一、土壤图的作用及精度 土壤图是为农业生产布局和生产发展条件而编绘的专业图件,主要用于农业区划、生产规划、土壤评价以及农、林、牧用地的选择。因此,从应用的需要评价土壤图的质量,主要是土壤图的精度高不高和生产实用性强不强两个问题。土壤图的实用性取决于编图资料是否可靠和密切联系生产以及编图设计的是否合理。土壤图的精度则是编图者在编图过程中对若干技术问题的处理是否妥当,如编图综合问题。 1.土壤图的实用性 调查资料越丰富可靠又密切联系生产、则编图的基础越好,因而编绘的不同类型、不同比例尺的图件的生产性就越强。全国第二次土壤普查内容齐全、资料空前丰富,县、市、省各级提供的成果图件种类都超过了全国的要求,并根据各自的需要增编了许多反映地方特点的图件;如盐分 I. The Effect and Precision of Soil Map Soil map is a professional map drawn up for the conditions of agricultural production layout and production and development. It is mainly used for the selection of agricultural zoning, production planning, soil evaluation and agriculture, forestry and animal husbandry. Therefore, the quality of the soil map needs to be evaluated from the needs of the application, mainly the two problems of high precision of the soil map and poor practicality of production. The usefulness of soil maps depends on the soundness and closeness of the layout information and the reasonableness of the layout design. The accuracy of the soil map is the editor in the process of compiling a number of technical issues on the handling is appropriate, such as coding synthesis. 1. The more practicable soil survey data is more reliable and closely related to production, the better the basis of the drawing is and the more productive the different types and scales of drawings are drawn. The second national soil census is complete in content and information is unprecedented in abundance. The types of output maps provided at all levels of the county, city and province have surpassed the requirements of the whole country and added many maps reflecting the local characteristics according to their respective needs. For example, Salt