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Open access

Jasia Tahzeeda, Mizan R. Khan and Raisa Bashar

Abstract

The main attractions of national parks include their scenic beauty, security, wildlife and trees. For preserving and maintaining national parks, an appropriate pricing policy can be used. The current study focuses on using the travel cost method (TCM) and contingent valuation method (CVM) as a non-market valuation technique to value the National Botanical Garden in Bangladesh, a developing country where little or no previous works of this kind has been conducted before. The main objective of the paper was to suggest an appropriate entrance fee for the park by assessing the willingness to pay (WTP) from the TCM and CVM; by determining a revenue maximizing entrance fee from the CVM; and by considering socio-demographics, the characteristics of visits and the motivation of the visitors to preserve the National Botanical Garden. The study sampled 100 visitors. These visitors participated in a survey which consisted of closed questions followed by a semi structured in-depth interview. For data processing, SPSS and Microsoft Excel were used. Based on the travel cost demand function using the TCM, the study found that the amount respondents were willing to pay for entrance was 0.955 US dollars and yearly consumer surplus was 593634.5 USD. From the CVM, it was estimated that the WTP was 0.225 USD for the entrance and revenue maximizing entrance fee was 0.376 USD. Finally, the entrance fee suggested for National Botanical Garden was around 0.225 USD.

Open access

Andrzej Wałęga, Marta Cebulska and Wiesław Gądek

Abstract

The objective of the research was to look into the role that bioretention systems play in a decentralized management of stormwater runoff from the impervious areas. The study took place at a catchment of a low permeability and equipped with a combined sewer system. Two rainfall options were selected: actual rainfall intensity q = 105.65 dm3∙s−1∙ha−1 and a hypothetic rainfall with a probability of exceedance p = 10% and q = 40.7 dm3∙s−1∙ha−1. All calculations were carried out using the SWMM EPA program (storm water management model; Environmental Protection Agency). They have shown that the bioretention system reduces the cumulative flow rates by over 55% and the flood wave volume by over 54%. Moreover, it was found that, a precipitation pattern significantly influences runoff from the urban catchment.

Open access

Barbara Kiełbasa, Stefan Pietrzak, Barbro Ulén, Jan-Olof Drangert and Karin Tonderski

Abstract

The paper presents the results of a scientific project focused on limiting nutrient losses from farms by introducing measures to apply fertilizers in a more sustainable way. It is a case study of selected aspects of farm management, focussing on the issue of sustainable agriculture and their tools. The main aim of the study was to analyse and evaluate farmers’ knowledge of the fertilizing process and its aspects, as well as applying sustainable agricultural activities on farms. The study emphasised the importance of nutrient management, as very important for sustainable farming. Also, the links between farmers’ opinions and their activities were analysed. The important issue concerned measures for sustainable farm management introduced on the farms, as well as measures to limit nutrient leaching into groundwater. Twenty-eight farmers from two regions in Poland were interviewed about their perceptions for the case study. In general, the farmers considered their farm activities to be more sustainable than in the past. They demonstrated an understanding of the general idea of sustainable agriculture. However, many farmers still demonstrated a poor grasp of nutrient flows and nutrient balances on farms. Their knowledge and perception was based on general, rather than specific knowledge gleaned from an academic/vocational course. The farmers demonstrated a realization that there were some new, or low-cost measures that could be introduced to make management more sustainable and pro-environmental, but there was still a need for wider adoption of sustainable agricultural practices.

Open access

Tomasz Spórna

Abstract

The Katowice conurbation is an example of a typical old industrial region in Central and Eastern Europe, whose socioeconomic transformation, initiated after 1990, has led to spatial and functional changes. The aim of this article is to present the suburbanisation process in the Katowice conurbation based on demographic changes and an analysis of migration flow. This process has been taking place in the area since the 2000s and takes on the shape of a multi-centre development of newly created individual and developed housing zones (both in the core and in the suburban area of the conurbation). Since 1990, the cities of the Katowice conurbation have been undergoing a process of shrinking. This process is manifested in the decline in number of urban residents in the years 1991–2016, amounting to 366 thousand people. Moreover, the cities face numerous social, economic and spatial problems. Since 1995, simultaneous with the shrinking of the cities of the Katowice conurbation, there has been an increase in the number of inhabitants in its suburban areas (since 2004, the trend has continued to be positive). Population increases have also been recorded in some inner-city zones of the conurbation. The suburbanisation process in the outer zone of the conurbation includes, in particular, the communes located north and south of the cities constituting its core, including the communes of Ożarowice, Psary, Mierzęcice in the north and Mikołów, Orzesze, Wyry in the south-west. On the other hand, the areas of intense inner-city construction development, located in the areas of the Katowice conurbation core, which are attractive in terms of environment and transportation, are undergoing so-called, “internal suburbanisation”.

