PRESENT STATE ANALYSIS OF EXTINCT POND AREAS AS A BASIS FOR FUTURE USE OPTIMISATION

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1 Proceedings of the 13 th International Conference of Environmental Science and Technology Athens, Greece, 5-7 September 2013 PRESENT STATE ANALYSIS OF EXTINCT POND AREAS AS A BASIS FOR FUTURE USE OPTIMISATION V. DAVID 1, and T. DAVIDOVA 1 1 Czech Technical University in Prague, Faculty of Civil Engineering, Department of Irrigation, Drainage and Landscape Engineering Thakurova 7, Prague 6 Dejvice, Czech Republic Organization and Department vaclav.david@fsv.cvut.cz EXTENDED ABSTRACT There are many extinct ponds within the area of the Czech Republic. The golden era of fish ponding is dated to the beginning of the 17 th century. The total number of ponds at that time is usually estimated at , while the present number is about This means a decrease to less than one third in total number. The reasons for extinction are various, but the two main reasons are destruction during wars and the demand for more arable land. The research project NAZV KUS QJ Assessment of former pond systems with the aim to achieve sustainable management of water and soil resources in the Czech Republic focuses on the present use of extinct pond areas and on the analysis of the optimal use of such areas with emphasis on the sustainability of soil and water resources. The complete methodology for the assessment is being developed at the Czech Technical University in Prague (CTU) in cooperation with Palacký University Olomouc (PU). This methodology will consider different aspects such as natural conditions, ecological criteria and stability, technical criteria and socio-economic aspects. The methodology will be defined using the comparison of possible future use based on the evaluation of different criteria. However, the identification of such areas and classification of the present state must be defined first as a basis for further assessment. This paper deals with the assessment of the present state of extinct pond areas for which both a data analysis and field survey have been used. As input for the data-based analysis a map worked out at PU by digitization of historical maps has been used in combination with different land use data sources. 29 localities of extinct ponds were surveyed in detail to obtain more detailed information about the present state of such areas. The results of the analyses recently carried out show that most extinct pond areas are now used as permanent grasslands. However, very different types of land use have also been identified. These include built-up areas, airports and other different types of land use. The results will be used in the definition of the methodology as all the possible types of land use change need to be considered. Keywords: extinct pond, land use, soil and water resources management, sustainability, geographic information system 1. INTRODUCTION Extinct ponds are specific localities in the landscape. They are specific in many ways; mainly their location along streams and soil influenced by ponding in the past make them different from other parts of the landscape. Their present state is also often similar to wetland conditions, which makes such areas attractive for organisms affiliated with a water environment, such as amphibians, which often lose their natural environment due

2 to other changes in the landscape (Cuardo et al., 2011). In the past two decades, the trend in the Czech Republic has turned towards stream restoration, natural environment development and landscape retention capacity improvement. Even though many activities are focused mainly on stream restoration, the flood protection of these activities is also considered (Matoušková, 2007). One part of the activities related to this trend consists in the building of new ponds and small water reservoirs. Some of the newly built reservoirs are built at locations of extinct historical ponds. The optimization of the future use of extinct pond areas is being researched within the research project NAZV KUS QJ Assessment of former pond systems with the aim to achieve sustainable management of water and soil resources in the Czech Republic and the options being considered are some of the most important. From the ecological point of view, it is necessary to consider both the possible influence of the future pond existence on its surroundings and the influence of its surrounding on the possible future pond which is, of course, necessary not only from the ecological point of view. The point is that although a pond is usually considered as a water environment which is a positive and stable part of the landscape, it can also affect the ecosystem in a negative way. One example of this action is that a pond can have the effect of a trap for amphibians living close to it. On the other hand, the pond can be importantly affected by agriculture in its surroundings if it is built as a habitat for amphibians (Cuardo et al., 2011). Another important factor, which cannot be neglected in considering pond restoration, is sediment and nutrient transport in the stream (Pokorny and Hauser, 2002; Passy et al., 2012). Hydraulic and hydrologic properties of ponds also affect the sediments and nutrients trapped in them as well as their performance (Persson and Wittgren, 2003); the size then importantly affects biodiversity (Oertli et al., 2002). There is very high number of extinct historical ponds within the whole area of the Czech Republic as there were an enormous number of ponds in the Middle Ages when fish ponding was one of the most important food sources. Many ponds have been destroyed or ceased to exist for different reasons since the 17 th century. The number of extinct ponds is estimated between and within the whole area of the Czech Republic (Vrána and Beran, 2008). This number indicates that the amount of extinct ponds is not inconsiderable mainly due to their potential for water retention in the landscape. The reason for this consists mainly in the fact that these areas are suitable for building new reservoirs due to their morphology. In many cases, there are also either rests or whole dams which can be considered for building new reservoirs. At the initial phase of the project implementation, an analysis of the present state of extinct pond areas was performed. The purpose for this was mainly to get an overview of the spectra of present land use in such areas. In total, 29 reservoirs were surveyed in the field and analysed using GIS tools and data. 2. SURVEY AND INPUT DATA FOR THE ANALYSIS Extinct ponds selected for the analysis were identified by comparing historical and actual maps. The maps of 2 nd Military Mapping were used as the source of historical data. These maps were produced in the period of (Zimova et al., 2006). This was a time when the boom of fish ponding was gone and many ponds were extinct or had ceased to exist. However, this is the oldest map source which is completely digitized and referenced for the whole area of the Czech Republic. For the selection, different types of landscape and present land use were considered to get a sample containing areas representing different types of landscape and land use dynamics. Extinct ponds selected for the analysis are spread over the area of the Czech Republic to cover different types of

