نتایج جستجو برای: climate change and temperature increase

تعداد نتایج: 16998988  

Journal: :international journal of environmental research 0
kh. ashrafi graduate faculty of environment, university of tehran, p.o.box 14155-6135, tehran, iran m. shafiepour graduate faculty of environment, university of tehran, p.o.box 14155-6135, tehran, iran l. ghasemi graduate faculty of environment, university of tehran, p.o.box 14155-6135, tehran, iran b. araabi faculty of electrical and computer engineering, university of tehran, tehran, iran

the objective of this paper is to develop an artificial neural network (ann) model which can beused to predict temperature rise due to climate change in regional scale. in the present work data recorded overyears 1985-2008 have been used at training and testing steps for ann model. the multilayer perceptron(mlp) network architecture is used for this purpose. three applied optimization methods a...

Journal: :desert 0
gh.r. zehtabian faculty of natural resources, university of tehran, karaj, iran a. salajegheh faculty of natural resources, university of tehran, karaj, iran a. malekian faculty of natural resources, university of tehran, karaj, iran n. boroomand faculty of soil science engineering, shahid bahonar university of kerman, kerman, iran. a. azareh faculty of natural resources, university of tehran, karaj, iran

climate change is found to be the most important global issue in the 21st century, so to monitor its trend is of great importance. atmospheric general circulation models because of their large scale computational grid are not able to predict climatic parameters on a point scale, so small scale methods should be adapted. among downscaling methods, statistical methods are used as they are easy to...

2014
Maria Waldinger

Understanding the economic effects of long-term and gradual climate change, when people have time to adapt, is a central question in the current debate on climate change. Empirical evidence, however, is scarce. I study the economic effects of climate change over a period of 250 years during the Little Ice Age, a historical episode of climate change, between 1500 and 1750. Historians have argued...

Journal: :journal of agricultural science and technology 2016
a. kumar p. sharma s. joshi

the current study assessed the climate change impacts on land productivity of major food and non-food grain crops in india. we compiled panel data for 30 years (1980-2009) using fifteen crops across thirteen agriculture intensive states. the value of production for each crop is estimated by farm harvest price (at constant prices, 1993-1994). aggregate value of production on per hectare land is ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Jason R Rohr Thomas R Raffel

The role of global climate change in the decline of biodiversity and the emergence of infectious diseases remains controversial, and the effect of climatic variability, in particular, has largely been ignored. For instance, it was recently revealed that the proposed link between climate change and widespread amphibian declines, putatively caused by the chytrid fungus Batrachochytrium dendrobati...

2009
Mingyuan DU Seiichiro YONEMURA Hiroyuki DEN Zhibao SHEN Yanbo SHEN

Monthly mean air temperature and precipitation data, monthly dust storm frequencies (times of dust storm occurrences) of 107 stations in North China were analyzed to clarify the relationship between the climate change and dust storm occurrence. Arid regions of North China were divided into five and trends of dust storm occurrence and climate changes showed different patterns for these regions, ...

Global warming and temperature rise will have many effects on different sectors, including agriculture, the warming of the earth will increase the rate of evaporation, and consequently the increase in the demand for agricultural products will increase. In this study, in order to monitor the effect of global warming on Mughan Plain wheat, using the LARS-WG model as a relatively inexpensive and a...

2008
Zhi Li Wenzhao Liu Xunchang Zhang

Soil water balance has response to climate change and evaluation of soil water change is one of the most important items of climate change impact assessment. GCM outputs under three scenarios were statistically downscaled during 2010~2039 to simulate the potential change of soil water balance in Wangdonggou watershed on the Loess Plateau with WEPP model. GCM predicted a 1.8 to 17.5% increase in...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تبریز 0

a semi-empirical mathematical model for predicting physical part of ignition delay period in the combustion of direct - injection diesel engines with swirl is developed . this model based on a single droplet evaporation model . the governing equations , namely , equations of droplet motion , heat and mass transfer were solved simultaneously using a rung-kutta step by step unmerical method . the...

fatemeh zakerhosseini, Kazem Hemmadi

In arid and semi-arid regions, soil surface warming is a considerable phenomenon causing a high thermal gradient which makes water flow intensely. The degree of soil temperature is effective on crop production, plant growth and soil microorganisms. In recent years, the ascending trend of temperature has been substantially noticed by researchers in the issues of pointwise climate change and at w...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید