Web Geographic Information Systems (GIS) are systems composed by software, hardware, spatial data and computing operations, whic h aim to collect, model, store, share, retrieve, manipulate and display geographically referenced data. The development of online geospatial applications is currently on the rise, but this type of application often involves dealing with concerns (i.e., pro perties) which are inherently volatile, implying a considerable effort for system evolution. Nevertheless, geospatial concerns (e.g., temporarily blocked streets), although changeable, are reusable. However, lack of modularization in software artifacts (in cluding system’s models) can compromise reusability. In this context, the use of requirements analysis patterns, enriched with aspect -oriented modeling techniques, can support reusability and improve modularity. In this paper, we introduce requirements ana lysis patterns for geospatial concerns, to facilitate modularity in GIS Web applications. These patterns are generated from the domain analysis of Web GIS applications and described using a template which is supported by a comprehensive tool, enabling the completion of specific geospatial patterns.