فهرست مطالب

نشریه مهندسی اکوسیستم بیابان
پیاپی 18 (بهار 1397)

  • تاریخ انتشار: 1397/03/31
  • تعداد عناوین: 6
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  • زهرا یارمرادی، بهروز نصیری*، مصطفی کرمپور، غلام حسن محمدی صفحات 1-14
    افزایش فراوانی طوفان های گرد و غبار نمادی از گسترش اکوسیستم بیابانی در هر منطقه است. بدین سبب تحقیق حاضر با هدف مطالعه روند فراوانی روزهای گرد و غباری در ارتباط با نوسانات اقلیمی در نیمه شرقی ایران انجام شد. بدین منظور داده های تعداد روزهای گرد و غباری، دما، بارش و باد 31 ایستگاه هواشناسی گردآوری شده و نوع روند و آهنگ تغییرات توسط آماره های ناپارامتری من کندال و سنس استیمیتور محاسبه شد. برای بررسی تاثیرپذیری طوفان های گرد و غبار از نوسانات اقلیمی، از همبستگی اسپیرمن استفاده شد. نتایج نشان داد فراوانی طوفان های گرد و غبار در ایستگاه های جنوب شرقی همچون زابل، زهک، کنارک و زاهدان به ترتیب با میانگین 165، 149، 142 و 78 روز به طور چشمگیری بیشتر از مناطق میانی و شمالی است. نتایج آزمون من کندال روند افزایشی معنی دار در ایستگاه های زاهدان، ایرانشهر، طبس، گرمسار، چابهار، کاشمر و سرخس نشان داد در مقابل 7 ایستگاه واقع در شمال منطقه، روند کاهشی معنی دار داشتند. نتایج همبستگی حاکی است فراوانی روزهای گرد و غباری با بارش، دما و سرعت باد به ترتیب در 9، 10 و 17 ایستگاه معنی دار است، اما با لحاظ داده های همه ایستگاه ها، ضریب همبستگی پارامترهای فوق الذکر با 36/0- ، 43/0 و 73/0 در سطح اطمینان 99% معنی دار است. نتایج این مطالعه می تواند در شناخت اثرات تغییرات اقلیمی در مناطق خشک شرق ایران و مهار بیابان زایی مفید باشد.
    کلیدواژگان: آزمون من کندال، پارامترهای اقلیمی، طوفان گرد و غبار، شرق ایران، همبستگی اسپیرمن
  • عباس علیپور، علی طویلی، حامد سنگونی*، احسان علیپوری صفحات 15-26
    در این پژوهش، امکان استفاده از سرباره فولاد به عنوان مالچ سنگ ریزه ای برای کنترل فرسایش بادی مورد ارزیابی قرار گرفت. برای این کار دو قطعه هزار مترمربعی به عنوان تیمار و شاهد در اطراف یوسف آباد نیشابور در نظر گرفته شد و سرباره مورد نیاز برای انجام مالچ پاشی از شرکت فولاد خراسان تامین شد. پس از مالچ پاشی، اثر عملیاتی آن با استفاده از سینی های اندازه گیری مورد ارزیابی قرار گرفت. همچنین با توجه به خطر فلزات سنگین موجود در سرباره، میزان این فلزات با استفاده از روش جذب اتمی اندازه گیری شد. در نهایت هزینه های اقتصادی اجرای این طرح هم مورد ارزیابی قرار گرفت. نتایج نشان داد که استفاده از مالچ سرباره باعث کنترل چشمگیر فرسایش بادی در منطقه شده و اختلاف بین شاهد و تیمار در سطح 1% معنی دار بوده است. در بخش ارزیابی اقتصادی هم میزان هزینه لازم برای منطقه هزار مترمربعی مورد مطالعه، حدود 642 هزار تومان برآورد شد. در نهایت می توان نتیجه گرفت که برای استفاده از این نوع مالچ، مهم ترین مانع، فلزات سنگین آن است که می تواند خطرات زیست محیطی به همراه داشته باشد. اما استعمال این روش با توجه به کارایی آن، در مواردی که نیاز به کنترل فوری فرسایش بادی و ریزگردها وجود داشته باشد، قابل توصیه است.
