A feathered concierge in Colombia’s Andean forest

شور شدن خاک‌ها و توسعه آن در مناطق شکننده خشک و نیمه خشک از جمله مخاطرات محیطی است که در سال‌های اخیر مورد توجه واقع شده است. شهرستان داراب از جمله مناطقی است که دارای شرایط محیطی خشک و نیمه خشک بوده و یکی از مخاطرات محیطی آن شوری‌زایی و شور شدن اراضی است. در این تحقیق با استفاده از تصاویر ماهواره‌ای لندست (سال‌های 1987 و 2010 میلادی) و روش خایر (2003) از طریق فنّ آشکارسازی(Band 5 – Band 7 / Band 5 + Band 7) در محیط نرم‌افزاری پهنه‌های شوری خاک و اراضی استخراج گردید. جهت صحت‌سنجی نقشه استخراج شده پهنه‌های شوری، از محدوده مورد مطالعه بازدید میدانی صورت گرفت که انطباق نقشه خروجی با واقعیت را نشان داد. بر اساس نقشه خروجی (تصویر 2010)، 37/545 کیلومترمربع از مساحت منطقه مورد مطالعه دارای شوری زیاد (33/8 درصد)، 69/1804 کیلومترمربع دارای شوری قابل ملاحظه (58/27 درصد)، 41/2343 کیلومترمربع بیانگر شوری متوسط (81/35 درصد)، 23/1645 کیلومترمربع نشان دهنده شوری کم (14/25 درصد) و 91/204 کیلومترمربع از شهرستان داراب دارای شوری بسیار ناچیز (13/3 درصد) هستند. مقایسه این نقشه با نقشه استخراج شده سال 1987 بیانگر کاهش پهنه‌های شوری زیاد، قابل ملاحظه و ناچیز و افزایش پهنه‌های شوری کم و متوسط است. نتایج تحقیق نشان داد گنبدهای نمکی عامل اصلی شور شدن اراضی و خاک‌های سطحی هستند که در این بین گنبد نمکی کرسیا بیشترین نقش را ایفا می‌کند. به نظر می‌رسد نقشه استخراجی پهنه‌های شوری شهرستان داراب می‌تواند نقش قابل توجهی در مدیریت محیطی جهت رسیدن به توسعه پایدار ایفا کند.

La población patagónica de Engraulis anchoita habita el sector costero comprendido entre los 42° y 46° S. Sus áreas de desove y cría se asocian al frente de marea de Península Valdés, que se forma a fines de la primavera y desaparece a principios de otoño. Las condiciones oceanográficas del frente generan una alta productividad primaria y elevada biomasa del zooplancton asociado, potencial alimento para larvas de peces. Se estimó la condición nutricional de larvas de anchoíta por medio de tres índices: el Factor de Condición de Fulton, la relación ARN/ADN y la performance de crecimiento. Se compararon dos secciones oceanográficas: una en la que se detectó la presencia del frente de marea y otra sin ese efecto. Los resultados de los índices evidenciaron una condición nutricional mejor en las larvas de anchoíta en la sección oceanográfica con persistencia del frente de marea. Para determinar las variables ambientales que influencian la condición larval de E. anchoita se realizó un estudio aplicando Modelos Lineales Generalizados, empleando el índice ARN/ADN como variable dependiente y la clorofila superficial, la abundancia de nauplii, el volumen de plancton gelatinoso y el largo estándar de las larvas como variables explicativas. Se observó una mejora de la condición nutricional con el incremento de la abundancia de nauplii de copépodos, alimento potencial de las larvas. En cambio, el índice ARN/ADN disminuyó con la abundancia de plancton gelatinoso, lo cual sugiere que en la zona estudiada, estos organismos competirían con las larvas de E. anchoita.

