Journal of Spatial Analysis Environmental Hazards
تحلیل فضایی مخاطرات محیطی
Journal of Spatial Analysis Environmental Hazards
Literature & Humanities
http://jsaeh.khu.ac.ir
1
admin
2423-7892
2588-5146
10.61186/jsaeh
fa
jalali
1401
2
1
gregorian
2022
5
1
9
1
online
1
fulltext
fa
ارزیابی ارتباط خشکیدگی جنگل و خشکسالی با استفاده از مدل های آماری در استان ایلام
Assessing the relation ship between forest drying and drought using statistical models in illam province
تخصصي
Special
پژوهشي
Research
<div style="text-align: justify;"><strong> در این مطالعه ارتباط بین خشکیدگی </strong><strong>درختان</strong><strong> بلوط ایرانی و خشکسالی در استان ایلام بررسی شده است. هدف اصلی تحقیق معرفی مدلی مناسب از روابط بین خشکیدگی بلوط و خشکسالی می باشد بنابراین از شاخصهای </strong><strong><span dir="LTR">SPI</span></strong><strong> و </strong><strong><span dir="LTR">NDVI</span></strong><strong> وآماره شاخص موران و آماره رگرسیون خطی </strong><strong>و تصاویر ماهوارهای مودیس و لندست در تحلیل ارتباط خشکیدگی جنگلهای </strong><strong>ایلام </strong><strong>با خشکسالیهای رخ داده در منطقه استفاده شده است. دادههای بارش 93 ایستگاه باران سنج در طول دوره آماری تحلیل شد و با توجه به ضرایب خشکی شاخص </strong><strong><span dir="LTR">SPI</span></strong><strong> لایه های پهنه بندی خشکسالی استان ایلام برای دو سری زمانی سالهای 2000 تا 2009 و سالهای 2010 تا 2019تهیه شد. لایههای رستری سبزینگی از تصاویر ماهوارهای مودیس برای سریهای زمانی ذکر شده تهیه شد. نتایچ تحلیل آماره موران همبستگی معناداری بین شاخص </strong><strong><span dir="LTR">SPI</span></strong><strong> و شاخص </strong><strong><span dir="LTR">NDVI</span></strong><strong> در بعد فضایی و مکانی نشان داد. </strong><strong>به روش تصادفی ساده 143 نقطه خشکیدگی بلوط در ابعاد 30 مترمربع که هر نقطه معادل یک پیکسل سایز بود با دستگاه </strong><strong><span dir="LTR">GPS</span></strong><strong> ثبت و با شبیه سازی در تصاویر ماهوارهای، لایه نقطهای خشکیدگی بلوط استخراج شد. هرچند رگرسیون خطی بین نقاط خشکیدگی بلوط استخراج شده با نتایج شاخص </strong><strong><span dir="LTR">SPI</span></strong><strong> و آماره موران معنی دار بود، اما نتایج ارتباط شاخص </strong><strong><span dir="LTR">NDVI</span></strong><strong> و آماره موران تاثیر روند خشکسالی در ابعاد مکانی و زمانی بر روند خشکیدگی بلوط با تحلیل فضایی و رگرسیون غیر خطی از معناداری و تبیین آماری مناسب تر و دقیق تری برخوردار است. بنابراین این روش در تحلیل خشکسالی و خشکیدگی بلوط مطلوب تشخیص داده و معرفی شد. </strong></div>
Introducing the appropriate model of oak forest and drought relations<br>
<br>
in Ilam province<br>
<br>
Introduction<br>
The forest ecosystems of the Zagros vegetation region have a very long history of exploitation in various<br>
forms. The material of the Zagros vegetation region is Iranian oak. In recent years, a significant<br>
proportion of oak forests have dried up or have experienced drought. Although the main cause of drought<br>
in these forests has not been determined yet, in the preliminary studies, factors such as climate change,<br>
increasing dust, increasing drought periods, pest infestation and disease, high user changes have been<br>
cited as reasons for drought in the Zagros forests. (Hosseinzadeh and Pourhashemi, 1396). Iran's location<br>
in the arid and semi-arid zone of the world (sub-tropical region) has often been associated with<br>
fluctuations in climatic and atmospheric elements and under the influence of atmospheric currents,<br>
synoptic patterns, irregularities in precipitation and temperature patterns (Rahmati, 2016; 1383).<br>
Comparison of the effect of climatic variables on healthy masses and affected by the decline of oak in<br>
Khorramabad city based on rainfall and temperature data using Pearson correlation coefficient, on annual<br>
growth rings of oak trees Effectiveness of drought of oak trees from both series In general, healthy trees<br>
have been more affected by monthly and seasonal temperatures and have shown the highest coefficient of<br>
correlation with the temperature of the region (Naseri Karimvand et al., 2016). , And the Standardized<br>
Rainfall Index (SPI) and the correlation between these two indicators in assessing and monitoring drought<br>
in different areas of Isfahan province, the results showed that NDVI plant index can be a good alternative<br>
to climatic indicators in drought assessment and monitoring) with the conclusion and colleagues, 2011:<br>
79).<br>
Data and Method<br>
So from SPI and NDVI indicators and Moran index and statistical regression statistics and satellite<br>
images of Modis and Landsat have used to analyze the relationship between dieback of Ilam forests and<br>
happened drought in the region. The precipitation data of 93 rain gauge stations were analyzed during the<br>
statistical period and according to the dry coefficients of SPI index, drought zoning layers of Ilam<br>
province were prepared for two time series of 2000 to 2009 and 2010 to 2019. Greenery's raster layers<br>
were prepared from Modis satellite imagery for the mentioned time series. The results of analysis of<br>
Moran's statistical showed a significant correlation between the SPI index and the NDVI index in spatial<br>
dimensions. By a simple random method, 143 points of oak dieback with dimension of 30 m 2 , which each<br>