    کلیدواژگان: امکان سنجی، رسوب، سرباره، فرسایش بادی، گرد و غبار
  • غلامرضا زهتابیان، علیرضا مقدم نیا*، حسین آذرنیوند، علی اکبر نظری سامانی، علیرضا نژاد محمد نامقی صفحات 27-36
    تغییر کاربری اراضی و بهره برداری بیشتر از توان طبیعت در اکوسیستم های مناطق خشک و نیمه خشک، باعث افزایش روند پدیده بیابان زایی شده است. برنامه ریزان بیابان همواره با فرایند های پیچیده اکولوژیکی مواجه اند. برای درک بهتر لازم است که عوامل ناپایداری محیطی بررسی شده و در مدل های ارزیابی، سهم هر عامل به درستی مشخص شود. در این تحقیق با بررسی عوامل ناپایداری محیطی با استفاده از دو مدل SLM و IMDPA نقشه های هریک تهیه و سپس با انجام مقایسه دو مدل، مهم ترین عوامل ناپایداری محیطی در منطقه مطالعاتی مشخص شد. این تحقیق در منطقه فدیهه تربت حیدریه با مساحت 8664 هکتار انجام شد. نتایج نشان داد که با تطابق و مقایسه نقشه های تهیه شده شدت بیابان زایی و ارزیابی مدیریت پایدار سرزمین، مهم ترین عوامل شناخته شده ناپایداری محیطی به ترتیب شامل شاخص بهره برداری از پوشش گیاهی در معیار پوشش گیاهی، شاخص نوع استفاده از زمین در معیار فرسایش آبی و شاخص پوشش گیاهی در معیار فرسایش بادی در منطقه مورد مطالعه است. با مقایسه روند تغییرات (مقایسه سال 1382 با 1393) شاخص افت آب زیرزمینی و معیار آب مهم ترین عامل ناپایداری شناخته شده است.
    کلیدواژگان: IMDPA، مدیریت پایدار سرزمین، اکوسیستم های خشک و نیمه خشک
  • محمدحسن صادقی روش* صفحات 37-48
    به منظور ارزیابی راهبردهای بیابان زدایی و ارائه راهبردهای بهینه با درنظرگرفتن مجموع معیارهای موثر از مدل های مختلف تصمیم گیری استفاده می شود که گاها نتایج اولویت بندی این مدل ها با هم همخوانی ندارد. این مسئله بستگی به ماهیت مدل، معیارهای در نظر گرفته شده و چگونگی وزن دهی معیارها توسط متخصصان به صورت گروهی دارد. لذا لازم است توابعی ارائه شود که بر مبنای منطق و اصول قوی و مبانی نظری مستدل از میان راهبردهای ارائه شده در هر منطقه توسط مدل های مختلف، ارجحیت راهبردها به صورت گروهی و نهایی ارائه شود. در این مقاله سعی شد این مهم توسط توابع رفاه اجتماعی به انجام رسد. در این میان از تابع B&C استفاده شد و راهبردهای بیابان زدایی منتج از 13 مدل تصمیم گیری در منطقه خضرآباد یزد مورد تحلیل قرار گرفت. به این منظور، پس از تشکیل ماتریس ترجیحات نسبی، تابع هدف شکل گرفت و مطابق مدل خطی B&C اولویت بندی نهایی حاصل شد. نتایج حاصل بیانگر این موضوع بود که راهبرد جلوگیری از تبدیل و تغییر نامناسب کاربری اراضی (18A)، توسعه و احیای پوشش گیاهی (23A)، تعدیل در برداشت از منابع آب زیرزمینی (31A)، کنترل چرای دام (20A) و تغییر در الگوی آبیاری و اجرای روش های کم آبخواه (33A) به عنوان راهبردهای ارجح می باشد.
    کلیدواژگان: اولویت بندی، بیابان زدایی، تابع رفاه اجتماعی B&، C، تصمیم گیری چندمعیاره
  • میلاد سلطانی، کریم سلیمانی*، محمود حبیب نژاد روشن، خلیل جلیلی صفحات 49-62
    تامین آب مورد نیاز مردم از اهمیت ویژه ای برخوردار است و شناسایی محل های مناسب برای احداث سیستم های جمع آوری آب باران، گامی مهم در این راستا می باشد. هدف از این پژوهش، شناسایی مناطق مستعد به منظور احیاء منابع آب استفاده در اکوسیستم های مختلف است. در این تحقیق، عوامل تاثیرگذار بر نفوذ و ذخیره آب باران در حوضه های آبخیز میخوران و خسروآباد شهرستان سنقر کرمانشاه مشخص و وارد فرایند تحلیل سلسله مراتبی شد. شاخص های انتخاب شده با استفاده از پرسش نامه و توسط نظریات کارشناسان و اساتید، طی فرایند مهندسی ارزش گذاری شد. ضرایب اهمیت آن ها و جداول مقایسات زوجی تکمیل گردید. در این راستا وزن معیارهای یازده گانه پوشش گیاهی، تاج پوشش، درصد و جهت شیب، بارندگی، سنگ شناسی، کاربری اراضی، گروه های هیدرولوژیک خاک، ژئومورفولوژی، طبقات ارتفاعی و فرسایش با استفاده از MATLABR2009a محاسبه و بر پایه محیط ArcGIS10.3 تهیه گردید که به ترتیب اعداد 0188/0، 0254/0، 1365/0، 048/0، 2509/0، 0608/0، 0575/0، 1539/0، 0589/0، 0808/0، 1084/0 به دست آمد. پس از تعیین وزن هریک از معیارهای مزبور، مناطق مستعد شناسایی و در محیط GIS به پنچ سطح بسیار مناسب، مناسب، متوسط، نامناسب و بسیار نامناسب تقسیم شد. نتایج این تحقیق نشان داد علاوه بر عامل بارندگی، دو عامل شیب و گروه های هیدرولوژیک خاک به عنوان دیگر عوامل اصلی از بقیه عامل ها تاثیر بیشتری دارند.