As one of the most important components of a flapping-wing micro air vehicle (FWMAV), the design of an energy-efficient flapping-wing has been a research interest recently. Research on insect flight from different perspectives has been carried out, mainly with regard to wing morphology, flapping kinematics, and unsteady aerodynamics. However, the link between the wing morphology and kinematics with passive pitching has been neglected in flapping-wing design. To address this, a model based on a quasi-steady aerodynamic model and the passive pitching motion was made. To simplify the model and make optimization more feasible, the wing is modeled as a stiff plate with uniform mass distribution and a torsional spring at the wing root. An optimization is conducted with the objective of minimizing power consumption for hovering flight using the six most influential wing morphological and kinematic parameters as design variables. The sensitivity of lift generation and power consumption to all the parameters is analyzed. Compared to traditional artificial wings with straight leading edges as pitching axis, wings with a part of wing area in front of the pitching axis and smaller aspect ratio are able to perform more energy-efficient hovering flights. Preliminary design suggestions regarding the selection of wing shape and kinematics for FWMAVs are given.

Introduction Invasive plants threaten the ecosystems of agriculture, forests and rangelands. In this regard, Centaurea balsamita is an annual plant of asteraceae family that invades the fallow and slope lands. This plant is reproduced by seed and distributed in Syria, Turkey, Iran, Afghanistan and Central Asia (Turkmenistan to Tian Shan). Given that, according to studies accomplished in the world, threats of invasive plants are widely known, and since most studies related to freezing and cold stress tolerance are conducted on crop plants and there is little information about invasive plants, and considering that the precise identification of problematic invasive species. This study was performed to evaluate invasive plant Centaurea balsamita cold acclimated in spring to chill and freezing stress. Materials and Methods The experiments were conducted at Ferdowsi University of Mashhad, Faculty of Agriculture, in 2014 in a completely randomized design. In this experiment Centaurea balsamita in 2 to 4 and 4 to 6 leaf stage after the period of cold acclimation in the spring exposed to ten chilling and freezing temperatures (4, 2, 0, -2, -4,-6, -8, -10, -12 and -14 °C). In the experiment the pots were kept in the nursery from March 12, 2014 to April 19, 2014 and after cold acclimation period under these conditions, they were exposed to Chilling and freezing temperatures using thermogradient freezer. Freezer temperature was 8 °C at the beginning of the experiment and after placing the samples inside, the temperature decreased with the speed of 8 °C per hour. The cytoplasm membrane stability of Centaurea balsamita was evaluated using electrolyte leakage; then the lethal temperature of 50% of samples was determined based on leakage percentage (LT50el). Survival percentage was evaluated by counting the number of live plants in each pot. Then, at the end of the recovery period, the lethal temperature for 50% of survival percentage (LT50su) and reduction temperature for 50% of dry weight (RDMT50) were determined (three weeks after the application of freezing treatment). Results and Discussion The lowest and highest percentage of electrolyte leakage in cold acclimated Centaurea balsamita, with spring conditions influenced by chilling and freezing temperatures were at 4 °C and -14 °C, respectively. Temperature reduction from -6 °C to -8 °C caused significant increase (P ≤ 0.05) in electrolyte leakage in Centaurea balsamita. In addition, the lowest and highest percentage of survival in cold acclimated Centaurea balsamita, with spring conditions influenced by chilling and freezing temperatures were observed at 4 °C and -14 °C, respectively. Temperature reduction from -6 °C to -8 °C caused significant decrease (P ≤ 0.05) in survival percentage in Centaurea balsamita. The highest and lowest dry weight in cold acclimated Centaurea balsamita, with spring conditions influenced by freezing temperatures, after the recovery period (21 days after application of freezing treatment) were observed at 4 °C and -14 °C, respectively. Temperature reduction to below -6 °C caused significant decrease (P ≤ 0.05) in biomass of Centaurea balsamita. According to the results of the present experiment, LT50el, LT50su and RDMT50 for acclimated Centaurea balsamita with spring conditions are -7.05 °C, -7.6 °C and -7.15 °C, respectively. Researchers reported that the plants with more tolerant to cold have less LT50el, LT50su and RDMT50. Conclusions This study showed that in invasive plants such as Centaurea balsamita, using electrolyte leakage and survival tests can be relatively good methods in assessing and identifying invasive plants tolerant to cold, and help to identify invasive plant cold tolerance, predict their distribution and invasion. However, to ensure more about the cold tolerance of this invasive plant, it is recommended to cold acclimate this plant in areas with higher elevation and colder than Mashhad to achieve more accurate assessment of cold tolerance. Yet, due to low LT50su of this plant when distributed, migration this invasive plant to wheat, barley and rangelands is highly plausible.

