Majid Kazemzadeh; Zahra Nouri; Majid Rahmani; Asghar Bayat; Salma Saedi Farkoush
Volume 32, Issue 2 , July 2025, , Pages 124-139
Abstract
Background and objective: In recent years, extensive watershed management measures including biological, mechanical and biomechanical measures have been carried out with the aim of flood, erosion and sediment control and water storage in the different sections of research, study and implementation ...
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Background and objective: In recent years, extensive watershed management measures including biological, mechanical and biomechanical measures have been carried out with the aim of flood, erosion and sediment control and water storage in the different sections of research, study and implementation in the country. Evaluation of watershed management plans in order to analyze the performance of implemented watershed management measures and develop basic solutions is one of the basic needs in watershed management. Therefore, the aim of this research is to quantitatively and qualitatively evaluate the effects of biological and biomechanical measures of watershed management on the vegetation cover changes in Azimieh watershed, Karaj, Alborz province.Materials and methodsIn this study, vegetation changes were determined using Landsat series 5, 7 and 8, satellite images, and NDVI index in a period of 20 years (2000-2019). Then, by using the polytrend model, the trend of linear and non-linear changes and the effect of water management measures implemented in the watershed on the vegetation cover in the Azimieh Karaj watershed, Alborz province, were investigated. Also, in order to evaluate the accuracy of the results and satellite images, field measurements were also used. Also, in order to investigate the effect of climatic factors on vegetation changes, drought index and rainfall data of Karaj station were used.ResultsResults of trend showed that 41.9% of changes were significant over 20 years. 88.3% of the significant changes in vegetation were increasing. The results of Polytrend method showed that the changes in vegetation were cubic, linear and quadratic with values of 63.4%, 27.8% and 8.8%, respectively. Evaluation of the effects of implemented measures to improving the vegetation status of the watershed showed that the percentage of canopy in the watershed was on average 28% before implementing the watershed management measures, which has increased to 34% after the implementation of watershed management measures. Of the total area of biological operations in Azimiyeh watershed (2724 hectares), in 70% of the area, changes in the vegetation status of the rangeland have been nonlinear and these changes were in projects such as seeding and tree planting and terrace. Also, the vegetation in a parts of the downstream areas of Azimiyeh watershed have been destroyed by non-linear trends due to the growth and development of residential areas and civil works such as the construction of Hemmat Highway.ConclusionThe performance evaluation of watershed management projects in Azimieh Karaj watershed showed that watershed management measures have caused a significant increase in vegetation in the region. On the other hand, development and urbanization in the downstream areas of the watershed has caused the loss and destruction of vegetation over the past years. The evaluation of watershed management plans can show the positive and negative results of the measures implemented over the years, and in this way, steps can be taken to solve their obstacles and problems.
Leila Didar; Mohammad reza Mahboobi; Gholamhossein Abdollahzade
Volume 28, Issue 4 , November 2021, , Pages 701-717
Abstract
The development of the cultivation of medicinal plants in sloping lands based on public participation has an important role in improving land productivity, employment status, and livelihood of communities. The aim of this study was to investigate the barriers to the participation of local communities ...
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The development of the cultivation of medicinal plants in sloping lands based on public participation has an important role in improving land productivity, employment status, and livelihood of communities. The aim of this study was to investigate the barriers to the participation of local communities in the project of cultivation of medicinal plants in the sloping lands of Chehel Chay watershed in Minoodasht County. The research was descriptive and survey. The statistical population was 350 people from local communities living in the watershed. Using Krejcie and Morgan's table and random sampling method with assignment, 184 of them were selected as the research sample. The data collection tool was a questionnaire whose validity was confirmed by experts and its reliability was obtained by calculating Cronbach's alpha at the rates of 0.74, 0.79, and 0.89 for social, economic, and organizational barriers, respectively. Data were analyzed using SPSS19 software. The results of the Spearman test showed a positive and significant relationship between organizational barriers to participation with the variables of the number of years of employment in agriculture, hours of listening to the radio and watching TV during the day, and negative and significant relationship with variables of the number of respondents traveling to the city per month, the relationship between respondents and extension worker per month and the number of medicinal plants cultivated by respondents. Also, the results of the Friedman test showed the importance of organizational barriers in the non-participation of respondents in the project of cultivation of medicinal plants. It is recommended to pay attention to teaching the cultivation of medicinal plants to local communities, more communication, and interaction of extension workers with them, providing inputs and creating a suitable market for medicinal plants.