    کلیدواژگان: جمع آوری آب باران، تحلیل سلسله مراتبی، سیستم اطلاعات جغرافیایی، مکان یابی، کرمانشاه
  • سارا مردانیان، خدایار عبدالهی*، رفعت زارع بیدکی، ابوذر صالحی صفحات 63-79
    آگاهی از اوضاع اقلیمی، کمک وافری به کاهش خسارات ناشی از بلایای طبیعی می کند، درحالی که این امر نیازمند پایگاه های اطلاعاتی گسترده و پیوسته ای است. به طور مرسوم در بسیاری از مطالعات قبلی، برای پرکردن خلاهای آماری بارش و دما از روش های وابستگی با ارتفاع، به عنوان متغیری کمکی استفاده شده است. از جمله معتبرترین و پرکاربردترین منابع اقلیمی، مدل های جهانی اقلیمی هستند که بسیاری از خلاهای محاسباتی با استفاده از خروجی آن ها قابل پوشش است. مطالعات پیشین در اکثر مناطق جهان، همبستگی خوبی بین داده های محلی ایستگاه ها و داده های اقلیمی گزارش کرده اند. طی این پژوهش با بررسی تمامی سناریوهای موجود عوامل ماهانه هواشناسی دما و بارش در سایت اقلیمی کانادایی (GCM/RCM) و با تکنیک حذف تعمدی داده موردنظر و درنظرگرفتن به عنوان داده گمشده، مرتبط ترین سناریوی اقلیمی انتخاب شد. با استفاده از روش حداقل مربعات خطا بهترین داده های اقلیمی با همخوانی مناسبی با داده های مشاهده ای ایستگاه محلی استخراج و اصلاح شد. همچنین خروجی این روش با روش همبستگی بین داده های ایستگاهی این دو پارامتر و ارتفاع مقایسه شد. نتایج روش استفاده از همبستگی با داده های اقلیمی سایت کانادایی و داده های مشاهده ای، با واقعیت انطباق بیشتری دارند. صحت سنجی از طریق مقایسه تعامدی نشان دهنده قابلیت به کارگیری داده های اقلیمی به عنوان متغیری کمکی برای بازسازی و پیش بینی داده های گمشده بارش و دماست.
    کلیدواژگان: مدل جهانی اقلیمی، تغییراقلیم، حوزه خانمیرزا، حداقل مربعات خطا و سایت اقلیمی کانادایی
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  • Zahra Yarmoradi, Behrooz Nasiri *, Mostafa Karampour, Gholam Hassan Mohammadi Pages 1-14
    Introduction
    The occurrence of dust storms in deserts or arid regions increases the suspended dust particles to more than the allowed threshold, and this has negative effects on atmospheric conditions, human health and agricultural production. Positioning of Iran in the world arid and semi-arid belt is exposed to various types of dust storm systems. Occurrence of severe dust storms in most parts of the world, especially in areas of east and southeast of Iran has disrupted people's lives and caused human and financial losses. As a result, increasing information on the dust storm variation and trend with using long-term observational data and evaluation of its relationship with other climatic parameters in the eastern part of Iran may help identify areas of crisis in terms of the occurrence of this phenomenon in the future, therefore it is useful for taking environmental management decisions and preparing to deal with dust storms.
    Materials And Methods
    In order to carry out this research, data of number of dusty days, temperature, precipitation, and wind speed of 31 weather stations in eastern Iran with a statistical period of 66 years (1951 to 2016) have been used. According to the World Meteorological Organization, dusty day is defined as the day in which, at least one code related to dust (including codes 06, 07, 30 to 35 and 98) has been reported in the present weather group (WW) among dust 8 SYNOPs reported from weather stations. Considering the above instructions, first data of number of days with dust in annual scale was provided. Then, the processes related to the averaging, spatial distribution and temporal variation of frequency of dusty days were performed. In order to study the decadal variation of dust storms, both regional averages and data of reference stations are divided into six decades and analyzed with averaging and charting processes. In the next step, to evaluate existence of trend in dusty day frequencies in eastern Iran, two non-parametric statistics of Mann-Kendall and Sen's Estimator Slop tests were used. Finally, to investigate the relationship between climate parameters and dusty days frequency in the region, Spearman correlation coefficient test was used.