3 landscape, e.g. agricultural land, highlands, submontane areas. The occurrence of extinct as well as present ponds in mountainous areas is quite rare and therefore mountains were not considered as areas where the assessment would be important. The purpose of the presented analysis consists mainly in collecting materials for the development of the methodology which should help to optimize future use of extinct pond areas. Figure 1. Location of extinct ponds selected for analysis of present state (map source: ArcGIS map service at Land Parcel Identification (LPIS) was tested as a free data source which can be used to get information about the agricultural land presence in the area of interest. This is a database containing single parcels together with information about the cultures, owners and other information. It is used mainly for the purposes of agricultural subsidies distribution and therefore it can be considered as spatially very accurate data (Trojacek, 2003). Building structures were identified using orthophoto and topographic maps available at ArcGIS Map Service at in this case because the detailed data which could be used for this purpose are very costly. The presence of buildings is considered as a rejection criterion for the pond restoration for purposes of the methodology being developed as it is usually not possible to demolish or remove them. 3. ANALYSES PERFORMED 3.1. Agricultural Use Agricultural use was analysed by clipping LPIS data using the polygon of each extinct pond. After clipping, the area covered by each category was calculated and related to the entire pond area to get the percentage. An example of LPIS data and the area of an extinct pond (ID 18) is shown in Figure 2.

4 Figure 2. Extinct pond ID 18 example of LPIS coverage Existence of Building Structures The existence of building structures in the areas of extinct ponds are considered as a reason for which the pond could not be restored. This is due to the fact that it cannot be assumed that the buildings would be removed. There are several ways to identify the presence of building structures. The most effective would be the use of detailed geographic data. These are available in the Czech Republic but this is quite an expensive data source which was not yet available at the beginning of the project implementation. Identification was therefore carried out using orthophoto which could be done according to the number of areas. However, it could not be done this way in the case of assessing the entire area of the Czech Republic. Building structures were thus identified manually in this phase of the project implementation. Extinct ponds with the presence of building structures are shown in Figure 2.

5 Figure 2. Extinct pond areas with the presence of building structures. 4. RESULTS Seven extinct pond areas were identified with building structures present in their former flooded area. These areas are shown in Figure 2. The restoration of these ponds cannot be considered as a possibility. Other land use types should therefore be assessed for the optimisation of future use. All 30 extinct pond areas were analysed from the point of view of present land use based on LPIS data. The results are limited by the fact that this database contains only parcels which are used agriculturally and which are registered in the database. The registration is needed for subsidies and therefore it contains mostly agricultural land. The results show that only half of the analysed extinct pond areas are covered by this data. Moreover, nine of 30 extinct ponds have no coverage by LPIS data. This means, besides others, that it cannot be used as the only input for land use assessment. Another result is that most of the agricultural land in the areas of extinct ponds is used as permanent grassland. This is one of the land use types which could be relatively easily changed to another type which means that the purpose of the proposed methodology can be fulfilled.

6 Table 1. Land Use according to LPIS database ID Area Arable land Orchard Permanent pasture Other grassland Other culture (2) (62) (71) (72) (93) Not registered in LPIS m 2 m 2 % m 2 % m 2 % m 2 % m 2 % m 2 % Σ CONCLUSION The analyses presented in this paper were performed for the purpose of the present state description of extinct pond areas with respect to the possibility of their restoration. Another purpose was to get information on the present land use related to agriculture in such areas. The results confirm that areas of extinct ponds are now mostly grasslands as opposed to other agricultural land use types. Another result is that there is a significant amount of extinct ponds which cannot be restored due to the existence of buildings in the area which would be flooded if the pond is restored.

7 ACKNOWLEDGEMENT The paper is based on research undertaken within the research projects NAZV KUS QJ Assessment of former pond systems with the aim to achieve sustainable management of water and soil resources in the Czech Republic funded by the Ministry of Agriculture and COST LD11031 Flood Characteristics of Small Catchments funded by the Ministry of Education, Youth and Sports. All the support is highly acknowledged. REFERENCES 1. Curado N., Hartel T., Arntzen J. W. (2011), Amphibian pond loss as a function of landscape change A case study over three decades in an agricultural area of northern France, Biol. Conserv., 144(5), Matoušková M. (2007), Revitalizace vodních ekosystémů a jejich význam v protipovodňové ochraně, In: Langhammer J. (ed.), Povodně a změny v krajině, Charles University and Ministry of the Environment, Oertli B., Joye D. A., Castella E., Juge R., Cambin D., Lachavanne J.-B. (2002), Does size matter? The relationship between pond area and biodiversity. Biological Conservation, 104, Passy P., Garnier J., Billen G., Fesneau C., Tournebize J., (2012), Restoration of ponds in rural landscapes: Modelling the effect on nitrate contamination of surface water (the Seine River Basin, France). Science of the Total Environment, 430, Pokorny J., Hauser V. (2002), The restoration of fish ponds in agricultural landscapes. Ecological Engineering, 18, Trojacek P., (2003), New land parcel identification system for agricultural subsidies in the Czech Republic, In: Geoinformation for European-wide Integration, T. Benes (ed.), Millpress, Rotterdam, Vrána K. and Beran J. (2008), Rybníky a účelové nádrže, Czech Technical University in Prague, 150 p. 8. Persson J., Wittgren H. B. (2003), How hydrological and hydraulic conditions affect performance of ponds. Ecological Engineering, 21, pp Zimova, R., Pestak, J., & Veverka, B. (2006), Historical military mapping of the Czech lands cartographic analysis. In: Proceedings of the First International Conference on Cartography and GIS, Borovets (pp ).