In order to deal desertification phenomenon it is necessary to identify its producing and increases causes. For this purpose several studies conducted inside and outside the country that have been led to submit regional models.. Each of these models has different pattern and use different indicators which can lead to different results. In this study, Fakhrabad plain of Mehriz region by extent of over 39,370 hectares was selected. Whit emphasizing wind erosion criteria, that is the dominant process of desertification in the study area, the current status of desertification evaluated by IMDPA and MICD Iranian models and the results of two models ware compared. The results of this evaluation showed that in both IMDPA and MICD methods, the middle class of desertification has greatest area that is 88/3% and 81/4% respectively. Comparison of desertification scores and different classes of land use using regression comparison of standardized values revealed that correlation between the obtained scores is about 33% while this correlation between the severity classes of current desertification is 42%. Also comparison of similar values of the corresponding showed that classes of desertification in IMDPA model is less than MICD model which can be related to the different nature of models in using of the geometric and the arithmetic sum of the indices. It can be concluded that MICD model is suitable for large-scale (with more accuracy& the less area) and IMDPA model is more fitted for smaller scales (with more area, less accuracy) of capacity.

Water resources management, especially in watersheds without statistics all data, requires the recognition of hydrological processes, especially runoff, as one of the most important and most practical phases of the hydrological cycle. The aim of this study was to determine the efficiency and usability of the SWAT model in simulating the water balance of the Fakhrabad watershed. For the initial implementation of the model, the data required for the model implementation include meteorological data (precipitation, minimum and maximum temperature, relative humidity, and wind speed), baseline maps of the region (digital elevation map, land use, slope and soil map) and monthly discharge data of Fakhrabad hydrometric station. Were used. After the initial implementation of the SWAT model, the output was called to SWAT-CUP software for calibration and validation after sensitivity analysis, the model was implemented to determine the sensitive parameters and the results were reviewed. Calibration and validation were performed for the period 1998-2014 and the accuracy of monthly runoff simulation using the coefficient of determination (R2) and Nash Sutcliffe (NSE) for the calibration phase of 0.73 and 0.71 and for the validation phase of 0.54 and 0.53 was obtained. Acceptable values were also obtained for the uncertainty assessment indicators. P-factor and R-factor were 0.56 and 0.65 for the calibration period and 0.54 and 0.68 for the validation period, respectively. The final results showed that on average of 67% of precipitation enters the atmosphere through evapotranspiration, 23% enters the canals as surface run off and subsurface flow. The results show the efficiency of the SWAT model in simulating the water balance of Fakhrabad watershed and helps to more accurately programing water resources in this basin.

Kuhbanan fault is located between Tabas and Yazd blocks in the south west margin of central Iran microplate, extending from North west of Kerman to East of Bafgh, with 300 km length and NW-SE strike. The fault is one of the most seismic structural trend in the region. The latest seismic activity of the fault occurred on the first of April, 2002 with Ms=4,3 over the north-east Dehzo-segment of the fault. Kuhbanan earthquake fault consists of several segments. Movement in the southeast and central segments has been dextral strike-slip with a large reverse component during Plio-Quaternary.Study of alluvial fan deposits in Zarand, Toghroljerd and Bahabad plains indicates that deposition, development and morphology of the alluvial fans have been affected by the tectonic activity of Kuhbanan fault segment and morphology of the alluvial fans have been affected by the tectonic activity of Kuhbanan fault segment which are located in the mountain front of Kerman-Kuhbanan and west Bahabad mountain ranges. Several coalesced alluvial fans exist which are adjacent to Tikdar-Gorcho, Khanok, Rigabad-Daho, Apang-Sarbagh, Gisk, Dartangal, Dehzo and NW Dehzo fault segments in the eastern margin of Zarand plain. The youngest part of the fans is formed in the fanhead area and apex of fans does not progress to the mountain front. Active and inactive areas are formed at the surface of fans some of the them are deeply dissected. Longitudinal profile of the fans is usually segmented and some show a decreasing slope. Vertical profile of the fans is wedge shape, with maximum thickness adjacent to the fault segments and some fans are lense shape. Internal structure of the fans is mostly buried, but imbricated and inset fan also occur Main channel is in the margin or edge of the fans. Fan deposits are poorly sorted, coarsening upward. Apparent neotectonic fractures occurred in Khanok, Sarbagh, Dehzo and NW Dehzo semi-consolidated fan deposits. Several coalesced alluvial fans also exist adjacent to Toghroljard, Abassabad, Dargaz-Godgaz, SE Gavar, Fakhrabad, Khoshabad, Hossinabad and Kuh-e-Sorkh fault segments in the eats margin of Toghroljard plain and in the west margin of the Bagabad plain. Apex of the fans does not progress to the mountain front. Active and inactive areas are formed at the surface of dissected fans. Main channel is in the margin or edge of the fans. Apparent neotectonic fractures occurred in Fakhrabad, Khoshabad and Hossinabad fan deposits. Based on the surface morphology, vertical variation and internal structure of the alluvial fans, it is concluded that 1) neotectonic activity of fault segments have caused continuous elevating of mountain front or sinking of piedmont, and right lateral displacement of mountains relative to plain at late Quaternary. 2) The highest tectonic activity have occurred over Khanok, Righabad, Gisk, Dartangal, Apang-Darbagh, NW Dehzo and Fakhrabad segments during and after deposition of alluvial fans.