    Results
    The highest and lowest activity of dust storms in study area was in 1971 and 1954 years with average of 58 and 7 days respectively during 1951 to 2016. Despite the relatively large regional differences, the annual variation of the average dusty days in eastern Iran has not been significant particularly since 1960, and often remains about 40±8 days per year. Decadal variation of dusty days indicates an increase in the number of storms in current decade, but geographic extent of storm activity is limited to the south east.
    The results of Mann-Kendall trend test indicate a significant increase in dusty days of Zahedan, Iranshahr, Tabas, Garmsar, Chabahar, Gorgan, Tabas and Sarakhs stations at 0.01 or 0.05 confidence levels, so that highest increasing rate was calculated in Iranshahr, Tabas, Zahedan, Gorgan and Sarakhs stations with 1.35, 0.96, 0.78 and 0.52 days per decade, respectively. Although Zabul, Zahak, Bojnourd and Gonabad stations have the most frequency of dusty days but they showed nonsignifican increasing trend. Investigating the relationship between dust storm frequencies with precipitation, temperature and wind speed results showed that dust storm in the eastern Iran show negative correlation coefficient on annual precipitation fluctuations. In contrast a direct significant relationship between dusty days with annual temperature and wind speed at most stations were revealed.
    Discussion and
    Conclusion
    The results of this study suggested that the Eastern Iran has no homogeneity in terms of frequency of dust and its process, so that it increases from north to south and from west to east. Based on the results obtained by combining two methods of Sen’s Estimator Median and Mann-Kendall, there is an increasing trend in most regions, but its focus is more in South, Southeast and Central regions. Dust storms activity increase is a symbol of the dominance of desert ecosystem and implies the spread of desertification in these areas. These regions have dry climate and flat topography, low altitude and sparse vegetation. Also, stations with a significant downward trend, are mainly located in Northeast Iran, where have less dust storms. Distance from the dust resources and being located in mountainous areas, as well as the expansion of cities (meteorological stations are located on their margins) can be a factor in the reduction of dust days in the northern regions. Of course, in a number of Southern stations, which have a lot of dusty storms, the trend was also downward. Finding the cause of such a downward trend requires further investigation. The worrisome issue is that in some areas (such as Kashmar, Damghan and Garmsar), where dust storm isn’t dominant climatic phenomenon, it’s likely that in future years, with increasing storm events, dusty storms be added to their climatic landscape. Also, in areas where dust storms occur with a relatively high frequency (including Chabahar, Zahedan and Tabas) increasing number of dusty days may create additional environmental problems. Correlation coefficients of climatic parameters with number of dusty days showed highest relationship with speed wind. With this interpretation, the most effective climatic controller of dust storms frequencies in East Iran is wind speed, which is a function of synoptic systems and regional pressure and temperature gradients. Given that the 120-day winds are the main cause of dust storm in the study area in warm period of year, and also the temperature gradient in this times is more than cold period, as a result, with warming of air and end of rainy season in warm period, climatic conditions is suitable for severe wind flows. These conditions, along with soil dryness and lack of vegetation provide favorable conditions for wind erosion and dust storm. It should be noted that the most effective environmental factor in Eastern Iran dust storms activity, is intensifying of speed and expanding spatial range as well as increasing activity duration of Sistan regional winds from 120 to 165 days.
    Keywords: Mann-Kendall Test, Climate Parameters, Dusty days, Eastern part of Iran, Spearman Correlation
  • Abbas Alipour, Ali Tavili, Hamed Sangoony *, Ehsan Alipoori Pages 15-26
    Introduction
    Wind erosion and the influx of sandy soils to economic facilities and biological resources are one of the main problems in the country. 14 provinces, located in arid and semi-arid regions, face wind erosion. Wind erosion and the influx of sandy soils are two important indicators in the occurrence of desertification and a serious threat to arid areas. The best and lasting way to prevent erosion is to deploy natural vegetation in areas at risk. But this will require a minimal fit for environmental conditions for the environment, and vegetation cannot be established in areas where these conditions are not met. For this reason, non-physical methods, such as the use of wind turbines and various types of mulches, are also of interest, each of which can, in certain circumstances, have the highest efficiency and efficiency. The mulch is defined as a coating that protects the soil from contact with the wind erosion current. In this study, the use of steel slag as a mulch for controlling wind erosion from different dimensions has been investigated.
    Materials And Method
    The selected area for field studies was located in Zebarkhan district of Neyshabour, near YousefAbad village. This area was selected according to the characteristics of erosion soil and regular wind power regime. Soil sampling was used to study the soil characteristics of the area and acidity and its salinity were determined. The atomic absorption method was used to measure the amount of heavy metals in the slag compound which is important in terms of environmental issues. The appropriate size of slag was 3 to 4 cm. Two thousand square meters were used for treatment and erosion measurements in YousefAbad area of Neyshabour. The two pieces were placed on the ground, both of which are perpendicular to the direction of the dominant and erosion of the wind. To determine the effect of applying slag mulch on each treatment and control part, nine fixed trays were placed on each 15 mm soil tray. Then, at 1-month intervals, the depth of soil was measured on each tray by a caliper and accurately one hundredth of a millimeter. The results of these two groups were compared using t-coupled test.
