Objective
- To develop a prototype remote sensing and geographic information system (RS/GIS) NPS pollution model to aid identification, delineation and mapping of areas with high NPS pollution potential and to help monitor pollution loading from nonpoint sources in the study area.
The general objectives :
- To establish a network of Mediterranean scientific organisations that will define, develop and apply The state-of-the-art of GIS, remote sensing and mathematical modelling methods in an integrated database for the control and surveillance of the Mediterranean coastal water resources and the estimation of NPS pollution impact;
- To create an integral and competitive methodology to be applied in all the Mediterranean basin assisting the development of Integrated Coastal Zone Management (ICZM) plans and sustainable use of water resources (Agenda 21, UNCED, Rio, l992);
- To deliver compatible GIS products to the EC for the extension of CORINE, NATURA 2000 Databases, etc.
The specific objectives :
- To integrate, by an appropriate computer-based solution, an agricultural NPS pollution model, a GIS, and relevant data sources;
- To apply the approach to several catchments, exploring the issue of NPS pollution under various scenarios;
- To evaluate the approach generally, and specifically for use in the other programme, and for analysing NPS pollution issues.
- To evaluate the possible effects of best management practices (BMPs), the SWRRBWQ model was run for several scenarios. The analysis of increasing BMPs included better land management practises to reduce soil loss, grass watershed and impoundment structures, animal waste management practices, and fertiliser management practices. The management scenarios demonstrated that reducing fertiliser application rates and availability levels will bring approximately proportional improvements in water quality related to NPS pollution.
- Further spatial analysis was carried out through the identification of critical areas. An analysis using the spatial capability of the model showed that the initial project definition of a critical area was a good surrogate for some pollutants, but not for others. The critical areas were displayed using the GIS.
- The use of the SWRRBWQ model integrated with the GIS was considered to be a powerful tool to the effectiveness of the project. The main strength of the GIS confirmed in this project is its communication potential and the visual impact of the information. Limitations cited include variation between actual and model data due to seasonal variations not captured by averaging, changes in actual information after data capture, input errors, unavailability of data (e g. conservation practice values), uncertainty in model relationships, and the applicability of a general regression model to the specific area of study.
- The use of GIS and RS has demonstrated that it would have been almost impossible to do some analyses without the GIS, and probably more of the processing could have been done using the GIS had more time and training been available. Certainly the overall approach was very cost-effective in terms of development time, data management, and scenario evaluation.
Follow-up
- The main priority of future research should be to increase source data accuracy, focusing on curve number related parameters and fertiliser application and availability estimates. More appropriate data sources are suggested as the main priority for improving the application;
- Further work is justified by the benefits of integrating the model and GIS which has been demonstrated to be a powerful combination in the communication of NPS pollution related issues of increasing concern;
- In addition in the future the use of GIS as a data resource should enable agencies and authorities to establish centralised georeferenced databases using GIS. These techniques also provide federal and state regulatory agencies with the information and tools needed to develop management measures for monitoring sources of nonpoint pollution. Such tools also allow these agencies to prioritise spending, concentrating resources on plans that will result in significant reduction of pollution.
- Selection of the NPS model
- Non-point pollution hydrological models are a part of loading models that represent and simulate the generation and movement of water and its pollution content from the point of origin (source area) to a place of treatment and/or disposal (discharge) into receiving waters. These models may be used for planning and design alone, or may interface with receiving water quality models that assess the impact of non-point pollution on the aquatic biota and beneficial downstream uses;
- The SWRRBWQ model was selected as the most appropriate. As the model is continuous in time, it can determine the impacts of management factors such as crop rotations, planting and harvest dates, and chemical application dates and amounts. Basins can be subdivided into subwatersheds (10 maximum) based on differences in land use, soils, topography, vegetation, rainfall and temperature. Sediment and associated chemicals are then routed to the basin outlet. ln the vertical direction, the model is capable of working with any variation in soil properties, as the soil profile is divided into a maximum of 10 layers. The components of SWRRBWQ can be placed into eight major divisions : hydrology, weather, sedimentation, soil temperature, crop growth, nutrients, pesticides and agricultural management.
