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Most approaches for modelling flood inundation and depth in lowland settings involve laborious parameterisation of stream channel and floodplain hydraulic characteristics and most require intensive inputs to set up and maintain. Such an approach is unrealistic in Bangladesh with its highly complex and dynamic hydrological network and sparse data collection system. This needs-driven research develops techniques that could be used in an operational, national system for monitoring and assessing floods and for monitoring riverbank erosion and dynamics of river channel morphology. Satellite synthetic aperture radar (SAR) images are used in a consistent, multitemporal data set for the 1998 monsoon flood season. The SAR images are processed and analysed with digital elevation models (DEM) and other spatial data for monitoring floodplain water levels. Compared water levels for the 24-day image acquisition cycle compare with field data by average absolute value difference of 33 cm and with regression coefficient of 0.86. Daily floodwater elevations are simulated through regression relation of the floodplain with conventional river gauge recordings. Flood depth is derived by difference with a DEM and used to create a series of daily flood depth maps that compare with field data by less than 40 cm absolute value difference. Because of the unusually high water levels during the 1998 flood, it is possible that there may have been an unusually direct hydrologic connectivity between the river and the floodplain. Such a relation has yet to be extended to other flood seasons or to other floodplain areas. A series of spatial data products demonstrates the uses of these daily flood data for flood risk and vulnerability mapping, flood damage assessment, river erosion monitoring, and other applications. Before the methods can become operational, data processing, modelling, and analysis will need to become more quantitative and more efficient. Furthermore, institutional linkages and multi-stakeholder co-operation and involvement will need to be ensured. Bangladesh lacks the financial resources for implementing and maintaining an operational system, however, it has the technical capability and the commitment of development partners.

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The aim of this research is to analyse the process of land transformation for an upazila (subdistrict) of Dhaka, the Capital of Bangladesh, using image interpretation techniques and GIS approaches. The analysis spansa time period at decenniali ntervals from 1951 (predevelopmenpt hase)t o 2001 (urbanisation stage). The upazila is considered in Bangladesh to be the main focal point of government planning, land management, environment and development policies. Savar Upazila has been selected as the study area because of its rapidly changing population density, socioeconomicp henomenaa nd land use/coverc hanges ince the independencefr om the Great Britain. The major sources of high resolution (up to a 2.4 metre resolution) remotely sensed data are panchromatic and infrared aerial photography (1953,1984 and 1990); CORONA K114 and K114b spy satellite panoramic film (1962 and 1972) and IRS-ID panchromatic imagery (2000); and DGPS based GCP coordinates of 2001. Digitally converted conventional and Historical administrative, settlement, planning, revenue and topographic maps have been digitised and used at a large-scale of up to 1: 3,960. Moreover, the enhanced 1951,1961,1974,1981,1991 and 2001 population censuses are used in parallel to help interpret images and related factors. In-depth survey and participatory approaches were used during the fieldwork at plot level to help interpret and develop a weighted land cover model and to understand factors responsible for change. In grid format, compatible to temporal image data, detailed land value data were converted into gridded format compatible with a decadal time-series of imagery and from the field for the early 1950s to 2001 integrated with mauza maps. The attribute data have been used as if it was an image data layer in order to visualise land value data. The results illustrate that significant and visible land transformations and population change have occurred over the last half-century from a completely river-dependent countryside to a modem road network orientation, with a change from the byde (low-lying flood-prone area) to chala (highland flood-free area) land economies. A spatio-temporal land transformation index is proposed to explain the complex micro-scale change that have taken place using land use and land value data. Remotely sensed data provides the context with which to interpret past and present land cover and land use. This study shows the importance of modem GIS techniques to integrate enhanced field and secondary data/maps with raster data as well as for mapping historical images and information on the future development, land reform/management, environmental study and planning in Bangladesh.

Banverket Trafik has a responsibility to make sure that the companies who traffic the Swedish railroad have the correct information about the status of the railroad. One of Banverket Trafiks information systems (Opera) presents the train’s actual position on a map and provides the user with physical information about the trains. Due to increasing demands on the information systems, Banverket Trafik needs to update the present system architecture in order to manage the increasing demands on map graphics and map functions. This paper analysis the information system Opera on the basis of theory and support of methods and discuss problems and demands for Opera. Further we investigate three GIS products to se if they meet the demands. Information about the products was gathered from both supplier and independent users to get a just picture of the products potentials. This paper comprises a suggestion of new system architecture that meet these needs. The suggested system architecture is capable of handling the map graphics and the map’s functions of more than one information system. Hopefully more than one information system will use the suggested system architecture as a map service.