Spatiotemporal Hydrological Modelling with GIS for the Upper Mahaweli Catchment, Sri Lanka

Sustainability of water resources is imperative for the continued prosperity of Sri Lanka where the economy is dependent upon agriculture. The Mahaweli river is the longest in Sri Lanka, with the upper catchment covering an area of 3124 sq .km .. The Mahaweli Development programme, a major undertaking in the upper catchment has been implemented with the aims of providing Mahaweli water to the dry zone of the country through a massive diversion scheme and also for generating hydropower. Under this programme, seven large reservoirs have been constructed across the river and large scale land use changes in the catchment have occurred during the last two decades. Critics now say that the hydrological regime has been adversely affected due to indiscriminate land use changes and, as a result, river flows have diminished during the last two decades, thus jeopardising the expectations of this massive development programme. Reforestation programmes have been recommended because of the benefits of forest in resource conservation and also the water derived from fog interception. Selection of the best sites for these forest plantations for maximum benefits, especially in terms of water yield from fog interception has the utmost importance. This created the need for a comprehensive model to represent the hydrology and to simulate the hydrological dynamics of the catchment In conceptual terms, GIS is well suited for modelling with large and complex databases associated with hydrological parameters. However, hydrological modelling efforts in GIS are constrained by the limitations in the representation of time in its spatial data ,structures. The SPANS GIS software used in this study provided the capability of linking spatially distributed numerical parameters with corresponding tabulated data through mathematical and statistical expressions while implicitly representing temporality through iterative procedures.The spatial distribution of land use was identified through the supervised classification of IRS-IA LISS II imagery. Daily rainfall data for a 30 year period and corresponding gauging locations derived from GPS were managed and retrieved through a Lotus 1-2- 3 database. The fog interception component was estimated based on elevation and the monsoon season. Hydrological processes such as interception and evapotranspiration were derived from individual sub models and finally combined within the overall hydrological model structure. The model was run with daily time steps on numerical 'values of each quad cell of the thematic coverage. The information on flow derived from the model was depicted as a series of thematic maps in addition to the time series of numerical values at subcatchment and catchment outlets. The results confirmed that the model is capable of simulating catchment response of the UMCA successfully. The time dimension was accommodated through a senes of non-interactive REXX programmes in developing the customised version of the model. It is concluded that the software architecture of SPANS GIS is capable of accommodating spatiotemporal modelling implicitly in its spatial data structures although changes in the model structure may necessitate considerable reprogramming. Sensitivity of the model for different spatial interpolation techniques was evaluated. Further, sensitivity of the model for the defined hydrological parameters, spatial 'resolution and land use was also assessed. The model is sensitive to land use changes in the catchment and it shows 15-35% annual increase of runoff when forests are converted to grassland. Further studies are required to develop a more detailed set of hydrological parameters for the model

An intelligent Geographic Information System for design

Recent advances in geographic information systems (GIS) and artificial intelligence (AI) techniques have been summarised, concentrating on the theoretical aspects of their construction and use. Existing projects combining AI and GIS have also been discussed, with attention paid to the interfacing methods used and problems uncovered by the approaches. AI and GIS have been combined in this research to create an intelligent GIS for design. This has been applied to off-shore pipeline route design. The system was tested using data from a real pipeline design project. [Continues.

Terrain Representation And Reasoning In Computer Generated Forces : A Survey Of Computer Generated Forces Systems And How They Represent And Reason About Terrain

Report on a survey of computer systems used to produce realistic or intelligent behavior by autonomous entities in simulation systems. In particular, it is concerned with the data structures used by computer generated forces systems to represent terrain and the algorithmic approaches used by those systems to reason about terrain