    Results
    The soil of the study area was Aridisol and its salinity was 1.408 dS m-1 and its pH was 7.48. Soil study using hydrometric method showed that 56% of this soil was Silt, 31% sand and 13% Clay. So the texture of this soil is silty loam; one of the most erodible types of soil in wind erosion. The results of measurements of heavy metals of chromium, cobalt, lead and cadmium by atomic absorption method showed that the amount of lead, cadmium and cobalt in slag is less than the critical level defined for them and their presence in the slag compound will have small impacts on the environment. But in the case of chromium, it was significantly high and should be considered as a potential risk factor. The results of measurements of soil changes in the studied parts showed that not only erosion was controlled in the slag mulch treatment part but also to the sedimentation occurred. However, there has been significant soil erosion in the control unit. The results of the comparison of these two groups using the t-test showed that there was a significant difference between them at 1% level and therefore, slag treatments had a positive effect and was able to control wind erosion in the study area. Considering all costs, the application of this kind of treatment in the studied area cost 642 thousand Tomans.
    Discussion and
    Conclusion
    The amount of heavy metals in most cases except chromium was not alarming. Considering the fact that chromium is one of the most hazardous substances for the environment, steel and iron slag should not be used without the precautions at large scales. Of course, it's important to note that only chromium 6 (Cr VI) is known as a toxic compound, and it quickly turns into chromium 3 (Cr III) in nature, which is a micronutrient needed by various living organisms. Also, since this chromium may not be free at all, the issue of the release of chromium in slag by natural processes should also be considered. According to the results of the measurements carried out in this study, it can be confidently stated that the use of slag mulch has a clear effect on reducing wind erosion in studied area. Even with regard to the results, it can be argued that this mulch, in addition to preventing soil particles from being removed by wind, can also trap eroded particles that are transported by wind in the creeping or jump process. Therefore, from an operational point of view, slag can definitely be recommended for the wind erosion control. These results are similar to those of Safaie (2012) and Babakhani (2011). Also, the results of Li et al. (2001) showed that the pebble mulch has not only the ability to control erosion, but also has a high capacity to trap wind deposits. If there is no potential area for effective vegetation cover in erosion control, or if wind erosion and dusts are required to be controlled quickly, this type of mulch by the coverage rate of 75% and the proposed particle size (3-4 cm) can do it well.
    Keywords: Dust, Feasibility, Sediment, Slag, Wind Erosion
  • Golam Reza Zehtabian, Ali Reza Moghadam Nia *, Hosein Azarnivand, Ali Akbar Nazari Samani, Ali Reza Nejadmohammd Namaghi Pages 27-36
    Introduction
    More than 168 countries face the phenomenon of land degradation and desertification. Land use changing and more exploitation of nature's potential in arid and semiarid ecosystems over the past three decades have increased the trend of desertification phenomena in these ecosystems. Deserts are dynamic ecosystems that are constantly evolving. Deserts are dynamic ecosystems that are constantly evolving. The management of ecosystems in arid and semi-arid regions is continuous and unstoppable. For this reason, desert planners are faced with complex ecological processes such as climatic, edaphic factor, and water resources. Therefore, in order to have a better understanding of these factors and processes, it is imperative that all of these environmental instability factors be investigated and properly identified in the evaluation models of the contribution of each factor.
    Materials And Methods
    The study area is Fadiyeh of Torbat Heydarieh basin, with an area of ​​8664 hectares and 40 work unit. .The IMDPA model was used to assess the intensity of desertification potential. Environmental criteria that are evaluated in this model include climate, geology and geomorphology, soil, vegetation, agriculture, water and irrigation, water erosion, wind erosion (Zahtabian et al. 2014). In this model, 35 indicators for 9 criteria are used to quantify the criteria. Based on its effect on desertification, according to the region's conditions, field research, and expert opinion, each indicator is weighted between 1 and 4. So that value 1 is the best and the 4 is the worst weight. A map is prepared for each index with respect to weighting. In this method, each criterion is obtained from the geometric mean of its indices according to the following relationships.
    IMDPA= [∩9i = 1Qi] 1/9=9√Q1 × Q2 ... Q9
    Criteria-x = [(Index-1) × (Index-2)... (Index - n)]1/n
    Criteria-x: Selected Criterion
    Index: Indicators of each Criterion
    n: Number of Indicators for each Criterion
    By analyzing the environmental instability factors, two models of SLM and IMDPA were prepared and then, by comparing two models, the most important environmental instability factors in the region were identified for future manager's planning
    Results
    Investigating the instability of the climatic factor: The average annual rainfall is 335 mm. The maximum monthly rainfall in March is 72 and the lowest rainfall in August and September is less than 1 mm, and it is also observed that in this area more than 50% of annual rainfall in the three months of the year, namely, February, March and April It takes place in the dry period in six months from mid-May to mid-November.
