人地系统是地理学最为重要的研究内容，区域可持续发展有赖于人地系统的合理结构与优化模式以及人们对此系统的有效调控。县级区域是一个具有复杂系统结构与功能的人地关系地域系统，本文以黄陵县为例，结合实地调查资料和统计数据，分析县域人地系统中人口、资源、经济和社会等结构特征。运用系统动力学理论与方法，建立人地系统演变的动态调控模型，对该系统进行多种发展方案调控试验，比较优选出人地系统协调发展的优化调控模式，为地区可持续发展提供决策依据。

study of human-earth system is the most important content in geography; regional sustainable development relies on the reasonable structure optimal model and effective regulation of regional human-earth system. County region is a complex and opening human-earth system, taking Huangling county as an example, the environment, resources exploitation, economic development and structure evolvement of industry were systematically analyzed. And the systematical dynamic model was established and multi-projects were simulated with the theory and method of system dynamic. Optimized regulation models of human-earth system evolvement were educed based on three projects: (1) Traditional evolvement method. The intensity of resource exploitation and environment pollution is the least, but the speed of its economy development is the lowest, which restrict social sustainable development and economic reproduction. (2) Economy development method. The intensity of resource exploitation and environment pollution is the worst, economic development mostly depends on higher investment and pollution, which is a traditional mode of unsustainable development. (3) Harmonious development mode. The mode considers not only economic sustainable development and natural recourses utilizing reasonably, but also gives more attention to environment protection and harmonious development of industry, agriculture, tourism and so on. It is the optimized mode of the human-earth system evolvement.