The hydrological basis for conservation of floodplain wetlands: implications of work at Narborough Bog,UK

1. Increasing concern for the environmental consequences of wetland loss has yet to be reflected in a wider application of hydrological techniques for their preservation. This paper looks at the specific example of floodplain wetlands by first considering how local hydrogeomorphological conditions may explain varied wetland occurrence. The effects of variations in individual hydrological fluxes are identified and the ability of standard hydrological monitoring programmes to represent these processes is considered. 2. These concepts are illustrated with reference to work on Narborough Bog, a small floodplain wetland in the UK. The characteristics of the wetland are outlined to illustrate how this determined the design of a monitoring programme investigating wetland hydrology and the practicalities of conservation. Measurements of water-table height were completed using a network of 30 piezometers located in the wetland and with additional measurements of river stage and meteorological variables. 3. The results of this data collection programme over the period 1991–1993 are described. The value of the data in characterizing the hydrology of the wetland is assessed and the need for sustained monitoring of variations in wetland water storage and flux is emphasized. The implications of the results for future wetland monitoring programmes are identified. 4. Hydrological data collected in this way can be used to develop a wetland mathematical model. This may be achieved by aggregating wetland sedimentological characteristics and by modelling specific periods of precipitation and evapotranspiration to determine the validity of the modelling process. Current shortcomings in the modelling process are discussed; however, wider application of this technique might help direct informed conservation of floodplain wetland landforms through improved understanding of the balance between internal and external water fluxes and their interrelationships. Similarly, models enable evaluation of the impacts of future catchment changes on wetlands. © 1997 John Wiley & Sons, Ltd.