Showing 3 results for Sabohi
J. Torkamani, M. Sabohi,
Volume 11, Issue 1 (spring 2007)
Abstract
The endogenous selection and determination of return reference level is important in specifying risk efficient set. Thus, using multi-objective programming, Target–MOTAD in the framework of Mean-PAD and maximin parametric analysis models was established to obtained reference level of return endogenously. To determine non–inferior set for the farmers understudy, at first, the pay-off matrix was obtained through maximizing objectives under consideration. Then, upper and lower bounds of non-inferior set were determined using non- inferior set estimation (NISE) technique. The results obtained from maximin model indicated that Min and Max of maximin model were 270252 and 217753 thousands Rials, respectively. Furthermore, a subset of non-inferior set was obtained using different return reference levels. Comparing the results of model and the current farmers' plan showed that the current acreage of crops, except for sugar beet was approximately placed in the range determined by the model. In addition, the results also indicated that farmers' plan could be a non- inferior set. Considering the importance and also scarcity of water in the study area, average water return in the farmers' plan was compared to non-inferior set which included all the upper and lower non-inferior set. The results showed that farmers obtained 18150 Rials per hours of used water. However, average water return changed the range of 19100 to 30200 Rials for non-inferior set, indicating that farmers are able to use water more efficiently. The results also showed that changing farmers' cropping pattern is a complicated task and that it is necessary to have a systematic view in ordere to achieve desirable change.
M. Sabohi, Gh. Soltani, M. Zibaie,
Volume 11, Issue 1 (spring 2007)
Abstract
The objective of this study was to evaluate the strategies for groundwater resources management, including competition groundwater pumping, optimal control in groundwater pumping, groundwater use and tax policy, water users' participation in groundwater pumping control, and cooperation among government and water user associations in Narimany plain located in Khorasan Province. Irrigation water demand of sugar beet growers was estimated for empirical assessment of the strategies. The results indicated that among the strategies, groundwater use and tax policy may lead growers to sustainable use of groundwater resources. Furthermore, the results showed a desirable strategy is affected by cultural, social, and economic characteristics of growers and general prevalent conditions of society. Moreover, each strategy calls for its obligations, for instance, it is necessary to have an efficient taxation system for the proposed strategy. Hence, by internalizing the external cost of groundwater overdraft (that is taxing water users) government can force them to consider the adverse effects of their decisions on other producers.
R Sabohi, S Soltani,
Volume 12, Issue 46 (fall 2009)
Abstract
Climate change has important effects on earth environment and human life. Therefor, investigation and study of climate change is very essential. This study investigated rainfall, temperature, relative humidity and wind variability by analyzing data for annual and monthly climatic factors collected at 13 synoptic stations (industrial cities of Iran) by using Mann-Kendall test. The results of monthly rainfall trends showed that most of synoptic stations have significant positive and negative trends in winter and spring months. About 23% and 1.7% of stations have significant negative and positive trends, respectively, in annual trend of this factor. The results of monthly number of rainy days showed the major number of significant trends occurs in spring. In autumn (September, October and November) like as summer most of the stations have no significant trends. Analyzing the annual number of rainy days trends also showed that 4 stations have significant positive trends and 2 stations negative trends. Trend of greatest daily precipitation is low throughout the year, so there is not any significant trend in winter. Annual investigations confirm the seasonal investigations. The major number of significant trends in monthly mean maximum temperature occurs in summer but there are not any significant trends in winter and March. The trend of mean minimum temperature is approximately high in all of the seasons and the major number of significant trends occurs in summer and autumn and then in spring and ultimately in winter. In annual investigation, most of the stations showed positive trends and only Oroomieh station has negative trends. Trend of mean temperature is high except for winter. Most of the stations showed positive trend, indicating increasing trends in this factor. Annual studies vertify the positive trends and about 63% of stations have significant positive trends.
