Data warehouses and OLAP systems help to interactively analyze huge volume of data. Spatial OLAP (SOLAP) refers to the integration of spatial data in multidimensional applications at the physical, logical and conceptual levels. Integration of GIS and OLAP systems rises several architectural and implementation problems. This paper presents GeWOlap, a web based integrated and extensible GIS-OLAP prototype, able to support spatial geometric dimensions by defining a fully synchronized usage of maps and pivot table and geographical measures. We describe our tool using a SOLAP application concerning supervision of French departments pollution.