نویسندگان

دانشگاه محقق اردبیلی

چکیده

یکی از ضروری‌ترین اطلاعات مورد نیاز مدیران منابع طبیعی، تهیه نقشه‌ پهنه‌های نمکی پلایاها می‌باشد. تهیه چنین نقشه‌هایی با استفاده از روش‌های سنتی مستلزم صرف زمان و هزینه زیادی خواهد بود. داده‌های ماهواره‌ای به دلیل دید وسیع و یکپارچه برای این امور مناسب می‌باشند. در این تحقیق روش جدیدی برای استخراج پهنه‌های نمکی از تصاویر ماهواره‌ای ارائه شده است که این روش پیشنهادی از ترکیب نسبت بین باندها و آستانه‌گذاری بر‌روی هیستوگرام تصویر تشکیل شده است. منطقه مورد مطالعه پلایای دامغان می‌باشد. پایش پهنه‌ نمکی پلایای دامغان با استفاده از تصاویر سنجنده‌ LISSIII ماهواره IRS-P6 در سال 2010 صورت پذیرفت. ابتدا پردازش‌های اولیه بر روی تصاویر اعمال گردید؛ سپس با نسبت‌گیری بین باندها و آستانه‌گذاری برروی هیستوگرام تصویر تولید شده، شاخص‌های پهنه نمکی نسبتی (RSCI) و پهنه نمکی تفاضلی نرمال شده (NDSCI) تعریف شده و نقشه نهایی پهنه‌های‌ نمکی به‌دست آمد. به منظور ارزیابی دقت حاصل از روش پیشنهادی، نتایج با نقشه‌های مرجع مطابقت داده شد. دقت پهنه نمکی استخراج شده از شاخص‌های RSCI و NDSCI برابر 81/0 و 89/0 برآورد شد. نتایج نشان می‌دهد که آستانه‌گذاری برروی هیستوگرام تصاویر نسبت‌گیری‌شده از جمله روش‌های معمول می‌باشد که می‌توان با استفاده از آن پهنه‌های نمکی را از تصاویر ماهواره‌ای استخراج نمود و شاخص‌های RSCI و NDSCI در مقیاس منطقه‌ای برای پایش این پدیده‌ها در مناطق خشک و نیمه خشک کارایی دارند.

کلیدواژه‌ها

عنوان مقاله [English]

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

نویسندگان [English]

  • M. Fathi
  • N. Sarmasti
  • F. Esfandyari

Mhaghegh Ardabili university

چکیده [English]

 Extended Abstracts  1-Introduction 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- Methodology 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– Discussion 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– Conclusion 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. 

کلیدواژه‌ها [English]

  • saline area
  • Damghan playa
  • Satellite Data
  • rationing spectral threshold