Introduction: Two of the main challenges in developing countries are food production and trying to get a high income for good nutrition and reduction of poverty. Cereals and legumes are the most important crops in the rainfed areas of the country occupying the majority of dry land areas. Irrigated production systems had a main role in food production in the past years; but unfortunately, in recent years, with high population and competition of industry and environment with agricultural sectors, getting adequate irrigation water is difficult. The main purpose of this study is to determine the best option of crop agronomic management. Rainfed agriculture is important in the world; because this production system establishes %80 of the agriculture area and prepares %70 of the food in the world. In the Lorestan province, production area for rainfed barley is 120,000 ha and the amount produced is 120000 ton (approximately 1009 kg per ha). The purposes of this study were to evaluate cost, benefit and profit of rainfed barley production, economical and non-economical substitution of treatments in different agronomic management, study of sale return, cost ratio, determining break-even of price and comparing it with the guaranteed price of barley and estimating the value of water irrigation. Materials and Methods: This research was carried out by sample farmers (12 farmers) on rainfed barley at the Honam selected site in the Lorestan province during 2005-07. At on-farm areas of the upper Karkheh River Basin (KRB) three irrigation levels were analyzed (rainfed, single irrigation at planting time and single irrigation at spring time) under two agronomic managements (advanced management (AM) and traditional management (TM). Data was analyzed by Partial Budgeting (PB) technique, Marginal Benefit-Cost Ratio (MBCR), and economical and non-economical test. For estimation of net benefit the following formula was used: (1) Where: N.B: Net income (Rials/ ha) , B(w) : Gross income, C (w) : Cost of production, YG: Crop yield (kg/ ha), PG : Price of crop(Rials/kg), YS: straw yield (kg/ ha PS : Price of straw (Rials/kg), C1: Total fixed cost without cost of water and irrigation (Rials/ ha), Pw: Price of water and irrigation (Rials/ m3) and W: Amount of water and irrigation (m3/ ha). Changes of incomes and changes of costs for every treatment in different crop managements were used as follows: (2) (3) Where j and j+1 show existence and substitution crop managements. In order to determine the price of irrigation water, total cost including pump and electromotor, semi deep well, power instrument, maps, pipe transport and implementation network, other primary cost and operation cost were used. The analysis period for the instruments (pump and electromotor, maps, implementation network) was 20 years and for the semi deep well was 30 years. In this study, total cost was referred to the present value with %15 discount rate by uniform series formulas. Then, the water was used in the farm. The price of water was determined. Capital recovery formula is as follows: (4) Where: A: Annual value of primary investment costs, P: Primary investment costs for irrigation system, i: Discount rate and n: analysis period. Results and Discussion: According to the results, the price of water and irrigation at the research region based on its components and under 15% and 25% interest rates were obtained to be 213 and 338.1 Rials per cubic meters, respectively. The barley grain yield and its net benefit under advanced management were more than that obtained under traditional management. In traditional management, the mean barley grain yield for treatments including rainfed, Single irrigation (SI) - planting and SI spring were estimated to be 1572, 2487 and 2670 kgha-1, respectively. The mean profit for rainfed barley production for treatments including rainfed, SI-planting and SI spring were estimated to be 1270.2, 2314.2 and 2607 (Thousand Rial.ha-1), respectively. In advanced management, the mean barley grain yield for treatments including rainfed, Single irrigation (SI) -planting and SI spring were estimated to be 2270, 3444 and 2853 kgha-1, respectively. The mean profit for rainfed barley production for treatments including rainfed, SI-planting and SI spring were estimated to be 1987, 3465.4 and 2519.8 (Thousand Rial.ha-1), respectively. In the research site, the mean net benefit of rainfed barley under sowing and spring single irrigation and AM, increased by about 173% and 98.4%, respectively. Conclusion: The results showed that the substitution of AM-SI planting treatment instead of other treatments was non-economical. On the other hand, in this substitution, decreasing of profit is more than decreasing of cost. Finally, at Honam site, recommended management include: AM + planting SI, AM + spring SI, and rainfed AM, respectively.

