Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 7
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The aim of the study was to compare two grouping methods for regionalisation of watersheds, which are similar in respect of low flow and chosen catchments parameters (physiographic and meteorological). In the study, a residual pattern approach and cluster analysis, i.e. Ward’s method, were used. The analysis was conducted for specific low flow discharge q95 (dm3∙s–1∙km–2). In the analysis, 50 catchments, located in the area of the upper and central Vistula River basin, were taken. Daily flows used in the study were monitored from 1976 to 2016. Based on the residual pattern approach (RPA) method, the analysed catchments were classified into two groups, while using the cluster analysis method (Ward’s method) – into five. The predictive performance of the complete regional regression model checked by cross-validation R2cv was 47% and RMSEcv = 0.69 dm3∙s–1∙km–2. The cross validation procedure for the cluster analysis gives a predictive performance equal to 33% and RMSEcv = 0.81 dm3∙s–1∙km–2. Comparing both methods, based on the cross-validated coefficient of determination (R2cv), it was found that the residual pattern approach had a better fit between predicted and observed values. The analysis also showed, that in case of both methods, an overestimation of specific low flow discharge q95 was observed. For the cross-validation method and the RPA method, the PBIAS was –10%. A slightly higher value was obtained for the cross-validation method and models obtained using cluster analysis for which the PBIAS was –13.8%.
Go to article

Authors and Affiliations

Agnieszka Cupak
1
ORCID: ORCID
Bogusław Michalec
1
ORCID: ORCID

  1. University of Agriculture in Krakow, Faculty of Environmental Engineering and Land Surveying, al. Mickiewicza 21, 31-120 Kraków, Poland
Download PDF Download RIS Download Bibtex

Abstract

The study aims at evaluating crop insurance effects on the farms’ production and investment indicators in Lithuania. The Common Agricultural Policy after 2020 considers measures helping farmers to adapt to climate change. For this reason, it is essential to evaluate existing risk management measures in order to propose appropriate schemes for the next programming period. In order to evaluate crop insurance effects on the farms’ production and investment indicators farm-level, data from Farm Accountancy Data Network dataset and propensity score matching approach was used. Study period was 2008–2017. The study revealed that participation in crop insurance schemes was influenced by the factors such as age of the farmer, wealth, specialization, and location of the farm. The study also demonstrated that crop insurance did not show statistically significant effects on the selected farms’ indicators. The main reason was support from the national and EU funds.
Go to article

Authors and Affiliations

Virginia Namiotko
1
ORCID: ORCID
Aistė Galnaitytė
1
ORCID: ORCID
Irena Kriščiukaitienė
1
ORCID: ORCID
Ahmet Ali Koç
2
ORCID: ORCID

  1. Institute of Economics and Rural Development of the Lithuanian Centre for Social Sciences A. Vivulskio Str. 4A-13, LT-03220 Vilnius, Lithuania
  2. Akdeniz University, Faculty of Economics and Administrative Sciences, Department of Economics, Antalya, Turkey
Download PDF Download RIS Download Bibtex

Abstract

The content of structural carbohydrates and lignin are important assessment criteria of the feed value of meadow plants. It is affected by many independent factors, including among others its development stage during the harvest as well as climatic conditions, especially the amount of rainfall. During the years 2014–2016, plant samples were harvested at weekly intervals, respectively five times from late April to late May. The effect of harvest date on cellulose, hemicelluloses and lignin contents was evaluated. The chemical composition of plants was varied, depending not only on harvest date but also on the year of study. Regardless of the course of meteorological conditions in subsequent growing seasons, the increase of cellulose (from 236.5 to 297.9 g∙kg–1 DM), hemicelluloses (from 159.3 to 210.8 g∙kg–1 DM), and lignin (from 31.5 to 43.1 g∙kg–1 DM) in the following dates of harvest were observed. These parameters were also positively correlated with the total rainfall from the begging of vegetation season to the date of plants sampling (R2 = 0.65, 0.12 and 0.44 for cellulose, hemicelluloses and lignin, respectively), and with the average daily air temperature in the moment of harvest (R2 = 0.66, 0.32 and 0.52 for cellulose, hemicelluloses and lignin, respectively). The cellulose and lignin content, regardless of the harvest date, were significantly higher in the first year of the study (2014), when moisture conditions for plant development were optimal.
Go to article