    Investigation of geoscience and geomorphology: Investigation of Stratigraphic Units: Geological Study Area. It is part of the Central Iranian mountain range. Geological units belonging to the Jurassic, Cretaceous, Neogene and Quaternary periods have been formed in terms of lithology development and diversity. The Jurassic organization consists of two units called the Jbe and the Esfandiar limestone (Je), which includes the oldest basement rocks.
    Investigation of Soil Agent Instability: According to the studies, the study area consists of 4 land types
    Mountain type: Very damaging lands with very high tide and height.
    Type of hills: Hills are equivalent to erosion or aggregation geomorphologic levels that have been completely destroyed. There is no remnant of the previous levels with a smooth surface.
    Type of plateau and upper terraces: This type of physiography is equivalent to eroding and cumulative geomorphologic levels that are currently affected by low to moderate erosion processes.
    Type of River Alluvial Plain: This type of land is formed by depositing small sediment deposited from a main active or inactive river stream.
    Investigation of plant vegetation instability: Rangeland condition is also poor in all types and pasture tendency is negative. The yield of plant production in these types is between 33 and 76 kg / ha, and most of the plant production is related to annual grasses.
    The results showed that by comparing desertification severity maps and assessing sustainable land management, the most important factors of environmental instability were, respectively; Vegetation utilization index in vegetation criteria, the type of land use index water erosion criteria, Vegetation index in wind erosion criteria. By comparing the trend of changes (compared to 1382 with 1393), groundwater drop index and water criterion are the most important causes of instability.
    Discussion and
    Conclusion
    The most unstable is in the upper plain area and the highest intensity of desertification potential in the plain area. By comparing the prepared desertification maps and assessing sustainable land management, the most important known environmental index in each criterion include Drought index in the climate criterion, vegetation cover index in vegetation cover, land use type index in the measure of water erosion and vegetation index in the wind erosion criterion in the study area. Among the criteria for assessment, vegetation and erosion criteria, show the highest weight for the region's instability and the severity of desertification. Due to the importance of this problem, various methods for estimating or evaluating desertification have been presented and criticized so far. However, despite the progress made, there are many problems with the use of desertification assessment methods, including the fact that these methods are still largely based on judgment and expert opinion that, with disagreement with the public opinion Relations with degraded lands have even led the national level.
    Keywords: SLM model, IMDPA model, sustainable land management, arid, semi-arid ecosystems
  • Mohammad Hassan Sadeghi Ravesh* Pages 37-48
    Introduction
    Desert ecosystem management includes a set of multiple management measures taken with the aim of optimal control of desertification phenomenon and reducing the economical, social and environmental losses. The issues related to the management of desert areas are complex matters because of the existence of multiple decision-making criteria and indices and there are several solutions to achieve a specific objective, each of which provides different preferences for the various environmental, social, political, economical, and organizational issues. These requirements necessitate using the Multi-Attribute Decision Making (MADM) methods which aim to choose the best answer from among the different solutions. By reviewing the literature, it can be found that the use of the decision-making models in providing the optimal strategies in the management of the desert areas is only limited to some studies such as Grau, Sadeghi Ravesh and Sepehr and Peroyan.
    The obtained results from the prioritization of strategies indicated that the conclusions made by the models of AHP, TOPSIS, Electra, Weighted Sum, permutation, BORDA, and etc. are largely similar. However, the obtained numerical values vary from each other due to the structure of these models. Therefore, it is necessary to offer some functions to prioritize the strategies offered in each region by using different models on the basis of logic and strong principles and theoretical foundations. In this paper, it has been tried to achieve this goal using the Social Welfare Functions. In this regard, the function of B&C was used in the present study and the desertification strategies derived from the 13 decision-making models were analyzed in the Khezrabad Rigion of Yazd.
    Materials And Methods
    The assessment method of B&C was first introduced by Asgharpour to provide the best view from the different options. The B & C function is a social welfare function that uses the majority method in priority, in such a way that transferability will be achieved in the process of prioritizing options. In this way, the objective function dn (P,L) reflects the sum of the "missed opportunity" of choosing the priority-ranking, or, in other words, indicating the total "disagreement with the prioritization with existing privileges" that should be minimized as a result.
    In summary, the procedures for using this method are as follows: - Formation of the matrix P according to Eq.1
    (1)
    - Formation of the matrix L according to Eq.2
    (2)
    -Convex Multidimensional Formation according to Eq.3
    (3)
    -Formation of the decision- making function of the majority d (P, L) according to Eq.4
    (4)
    -Prioritize the desired options (strategy) according to Eq.5
    (5)
    Results
    In order to comparative compare, prioritizing the strategies was done in the form of 13 multi-criteria models for decision-making in the plains of Khezrabad in Yazd. The results of evaluating the strategies based on the decision-making models showed that although about 70 percent of the results are similar, the rankings obtained are somewhat different, that these results are due to the method's structures. Therefore, in order to achieve strategic priority as a group and the final solution of the total results of decision-making models, the Social Welfare Functions of B&C was used according to the literature.