The main part for a vehicle suspension is the shock absorber, which is manufactured for reducing shock impulse. Shock absorber work on the principle of fluid displacement on compression and expansion cycle. They are used in motorcycles for providing better handling, prompt braking, safety and comfort by keeping the passengers isolated from road noise, bumps and vibration. The common type of the front suspension in motorcycle is Telescopic forks which are replaced by the Mono Shocks that gives a superior vehicle handling and provides safety while braking. Mono shock also allows the rider to fine tune the machine to give better control over the machine when riding. The springs in Mono Shock have been designed by taking considerations of many practical conditions like dynamic resistances, road tracks and aerodynamic properties. In this design the uneven vibrations in the telescopic forks have been balanced by using the Mass Centralization concept in the pivoted centre point of the front suspension in the motorcycle using Mono Shocks. The Mono Shock geometry gives a rising rate of damping characteristics to the front suspensions and the designed springs used to restrict a downgraded dynamics when it returns to the immobility state posterior to humps and bumps. This design of front suspension using mass centralization concept may antiquate the present telescopic forks

مقدمه: حیوان گزیدگی همچنان به عنوان یکی از معضلات مهم بهداشتی در ایران و سایر کشورهای جهان مطرح است. علیرغم پیشرفت های گسترده ای که در امر پیشگیری و درمان حاصل شده است، موارد حیوان گزیدگی هنوز از روند رو به رشدی برخوردار است. طبق برآوردهای سازمان بهداشت جهانی سالانه بیش از ده میلیون نفر در مناطق مختلف دنیا به دنبال گزیدگی، تحت درمان قرار می گیرند. با توجه به اهمیت عوارض ایجاد شده توسط حیوان گزیدگی و در عین حال قابل پیشگیری بودن آنها در این مطالعه بر آن شدیم تا به بررسی اپیدمیولوژی موارد حیوان گزیدگی در شهرستان رشت در سال 1391 بپردازیم. روش کار: این مطالعه به صورت گذشته نگر و مقطعی می باشد. داده های مرتبط با کلیه موارد حیوان گزیدگی در شهرستان رشت در سال 1391 بر اساس اطلاعات موجود در دفاتر ثبت موارد حیوان گزیدگی شهرستان جمع آوری گردید. برای تمامی بیماران چک لیستی شامل سن، جنس، شغل، نوع حیوان، وضعیت حیوان، محل سکونت، عضو گاز گرفته شده، فصل گزش و نوع زخم تکمیل گردید. يافته ها: در مجموع 1014 مورد حیوان گزیدگی گزارش گردید (72/5 درصد مرد). میانگین سنی افراد مورد مطالعه 17/81±33/63 سال بود. بیشترین موارد حیوان گزیدگی مربوط به سگ (79/2درصد)، حیوانات اهلی (88/3) و در محیط های روستایی (61/3 درصد) بود. بیشترین عضو گزیده شده دست (55/2 درصد)، بیشرین فصل بروز حادثه بهار (29/8 درصد) و بیشترین نوع زخم از نوع سطحی (64/3 درصد) بود. افرادی که از ناحیه سر و صورت دچار گزش شده اند به طور معنا داری کم سن تر از افرادی بودندکه از ناحیه دست یا پا دچار آسیب شده بودند (0/001=p). همچنین افرادی که توسط سایر حیوانات به جزء سگ و گربه دچار گزش شده بودند به طور معنی داری کم سن تر بودند (0/002=p). نتيجه گيری: بر اساس نتایج مطالعه حاضر بیشتر موارد حیوان گزیدگی در شهرستان رشت استان گلستان در فصل بهار، توسط سگ های اهلی، در مردان روستایی، بصورت سطحی و در گروه سنی 20 تا 29 اتفاق می افتد. فراوانی حیوان گزیدگی با جنس، سن و محل سکونت ارتباط داشته و هنوز یکی از مشکلات مهم بهداشت عمومی است که فعالیت های آموزشی می تواند نقش به سزایی در کنترل آن داشته باشد.