- Use of Remote Sensing /GIS Methodology
- A geographic information system (GIS) offers major benefits to modelling, through its capacity to manage large data volumes cost-effectively, in a common spatial framework its potential to integrate with other key technologies such as remote sensing, and its ability to communicate spatially complex natural resource issues simply in graphical form via maps;
- The close relationship between remote sensing and GIS arises from the capability of remote sensing to efficiently supply large volumes of relevant data to GIS, which can then be merged and analysed with other data input from other sources.
- Development of a GIS Database
- NPS models may require data stored in a GIS database such as climatic/weather input data and model parameters derived from measurements of climate, topography, soil physical and chemical properties, geology, land cover, hydrography and water quality.
These data have vastly different temporal and spatial scales of variability and measurement. Often the scale and method of measurements are not directly compatible with the scale needed by the model. Furthermore modelling applications require data georeferenced to a common system of grids, polygons, lines or points.
- Integration of GIS And NPS Model
- The spatial capability of a GIS, in conjunction with a non-point source pollution model has its most critical limits regarding the difference in the data models and in the way relationships between variables are handled in GIS and in hydrologic models. The GIS data model is a spatial relational data model that is extremely efficient at processing vast quantities of data on individual layers of information in a uniform way over a large area of space. In hydrologic model the focus is generally local rather than global;
- The most obvious accomplishment in linking GIS and hydrologic models is for GIS to provide a digital database representing the land surface environment that can be used to build up the input data for a hydrologic model without having to measure or planimeter those data from paper maps. Second GIS can act as a display environment from the output from the hydrologic models;
- The watershed elements stored in GIS database comprised component maps showing land use, soil types, stream network, slope, subwatershed boundaries, etc. Remote sensing has a significant potential to add to hydrologic modelling through quantification of land use obtained from satellite images, aerial photographs and CORINE nomenclature;
- The GIS used in this project is ARC/INFO (ESRI), and the NPS model used is the SWRRBWQ because of its ability to reflect changes in management practices. To achieve the integration of the SWRRBWQ model, the RS/GIS, and the data sources, an interfacing software was used to write programs to transfer and process data as required;
- The result was an integrated NPS-GIS software package that has been applied in four areas in Italy, Greece, Turkey and Egypt.
- Applications in ltaly, Greece, Turkey & Egypt
- According to the scope of the project one application at the Alphone watershed in Italy has been developed providing all the technical information of the NPS model SWRRBWQ. Considering this application, two other applications in Turkey and Egypt have been developed and one in Greece for the Sperchios River catchment. These last application has provided all the information on CORINE classification, GIS and RS as well as on the hydrodynamic and water quality mathematical model;
- The applications involve the integration of the agricultural non-point source pollution model (SWRRBWQ), the RS/GIS ARC/INFO, data sources and connecting software. The primary objective to achieve this integration was met, and a number of scenarios established to explore rainfall variation, model sensitivity, and changes in management practices.
- Workshops, Training, Networking. Dissemination
- In the framework of this activity, members of the consortium have :
- participated in 3 Workshops/seminars on remote sensing and on the SWRRBWQ model;
- lectured in the Advanced European Training Course on Remote Sensing for Marine Applications, (18-29 September 1995, Enschede, The Netherlands);
- prepared a book : "Coastal Management and Habitat Conservation";
- participated with poster and paper at the ESRI international conference held in 1995 and 1996 in Palm Springs CA, US.
- Also members of the consortium have disseminated data and results via the internet to the EC projects :
- ENVIDUCATION (environmental education for children between 8-16 years old) funded by the EC programme IMPACT
- ENVISYS funded by the EC programme Telematics on Environment
- ENVIROCITY funded by the EC prograrnme Telematics on Environment
- LIFE (integrated management of Sperchios river basin)
- Control Measures, Surveillance And Closures
- In the frame of this activity each partner has formulated strategies and control measures for sustainable use of water resources in its country and has designed a future extension of database. The overall project has established control measures that will benefit the countries involved in the future. The overall surveillance has been undertaken on laboratories and institutes across the Mediterranean active in the same areas of science and decision making.
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
15125 Marousi
Greece