مجله علوم و مهندسی آبخیزداری ایران
پیاپی 57 (تابستان 1401)

Management based on the flexibility, fairness, and sustainability characteristics of water resources may play a key role in preventing the continuation of the crisis process as well as reducing water users’ conflict. In the present research, the framework for the optimal allocation of shared water resources was presented using a combination of bankruptcy concepts and asymmetric Nash bargaining. To this end, Atrak basin including Golestan, Northkhorasan, and Razavikhorasan provinces was chosen as the study area. The optimal answer to the bargaining method was compared with the results of water bankruptcy rules. The results revealed that considering different hypotheses, the proposed model could cover the results of common bankruptcy rules. Subsequently, for optimal and sustainable use of water resources in the studied basin, several indices like political, social, and economic criteria were employed to include and investigate the effect in the proposed model. Using Topsis-Entropy in the determination of the relative weight, it was observed that water users playing the key role in the water resources production in the basin would obtain a more equitable supply percentage of their demand. The results of multi-criteria water allocation in Golestan, Northkhorasan, and Razavikhorasan provinces respectively are 104, 809, and 164 MCM per year.

The aim of this study is to investigate the trend of spatial and temporal changes in the future extreme temperature of Iran. The data used include daily data of minimum temperature and maximum temperature of CCSM4 model during the basic period of 1986-2005 and the future period of 2006-2050 under scenarios of 4.5 and 8.5 in Iran. The results of studying the trend of warm and cold extreme during the basic period showed that in general, warm extreme has a positive and increasing trend and cold extremes has a negative and decreasing trend in Iran. The results of investigate the trend of future extreme temperature in Iran during the two periods of 2006-2025 and 1428-1404 showed that in the first period and based on scenario 4.5, the trend of cold and warm indicators in most parts of iran have the same conditions as the base period. In the second period, these conditions can be seen with limited changes in the spatial distribution of decreasing trends as in the first period. These results indicate an increase in temperature changes and consequently an increase in extreme events, especially extreme events in different parts of Iran.

Identification and monitoring of surface water using remote sensing have become very important in recent decades due to its importance in human needs and political decisions. Therefore, surface water has been studied using remote sensing systems and Sentinel-1 and Sentinel-2 sensors in this study. In this paper, two data fusion approaches and decision fusion improve the accuracy of surface water identification for the two study areas in Mazandaran province, Iran, due to dense forests, turbid rivers, and land Agricultural products have been proposed. Data fusion approach by increasing the spatial resolution of Sentinel-2 optical sensor from 20 meters to 10 meters and using radar dataset and water indices in one layer, monitoring surface water with much higher accuracy by classification using supervised classifiers such as Support Vector Machine (SVM), Neural Network (NN), and Random Forest (RF) were performed. Then, by combining the results using the Maximum Voting (MV) method, the accuracy of the results compared to the data fusion approach increased by 4 percent to 5 percent. Since narrow and confused rivers are not easily identifiable and extractable, the proposed approach was able to extract an accurate map of surface water.

Drought is one of the major problems facing countries in subtropical offerings such as Iran. Fars province, which is one of the southern provinces in the field of tourism and agriculture, has long been facing the problem of drought and water shortage, so the study of drought in this province to better manage the problem of drought and improve the situation of agriculture and agricultural tourism is necessary. The purpose of this study is to investigate the drought trend in this province using drought index and drought identification index. The parameters used in these indicators are potential rainfall and evapotranspiration. In this regard, rainfall and maximum temperature data of 10 stations in the statistical years 1999-2020 were used and the evapotranspiration of each station was calculated using Larry-Johnson method. Necessary indicators and diagrams were drawn by MATLAB software (a2020) and based on the obtained results, the average maximum and minimum drought intensity occurred in 2008 and 2004, respectively, also in 2020 showed a dry and normal situation. Finally, according to the zoning maps obtained from ArcMap software (10.8), an increase in drought intensity was observed in the southern and central parts of the province.

The Sistan Plain for a long time has faced hazards of flood, drought and sandstorm. Also due to existence of abundant water resources it had been one of the important places for men’s placement. So far, no comprehensive study has been done on environmental hazards which would include ways to overcome or decrease their impacts in Achaemenid era. The present survey aims for studying the reciprocal relation between Achaemenid settlements and natural environment in areas based on environmental limitations. This research has been carried out through the descriptive- analytical- historical method using GIS software. After environmental conditions had been studied, variables types and distance from water resources, slope, soil type, Geology and wind were studied and the results indicate surface water resources effective role in settlements placement. The Water resources existence, gentle slope and consequently ease of waterflow down to plain and canals creation capacity to keep suitable distance to river and placement on Alluvial terrace to avoid flood hazards are among the factors turned area to population absorbing one despite shortage of aquifers and reliance on surface water resources. Being located on delta fans would lead to change of the direction of river canals, which causes relocations of settlements.

Today, the use of data recorded in synoptic stations of the country is one of the most significant sources of applied research for researchers. Data recorded automatically or manually at synoptic, climatological, and other stations are analyzed for statistical analysis. In this research, the data recorded in the synoptic stations of Iran, which are used to determine the days of dust, were analyzed using the science of monitoring and data analysis using ensemble classification. In this study, data from 36 synoptic stations, were used. These stations are in Isfahan, Kerman, Yazd, Sistan and Baluchestan, Semnan, Markazi, Khorasan Razavi, Hamedan, Qom, and South Khorasan. The parameters of daily average temperature, daily rainfall, station height, geographical location of the station, maximum wind speed, maximum wind speed, and dew point were used for the classification. The results showed that the most important factor among these parameters for dust is the maximum wind speed, which was identified as the most significant factor in all classification methods. Also, three classifiers, KNN, SVM with RBF kernel, and MLP neural network, were selected as members of the ensemble, which accurately detects 90.7 percent of the source of dust production (from the inside and outside the dust).