Open access

Pratibha Warwade, Shalini Tiwari, Sunil Ranjan, Surendra K. Chandniha and Jan Adamowski

Abstract

This study detected, for the first time, the long term annual and seasonal rainfall trends over Bihar state, India, between 1901 and 2002. The shift change point was identified with the cumulative deviation test (cumulative sum – CUSUM), and linear regression. After the shift change point was detected, the time series was subdivided into two groups: before and after the change point. Arc-Map 10.3 was used to evaluate the spatial distribution of the trends. It was found that annual and monsoon rainfall trends decreased significantly; no significant trends were observed in pre-monsoon, monsoon, post-monsoon and winter rainfall. The average decline in rainfall rate was –2.17 mm·year−1 and –2.13 mm·year−1 for the annual and monsoon periods. The probable change point was 1956. The number of negative extreme events were higher in the later period (1957–2002) than the earlier period (1901–1956).

Open access

Manish K. Nema, Deepak Khare, Jan Adamowski and Surendra K. Chandniha

Abstract

A quantitative and qualitative understanding of the anticipated climate-change-driven multi-scale spatio-temporal shifts in precipitation and attendant river flows is crucial to the development of water resources management approaches capable of sustaining and even improving the ecological and socioeconomic viability of rain-fed agricultural regions. A set of homogeneity tests for change point detection, non-parametric trend tests, and the Sen’s slope estimator were applied to long-term gridded rainfall records of 27 newly formed districts in Chhattisgarh State, India. Illustrating the impacts of climate change, an analysis of spatial variability, multi-temporal (monthly, seasonal, annual) trends and inter-annual variations in rainfall over the last 115 years (1901–2015 mean 1360 mm·y−1) showed an overall decline in rainfall, with 1961 being a change point year (i.e., shift from rising to declining trend) for most districts in Chhattisgarh. Spatio-temporal variations in rainfall within the state of Chhattisgarh showed a coefficient of variation of 19.77%. Strong inter-annual and seasonal variability in regional rainfall were noted. These rainfall trend analyses may help predict future climate scenarios and thereby allow planning of effective and sustainable water resources management for the region.

Open access

Hanene Bessaklia, Abderrahmane Nekkache Ghenim, Abdessalam Megnounif and Javier Martin-Vide

Abstract

In this study, the spatial variation of daily and monthly concentration precipitation index and its aggressiveness were used in 23 rainfall stations in the extreme north-east of Algeria over the period 1970–2010. The trend was analysed by the Mann–Kendall (MK) test. The results show that daily precipitation concentration index (CI) values are noticeably higher in places where the amount of total precipitation is low, the results of MK test show that areas of high precipitation concentration tend to increase. The seasonality and aggressiveness of precipitation are high in the eastern and western parts of the study region (eastern and central coastal of Constantine catchments), whereas a moderately seasonal distribution with low aggressiveness is found in the middle of the study area (plains and central Seybouse catchment). As a result, the modified Fournier index (MFI) has a significant correlation with annual precipitation, whereas the CI and monthly precipitation concentration index (PCI) show an opposite correlation in relation to annual precipitation.

Open access

Damian Bocheński

Abstract

This paper presents a new original method of selection of main engines for hopper suction dredgers with regard to probabilistic models. It was proposed to use the normal distribution to describe the operational loads of the main receivers. The principles for determination of parameters of load distribution and design power of the main engines were formulated. Lastly, the principles of selection of the size and number of main engines has been proposed.

Open access

Bogdan Rozmarynowski and Tomasz Mikulski

Abstract

The paper deals with sensitivity and reliability applications to numerical studies of an off-shore platform model. Structural parameters and sea conditions are referred to the Baltic jack-up drilling platform. The sudy aims at the influence of particular basic variables on static and dynamic response as well as the probability of failure due to water waves and wind loads. The paper presents the sensitivity approach to a generalized eigenvalue problem and evaluation of the performace functions. The first order time-invariant problems of structural reliability analysis are under concern.

Open access

Tomasz Hajduk

Abstract

The presence of deposits on heat exchange surfaces in condensers and regenerative exchangers of ship and land steam power plants is always connected with the increase of the wall temperature on the water vapor side due to additional thermal resistances resulting from accumulated deposits. This increase always results in an increase in the condensing pressure, which results in the deterioration of the condensation process of the water vapor, leading to thermal degradation of a given heat exchanger. In addition, the resulting deposits form unevenness with a diversified, often stochastic, geometric structure of the surface layer surface, whose measure is most often the roughness parameters, describing the geometric structure of the surface. In addition, the increase in surface roughness of the heat transfer surface on the water vapor side promotes the formation of a thicker layer of condensate, thus worsening the organization of condensate runoff, which results in interference of the thermal degradation phenomenon of a given heat exchange apparatus. As a result, these phenomena lead to a reduction in the efficiency of a given thermal system, and thus entail an increase in the costs of energy conversion and consequently cause an increased degradation of the natural environment. In the article, based on the results of the author’s own experimental research, the types of pollution accumulating on heat exchange surfaces on the water vapor side of heat exchange apparatus in marine and land steam power plants and quantitative measures of the unevenness of the surface layer of these sediments are presented.