Monitoring area of Damghan salt playa by multi-spectral satellite data processing

1- Playa saline zones as ecological environment has been regarded by researchers and many researchers have been seeking new methods for studying this phenomenon, because access to these areas due to special circumstances, it has always been difficult and limited (Metternicht et al, 2010: 324). Monitoring of saline arid zones in sustainable development and environmental protection is an important parameter. Monitoring of this phenomenon requires extraction and thematic maps at different times. Remote sensing technology is an effective method for obtaining the required data. This procedure avoids the usual constraints of time and place (Rezaie Moghadam, 2005: 221). Limitations on the use of satellite data to produce maps of salt affected areas of the spectral behavior of salt types, spatial distribution of salts on the surface, the changes in salinity, vegetation as barrier and spectral mixing with other levels of the ground depends (Alavipanah, 2002: 451). The main objective of this study was to assess methods saline mining zones and provide a new method for monitoring the spatial extent of this phenomenon with the satellite images of Playa. With regard to the above and the saline playa zones, monitoring area of saline cover in this study using IRS-P6 satellite images LISSIII sensor can be studied in 2010. The study area for this research is the watershed cover at 35 degrees 53 minutes north latitude and 36 degrees 17 minutes and 54 degrees 35 minutes east longitude and 55 degrees 18 minutes East province is located in the southeastern city of Damghan which has a stretch east - west with an area of 2474700 hectares. Cover an area of ​​239,100 hectares where the desert playa Haji Aliguli (Chjam) with an area of ​​46,600 hectares is located. 2- The data used in this study, IRS-P6 satellite image sensor LISSIII 2010. This sensor is equivalent bands TM2, TM3, TM4 and TM5 and ground resolution 5/23 meter bands visible light and near- infrared and mid- latitude and their shooting is 140 kilometers (Alavipanah, 2006: 53). According to a study that evaluates conventional separation zones cover and thematic mapping of the salt processing satellite imagery, the methods of research proposed in this color eye pseudo seizure interpretation, use of the combine the gangs respect on the threshold Histogram images. After applying this correction, the entire image area of ​​study was attempting to cut a small part of the full frame range used in satellite images. Thus, the next operation was performed on the cropped area. Next, in order to separate the saline from the area of ​​the image with the proposed method, the images were ILWIS3.3 software. Due to the complex interaction of a range saline and other phenomena in the area of ​​Playa cover and requires high precision in the final output efficiency of each of the proposed methods mentioned were analyzed. 3– Powerful tool in the field of remote sensing to study different ecosystems, such as Playa environments in order to produce valuable data and useful. Threshold on the histogram of the common methods that can be used to blank the saline extracted from satellite images. Due to the fact that the spectral reflectance of salt compared to other phenomena in the mid-infrared bands is very small allotment and close to zero, so the blank extract saline from satellite imagery, the action threshold are one of the mid-infrared bands. It should be noted that the choice of the threshold value is difficult in practice because the same underlying removing salt from saline zones is not possible or careless. Although this method has high accuracy, but it can be easily extracted automatically and quickly raised. Ratio between the bands used to extract saline zones is also difficult because of the different coatings than in places where the ground does not have the results. 4– Due to the variable nature of the salt zone boundary lines are part of its natural features, its continuous monitoring does not appear very good based on visual interpretation. Due to the complex nature of these problems and Damghan playa new method presented in this study and were analyzed. This method is based on combining the method of threshold and ratio between bands. This study aimed to investigate the feasibility of monitoring area Saline Damghan playa LISSIII sensor image processing was done in 2010 found that between two methods of spectral bands and threshold rationing on the image histogram for monitoring and mapping arid zones saline is a good way. The results also showed that measures of Damghan playa salt RSCI and NDSCI the resolution satellite imagery mapping and monitoring their performance.