    Taking in to account the totality of criteria and alternatives and with analysis, in general, that alternative of prevention of unsuitable land use changes (A18), alternative of vegetation cover development and reclamation (A23), modification of ground water harvesting (A31), Livestock grazing Control (A20) and Change of irrigation patterns (A33) are the most important alternative in de-desertification prosess in the study area, respectively. Therefore , we accept this ranking as a final and collective ranking. So, by the use of these alternatives in de-desertification projects, we can prevent desertification phenomenon in this area and do something for reclamation of degraded land.
    Discussion and
    Conclusion
    Detailed assessment of the strategies and choosing the optimal strategies are important factors in increasing the effectiveness of desertification plans, otherwise, wasting the resources such as time, energy and other inputs have serious and destructive impacts on achieving the results. In the meantime, decision-making models are used to achieve the optimal strategies, that for different reasons their results are somewhat different in each region. In order to achieve the group and final strategies, in the present study we used the social welfare function of GRV and the desertification strategies resulted from 13 decision-making models were analyzed in the region of Khezrabad in Yazd. The results showed that the strategy order of A18> A23> A31> A20> A23 is the best presented strategy order.
    Finally, it is recommended that the desertification programs in the study regions should emphasize on these strategies to prevent wasting the limit capitals and increase the output of the control, rehabilitation and reconstruction programs.
    The results of the present study enable the managers of the desert areas to use the limited funds allocated to control the desertification process in a Correct and efficient manner to in addition to achieve better results, prevent wasting national wealth.
    Keywords: Desertification, Multiple Attribute Decision-making (MADM), Ranking, Social welfare function B, C
  • Milad Soltani, Karim Solaimani *, Mahmoud Habibnejad Roshan, Khalil Jalili Pages 49-62
    Introduction
    Water, along with issues such as preserving the environment and eradicating poverty and hunger, is a fundamental issue in sustainable development and is an essential element of human survival and well-being. The lack of water in the arid and semi-arid regions of the world has caused the environmental conditions to be fragile. Therefore, the purpose of this research is to identify areas susceptible to rainwater harvesting in order to rehabilitate water resources in different ecosystems using a hierarchical decision making method based on spatial analysis in the GIS environment.
    Materials And Methods
    In this research, the factors affecting rainwater penetration and storage in the soil profile of the Ghiran and Khosrowabad watersheds of the city of Sangar, Kermanshah Province, were identified and entered the hierarchical analysis process. At first, by using expert opinions, relevant faculty members and experts, by means of paired comparison and in accordance with the method of time, the tables of value were completed and then analyzed by special vector method. For each matrix, the result of the division of the inconsistency index into the random matrix inconsistency matrix, then the matrix, is a suitable criterion for judging the incompatibility, which is called incompatibility rate. If this number is less than 0.1, the system compatibility is acceptable. Then, their importance coefficients were determined and the paired comparison tables completed. In this regard, the weight of 11 variables of vegetation, canopy, percentage and direction of gradient, rainfall, lithology, land use, soil hydrologic groups, geomorphology, elevation and erosion classes were calculated using MATLABR2009a software and based on the ArcGIS10.3 environment. Which were respectively 0188/0, 0254/0, 1365/0, 048/0, 2509/0, 0608/0, 0575/0, 1539/0, 0589/0, 0808/0, 1084/0 Came out. After determining the weight of each of these criteria, the susceptible areas of rainwater storage were identified and in the GIS environment, five levels were classified as very suitable, appropriate, moderate, unsuitable, and unsuitable, respectively, for the areas of beer and Khosrowabad, respectively (% 33, 32/41, 46/8, 47/7 and 47/5, 08/41, 53/37, 31/8, and 64/5 of the area of ​​the basin. 59 benchmarks were expressed in general, of which 11 were the main criteria and 48 sub-criteria were considered. The selected indicators were used by the questionnaire and by experts, experts and experienced experts by group method during the process of engineering value and Individual and comparative method was double-valued. Tables (1 to 9) show the results of pairwise comparison of the parameters and weights obtained after the formation of a pair comparison matrix. In the AHP method, the criteria are first qualitatively and then are presented quantitatively using the table. In this process, the ratio of incompatibility is determined and if its value is less than 0.1, then there is an indication of the acceptable level of compatibility of the pairwise comparisons. In this study, the degree of inconsistency for each of the main criteria and its sub-criteria is indicated separately in the tables below given.