4Sensing - decentralized processing for participatory sensing data

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática.Participatory sensing is a new application paradigm, stemming from both technical and social drives, which is currently gaining momentum as a research domain. It leverages the growing adoption of mobile phones equipped with sensors, such as camera, GPS and accelerometer, enabling users to collect and aggregate data, covering a wide area without incurring in the costs associated with a large-scale sensor network. Related research in participatory sensing usually proposes an architecture based on a centralized back-end. Centralized solutions raise a set of issues. On one side, there is the implications of having a centralized repository hosting privacy sensitive information. On the other side, this centralized model has financial costs that can discourage grassroots initiatives. This dissertation focuses on the data management aspects of a decentralized infrastructure for the support of participatory sensing applications, leveraging the body of work on participatory sensing and related areas, such as wireless and internet-wide sensor networks, peer-to-peer data management and stream processing. It proposes a framework covering a common set of data management requirements - from data acquisition, to processing, storage and querying - with the goal of lowering the barrier for the development and deployment of applications. Alternative architectural approaches - RTree, QTree and NTree - are proposed and evaluated experimentally in the context of a case-study application - SpeedSense - supporting the monitoring and prediction of traffic conditions, through the collection of speed and location samples in an urban setting, using GPS equipped mobile phones

Development of a Geographic Visualization and Communications Systems (Gvcs) for Monitoring Remote Vehicles

The purpose of this project is to integrate a variety of geographic information systems capabilities and telecommunication technologies for potential use in geographic network and visualization applications. The specific technical goals of the project were to design, develop, and simulate the components of an audio/visual geographic communications system to aid future real-time monitoring, mapping and managing of transport vehicles. The system components of this feasibility study are collectively referred to as a Geographic Visualization and Communications System (GVCS). State-of-the-art techniques will be used and developed to allow both the vehicle operator and network manager to monitor the location and surrounding environment of a transport vehicle during shipment

The Design and Implementation of a Truly Integrated GIS Using the Persistent Programming Language Napier88

This thesis is concerned with the design and development of an integrated geographical information system (IGIS) based on the use of a persistent programming language called Napier88. It reports on the research carried out to implement a wholly new approach to deal with the problems of constructing a truly integrated GIS. The main aspects discussed within the context of this thesis are: an overview of the current status and trends in IGIS development; the characteristics and functions of the persistent programming language Napier88; the design considerations and the definition of the system architecture of an IGIS; the integration of vector map data and raster image data in a persistent store; the multiple data modelling of geographical data; the superimposition and cross indexing of vector maps and raster images; the spatial indexing and querying of geographical data; the management of geographical data in a persistent database environment; and the implementation of a prototype IGIS. This thesis concludes that the Napier88 language can provide a sound framework for the construction of a truly integrated GIS, although some current deficiencies in the language need to be overcome. Since persistent programming languages are still in the stage of research and development, more research is necessary to investigate other features that they could provide which may be beneficial to the development of a truly integrated GIS

A GIS based dataset to assess the influence of countryside planning policies on landscape change in Bedfordshire

A GIS database for a study area (96 Km^) within the county of Bedfordshire (southern England) was established to provide statistical and mapped information on the distribution, extent and change through time of land-cover and landscape features between 1968, 1981 and 1991. A major aim of the project was to investigate the character of the countryside designation zones operating in Bedfordshire in terms of detailed local landscape. The effectiveness of the policies for the countryside was assessed in terms of the landscape changes monitored in each area. To this purpose a census of landscape features was carried out by means of aerial photographic interpretation and the differences between the three dates were measured. The classification scheme included 19 land-cover types (area features), 6 linear features and 6 point features. A Digital Terrain Model was used to analyse the land-fonn of the study area and its influence on the distribution of land-cover types. The countryside designation zones were digitised from the Local Plans and processed with the land-cover maps. The results of the project are represented by maps, tables and charts of landscape features for each date and their changes between each date, in the study area and in the countryside designation zones. The study area is shown to be intensively managed since agro-pastoral and developed land cover most of its area. Countryside designation zones showed a strong agro-pastoral character, except for the Sites of Special Scientific Interest and the National Nature Reserve. Generally, over the two decades analysed, both the study area and the countryside designation zones suffered changes in landscape features.MPhi