point was equivalent to a pixel-size, were recorded with a GPS device, and by simulating in satellite<br>
imagery, the droplet layer of oak dieback was extracted.<br>
Result and Discussion<br>
What is debatable about the results of the implementation of methods for obtaining drought ranges and its<br>
relationship with oak drought points or masses is that the results of the models show a statistically close<br>
and direct relationship between drought and oak drought. . The general trend of oak drought and drought<br>
in these two decades has been from the southeast to the northwest of Ilam province, with increasing<br>
temperature and decrease in rainfall in the southern and eastern regions of the province and increasing<br>
rainfall and decrease in temperature in the central and northwestern regions of Ilam province. The data of<br>
the synoptic stations are consistent. Analysis of satellite imagery and declining greenery in the models<br>
although the study was aimed at meteorological drought and precipitation fluctuations, but spatial<br>
changes of arid points and masses in the province were adapted to field visits and human intervention,<br>
especially in the southeast with agriculture. Under the rubble and the remnants of the dried trees, the ax<br>
has been placed on the roots of these trees, and this trend is spreading in almost other parts of the arid<br>
areas of the province. Therefore, due to the irregularity in the pattern of precipitation and temperature of<br>
the research country (Rahmati, 2016; Zandi Army, 2004) and the effect of monthly and seasonal<br>
<br>
نشریه تحلیل فضایی مخاطرات محیطی، سال نهم، شماره 1، بهار 1401 2<br>
temperature on the growth and decline of oak trees in the study (Naseri Karimvand et al., 2016) and other<br>
related research and The flooding situation in the basins of Ilam province, the rainfall, the impermeability<br>
of the soil and their erosion, and finally the lack of moisture in the months before the oak trees grow in<br>
the soil and the increase in temperature in the dry season, which leads to reduced humidity and eventually<br>
greenery. Variables affecting oak drying in linear regression are not responsive, but more accurate results<br>
will be obtained in multivariate regression, although regression analyzes are spatially empty, and X and Y<br>
represent a one-way, quantitative analysis based on the number of dried trees with pixel counts. Drought<br>
range is measured which this defect in SPI method despite its spatial and statistical analysis using Moran<br>
statistical index due to non-compliance in the coefficients of this index with the range of changes in<br>
Moran statistical analysis in statistical analysis is a more appropriate explanatory coefficient than The<br>
regression models showed but at a lower level than the NDVI method it placed. The advantage of NDVI<br>
method with Moran statistical analysis is the relationship between pixel and pixel, ie in spatial analysis,<br>
all pixels that have green changes have been analyzed in the same domain of spatial changes with oak<br>
trees. High results and higher statistical explanation coefficient were obtained than other models.<br>
Conclusion<br>
Although linear regression between extracted oak dieback points with SPI and Moran statistical indicators<br>
was significant, but the relationship between NDVI index and Moran statistic has the effect of<br>
independent variable of drought trend in spatial and temporal dimensions on the dependent variable<br>
process of oak drought with spatial analysis. And nonlinear regression has a more appropriate and<br>
accurate statistical significance and explanation. So this method as desirable method has been introduced<br>
for analyzing of drought and oak dieback.<br>
Keywords: Ilam province, oak forest drought, drought, Moran index
استان ایلام, خشکیدگی جنگل, خشکسالی, مدل آماری
Ilam province, oak forest drought, drought, statistical models
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http://jsaeh.khu.ac.ir/browse.php?a_code=A-10-464-2&slc_lang=fa&sid=1
SHAMSOLLAH
ASGARI
شمس اله
عسگری
shamsasgari@yahoo.com
100319475328460010632
100319475328460010632
Yes
Assistant Prof, Soil Conservation and Watershed Management Research Department, Ilam Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Ilam, Iran
خش تحقیقات منابع طبیعی و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان ایلام،
Tayeb
Raziei
طیب
رضیئی
tayebrazi@yahoo.com
100319475328460010633
100319475328460010633
No
Associate Prof, Soil Conservation and Watershed Management Research Institute (SCWMRI), Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
پژوهشکده حفاظت خاک و آبخیزداری، سازمان تحقیقات، آموزش و ترویج کشاورزی،
MohamadReza
Jafari
محمدرضا
جعفری
mg_jafari@yahoo.com
100319475328460010634
100319475328460010634
No
Assistant Prof., Research Division of Natural Resources, Ilam Agricultural and Natural ResourcesResearch Center (AREEO), Ilam
تحقیقات منابع طبیعی و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان ایلام،
Ahmad
Hosini
احمد
حسینی
ahmad.phd@gmail.com
100319475328460010635
100319475328460010635
No
Assistant Prof., Research Division of Natural Resources, Ilam Agricultural and Natural ResourcesResearch Center (AREEO), Ilam,
تحقیقات منابع طبیعی و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان ایلام،