Wyniki wyszukiwania - Biblioteka Nauki

1

Infuence of biochar amendment on stormwater management in green roofs: experiment with numerical investigation

100%

Gan L. , Garg A. , Wang H. , Mei G. , Liu J.

|

tom Vol. 69, no. 6

2417--2426

EN

Green roof is known to minimize urban waterlogging owing to its water retention capacity due to the presence of substrate soil layer. Biochar, which is a carbon-negative material, appears to be an essential soil amendment in green roof due to its water-holding capacity and stability. Recently, incentives are provided in developed countries to enhance commercial pro duction of biochar for usage in green infrastructure, with an aim to meet carbon reduction goals of 2030. Further, biochar has a longer half-life (over 100 years), compared to other materials that are easier to degrade. In this study, the influence of different biochar contents on hydrological performance of green roof is evaluated using a combination of experiment and numerical simulation. Four soil columns with different biochar contents (0, 5, 10 and 15%) were subjected to artificial rainfall. Hydraulic parameters were obtained using inverse solution from the collected rainfall data. Numerical simulations were used to explore the impact of different biochar contents on green roof rainwater management performance during real rainfall process. Biochar is found to enhance saturated water content and, however, tends to reduce saturated hydraulic conductivity. The green roof with 10% BAS (10% biochar content) has better ability of comprehensive rainwater management, with the highest peak outflow reduction and the longest rainwater outflow delay. Green roof with 5% BAS has highest runoff reduction and longest peak outflow delay. These results provide a suitable selection of biochar content for urban areas with different rainwater management requirements.

2

Hydrological processes in water and land ecotones

100%

Kotwicki V.

|

nr 1-2

EN

Water and land ecotones harbour complex interactions of hydrosphere, biosphere, atmosphere and lithosphere. Exchange processes at their interfaces involve multiple feedback mechanisms which to a large extent affect the overall conditions on earth. Hydrological processes affect ecotones and vice versa. The paper outlines briefly some of the effects and gives examples of ecotones in arid and urban environments.

3

Ecohydrology - integrative science for sustainable water, environment and society

100%

Zalewski M.

|

nr 1-4

EN

In the face of increasing pressure on freshwater resources, there exists an urgent need for new practical tools to achieve their sustainable management. Sustainable water resources and ecosystem services at the global scale can be achieved by two types of actions: first, the reduction of energy and material use per capita — expressed by the UNEP Concept of Ecoefficiency and second, by enhancement of the absorbing capacity of ecosystems. The Ecohydrology concept developed during UNESCOs International Hydrological Programme is a new approach in environmental sciences. It is based on the assumption that the control and regulation of nutrients and water cycling by synergistically integrated hydrological and biotic processes at the catchment scale should provide opportunities for restoration and enhancement of the absorbing capacity of ecosystems against human impacts. The new dimensions of ecohydrological research, which are introduced in this special issue, emerged during a conference in Venice and are focused on multidimensional feedbacks between water, biota and society. Based on the Ecohydrology principles formulated during the first phase of the Eecohydrology Project (EH IHP V 2.3/2.4) the development of research on such issues in the framework of IHP VI should provide a new tool for improving water resources, environmental quality, ecosystem services and socio-economic development.

4

Hydrological processes in a catchment scale under global climate change

100%

Kaczmarek Z.

|

nr 1-4

EN

The following areas of research related to the climate\water resources interface may be identified: detecting changes in atmospheric and hydrological variables by means of measurable indicators, including paleohydrological data; assessing sensitivity of land surface processes to climate characteristics; analyzing implications of climate change on regional water supply and demand; assessing the impact of climate change on physical, chemical and biological processes in water bodies. There is a possibility of applying a range of approaches, from simple empirical relationships to complex conceptual models based on simplified representation of the processes involved in the hydrological cycle. There are still uncertainties propagated through the numerous levels of analysis as one moves from CO2 scenarios, through the transference of climatic data to hydrologic characteristics, impacts on water sectors and on management decisions and socioeconomic impacts of response measures. Climate/hydrology impact studies should allow answering questions important for decision making: e.g. is the water system able to fulfil required tasks for the current economic, climatic and hydrologic conditions? If not, what action should be taken to improve the situation? Will the system be able to meet requirements 20 to 50 years from now, assuming stationarity of hydrological processes? If not, what kind of measures must be foreseen to enhance system's ability to cope with water deficits and floods? To what extent a water resource system may be affected as a result of climate change? How to deal with uncertainties? What are the adaptation options? How the analysts should communicate with decision makers in order to demonstrate that there is a problem to be addressed? Based on the current knowledge, the following conclusions seem to be justified: there are reasons for decision makers to be concerned, because the water supply and demand may be affected by the climate change; water systems may be effectively adapted to changed climatic conditions; cost of adaptation in various regions of the country will vary depending on the depth of expected water deficits; the vulnerability of water systems to changes decrease as the level of water system development increase; improved demand management and institutional adaptation are primary components for increasing the robustness of water resources systems; a continuous adaptation of design criteria, development plans, operating rules and water allocation policies to the newly developed climate scenarios is needed.