    Result
    The results of this study showed that, in addition to the rainfall factor which is the main factor, two slope factors and soil hydrological groups as the other main factors for collecting rainwater from the rest of the factors have more and more impact. According to the results obtained and the tables shown, the lowest inconsistency rate related to the gradient direction, which is equal to 0.123 (Table 8), and the highest is related to erosion, which is equal to 0906 (Table 1). The results also showed that slopes of 20-30%, which are mostly pasture and pastures, are suitable places for storing runoff. Areas with Ptanicyle have a very good harvest area that is best suited to store atmospheric precipitation in terms of coverage, slope and permeability. According to the obtained map of Figure 2, the total area of Khosrow Abad watershed (1819.68 hectares) has a total of 26.26 hectares, has a very suitable potential, 769.79 hectares suitable, 696.59 hectares average, 154.27 hectares inappropriate and 77/104 hectares are very inappropriate for collecting rainwater.
    Discussion and
    Conclusion
    The results of this study indicate that the method used has high credibility in zoning the suitable areas for implementing rainwater harvesting projects and using the process of analyzing hierarchy in the GIS environment as an effective spatial decision system in the location of areas susceptible to rainwater harvesting.
    Keywords: Rainwater harvesting, AHP, GIS, site selection, Kermanshah
  • Sara Mardanian, Khodayar Abdollahi *, Rafat Zare Bidaki, Abozar Salehi Pages 63-79
    Introduction
    Due to importance of data quality, issues relating to filling the missing data has found a great deal of interest. Regeneration methods for missing data can be classified into two kinds of classical and modern categories. Application of statistical methods such as relationship with nearby stations and approaches on the base of hydrological, climatological or physiographical similarity are among the common techniques for gap filling. For such cases, correlation with elevation is one of the common techniques. The modern methods make use of approaches such as data mining, ANN, fuzzy arithmetic and so on to improve the completeness of data. Typically, the output of climate models is used for future predictions/assessment. After development of climate model like general circulation model (GCM) several researchers have reported a good correlation between global atmosphere or ocean and local station data. This correlation has a potential usage for estimation of missing data at local scale.
    Materials And Methods
    Two types of data, including meteorological data and climatic data outputs, were used in this study. Reconstruction of two key variables at monthly scale, temperature and precipitation, were investigated over a period of 20 years (1995-2016). Climate data for these two climatic parameters downloaded from Canadian website site (GCM / RCM), were used as an auxiliary variable for data reconstruction. The least squares error method was applied to determine the scenario with the most realistic site-based conditions. The coefficient of determination was used as a measure to assess how well scenarios was able predicts observed data. For this purpose, four scenarios that generally showed either a high linear or non-linear correlation were selected. Then, by means of cross validation and the evaluating relationship between these two series of data and observation were tested. The outcome at this stage was 4 out of climate scenarios which show a high correlation with local station. Cross validation was employed the final scenario. Here the correlation between climate data and station data was utilized as an auxiliary variable for reconstruction of missing values. The outputs of new method were compared with elevation-based method.
    Results
    The established relationship between observations and climatic data (climate model output) by the least squares error method showed a high correlation for the selected models, thus ECHO-G and NCARCCSM3 models were selected for rainfall and temperature respectively. The performance of these predictive models was tested by evaluating them after assuming each row data as missing data. The observational data was re-organized into monthly, seasonal and annual time interval. The obtained coefficients were successfully verified against observed data by eliminating the data for each month and establishing a new relationship. Four scenarios including ECHO-G (SR-A1B), ECHO-G (SR-A2), NCARCCSM3 (SR-A2) and NCARCCSM3 (SR-B1), showed a high correlation between climatic and calculated data. Although the correlation coefficient between rainfall and the climatic model output was low but a good correlation between the combination factor of rainfall and temperature with observed data was found in the study area (r=0.98). The established relationships for local station even can be used for future (up to 2050) predictions. A comparison of the developed method with the elevation-based method showed a better performance at monthly scale.
    Discussion and
    Conclusion
    Awareness of climatic conditions is a helpful strategy to reduce the damage caused by natural disasters. This most often requires an extensive and continuous data sets. Traditionally, correlation with elevation was used as an auxiliary variable to fill the gaps in rainfall and temperature data. Previous studies have reported a strong correlation between the local data of stations and climatic data. This study was conducted to investigate the possibility of using downloaded data from Canadian climate site (GCM / RCM for filling temperature and precipitation meteorological data. The results of the new method were more consistent with observed data. Cross validation indicates the applicability of using climate model as an auxiliary variable for regenerating missing rainfall and temperature data or predicting these variables in the area of interest. In addition to fill the missing data, the common advantage the use of climate model output is that, it could be used as future predictor. On the other hand, the comparison of the above mentioned method with the elevation-based method with observational data indicated that the new approach provide a solution especially for the case that there exist no or limited number of neighboring stations.
    Keywords: Global climate model, Climate change, Khanmyrza Basin, Least square error, Canadian climate