SWAT（Soil and Water Assessment Tool）是由美国农业部（USDA）的农业研究中心（ARS，Agricultural Research Service）Jeff Amonld博士1994年开发的。模型开发的最初目的是为了预测在大流域复杂多变的土壤类型、土地利用方式和管理措施条件下，土地管理对水分、泥沙和化学物质的长期影响。它是一种基于GIS基础之上的分布式流域水文模型，近年来得到了快速的发展和应用，主要是利用遥感和地理信息系统提供的空间信息模拟多种不同的水文物理化学过程，如水量、水质以及杀虫剂的输移与转化过程。现在使用的SWAT2005版本可以在Arcview、ArcGIS等常见的软件平台上运行，具有良好的用户界面
SWAT (Soil and Water Assessment Tool) by the United States Department of Agriculture (USDA) Agricultural Research Center (ARS, Agricultural Research Service) Jeff Amonld Dr. 1994 developed. The original purpose of the model developed to predict the complex soil type in large watersheds, land use and management measures under the conditions of the land management of water, sediment and chemicals in the long-term impact. It is a distributed hydrological model based on GIS basis, and in recent years has been the rapid development and application of spatial information is provided by the use of remote sensing and geographic information system to simulate a variety of different hydrological physical and chemical processes, such as water, water quality and pesticide transport and transformation process. The now use SWAT2005 version can run on a common software platform Arcview, ArcGIS, has a good user interface (2012-10-26, PDF, 59KB, 下载75次)
这个程序源码实现了mapx的绝大部分功能，非常经典！！并且我增加了一个重要功能，网上有许多人提出了这个功能，但是没有很好的解决。修改后，可以实现图层的动态移动，在创建折线时，当鼠标位于窗口边缘时，图幅自动平移，就像mapinfo一模一样的效果，并非简单的移动视图中心。当然你可以根据需要将功能扩充到在画直线、画多义线、画多边形的时候实现动态移动。具体功能与说明请下载后参阅ReadMeFirst。
the process to achieve the source of most of the functionality MapX, very classic! ! And I added an important function, the Internet has made many of the features, but not a very good solution. After revisions, the layer can be achieved for the dynamic movement, in the creation of dogleg, when the mouse is located at the edge of the window, maps automatic translation, like MapInfo exactly the same effect, is not a simple mobile View Center. Of course, you may need to expand the functions of the painting straight line paintings, the paintings polygon Dynamic Mobile. The specific function and description of downloading information ReadMeFirst. (2005-02-17, Visual Basic, 1840KB, 下载309次)