Hydrological Modeling of the Influence of Ecological Dams for the Restoration of the Water Regime in Peatlands – Case Studies

The aim of this study is to model a rapid maximum runoff, response to a calculated rain with a probability of occurrence of 1% for several case studies within the Northwest Region of Romania, studied through NWPEAT project. The purpose of the study is focused also to identify the effect of raising ecological dams made of local materials in modifying the maximum torrential runoff at the outlet area from the peatlands sites. The methodology was applied to representative case studies, which revealed different/diversified conditions, both from the climatic, morphological, pedological, land cover or hydrological points of view. The first stage of the methodology focused on evaluating the inventory of the studied sites, the peatlands catchment features, their spatial analysis using morphological units and within the water balance, the analysis of runoff and aridity coefficients, etc. The modeling of the rain-runoff process was applied for two scenarios for each site, involving the presence or absence of the ecological dam. The results are quite dispersed from one case to another. Thus, we noticed a reduction in the maximum runoff of 70% in the case of the Mlaștina de la Iaz peatland, 40% in the case of the Lacul Manta peatland and only 8% in the case of the Ic Ponor peatland site. The difference between the three cases is made by the different patterns of some natural factors, among which are the peatland area, catchment area, shape of the basin and the slope, the degree of coverage with trees or less developed vegetation, the different layout of the sites compared to the flow directions of water vectors on the slope, etc.