COVID-19 has changed the daily lives of citizens around the world and exposed the vulnerability of life and the functioning of cities. The pandemic has forced citizens to adapt to new models of remote work during quarantine and access to smart technology-based services. The article aims to assess citizens' perceptions of the technological solutions provided by smart cities and, in particular, the municipality of Paphos before and after the Covid-19 pandemic, as well as to evaluate their impact on citizens' mental health. The results of the study contribute to the understanding of the mental health benefits for citizens living in smart cities compared to people living in low-tech areas, revealing the potential positive effects of smart technologies, as well as the change in people's digital decision-making before and after the pandemic

As a main economic crop in China, tea plant is prone to frost disaster when it germinates in early spring. The research progress and main achievements of tea plant spring frost disaster are systematically summarized. In southern Yangtze River, the research on disaster index and risk assessment of tea plant spring frost disaster is abundant. As for the spatio-temporal distribution characteristics of the disaster, most of the existing studies are based on regional scales and provincial scales, focusing on Southern Yangtze River. There are few reports on the spatio-temporal distribution on the national scale. Tea plant spring frost disaster index can be divided into three categories based on classification criteria. According to data acquisition method, it can be classified into morphological index and laboratory physiological morphological index. According to data category, it can be determined only by meteorological data, or by both meteorological data and tea plant disaster symptoms. According to the time scale of meteorological data, it can be further subdivided into daily scale and hourly scale. In the context of global warming, although the frequency of tea plant spring frost is declining, its harm cannot be ignored. The frequency of tea plant spring frost in Southern Yangtze River shows latitudinal distribution characteristic that gradually increases from south to north. And the topographic distribution characteristic is also revealed that the frequency of tea plant spring frost increases with elevated altitude. For the impact assessment of tea plant spring frost, the areas, including Jiangsu, Zhejiang, Anhui, and Jiangxi provinces, are paid close attention, and the research method is gradually developing from qualitative assessment to quantitative assessment. The risk assessment methods of tea plant spring frost mainly include fuzzy mathematics method and information diffusion method. In recently researches, risk levels are determined by models based on the natural disaster risk formation mechanism. In the future, the construction of tea spring frost disaster index based on the micro-climate factors in tea gardens will become hotspot. Furthermore, the meteorological index of tea spring frost should be improved, and the spatiotemporal distribution characteristics on national scale, and the refined risk assessment will also be paid more attention.

In documenting biological response to climate change, the Intergovernmental Panel on Climate Change used phenology studies from many parts of the world, but data from high latitudes of North America are scarce. This thesis reports climate trends and corresponding changes in sequential bloom times for seven plant species in the central parklands of Alberta, Canada (52–57° north latitude). The data span seven decades (1936–2006), drawing on historic Agriculture Canada data, observations by the Federation of Alberta Naturalists, and the Alberta PlantWatch program in both urban and rural areas of central Alberta. An analysis of historical weather station data revealed a substantial warming signal over the study period (1936–2006), which ranged from +5.3°C for mean monthly temperature in February to +1.5°C in May. The earliest blooming species (Populus tremuloides and Anemone patens) advanced their bloom dates by two weeks over seven decades, while the later species advanced their bloom dates between zero and six days. Early-blooming species advanced faster than predicted by thermal time models, which may be due to decreased diurnal temperature fluctuations. This unexpectedly sensitive response resulted in an increased exposure to late spring frosts. A criticism by climate change skeptics is that the observed warming signal is an artifact of the increasing heat island effect of growing cities. The current dataset offered the opportunity to test this claim due to the spatially and temporally extensive phenology database. The data indeed show an increasing heat island effect over the period 1931–2006 in both weather station data and plant phenology response. Across all seven plant species, the advance in phenology observed in Edmonton was 2.1 days (±0.9 SE) greater than in the surrounding rural areas over the last 70 years. This accounted for one third of the general warming signal, while the remaining advance of 3.7 days observed in rural settings was attributed to climate change. Finally, as guidance for those initiating new observer networks, an analysis of factors that determined the quality of the PlantWatch phenological data was carried out. The thesis concludes with recommendations for effective volunteer training, observer motivation, and program protocols.

