地表和地下水集水区对污染的脆弱性因土地利用、土壤类型、水文、地质和气候等多种因素而显著不同。这适用于各种潜在污染物，尤其是杀虫剂。虽然对潜在污染物的全面控制和鼓励一般良好做法措施将在保护集水区方面有所裨益，但真正有效的保护只能通过基于对当地脆弱性的具体评估的有针对性的措施来实现。因此，我们开发了一种新型的、基于计算机的流域规划系统，称为CatchIS。这为操作各种GIS和非GIS数据库提供了一个强大而灵活的系统，以及农药和其他污染物的特定径流和淋滤模型。该系统提供了一个强有力的管理工具，以促进鼓励使用污染较少的农药的做法。 此外，它还为水利设施规划提供了许多其他重要机会。

The vulnerability of surface and groundwater catchments to pollution varies significantly depending on a variety of factors including land use, soil type, hydrology, geology, and climate. This is true for a wide range of potential contaminants including particularly pesticides. While blanket controls on potential pollutants and encouragement of general good practice measures will be of some benefit in protecting catchments, truly effective protection can only be achieved by targeted measures based on specific assessment of local vulnerability. For that reason we have developed a novel, computer-based catchment planning system, known as CatchIS. This provides a powerful and flexible system for manipulating a variety of GIS and non GIS databases, in conjunction with specific runoff and leaching models for pesticides and other pollutants. The system provides a powerful management tool for promoting practices which encourage less polluting pesticide use. In addition it offers a number of other significant opportunities for water utility planning purposes.