Topographic Analysis for Distributed Hydrological and Erosional Modelling of Landscapes

对水文和土壤侵蚀模型的核心重要性是建立适当的地形表示。这样的表示必须能够产生对任何点的高程、坡度和坡向的精确估计。然而，由于这一问题的复杂性，在解决这一问题方面进展甚微。例如，目前用于预测土地利用措施和农业管理措施对非点源污染影响的模型，由于无法充分考虑三维影响而受到限制。基于地形可以用离散多边形的形式表示，每个离散多边形由两个等高线段和两条内插流线界定，调查人员将开发一种技术，以处理大流域和河流流域属性的空间变异性。该项目将改进并开始测试已建立的水文模型，该模型整合了为更具体的模型开发的算法。这项创新的研究旨在开发包含三维效果的方法，并且比目前的方法更容易、更准确、更实用地供工程师、土壤科学家和其他从业者使用。解释表示地形的方法，以及在计算这种表示时必须处理的主要统计问题，将有助于地理信息系统的发展。这些方法有可能促进在模拟管理和土地利用做法对非点源水质和水量的影响方面取得进展。所开发的技术也可能适用于地下水的移动和相关的地下水应用，而这又可能是制定可靠的补救措施时的基本考虑因素。

Of central importance to hydrologic and soil erosion modelling is the development of an adequate representation of terrain. Such a representation must be capable of yielding precise estimates of elevation, slope, and aspect at any point. Little progress has been made in solving this problem because of its complexity, however. Present models for predicting effects of land use practices and agricultural management practices on nonpoint source pollution, for example, are limited by their inability to adequately consider three-dimensional effects. Based on the idea that terrain can be represented in the form of discrete polygons, each bounded by two contour segments and two interpolated streamlines, the investigators will develop a technology to handle spatial variability of the attributes in large watersheds and river basins. This project will refine and begin testing of an established hydrological model that integrates algorithms developed for more specific models. This innovative study aims to develop methods that encompass three-dimensional effects and that are more tractable, accurate, and practical for use by engineers, soil scientists, and other practitioners than are current methods. Explanation of means of representing terrain, and the central statistical questions that must be dealt with in working out this representation, will contribute to the development of geographic information systems. These methods have the potential to facilitate progress toward modelling the effects of management and land use practices on nonpoint source water quality and quantity. The techniques developed may also be applicable to subsurface water movement and to related groundwater applications, which in turn are likely to be essential considerations in the development of reliable remedial measures.