Fatemrh Dargahian; sakineh lotfinasabasl
Volume 27, Issue 2 , June 2020, , Pages 300-320
Abstract
This study investigates and analyzes the decades of change in climatic zones in Karkheh, Karoun, and Zohreh - Jarahi watersheds. For this purpose, the database of temperatures and precipitation networks during the period 1976-2015, with a spatial resolution of 15 x 15 km, formatted in the conical Lambert ...
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This study investigates and analyzes the decades of change in climatic zones in Karkheh, Karoun, and Zohreh - Jarahi watersheds. For this purpose, the database of temperatures and precipitation networks during the period 1976-2015, with a spatial resolution of 15 x 15 km, formatted in the conical Lambert image system, was used. In fact, because these two elements are the most important climatic drivers in the study area and the changes of other elements in these two elements are more visible, they have been used to study and analyze the climate change zone. After establishing the database, cluster analysis was used to identify climatic regions, and the audit analysis was used to validate it. Cluster analysis was performed on 52 indices of temperature and precipitation (monthly and annual average, coefficient of variation of temperature, and precipitation monthly and annual changes) during different periods, and climatic zones and their changes were analyzed. Based on the results, three climatic zones including humid and moderate zone, hot and dry zone, and very hot and dry zone were identified in the study area. The results showed that in recent periods, the humid area, in addition to having spatial displacement, its area reduced so that in the fifth period, the area reached less than five percent. Also, the hot and dry zone, stretched as a strip from the northwest to the southwest of the study area, had less spatial displacement, unlike the humid area, while its area increased in recent periods. On the other hand, the area of the very hot and dry zone has increased towards recent periods. Spatial and temporal increase of hot and dry climates and very hot and dry climates and decrease of the humid zone has been able to lead to the development and intensification of dust source, especially downstream of the studied watersheds.
Ali Akbar Jamali; Parvaneh Ashouri; Sedegheh Zarekia
Volume 17, Issue 1 , September 2010, , Pages 106-114
Abstract
Flood spreading will be more important and critical if drought occurred in arid and semi arid regions. Object is determination and prioritizing of flood spreading suitable sites for qanats, wells, and springs recharging in arid regions by using spatial multi criteria methods and GIS to combat with aridity ...
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Flood spreading will be more important and critical if drought occurred in arid and semi arid regions. Object is determination and prioritizing of flood spreading suitable sites for qanats, wells, and springs recharging in arid regions by using spatial multi criteria methods and GIS to combat with aridity and drought critic. Miankouh watershed in south of Yazd with 618 Km2 was selected as study area. In this study spatial economical factors such as proximity to road, qanat, well and spring were considered. Spatial natural factors and constraints such as vegetation cover density, geomorphology, land use and slope were interposed in the tree model. In spatial multi criteria evaluation method, factors were standardized through Boolean and fuzzy logics. Factor weights determined with ranking method. In next step with tree model and visual programming layers were combined in GIS environment that its result was composite index map (CIM) with fuzzy values. As a result, suitable region for flood spreading with values near to one were consisted areas with 15.02 km2 and all three priorities 2.43% of whole area in the watershed. This district had suitable common cover with region implemented flood spreading project. So, this method is recommended for determining suitable flood spreading sites in the same watershed areas.
Mohammad Tavakoli; Jamal Ghoddousi
Volume 9, Issue 3 , September 2001, , Pages 975-990