In this paper, Qeera wastewater containing stream, found in Bakkee-Jamaa district of Nekemte town, was assessed for selected metals and physico-chemical properties. The metals were determined by flame atomic absorption spectrophotometry (FAAS). Additional water samples collected from Dangi spring water, which is found about 10 km far away from the town, and Chalalaqi waste water containing stream were also assessed for reference. Analysis of concentration of Pb, Cd, Cr, Ca, and Ni metals were carried out using FAAS. For metal analysis good linearity were obtained with coefficient of determination (R2) 0.998 or better. The LOD for the metals were in the range of 0.003 to 0.018 mg L−1 and LOQ, 0.010 to 0.06 mg L−1. Recovery studies ranged from 92 % to 104 % for the metals. The study shows that Ca, Cd and Ni are quantified in all the three water bodies. Overall, the level of the metals studied is higher in the urban area streams than that of Dangi spring in the rural area. The average concentrations (in mg/L) of Ca, Cd and Ni were found to be 9.56., 0.22 and 0.38, respectively. When compared with international guide lines for the quality of irrigation water, Cd and Ni are above permissible levels and show significant pollution of the water. The data obtained from the study of selected physico-chemical properties (EC, TDS, pH, TSS and Cl¯) of the water samples were found to be within the recommended level except TSS.

Short-term variability of chlorophyll a concentration, abundance and composition of phytoplankton and ciliates and of abiotic parameters were analyzed at the Patos Lagoon estuary during two seasons, in the austral spring (October/November 2004) and summer (January/February 2005). Sampling was carried out at a fixed station every 2h30min for chlorophyll a, salinity, water temperature, transparency, water flow velocity and direction and, once a day, for phytoplankton and ciliates, seston and dissolved inorganic nutrients analysis. In austral spring, wind direction changed approximately every two days between northerly and southerly, and rainfall was high (212.9 mm), while in the summer period the wind direction changed less, approximately every five days, and rainfall was low (32.5 mm). The action of rainfall and wind direction fluctuation controlled temperature, salinity, water transparency and chlorophyll a, associated with shorter cycles in the spring than in the summer periods. The concentration of inorganic nutrients also differed, silicate was high in the spring (mean 108 µM) compared to the summer (mean 69 µM) period, and the main nitrogen source in spring and summer was nitrate and ammonia, respectively. The presence of freshwater and marine species in the study area was typically a wind-salinity response, with southerly wind inducing the inflow of marine diatoms and dinoflagellates, and NE wind leading to water discharge containing freshwater cyanobacteria and chlorophytes. The time lag of the wind action on the salinity-biotic response was generally short (hour scale) but may be delayed with low rainfall as it was observed in summer. It was shown that high frequency processes, in the same period of cell-division, 1-2 days, are of primary importance for the lagoon ecology. The fluctuation of freshwater outflow and wind driven processes may prevent, delay or prompt phytoplankton biomass accumulation in the estuarine area, acting as the timing mechanism of the diatom spring bloom. In summer, the increased benthic and pelagic herbivore activity apparently acted as an important chlorophyll a control typical of top-down processes.

