Sustainable Land Use For Lakes Basins
Abstract
Since some years, diffuse sources of agrochemicals have become a high relevance issue for environment safety. Lake Vico basin (Central Italy, about 60 km northern to Rome) is an optimal site to investigate this problem. In fact, it is clear the increasing of lake trophic state, due to agricultural diffuse nutrient sources, above all phosphorus. This territory needs a plan for Best Management Practices (BMPs) and model approach is fundamental to assess them. In particular, it is necessary to evaluate phosphorus export zones that more contribute to environmental concerns, to plan related BMPs and to evaluate their effectiveness. P export from a lake basin can be considered the impact (load) of land use on the water body and it is the starting point for the evaluation of lake trophic state (Vollenweider, 1976) and water quality status, also in recent European regulations (the 152/1999 Italian law and connected CE/60/2000). Methods to evaluate P load are various: - consider simple export coefficients only depending on land use (Reckhow et al., 1980) or also on some synthetic indices of hydrological characteristics (Frink, 1991). This approach has the advantage of easy application, but, necessarily, cannot interpret specific reality and environment -anthropogenic complexity, typical of diffuse sources problems. In consequence, it is not sufficiently detailed to evaluate BMPs incidence. - Apply field scale, simulation models, such as GLEAMS, which has the advantage to be enough detailed to interpret environment -anthropogenic complexity, but it involves a small area (it is a field scale model). - Apply basin scale models, such as SWAT, which has the advantage of wide area involvement, joined to a good detail. But it is necessary a high quantity of data and parameters in awide area (often not available in real cases), that means to introduce new uncertainty factors. In this paper, the three approaches are compared and discussed from the point of view of the P load from the basin to the lake, consequence of the land use. It is then proposed a new method to evaluate P load on the lake, more simply to apply (its simplicity is comparable with export coefficients methods), but much more detailed, because the detail comes from the application of a field scale model, which allows to highlight the effects of land use and to plan the BMPs, their allocation and effectiveness, i.e. to plan a sustainable land use.
- Publication:
-
EGS General Assembly Conference Abstracts
- Pub Date:
- 2002
- Bibcode:
- 2002EGSGA..27.2778L