利用计算机模拟生成的数字地形，其真实感很大程度上来源于其包含的与真实地形相似的结构特征和空间关系。为了使模拟生成的随机地形具有流水地貌中水系与地形相互套合的空间形态关系，引入一种新的数字地形模拟生成方法。该方法利用受粘结系数和平均场参数控制的受限扩散凝聚（DLA）模型生成谷底线，并在此基础上利用逐级膨胀操作模拟生成数字地形。实验结果证明，使用该方法生成数字地形在过程上具有良好的可控性，在形态结构上具有随机性，且具有类似于自然环境中的树状沟谷结构特征。

The structural features and spatial relations in a digital terrain are definitive manner in terrain simulation by computer. It determines whether a digital terrain is similar to the natural ones. In the natural environment rivers are embedded in mountains. To bring this spatial modality into a stochastic terrain built by computer, a new method is introduced in this paper. In the method, a valley line is generated from a revised DLA model (Diffusion Limited Aggregation) controlled by sticking coefficient and mean field parameter. After a simplification of the valley line, a continuous expanding operation is used to establish the digital terrain subsequently. The experiment result shows that this method is controllable in the process of establishing the terrain. And the terrain is stochastic with natural dendritic valley in it.