هدف از پژوهش کنونی بررسی دورنمایی از اثرات احتمالی تغییر اقلیم بر جابه‌جایی زمانی تاریخ وقوع اولین و آخرین یخبندان‌های پاییزه و بهارۀ ایران است. بدین منظور از داده‌های دیده‌بانی 43 ایستگاه همدید کشور (1981-2010) و داده‌های شبیه‌سازی شدۀ LARS WG در دو مدل آب‌وهوای جهانی GFCM21 و HadCM3 در بازه‌های زمانی (2065-2046) و (2099-2080)، تحت سه سناریوی انتشار A1B، A2 و B1استفاده گردید. نتایج، بیانگر جابه‌جایی اولین یخبندان پاییزه‌ به سمت اوایل زمستان و جابه‌جایی آخرین یخبندان بهاره به‌سوی اواخر زمستان در گسترۀ ایران است. پراکنش زمانی-مکانی تغییرات متفاوت است؛ به‌گونه‌ای که بیشترین جابه‌جایی‌های مثبت در رخداد اولین یخبندان پاییزه در دورۀ (2065-2046) در ایستگاه‌هایی چون خرم‌‌آباد، رشت و گرگان مشاهده می‌شود. میزان تغییرات در ایستگاه‌های شمال شرقی (سبزوار و سمنان)، نیمۀ جنوبی (کرمان، بم و آباده) و بیشتر ایستگاه‌های شمال‌غرب نسبت به دیگر مناطق کمتر است. در دورۀ (2080-2099) بیشترین روند منفی در ایستگاه‌های گرگان، رشت، اردبیل و شهرکرد خواهد بود. خوی، قزوین، بم و کاشان کمترین جابه‌جایی منفی خواهند داشت.

شناخت آسیب پذیری جمعیت و گروه های انسانی به عنوان اقدامی ابزاری در راستای پیشگیری از زایش فاجعه مبتنی بر زیستن در نواحی پر خطر مطرح است. تحلیل آسیب پذیری کانون‌های جمعیتی واقع در عرصه های خطر اقدامی علمی برای فراهم سازی زیر ساخت اطلاعاتی مناسب از درجه و میزان خطرپذیری از رخداد مخاطره است. بر اساس چنین دیدگاهی مسئله تحلیل آسیب پذیری ناشی از مخاطرات ژئومورفولوژیک فرونشست در جنوب شهر تهران مورد توجه قرار گرفته است. بدین منظور در ابتدا با استفاده از تکنیک تداخل سنجی راداری نرخ و دامنه فرونشست در محدوده مورد مطالعه استخراج گردید. سپس برای تولید نقشه فضایی عرصه های پر مخاطره نرخ و دامنه فرونشست به عنوان فاکتور عامل در زایش مخاطره به تحلیل گر سیستم در محیط GIS وارد گردید. نقشه خروجی معرف سلول‌های واجد ارزش متفاوت از فاکتور زایش مخاطره است. استخراج عرصه متعلق پهنه در معرض مخاطره نشان داد که از مجموع مساحت محدوده 7/12 درصد در پهنه های بسیار پرخطر، 7/14 در عرصه پرخطر،5/15 در عرصه نسبتاً پرخطر بیش از نیمی از محدوده (57درصد) در عرصه نسبتاً کم خطر قرار گرفته‌اند. برای ارزیابی میزان خطرپذیری، الگوی توزیع فضایی تأسیسات و ساخت‌وساز های موجود با نقشه عرصه های در معرض خطر هم نهاد گردید. مبتنی بر این اطلاعات و با استفاده از پیمایش میدانی اقدام به بررسی آسیب پذیری جمعیت ،مساکن و تأسیسات موجود در محدوده مورد مطالعه صورت پذیرفت. یافته های تحقیق موید آسیب پذیر بودن اکثر سکونت گاه‌ها و جمعیت ساکن درآنهاو تأسیسات موجود در محدوده می‌باشد. همچنین بر اساس پایش های میدانی صورت گرفته مشخص گردید که اکثر ساخت و سازهای موجود در منطقه غیر اصولی بوده که این امر باعث فراهم آوری زیرساخت آسیب پذیری برای مستحدثات در شرایط خطرپذیر است.

Drivers of Departure and Prospecting in Dispersing Juvenile Red Kites (Milvus milvus)