V. David, L. Strouhal, T. Davidova
Monday 5 August 2013 by Libadmin2013

References: 13th SGEM GeoConference on Water Resources. Forest, Marine And Ocean Ecosystems, www.sgem.org, SGEM2013 Conference Proceedings, ISBN 978-619-7105-02-5 / ISSN 1314-2704, June 16-22, 2013, 245 - 252 pp


In recent two decades, many new ponds have been built within renaturalization activities in the landscape which aim mainly at the foundation of new ecosystems and water retention. Many of these ponds were supported from different subsidy programs and built only with respect to property rights to land and ignoring morphologic parameters of the profiles. On the contrary, there is high number of ponds which ceased to exist in the area of present Czech Republic in the past. These ponds were usually built in suitable profiles and therefore it can be advantageous to find extinct ponds which could be restored when planning building of new small water reservoirs.
The golden age of fish ponding is dated to the seventeenth century for which period the total number of ponds is estimated to be about 75 thousands. Since that time, about two thirds of these ponds ceased to exist due to different reasons. Besides others, destruction during war conflicts and increasing demand on arable land can be mentioned. The identification of extinct pond areas is one of the tasks of the research project NAZV KUS QJ1220233 “Assessment of former pond systems with aim at achieving sustainable management of water and soil resources in the Czech Republic”. Main task of this research project consists in the development of methodology for the assessment of such areas with respect to the optimization of their future use. This methodology is supposed to involve different criteria. Optimization of future use is assessed from different points of view to avoid omission of some important aspect of landscape development.
Morphometric properties of former pond areas are considered as important mainly because of the suitability of the area for building a dam effectively. One of the most easily assessable morphometric parameters is the average slope. However, it is obvious that this parameter cannot be used without other information, as the direction of most slopes together with the main direction of watercourse affect the effectiveness of dam building importantly. Volume ratio can be used as another indicator suitable for given purpose. This index is calculated as a ratio of reservoir volume to the volume of the dam.
This paper focuses on the analyses performed to describe morphometric characteristics of extinct pond areas. These analyses were carried out based on GIS tools application and high resolution terrain data. The results show that it is quite complicated to build general methodology for such data processing which could be used as a part of methodology for the multicriterial assessment of extinct pond areas with respect to improved management of soil and water resources.

Keywords: extinct pond, GIS analysis, terrain data