The dynamic forces of geo - environmental changes are the gravitational force of celestial bodies , endogenetic force in the earth , exogenetic force on the earth surface and human activities 地质环境变化的动力是地外天体引力、地球内动力、地球表层外动力和人类社会工程经济活动4种地质作用。
2.
In accordance with coal sample observation by scanning electron microscope ( sem ) and researches based on such subjects as anthracology , tectonic geology and material mechanics , the endokinetic fractures in coal are further classified into dewatering fractures , condense fractures and static pressure fractures , while the exogenetic fractures are further divided into tensile fractures , pressure fractures , shrink fractures and slack fractures , consistent with the development regularity of the geometric shapes , sizes and arrangement of fractures 摘要分析、归纳了大量的扫描电子显微镜观测结果，以煤岩学、构造地质学研究?基拙，依锯煤中显微裂隙的形态、大小、排列组合等发育特征，将内生裂隙进一步划分?失水裂隙、缩聚裂隙、静压裂隙，将外生裂隙进一步划分?张性裂隙、压性裂隙、剪性裂隙、松弛裂隙。
3.
( 2 ) the conception of the danxia landfonn that is a kind of the red clastic rock ( silthstone - conglomerate stone ) landfonn , derived of the of work the exogenetic and endogenetic force , characterized by red cliff , fortress , pagoda , wall , peak cluster , peak forest , etc . this article systematically summarized the evolvement , type and character 其次，界定了丹霞地貌的概念，丹霞地貌是发育在以红色粉砂- -砾岩为主的地层中，受内力、外力(重力崩塌、风化、流水等)作用形成的地貌，具有赤壁丹崖、方山、岩堡、岩塔、岩墙、孤峰、群峰等特征。
4.
The complex characteristic of the danxia landfonn derived of the development and evolvement of the danxia landfonn under the exogenetic and endogenetic force work together in the different conditions such as weather , stone and tectonic . on the basic of the investigation of the danxia landfonn and according to the tourism principle , the article analyzes and assesses the danxia landform s resource and its exploitation and protection . the article discusses the following main problem 本文在研究丹霞地貌的基础上，根据旅游学的原理，对丹霞地貌资源的评价、开发和保护进行分析，并作了实证研究，文章主要探讨了以下内容：首先，本文总结了国内对丹霞地貌与丹霞旅游资源研究历史及其发展趋势，指出丹霞地貌的定义不够完善，丹霞地貌的理论研究较缺乏；丹霞旅游资源评价主要集中在资源的定性评价，评价体系还不够完善。
