چکیده:
مناطق خشک و نیمهخشک جهان براثر عوامل انسانی و طبیعی، دچار تغییر و تخریب شدید شده است. این مناطق بهعلّت دارابودن اکوسیستمهای منحصربهفرد و منابع غنی، نیز مناطق مستعد ازنظر توسعة اقتصادی، نقش مهمّی در کاهش بلاهای طبیعی و رفاه بشر دارند. در این راستا بهمنظور برآورد تاثیر فشارهای انسانی بر ظرفیت زیستی در شهرستان اصفهان در طول سالهای 1379 تا 1398، شاخص فشار ردّ پای مصرف و شاخص فشار ردّ پای تولید با تکیه بر مفهوم ردّ پای اکولوژیک استفاده شد؛ همچنین بهمنظور برآورد فشارهای ایجادشدة حاصل از ردّ پای مصرف و تولید پسماند (ورودی و خروجی) شاخص توزیع ردّ پای اکولوژیک ارزیابی شد. در پژوهش حاضر برای بررسی سطح امنیّت اکولوژیک خدمت ذخیرة کربن با شاخص ردّ پای اکولوژیک ادغام شد تا عملکرد اکوسیستم نیز بهعنوان معیاری در ارزیابیها لحاظ شود. نتایج نشان داد که باوجود نوسانات متفاوت در روند تغییرات شاخص فشار ردّ پای مصرف و شاخص فشار ردّ پای تولید در طول دورة مطالعاتی، بهطور عمده این شاخصها روند کاهشی داشتهاند؛ افزون بر این، منفیبودن مقدار شاخص توزیع ردّ پای اکولوژیک نشاندهندة اثرگذاری بالاتر ردّ پای مصرف در تعیین شاخص امنیّت اکولوژیک نسبت به ردّ پای تولید بوده است و با توجّه به مدل تصمیمگیری، این شاخص در کلاس «ریسک بالا» قرار گرفته است. مقایسة ظرفیت زیستی با ردّ پای اکولوژیک نمایانگر کسری شدید اکولوژیک و امنیّت اکولوژیک پایین در شهرستان اصفهان در طول مدّتزمان مورد نظر است. نتایج بهدستآمده از نوشتار پیش رو به سیاستگذاران و تصمیمگیران کمک خواهد کرد تا با توجّه به ضوابط آمایش سرزمین، راهبردهایی همچون سناریوی کاهش ردّ پای اکولوژیک یا افزایش ظرفیت زیستی را اتّخاذ نمایند.
Arid and semi-arid regions of the world have been severely degraded by human and natural factors. These regions play an important role in reducing natural disasters and improving human well-being due to their unique ecosystems, rich resources and economically suitable areas. In this regards, in order to estimate the effects of man-made pressures on biological capacity of Esfahan city, consumption footprint pressure index (CFPI) and production footprint pressure index (PFPI) were used based on the concept of ecological footprint during 2000-2019. Besides, the ecological footprint distribution index (EFCI) was evaluated to investigate the pressures created by CFPI and PFPI. In this study, carbon storage service was integrated with ecological footprint index to evaluate the level of ecological security index (ESI) for consideration of the performance of the ecosystem as a criterion in the evaluations. The results showed that despite the different fluctuations in the trend of CFPI and PFPI variations during the study timespan, these indices have approximately a decreasing trend. In addition, the negative values of EFCI illustrates the higher effectiveness of the consumption footprint in determining the ecological safety index than the production footprint, and according to the decision-making model, this index in the ‘high risk’ class. Comparison of the biological capacity and the ecological footprint highlighted a severe ecological deficit and weak ecological security in Esfahan city during the studied timespan. The outcomes to this study could help policy makers and decision makers to adopt strategies such as the scenario of reducing the ecological footprint or increasing the biological capacity considering the land management criteria. Extended Abstract 1-Introduction Ecosystems have been altered and destroyed by the pressures of human activities and natural hazards around the world. The emergence and intensification of these pressures called the experts and policymakers to consider the concepts of carrying capacity to achieving sustainable development, especially in crowded areas which have sensitive ecosystems. Ecological security is known as a strategically important issue from a social, economic and political point of view, and in fact, maintaining the ecological security of a small region will maintain global and regional ecological security which allow economic growth and sustainable development. This study aimed to investigate the variations of carrying capacity and ecological security with the approach of ecosystem services in the arid and semi-arid ecosystems of Esfahan city during 2000 – 2019. 2-Materials and Methods In order to estimate the effects of man-made pressures on natural resources in Esfahan city, consumption footprint pressure index (CFPI) and production footprint pressure index (PFPI) were used based on the concept of ecological footprint. In this regard, at first, the trace of product distribution, the imported and exported product for different products and wastes were calculated and biological capacity was calculated based on the classification of satellite images in the time period. Besides, the ecological footprint distribution index (EFDI) was evaluated to estimate the pressures created by CFPI and PFPI. The ecological security index modeled to assess the level of ecological security in Esfahan using these indices. 