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Proposed dam Skalička – conflicts and challenges

Říha Jaromír, Špano Miroslav, Julínek Tomáš

Gospodarka Wodna

2021

Nr 9

29--34

The construction of the Skalička embankment dam is planned in the Moravian part of the Czech Republic on the river Bečva. Its main purpose is to protect the area downstream of the dam against floods; its additional purposes may be water supply, hydropower production, environmental and social effects. The location of the dam is exposed to complicated geological and hydrogeological conditions, as well as environmental and social conflicts. Recently, the appropriate variant of the scheme has been searched for using the multi-criteria analysis, where all aspects are carefully investigated and assessed. As the dam is located in the karst region, the most important challenges are the hydrogeological issues including the assessment of the dam’s impact on the adjacent spa Teplice nad Bečvą, where the mineral water is extracted from the karst system. Another task is to verify the technical design of the dam, mainly the method and the extent of the sub-base sealing, the drainage system and its impact on the local groundwater regime. The paper describes and discusses the proposed variants of the dam layout. It also presents the results of the hydrogeological research and modelling, as well as recommendations concerning the technical solutions used for the dam. The authors lists and shortly discuss the basic aspects taken into account in the multi-criteria analysis, along with the main conflicts accompanying preparation of the scheme.

W morawskiej części Republiki Czeskiej na rzece Bečva planowana jest budowa zapory skalnej Skalička. Jej głównym celem jest ochrona przeciwpowodziowa obszaru poniżej zapory, dodatkowymi celami mogą być zaopatrzenie w wodę, energetyka wodna, efekty środowiskowe i społeczne. Lokalizacja zapory jest narażona na skomplikowane warunki geologiczne i hydrogeologiczne oraz konflikty środowiskowe i społeczne. Ostatnio odpowiedni wariant schematu jest poszukiwany za pomocą analizy wielokryterialnej, w której wszystkie aspekty są dokładnie badane i oceniane. Ponieważ zapora będzie zlokalizowana w obszarze krasowym, najważniejszymi wyzwaniami są kwestie hydrogeologiczne, w tym ocena wpływu zapory na sąsiednie uzdrowisko Teplice nad Bečvą, gdzie z systemu krasowego czerpana jest woda mineralna. Innym zadaniem jest sprawdzenie projektu technicznego zapory, głównie sposobu i zakresu uszczelnienia podłoża, systemu odwodnienia oraz jego wpływu na lokalny reżim wód podziemnych. W artykule opisano i omówiono proponowane warianty zapory. Przedstawiono wyniki badań i modelowania hydrogeologicznego oraz zalecenia dotyczące technicznego rozwiązania zapory. Wymienione są i krótko opisane podstawowe aspekty brane pod uwagę w analizie wielokryterialnej wraz z głównymi konfliktami towarzyszącymi przygotowaniu schematu.

The effects of litter layer and soil properties on the soil-atmosphere fluxes of greenhouse gases in karst forest, Southwest China

Cheng J., Lee X., Zhou Z., Wang B., Xing Y., Cheng H., Tang Y.

Polish Journal of Ecology

2013

Vol. 61, nr 1

79--92

Temporal variation is a major source of the uncertainty in estimating the fluxes of the greenhouse gases (GHGs) in terrestrial ecosystems, and the GHG fluxes and its affecting factors in the karst region of southwest China remains weakly understood. Using the static chamber technique and gas chromatography method, the CO2, CH4 and N2O fluxes were carried out between 9 and 11 a.m. at 15 day intervals from June 2008 to May 2009 in a Pinus massoniana forest. Two treatments were chosen for this study: undisturbed (soil with litter layer) and disturbed (surface litter removal). Both treatments were found to be the net source of atmospheric CO2 and N2O, but a sink of atmospheric CH4. The seasonality of soil CO2 emission coincided with the seasonal climate pattern, with high CO2 emission rates in the hot-wet season and low rates in the cool-dry season. In contrast, seasonal patterns of CH4 and N2O fluxes were not clear, although higher CH4 uptake rates were often observed in autumn and higher N2O emission rates were often observed in spring (dry-wet season transition). The litter was active in GHG fluxes, and removal of the litter layer reduced soil CO2 emission (17%) and increased CH4 uptake (24%) whereas N2O fluxes were not affected distinctly in the pine forest, indicating that litter layer had an important effect on C exchanges. In the pine forest, soil CO2 emissions and CH4 uptakes correlated significantly with soil temperature (r2 = 0.87, P <0.01; r2 = 0.34, P <0.05, respectively), but had no significant relationship with soil moisture. And there was a significant correlation between CH4 flux and NH4+-N (r2 = 0.39, P < 0.05) and soil inorganic N (r2 = 0.48, P <0.05), but no significant correlation was found between CH4 flux and NO3--N. Moreover, we found a significant negative logarithmic correlation between N2O flux and soil NO3--N concentration (r2 = 0.41, P <0.05), and the relationship between CO2 emission and soil inorganic N content (r2 = 0.35, P < 0.05). These results suggested that soil temperature and mineral N dynamics largely affected the temporal GHG exchanges between forest soil and atmosphere.