Authors and Affiliations

Barbara Wróbel
1
ORCID: ORCID
Waldemar Zielewicz
2
ORCID: ORCID
Anna Paszkiewicz-Jasińska
1
ORCID: ORCID
Bartosz Spychalski
1
Zuzanna Jakubowska
1

  1. Institute of Technology and Life Sciences – National Research Institute, Falenty, al. Hrabska 3, 05-090 Raszyn, Poland
  2. Poznań University of Life Sciences, Department of Grassland and Natural Landscape Sciences, Poznań, Poland
Download PDF Download RIS Download Bibtex

Abstract

According to many experts, the water crisis will be one of the most important challenges in the coming years on the planet. Watershed management is one of the most effective ways to conserve rainwater and develop water resources. The purpose of the study was to obtain a model of critical land management in the Welang watershed area. This study uses a dynamic systems approach based on a causal philosophy (cause and effect) through a deep understanding of how a system works. The parameters used are based on sustainable agriculture in terms of physical sustainability aspects/critical land from erosion factor indicators. Model validation is done by comparing the behaviour of the model with a natural system (quantitive behaviour pattern comparison), namely the Mean Absolute Percentage Error (MAPE) Middle-Value Test. Modelling is supported by Powersim Studio Express Software ver. 10. The results show that the physical sustainability model/critical land using a simulation scenario of 25% erosion control funds shows a trend of increasing production land area and tackled land area followed by a decrease in annual erosion weight. The economic sustainability model obtained results at the end of the projected year showing farm revenues IDR 63,591,396 (USD1 ≈ IDR14.27 thous. in average in 2021). This means that the higher the acceptance value, the farming can provide economic welfare for farmers.
Go to article

Authors and Affiliations

Maroeto Maroeto
1
ORCID: ORCID
Wahyu Santoso
2
ORCID: ORCID

  1. Universitas Pembangunan Nasional “Veteran” Jawa Timur, Faculty of Agriculture, Department of Agrotechnology, Surabaya, Jawa Timur 60294, Indonesia
  2. Universitas Pembangunan Nasional “Veteran” Jawa Timur, Faculty of Agriculture, Department of Agribusiness, Surabaya, Jawa Timur, Indonesia
Download PDF Download RIS Download Bibtex

Abstract

This study aims to evaluate the construction mode of small-scale farmland water conservancy using secondary data from the China statistical yearbook (2000–2019), which was simply and statistically computed. To put it briefly, the simple linear regression model was used to analyse the number of small-scale reservoirs and irrigated areas relative to their capacities and effectiveness. The results showed that the number of small-scale reservoirs increased by 122.2 units of their capacity and the number of small-scale irrigated areas increased by 6.8 units of their effectiveness. The present study introduces the simple linear regression model and accounts for how the number of the small-scale reservoirs and irrigated areas has increased (the total number of reservoirs was 83,260 in 2000 and 98,822 in 2018) relative to their capacity and effectiveness, respectively. Of course, the capacity of water harvesting and the effectiveness of irrigated areas have shown a linear increase over time. Between 2000 and 2019, the capacity increased from 3842 to 7117 for large-scale reservoirs, from 746 to 126 for medium-scale reservoirs, and from 594 to 710 for small-scale reservoirs and their ranges were 3.2, 380, and 116, respectively. Furthermore, the findings of this evaluation provide insights for making decisions on water conservancy interventions.
Go to article

Authors and Affiliations

Belachew D. Hambebo
1
ORCID: ORCID
Hui Li
ORCID: ORCID

  1. Hunan Agricultural University, College of Economics, 1 Nonda Rd, Furong District, Changsha, China
Download PDF Download RIS Download Bibtex