3-Results and Discussion The results illustrated that CFPI, PFPI had the average per capita of 9 and 7 global hectares, respectively, during 2000 – 2019. Moreover, consumption footprint capita index (CFCI) and production footprint capita index (PFCI) had the average of 3.05 and 3.89 global hectares, respectively, during 2000 – 2019. In addition, CFPI, PFPI, and CFCI decreased, while PFCI indicated ascending slope during the study timespan. According to the results of present study, the negative value of EFDI indicated that the ecological security is more affected by CFPI when compared with PFPI in Esfahan during 2000-2019. The biological capacity per capita decreased from 0.48 to 0.389 global hectares in Esfahan between 2000 and 2019. Although, it was observed higher fluctuation in the trend of EFDI, it showed reducing slope with the average of -0.22 over the studied years. Generally, the ecological security index exposed to drastic risk and according to the decision-making model, this index is classified as the ‘high risk’. 4-Conclusion The value of 0.44 hectares worldwide indicates low biological capacity in the city of Esfahan. The per capita ecological deficit in the city of Esfahan is equal to -3.5. In addition, the rate of resource using raises the potential concerns at this level. On the other hand, the lack of biological capacity of Isfahan city compared to the country (one fourth) shows that development has occurred in areas that do not have good ecological capacity and this issue is considered as a warning for development. According to the analysis of changes in consumption footprint and production footprint of different types of land use from 2000 to 2019, it can be seen that this risk in terms of consumption footprint is mainly related to energy and then agriculture. Accordingly, the production pressure index has decreased from 3.17 in 2000 to 2.22 in 2019. However, the production pressure index has decreased slightly in the same period. This has tripled due to the need for energy consumption, which leads to carbon dioxide emissions. Comparison of the biological capacity and the ecological footprint highlighted a severe ecological deficit and weak ecological security which is due to the surplus demand, pressures on production resources, and higher consumption than the biological capacity in Esfahan city during the studied timespan. Induced pressure on resource to make products, high energy consumption, degradation of the ecosystem function, and reduced biological capacity are the main components of the reducing EFDI in the study area, which illustrated the significant effects of CFPI on the ecological security of Esfahan. It should be considered that the decreasing biological capacity has played an important role in increasing the ecological footprint due to human and natural causes. Finally, it is suggested that the decision-makers adopt strategies such as the scenario of reducing footprint or increasing biological capacity in their agenda, based on the principles of land use management and taking into account the needs of stakeholders.
خلاصه ماشینی:
شهرستان اصفهان به عنوان يکي از بزرگ ترين مناطق تمرکز جمعيت در مرکز کشـور در سـال هـاي اخيـر رشـد شتاباني به خود گرفته که منجر به تخريب بسياري از مناطق بکر محيط زيست پيرامـونش شـده اسـت و در صـورت 19 ادامۀ روند فعلي و بهره وري ساکنان منجر به زوال منابع شهرستان اصفهان خواهد گرديد (منصورفر و حـق شـناس ، 1- Millennium Ecosystem Assessment (MEA) 2- Li 3- Qiu 4- Fu 5- Chuan 6- Lundquist & Sommerfeld 7- Jomepour & Hataminejad 8- Mohmadai 9- Huang 10- HE 11- Zhang 12- Zhao 13- Bartel 14- Han 15- Xu 16- Mobarghai 17- Mancini 18- Peng 19- Mansourianfar & Haghshenas 2 ٢٠١٨؛ کريم زاده مطلـق ١ و همکـاران ، ١٣٩٩).
1- Landsat 7 (ETM ) and Landsat 8 (OLI) 2- AR4 3- Intergovernmental Panel on Climate Change (IPCC) 4- Keshtkar 5- Asadolahi and Salman mahini 6- Isfahan Agricultural Jihad Office 7- General Department of Fisheries of Isfahan Province رد پاي اکولوژيک توليد براي هرکدام از سکنۀ شهرستان اصفهان ، تغييراتي را داشته اسـت کـه سـرانۀ آن از ٣/١ به ٢/٢ هکتار جهاني کاهش يافته است ؛ از اين رو براي سال ١٣٩٨ با توجه به جمعيت ٢٢٠٩٦٠٦ نفـري شهرسـتان (سالنامۀ آماري مرکز آمار، ١٣٩٨)، براي برطرف کردن نيازهاي کل افراد، زميني معـادل ٤/٩ ميليـون هکتـار جهـاني لازم است که اين مهم در سال ١٣٧٩ برابر با ٤/٨ ميليون هکتار جهاني بوده است .