Showing 7 results for Rahdari
A Soffianian, S Maleki Najafabadi, V Rahdari,
Volume 13, Issue 49 (Water and Soil Science 2009)
Abstract
Landscape ecology as a modern interdisciplinary science offers new concepts, theories, and methods for land evaluation and management. One main part of landscape ecology is describing patterns in the landscape and interpreting the ecological effects of these patterns on flora, fauna, flow of energy and materials. Landscape studies require methods to identify and quantify spatial patterns of landscape. Quantification of spatial patterns is essential to understand landscape functions and processes. Landscape indices as diversity and naturalness can provide quantitative information about landscape pattern. Remote sensing and GIS techniques have high ability for landscape researchers to specify, map and analyze landscape patterns. The objectives of the research include mapping and quantifing diversity and naturalness indices for Mooteh wildlife refuge by land use/land cover map derived from remote sensing images. Finally, diversity and naturalness were classified in 4 and 6 classes, respectively. Results showed that the intermediate and high diversity classes (class 1 & 2) have occupied the largest area in the study area. Among naturalness classes, class 1 which represents the high level of naturalness has taken the largest area in Mooteh W.R.
V. Rahdari, A. R. Soffianian, S. Pourmanafi, H. Ghaiumi Mohammadi,
Volume 22, Issue 3 (Fall 2018)
Abstract
Determining the cultivation crops area is important for properly supplying crops. The aim of this study was mapping the cultivation area crops in Chadian city for spring and summer during 2015 by using the time series data of the Landsat 8 satellite of OLI imagery. At first, the under cultivation area was determined by setting a low threshold in the marginal pixels of the agricultural rain fed in the spring image NDVI index. The area cultivated with wheat and alfalfa was prepared by subtracting spring and summer NDVI values. Cultivation maps, which were cultivated with potatoes, corn and orchards, were prepared using the supervised classification with the FISHER method in a step by step manner. Spring and summer cultivation maps were combined; finally, the major cultivation crops maps were produced by the hybrid classification method. Map accuracy assessment was done by producing error matrix and calculating kappa coefficient, total accuracy, commission and omission error, producer, and use accuracy; in all indices, they had an acceptable value, showing the capability of OLI and the used methods in separating each cultivation.
V. Rahdari, A. Soffianian, S. Pormanafi, H. Ghayomi Mohammadi, S. Maleki, V. Pormardan,
Volume 23, Issue 4 (winter 2020)
Abstract
In this study, to evaluate the rain- fed land capability in the west of Gavkhooni basin and Plasjn sub- basin, a multi- criteria evaluation method was used. First, by reviewing the literature and expert knowledge, proper data were determined. Criteria and constraint were standardized by Fuzzy and Boolean methods repeatedly and the criteria weights were determined using the analytic hierarchy process. Calculated weights showed that soil and climate criteria with 0.27 and 0.26 had the highest weights among other criteria. Criteria and constraints were combined by considering criteria weights and using the weighted linear combination method; then the rain- fed land capability model was prepared. By re- classing the prepared model, the rain- fed land capability map was produced in 6 capability classes. The results showed that 178430 hectares of the study area was related to very high and high rain- fed capability classes. To determine the rain-fed agriculture sustainability, rain- fed agriculture locations were determined in each land rain- fed capability map. The results showed that 19686 hectares of rain- fed areas were located in high and very high capability and 5999 hectares were the in lower classes.
A.r. Nourafar, A. Pahlavanravi, M. Nohtani, V. Rahdari,
Volume 26, Issue 1 (Spring 2022)
Abstract
Wind erosion is one of the most important natural processes in arid and semi-arid regions. Sistan plain has a hyper-arid climate and is one of the windy regions of the country. Due to the soil characteristics of the Sistan plain, wind erosion is very intense in this region. In this study, the relationships between some soil's physical and chemical properties and wind erosion were investigated in different land cover in a part of the central region of Sistan in 2018. A map of land cover in five classes was prepared using the results of field studies and the classification of satellite images. Fifty soil samples at a depth of 10 cm were collected to investigate the physical and chemical soil properties and the wind erosion threshold was determined at each location using a portable wind tunnel device. Also, the relationship between physical and chemical soil properties including soil texture, soil moisture, specific apparent weight, EC, SAR, ESP, Na+, k+, with the speed of wind erosion threshold was investigated. According to the results, the highest and the lowest threshold speed were 8.2 and 3.8 m s-1 and occurred in agricultural lands and hilly lands, respectively. The results of this study indicated that the velocity of wind erosion threshold in different lands adjacent to sandy areas is less than the average of that cover. Also, the soil texture, EC, and SAR have the most significant effect on soil wind erodibility at P <0.05 in the study area.