Drought is a widespread phenomenon that its intensity varies in time and place. Drought monitoring using meteorological data alone, is not accurate due to small number and inadequate distribution of meteorological stations. Therefore, the use of remote sensing technique and vegetation indices is important as a useful integrated solution for the study of drought. The present study was conducted for Drought zoning in Yazd-Ardakan plain by combining meteorological and remote sensing data. In this research, data of meteorological stations of Yazd, Meybod and Mehriz between 2002 and 2015 have been used. First, the Standard Precipitation Index (SPI) was calculated in monthly scale for all three stations. The mean values of monthly SPI computed and mapped. Using Landsat images, the SAVI index was calculated and its map was prepared in 16 different times. Due to the role of the temperature in the occurrence of drought, the IDI (Integrated Drought Index) was calculated using temperature and precipitation and SAVI index. Zoning of mean SPI values showed that the lowest SPI values are in the middle, north and southeast and the highest values are related to the western heights of the plain. SAVI zoning showed that the rangelands of Meybod and Yazd regions have the lowest density. The correlation coefficient of SPI and SAVI values varies between 0.5 to 0.65, and larger values belong to Mehriz region. IDI values are lower in higher rangelands, meaning that these areas have been less affected by drought. The mean values of IDI in Mehriz, Yazd and Meybod regions reach a maximum of 5, 100 and 160. Temporal changes in drought indices showed that when rainfall increased, the IDI index decreased. The possibility of lag time between precipitation and changes in IDI was also observed. Comparison of monthly IDI values and rainfall showed that the time effect of rainfall on IDI index is about three months.

Soil erosion, is undoubtedly one of the most important problems in natural areas of Iran and has destructive effects on different ecosystems. Considering that the calculation of the sediment rate in sediment stations and direct measurements of erosion process is costly and difficult, it is critical to find ways to accurately estimate the amount of sediment yield in catchments especially in arid and hyper arid areas because of their high ecological sensitivity. One of the most commonly used methods in these areas is the sediment rating regression method. Therefore, in this study sediment observed data for 48 events (the corresponding discharge and sediment) in a 23-year period from Fkhrabad basin (Mehriz) were compared to the estimated data obtained from Multi-line rating method, extent middle class, middle class rating curve with correction factor QMLE, SMEARING correction coefficient FAO and Artificial Neural networks (ANNs). Finally, the accuracy of these methods were assessed using different evaluation criteria such as Root mean square error (RMSE), coefficient of determination (R2) and the standard Nash (ME). Results showed that ANN outperformed the other methods with the RMSE, R2 and ME of 203.3, 0.86 and 0.66, respectively. The results suggest that these methods should be used cautiously in estimating the suspended sediment load in arid and hyper arid regions due to the nature of the observed data and temporal and seasonal flow Systems in these regions. It was also indicated that the artificial neural network models have higher flexibility than other methods which makes them to be useful tools for modeling in poor data conditions.

