roya vazirian; Ali Akbar Karimian; Alireza Afshani; Mohammad-Taghi Dastorani
Abstract
In Collaborative management of arid regions, it is necessary to analyze the social relationships between farmers. The purpose of this study was to evaluate and analyze the social network of farmers in trust links and to participate in irrigation, marketing and cultivation activities in three villages ...
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In Collaborative management of arid regions, it is necessary to analyze the social relationships between farmers. The purpose of this study was to evaluate and analyze the social network of farmers in trust links and to participate in irrigation, marketing and cultivation activities in three villages of Aryan, Hareth Abad and Robat Sarpush in Sabzevar. For this purpose,in the firstusing with qualitative studies of survey approach,direct observation method and target population interview were identified. Then, the quantitative network analysis method, four important indices consist of "density", "reciprocity", "transitivity" and "average geodesic distance" in the links of trust and participation in agricultural activities of the farmers' network were evaluated. According to the results, the density of the four transplants was higher in Aryan village than the other villages, which is indicating more social cohesion in this village. The results of reciprocity and transitivity indexed in the studied links show more balance, equilibrium and stability of the network in Aryan village than the other villages, thus there is more social capital in this village. The average geodetic distance results also indicate the most favorable geodetic distance among the farmers in Aryan village. Increasing the cohesion and solidarity of these villages will speed up the flow of information and exchange, as well as increase social capital in them, and will help people to coordinate and access each other with less cost and time. Therefore, reinforcing trust and social participation is essential for increasing social capital as a necessity for participatory management
mojdeh mohammadi; Hossein Malekinezhad; Mohammad Taghi Dastorani
Abstract
Main problems in flood frequency analysis are limited number of gauging stations and recorded data, together with the inaccurate at-site estimations in the study area. These problems have caused increasing application of regional methods. Regional analysis seems to be a useful method for estimating peak ...
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Main problems in flood frequency analysis are limited number of gauging stations and recorded data, together with the inaccurate at-site estimations in the study area. These problems have caused increasing application of regional methods. Regional analysis seems to be a useful method for estimating peak flow at an area of no data or low-recorded length. Regional flood frequency analysis relies on physical and climatic characteristic of basins and applies statistical method to study flow records. The methods of regional analysis are numerous that the selection of each one of them in any study area depends on data length, climatic factors, data type and expected return periods. In this study, four techniques of regional analysis were used to evaluate the priority and importance to estimate the peak flow for different return periods. The Hybrid, Multiple regression, L-moments and Canonical Correlation Analysis are the four approaches applied for some watersheds of Isfahan–Sirjan and Yazd-Ardakan Basins. A number of 16 stations were selected and their data were analyzed to find out peak flow. The results of this analysis were compared to the Hybrid and Multiple regression approaches using RRMSE and MAE statistics. The results showed better performance of the CCA method rather than other methods in all return periods. After CCA, Multiple regression methods were selected to estimate the peak flow (Model 2, 3). Therefore, CCA method can be adopted as regional flood frequency method for the study area.
Masoud Eshghizadeh; Mohammad-Taghi Dastorani; Ali Talebi
Abstract
The management of sedimentation problems in rivers and reservoirs depend greatly on the sediment yield from the catchment land surface. In this research the effects of biological measures and ranges enclose on suspended load in two sub-catchments of Kakhk experimentalWatershed in Gonabad has been studied. ...
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The management of sedimentation problems in rivers and reservoirs depend greatly on the sediment yield from the catchment land surface. In this research the effects of biological measures and ranges enclose on suspended load in two sub-catchments of Kakhk experimentalWatershed in Gonabad has been studied. This catchment contains both control and experimental sub-catchments. These sub-catchments are similar in all aspects and differ only based on watershed management operations. Experimental sub-catchment has been under rangeland enclosures and operation of biological, biomechanical and mechanical measurements since 1998 whereas control sub-catchment is under normal operation. To determine the biological impact of management and biological measurements on sediment production, the yield suspended load on hillslopes in 18 experimental erosion plots during 4 rainfall events occurred in 2011-2012 has been analyzed in both control and experimental sub-catchments. Analysis was performed in SPSS software using independent-sample T test and ANOVAwith repeated measure test. Based on these comparisons, difference between the amount of suspended load in two sub-catchments was significant at 1 percent level, while runoff depth was significant at 5 percent level. Also results showed that correlation between the runoff depth and suspended load has been 94 percent in Control sub-catchment and 62 percent in Sample sub-catchment. Slope of the line changes between the runoff depth and suspended load in Control sub-catchment has been 5.3 times of the Sample sub-catchment. The research clearly showed the effect of the biological measures and ranges enclose on reduction of suspended load and runoff depth in experimental sub-catchment.