V. Rahdari, A.r. Soffianian, S. Pormanafi, S. Maleki,
Volume 27, Issue 3 (Fall 2023)
Abstract
Industrial development is necessary to create employment and achieve welfare. Nevertheless, due to the important environmental effects of these uses, it is necessary to consider the environmental issues in industrial area land allocation. The current research used the multi-criteria evaluation method and the combination with fuzzy concepts to investigate the land capability for industrial development in the Plasjan sub-basin in the Zayandeh-rood river basin. Evaluation criteria were determined by literature reviewing and using experts' knowledge, and standard applying fuzzy method via proportional functions and weighted using the hierarchical method. The combined classification of satellite images prepared the land use and land cover map. Then, the standardized criteria were combined in the form of a weighted linear combination and the industrial development capability model was prepared for this area and classified into five land capability classes. The results showed that environmental considerations have the most weight with 0.23, and geological and soil texture criteria have the least weight with 0.06. According to the results, only 213 hectares of the region were allocated for industrial and mining use at the time of the study. In comparison, 2325 hectares of the region have very high industrial potential which shows the capability for increasing industrial areas. Also, the highest class of land capability was related to areas without the capability for industrial development with an area of 246375 ha, equivalent to 60% of the entire region, which shows the importance of conservation of the important functions of this region in water supply and ecological resources.
M. Salari, V. Rahdari, S. Maleki, R. Karami,
Volume 27, Issue 4 (Winter 2023)
Abstract
the countries of Iran and Afghanistan. A long period of drought has happened in this area by human interventions after 1999. The objective of current study is to predict the Hamoun wetland situation in scenarios with and without human intervention using the Markov model-automated cellular for 2019 and the next forty years. Land cover maps of the study area using satellite images for 1987 as a normal year, 1991 as a wet year, and 2019 as a year with human effects were prepared. Then, prediction model for 2019 were prepared using 1987 and 1991 cover layers in four scenarios, prediction models were prepared for the next forty years in normal, drought, and wet conditions. If the natural process of watering of Hamoun wetland continues, lower than 362735 hectares of wetland should become watering in 2019, while, according this year land cover map, less than 50000 hectares of wetland have water. Also, by continuation of the current trend and the effect of human activities in the 40-year models, 11230 hectares of the area will be watering, and if the natural process of the wetland continued using the model of 2019 this amount was equal to 373311 hectares. The results of the research show the completely different situation of the Hamoun wetland in the case of no human intervention in the watering of this wetland in 2019 and the model of the next forty years.
A. Salar, M. Shahriari, V. Rahdari, S. Maleki,
Volume 28, Issue 2 (Summer 2024)
Abstract
Unbalanced development of different land use/cover in basins without considering the contribution of all components, can cause serious damage to the stability of the entire basin. The development of agricultural areas by increasing the amount of water use and creating dams upstream of rivers are the most important threats to wetlands in many places. Jazmorian wetland is one of the seasonal wetlands in the south-east of Iran. The most important source of water supply for this wetland is the Halil-Rood River. To investigate the land use/cover changes of Jazmurian wetland and
Halil-Rood River, the time series of Landsat satellite data for the years 1354, 1374, 1387, and 1401 were used in the present research. The Landsat satellite images were classified using a hybrid classification method and the land use/cover of the study area maps were prepared. The accuracy of the prepared maps for the latest image was calculated by preparing the error matrix, calculating the kappa index, and the overall accuracy of more than 0.8 and 9%, respectively. The investigation of the prepared maps showed that the area of land under water increased from 1354 to 1374 and then decreased from 119,552 hectares in 1374 to 723 hectares in 1401. The area of agricultural land increased from 2131 hectares in 1354 to 133913 hectares in 1387 and declined to 105795 hectares in 1401. The results of this study show that in this period, with the construction of a dam upstream of the Halil-Rood River, and the development of agricultural lands, the water volume level of the wetland decreased, and the wetland completely dried up in 1401. The present study indicates the necessity of considering different components of a watershed in development planning to achieve sustainable development.
