Revista de Engenharia Civil e Ambiental

The impact of climate change on modeling of hydrological extremes is needed to asses at regional and local scales since these vicissitudes are not uniform over the globe. This work stresses on climate change impact on the hydrological extremes (MMAX, CMAX, NNHF, Q10, MMIX, CMIX, MIN7, and Q90) and precipitation extremes (MLWD, MLDD, ADMT, ADMP) during the far future (2071-2100) period over the selected sites across the upper Blue Nile River basin (UBNRB), Ethiopia. The change in extreme indices were calculated based on daily precipitation and temperature data derived from the most recent CMIP5 climate projection scenarios compared to the reference period (1971-2000). The raw outputs from the climate models were corrected in order to reduce biases using distribution based quantile mapping technique. The validation and calibration demonstrates that the seasonal maximum cycle of precipitation and temperature in the reference period is reproduced reasonably in the bias-corrected climate results. The projections of climate change impacts on the hydrological extremes were evaluated using three generalize lump conceptual hydrological models: GR4J; HBV; HMETS and two objective functions: NSE and LogNSE. These hydrological models are calibrated in the period of 1971-2000 and validated in 2001-2010 period. The optimized hydrological parameters are adopted for the future hydrological simulations (2071-2100). The results indicate that the wet/dry spell will significantly decrease/increase due to climate change in some sites of the region (sites 2 and 6), while in sites 1 and 5, there is increase/decrease in wet/dry spell but not significant, respectively. Far future maximum river flows in the study area will be less extreme and more variable in terms of magnitude, and more irregular in terms of seasonal occurrence, than they are at present. Low flows may become less extreme and variable in terms of magnitude, and more irregular in terms of seasonal occurrence. Most areas of northern, western, and northeastern part of the river basin will likely become wetter in the wet season and drier in dry season. Whereas, indices that related to low flows are projected to increase most prominently for lowland sites, due to the combined effects of projected decreases in summer precipitation, and projected increases in evapotranspiration that reduce residual soil moisture in late summer. Whereas the indices related to the high flows are projected slight increase in the central and upper part of the basin. According to the evaluated scenarios, climate change may have favorable impacts on the distribution of hydrological extremes in the study area.

This article highlights the key observation of various studies conducted in Indian scenario. In India, the major sources of volatile organic compounds (VOCs) are vehicle exhaust. Other sources include emissions from diesel internal combustion engines, oceanic emission and evaporative emissions. Various aspects of VOCs are studied in detail by various authors in the Indian context. VOC sampling methods vary from each other depending on the techniques, the type of adsorbent used, and the method of extraction, analysis and identification techniques. In India, the most widely used method for VOCs sampling are pre-concentration on sorbent tubes or whole air (grab sampling) sample taken in canisters or tedlar bags. From the studies, it can be concluded that ambient VOCs show a clear seasonal pattern and found to be higher during winter months due to temperature inversion in Delhi and Kolkata. For better understanding; accurate characterisation of vehicular emission contribution is required for the country like India.

A positive water balance is the main prerequisite for successful hydro-reclamation of residual mining pits. Under the current conditions of climate change, long dry periods occur more frequently, which may have a negative impact on the water supply to fill the pit lakes. This study deals with the hydrological balance of the Medard mining pit, which has been computed with the help of the Water Balance Conceptual Model (WBCM). The purpose of this study is to test the feasibility of the WBCM model for water balance estimation in endorheic catchments. The water contribution of the Medard mining pit’s own catchment was quantified, in order to determine if an external supply of water is necessary to fill the pit within several years. The outcomes of the study have shown that the internal water sources of the Medard catchment can hardly provide sufficient water supply, either during a normal, or during a dry hydrological year. Thus, an external water supply from the Ohre River is needed in addition to the water from the mining pits (the quality of the water from the mining pits must of course be carefully monitored). The WBCM-6 model can serve as a useful tool in hydro-reclamation of residual mining pits. However, the final performance regulations of pit lakes must be based on water management balance, including human-induced activities.

The aim of the article is to assess the variability of the risk of flood risk with the use of distributions maximum values. The copyright research is hydrological data in the form of daily water levels from the period 1981-2011. The collected data are derived from the hydrological station Bystrzyca Klodzka for the Nysa Klodzka river and the hydrological station Lesna for the Kwisa river. For the purpose of estimating flood risk from the collected data has been selected quarterly maxima of daily water levels. As a measure of the flood risk authors accepted the likelihood of exceeding the alarm condition in the test sections of the rivers. This risk is calculated by using the theoretical cumulative distribution distribution of quarterly highs water levels. The study was used Gumbel distribution. At the same time the article was paid significant attention to the possibility of using the solutions for integrated flood risk management process in accordance with applicable national legislation and European.

The significant investigation was performed to establish a chemical baseline for snowfall in Northeast of China since there was no such record. The chemical and mineral composition of snowfall samples were evaluated in Jilin Province, Northeast China. The specific purposes of the present study are to characterize the chemical and mineral composition of melted snow-water samples and to identify the sources of atmospheric pollutants, as well as to investigate the spatial variability of melted snow-water chemistry in this region. Snowfall and aerosol samples were collected from Changchun city, Baicheng city, and Yanji city during November 2015 to March 2016. All the filtered (0.45 m) snow-water was analyzed for conductivity, pH, major cations (Na+, K+, NH4 +, Ca2+, Mg2+) and anions (F−, SO4 2−, Cl−, NO3 -, HCO3 -). The pH of these samples ranged from 6.01 to 7.10, with an average value of 6.44. The conductivity ranged between 17.50 μs cm-1 and 86.00 μs cm-1 with an average value of 55.0 μs cm-1. These parameters indicated high chemical concentrations in the snow-water. It was observed that Ca2+ and NH4 + were the major cations which accounted the concentration for 5.05% to 18.71% and 3.47 to15.54%. HCO3 - and SO4 2- were major anions which accounted the concentration for 23.41% to 38.49% and 21.10% to 35.24%, respectively. (SO4 2- + NO3 -)/ (Ca2+ + NH4 +) was 1.38. The organic carbon of particles in the snowfall was higher and the average content was 52.85 g kg-1. The size of the snow-water particles in the three Cities was mainly based on clay complexes (<2 μm). The order of average content was: (<2 μm)> (>200 μm)> (20-200 μm)> (2-20 μm). The dominant mineral of particles in the snow-water was quartz and feldspar, while clay mineral was composed of montmorillonite, illite, kaolinite and vermiculite. According to the above analyses, the possible sources of the particles in the snowfall should be soil and ground dust and co al-burning.

This paper is exploring the process protocol map in industrialized building systems. Several critical success factors were identified and classified in seven groups namely; just-in-time factors, total quality management factors, business process reengineering factors, concurrent engineering factors, last planner system factors, teamwork factors and value based management factors. Using the Delphi technique, factors were established first by experts of construction projects. Afterward, the groups of factors were confirmed by the construction industry experts using the questionnaires based on Fuzzy AHP techniques for factors comparison. Based on the results the lean construction critical success factors are concurrent engineering and just in time factors respectively, which are the most important critical success factors in lean construction projects according to the industrialized building system process protocol map.