Mehriz historic city is located near the Yazd-Kerman road almost 25km to the south of Yazd. It is a good example of a desert town in the central Iranian plateau، where the weather is extremely hot with arid and semi-arid climate conditions and where the water is provided only by the qanats. Living with the desert means a consistent process of environmental adaptation and a harmonious interaction between man and nature that is reflected in earthen built fabric. The exiting physical structure of Mehriz has، therefore، captured a long process of formation and transformation that is resulted in the today’s garden city. This study is an effort in identification and understanding of the historical processes of urban development and physical changes in the city''s historic neighbourhoods. Along with tracing historical and morphological development of Mehriz over time، and on the basis of field observation and document analysis، three main issues were studied: first، investigating neighbourhood centres and places of public gathering and social relation; secondly، understanding the defensive system and the issue of urban security; and thirdly، surveying the water supply and distribution systems. Results show that each of the traditional neighbourhoods of Mehriz had separate neighbourhood centres and people exercised their religious practice in their own locality. Moreover، each of these neighbourhoods has a specific water supply system and a defence system apt for its own population. These neighbourhoods have been relativley independent villages in the past، and had their own local management، water and land for gardening and agriculture. The question whether Mehriz has been established on the basis of the idea of a garden-city or is the result of a long process of physical accumulation، integrating several villages and outskirts in the bigger framework of the current city has been scrutinised. This paper demonstrates that although today Mehriz reflects the image of a garden city، this is the result of a long process of morphological development، integrating the old boroughs and agricultural and rural landscape into the current frame of the old borough of Mehrijerd. Thus، Mehriz in the past has not been an integrated garden city and has only gradually evolved into such urban form.

The main objective of water spreading projects is recharging aquifersþ.þ In this study, changes of soil surface permeability in Yazd water spreading projects, including Sirizi in Bafgh, Herat ýand Miankouh in Mehriz were investigated. Using a double ring, 12 Permeability tests (in first ýand fourth strips and three tests for each strip) were performed. Using measured data the ýperformance of permeability equations such as Kostiakov, Kostiakov-Lewis, Horton, SCS, ýand Philip were compared in estimating cumulative infiltration and infiltration rate in the ýstudy areas. Results showed that average permeability for Bafgh, Herat and Mehriz water ýspreading projects were about 1.06, 1.52 and 2.94 cmhr-1, respectively. The best equation for ýestimating cumulative infiltration in Bafgh was the Horton equation with RMSE and Nash ýSutcliffe coefficients of 0.097 and 0.992, respectively, while in Herat and Mehriz the best ýequation was the Kostiakov-Lewis equation with Nash-Sutcliffe coefficient and RMSE of ý0.385, 0.994, 0.081 and 0.991 respectively.

The areas of natural resources and vegetation in the Taft and Mehriz townships in recent decades have undergone changes due to its close proximity to the capital of Yazd province. The purpose of this study is to assess the extent and direction and prediction of land and vegetation changes in these two cities. In this study, Landsat 5 (1998, 2004 and 2008) and Landsat 8 (2017) satellite images in the period from May to June was used. Modeling land use/land cover changes were carried out based on supervised classification. The process of changes was analyzed using land change modeling and perceptron neural network method. The results showed that 3% (558.8 ha) of land and vegetation cover of Taft to Bayer and 1.3% (209.9 ha) were added to the urban lands and reduced from the lands of gardens by 4.3% (559.2 ha), this is the highest rating. The amount of 2.8% (678.8 ha) of land and vegetation in Mehriz Bayer and 1.7% (184 ha) has been changed to urban residential land. In terms of urban expansion, Mehriz has had the highest amount of reducing vegetation. The results show that land use and land cover changes in Taft city where more than Mehriz city so that most of these changes were related to gardens, but in terms of area of land use and land use conversion in Mehriz city has the highest value More intense.