جستجوی مقالات مرتبط با کلیدواژه "gini coefficient" در نشریات گروه "آب و خاک"

Water allocation needs to adhere to the principles of efficiency, equity, and sustainability, but, equity usually is less considered. Foumanat irrigation area with five command areas is one of the three areas of Sefidroud irrigation and drainage network that more than 90% of it is covered by paddy fields. Since water plays a key role in paddy fields, the lack of uniform distribution of water resources throughout the irrigation area during the rice cultivation period causes irrigation water scarcity and severe damage to some irrigation areas. In this study, the equity of groundwater withdrawal and the received surface water from Sefidroud irrigation and drainage canals according to the shared water resources among Foumanat’s command areas were evaluated using the Gini coefficient. Therefore, a water allocation optimization model was developed to maximize the equity in the allocation of groundwater and surface water of canals according to the minimum current economic benefit in the command areas. The results showed that in optimum conditions, the equity of groundwater and surface water resources allocation was increased by 46.3% and 43.7%, respectively. The evaluation of the optimal allocation of available water resources also showed that the amounts of groundwater withdrawal and the received surface water from canals are distributed equally among command areas.

The allocation of water reservoirs with three basic conditions, equality, efficiency and sustainability is a prerequisite for sustainable development. Due to the limited availability of renewable water sources at the river basin level and the increasing demand for water in various uses (agriculture, domestic, industry and the environment) due to population growth and competition over resource use, the need to pay attention to The allocation of water resources has increased, and this calls for attention to different ways of optimizing water resources allocation. Therefore, in this research, we have tried to provide a model that can consider different criteria for water allocation, especially two basic criteria of justice and efficiency, and to comply with different environmental criteria.The new constructed dam of Givi With a normal volume of 54 million cubic meters is located in the catchment area of the Givi Chai River With an area of about 600 square kilometers from the subbasins of the Ghezel Ozan River and due to the fact that the dam's irrigation network has not been constructed and reservoir allocation details are not known yet, In this study, we tried to provide a model for the sustainable development of the area by paying attention to the agricultural and industrial potential of the region, as well as the needs of domestic in the present and in the 20 years horizons.The output of the model was obtained for various coefficients for the objective functions (efficiency and equity) and the results were shown by increasing the coefficient of efficiency function and reducing the function of justice (the function of Gini) and finally, using the AHP method and obtaining the Paired Comparison matrix, The optimal model and thus the coefficients of optimal efficiency and equity functions were calculated. The results show that the coefficients of the target functions (0.6 and 0.4) are optimal for the functions of efficiency and equity, respectively. And in fact it's a global optimum point.

Consumption of goods and services by households is an important index of their level of economic welfare. State of consumption distribution among households is an important index of equity in economic welfare. In this research, two important dimensions of consumption distribution have been studied: 1) Trend of changes of consumption distribution between Iranian rural and urban households 2) Changes of consumption distribution among households within rural and urban areas in different provinces. Secondary data were used in this research from rural and urban households surveys of expenditure and income for different years. The results show that the ratio of urban household expenditures over rural household expenditures during 1965-96 has had a decreasing trend, though the gap is still high. To compare consumption expenditure distribution changes within rural and urban areas in different provinces, the data for the two years of 1986 and 1996 have been used. The results show that countrywide the Gini coefficients in 1986 and 1996 in rural areas were higher than those in urban areas in rural areas the coefficients were 0.458 and 0.421 and in urban areas 0.430 and 0.403, respectively, which indicate a decrease of 8.08 and 6.28 percent, respectively. Among the rural areas of 24 provinces, the Gini coefficients of 9 provinces increased and those of 15 provinces decreased from 1986 to 1996. This is while the comparison for the urban areas in the same provinces and for the same period indicates that the Gini coefficient of 6 provinces increased but that of 17 provinces decreased. No change occurred in the case of Tehran Province.