the fitting effect of the model. Compared with other dummy variable setting methods，the fitting de‐ termination coefficient is increased by 0. 26. The drop test value of the yield table of each grassland type is greater than 75%. In conclusion，the preparation method of grass yield number table based on grassland classification can meet the requirements of grass yield estimation in field survey of grassland resources.