顾及梯田地形的Grid-TIN混合格网数字高程模型研究

Research on the Terraces-Considered Grid-TIN Hybrid Mesh DEM

针对格网DEM难以对黄土高原梯田地形进行有效数字表达的问题,基于面向对象思想提出了能够顾及梯田地形的Grid-TIN混合格网DEM(Grid-TIN based DEM,GT-DEM)概念及其数据模型,并阐明其主要特征及与传统DEM的关系。以陕西绥德县辛店沟小流域水平梯田为例,利用现有1∶1万格网DEM、梯田特征点线及其外围边界线,构建出能够充分顾及梯田地形的GT-DEM。研究表明,利用现有格网DEM和梯田地形特征点线构建顾及梯田地形GT-DEM的技术可行。GT-DEM不仅可对研究区全局地形进行粗略表达,而且可对其局部梯田地形进行精细表达。该研究是对如何提高DEM的梯田地形数字表达能力的有益探索,对进一步提高DEM对淤地坝、鱼鳞坑等其他人工地形的数字表达能力具有重要借鉴意义。

The concept and data model of a new terraces-considered Grid-TIN based DEM（GT-DEM） are put forth on the basis of object-oriented thought to solve the problem that the terraces terrains on loess plateau are difficult to be represented by gridbased DEM, and its main characteristics and the relationship with traditional DEM are also clarified. Taking the level terraces in the Xindiangou small watershed of Suide County in Shaanxi Province as example, this paper constructs terraces-considered GT- DEM successfully by use of 1： 10 000 grid-based DEM and feature points and lines of terraces and its outer boundary. The study shows that it is technically feasible to construct terraces-considered GT-DEM by use of grid-based DEM and feature points and lines of terraces and its outer boundary. Not only the global terrains of study areas can be represented roughly by GT-DEM, the local terraces terrains can also be represented refinedly by it. This research is useful exploration for improving the abilities of DEM for the digital representation of terraces terrains and will be of great importance in improving the abilities of DEM for the digital representation of other artificial terrains like check-dams and fish-scale pits in the future.