Abstract

Anthropogenic pollution leads to increased concentrations of metals in the freshwater and macrophyte. Aquatic plants substantially contribute to the structure, function as well as and service provision of aquatic ecosystems. Our microcosm experiments were to test the possibility of the physiological response of Hydrocharis morsus-ranae to metal (Cd, Pb, Cu, Zn, Mn, Fe at three level of concentration) contaminated waters. Biomass was analysed at the beginning and at the end of the experiment. At the same time contents of photosynthetic pigments in leaves were estimated spectrophotometrically. We found that this macrophyte had the ability to grow in contaminated waters, but the effects of high concentration of isolated metals in water will indicate changes consisting in the disappearance of a significant part of biological populations were which manifested in alteration of the content of photosynthetic pigments as well as this plant’s growth. We show that generally stress of Zn and Cu influenced the drop of dry biomass which was connected with a positive correlation between the amount of dry biomass and the content of chlorophyll a and carotenoids, or only carotenoids, respectively. The highest stress of Pb and Fe (third concentrations of these metals) also influenced the drop of biomass. We concluded that none of Cd concentrations were toxic to this plant, but the effect of Mn stress was not unequivocal. Moreover, plant growth was stimulated by low Fe concentrations (first concentration) demonstrating the hormesis effect. When plants were exposed to this metal, there was no evidence of damage to the photosynthetic processes.
Go to article

Authors and Affiliations

Małgorzata Gałczyńska
1
ORCID: ORCID
Jacek Wróbel
1
ORCID: ORCID
Katarzyna Bednarz
1

  1. West Pomeranian University of Technology in Szczecin, Faculty of Environmental Management and Agriculture, al. Piastów 17, 70-310 Szczecin, Poland
Download PDF Download RIS Download Bibtex

Abstract

Global climate change is a fact that affects all components of the environment. The main aim of this research was to conduct the retrospective monitoring of soils in the Trans-Ural Steppe Zone (Russia) and the analysis in changing of key climatic parameters for the periods 1937–1982 and 1982–2019. We investigated average temperatures and precipitation (monthly and annual) using archived data from a nearby weather station, as well as data from NASA and weather forecast websites. We identified a decrease of soil fertility and an increase in alkalinisation processes over the past 37 years for the studied area. Comparison of these periods showed an increasing the average monthly and annual air temperatures (on 1.4°C) and a decrease in the amount of precipitation in the summer (on 4.4 mm) period. We found that a more arid climate accelerates the rate of soil salinization due to the active evaporation of groundwater. Nevertheless, in some areas there were found the soil desalinization due to the change in the hydrologic regime and lowering of the groundwater level. In general, the climate changing in the studied region is consistent with global warming trend. Increased average annual temperature and reduced precipitation in summer period contribute to aridization of the region. Such conditions will more restrict soil fertility due to development of salinization and desertification processes.
Go to article

Authors and Affiliations

Azamat Suleymanov
1 2
ORCID: ORCID
Ilyusya Gabbasova
1
ORCID: ORCID
Ruslan Suleymanov
1 3
ORCID: ORCID
Mikhail Komissarov
1
ORCID: ORCID
Timur Garipov
1
ORCID: ORCID
Ludmila Sidorova
1
ORCID: ORCID
Fliza Nazyrova
1
ORCID: ORCID

  1. Ufa Institute of Biology, Ufa Research Center, Russian Academy of Sciences, Laboratory of Soil Science, Pr. Oktyabrya 69, 450054, Ufa, Russia
  2. Ufa State Petroleum Technological University, Department of Environmental Protection and Prudent Exploitation of Natural Resources, Kosmonavtov St 1, 450064, Ufa, Russia
  3. Bashkir State University, Department of Geodesy, Cartography and Geographic Information Systems, Ufa, Russia

This page uses 'cookies'. Learn more