نتایج جستجو برای: arid and rainfall in arid and semi

تعداد نتایج: 21762861  

Journal: :The New phytologist 2008
Anna L Jacobsen R Brandon Pratt Stephen D Davis Frank W Ewers

Plant adaptations to the environment are limited, and therefore plants in similar environments may display similar functional and physiological traits, a pattern termed functional convergence. Evidence was examined for functional convergence among 28 evergreen woody shrubs from three plant communities of the semi-arid winter rainfall region of southern California. Both leaf and water relations ...

2009
P. J. O’Farrell

Introduction ‘Everybody talks about the weather, but nobody does anything about it’, said Mark Twain. But this famous quote is decidedly inaccurate: people have long contemplated weather modification, and both adapt or adjust to weather conditions, and move towards or away from certain climatic regimes. Southern Africa generally has a high coefficient of rainfall variation, making droughts a fr...

Journal: :desert 2012
h. azarnivand m.a. zare chahouki h. joneidi

one of the characteristics in iranian model of desertification potential assessment (imdpa) is vegetation. sincevegetation is very important factor in the degradation of land, so some indices were determined for this item in order toevaluate desertification potential of arid, semi arid and arid sub humid areas of iran. the indices included vegetationcondition, exploit and revegetation. to calib...

2015
Taijun Li Bowen Ren Dahui Wang Guobin Liu

Knowledge about the long-term influences of climate change on the amount of potential carbon (C) sequestration in forest ecosystems, including age-related dynamics, remains unclear. This study used two similar age-sequences of black locust forests (Robinia pseudoacacia L.) in the semi-arid and semi-humid zones of China's Loess Plateau to assess the variation in C stocks and age-related dynamics...

2006
Jingfen Sheng

This paper examines the effects of urbanization on the flood hazard in semi-arid/arid southern California using traditional hydrograph, frequency-magnitude and statistical analysis augmented with GIS-based variable parameterizations and visualizations. It was found that the peak flood discharges were significantly increased in urban watersheds in conjunction with increasing mean baseflow in the...

Journal: :زراعت دیم ایران 0
عبدالعلی غفاری موسسه تحقیقات کشاورزی دیم کشور ادی دپائو مرکز بین المللی تحقیقات کشاورزی در مناطق خشک- ایکاردا سید ابوالفضل میرقاسمی سازمان جنگلها. مراتع و آبخیزداری کشور

an agroecological zones (aez) map is an essential tool for agricultural planning. by integrating the key components of the agricultural environments, it offers a bird's-eye view of internal diversity, agricultural potential and constraints that decision-makers find easier to understand than a pile of single-theme maps. in this study, aez map of the karkheh river basin has been prepared usi...

ژورنال: فیزیک زمین و فضا 2018

Rainfall is one of the most important elements of water cycle used in evaluating climate conditions of each region. Long-term forecast of rainfall for arid and semi-arid regions is very important for managing and planning of water resources. To forecast appropriately, accurate data regarding humidity, temperature, pressure, wind speed etc. is required.This article is analytical and its database...

1999
R. M. Otsyina B. W. Norton M. Djimdé

Arid and semi-arid lands constitute a large proportion of available agricultural and rangeland in the world. These lands are characterised by low and unreliable rainfall, low land productivity, and low socioeconomic status of the inhabitants. Livestock plays a very significant role in their economies. Leguminous trees and shrubs, which dominate the natural rangelands, are often higher in crude ...

جعفری, رضا , سلطانی, سعید, عباسی, ندا ,

Drought is one of the main and significant factors that increase the potential risk of fire in forests and rangelands. This study was conducted to assess the potential of a soil-moisture index called Keetch-Byram Drought Index (KBDI) for mapping fire risk in the forests and rangelands of Isfahan province using daily climate data in 2006- 2010 period. KBDI is a drought/fire index that ranges fro...

2011
Elizabeth Bryan Claudia Ringler Barrack Okoba Carla Roncoli Silvia Silvestri Mario Herrero

Kenyan farmers’ livelihoods are closely linked to climate conditions. Almost three-quarters of the labor force depend on agriculture for their livelihoods, and almost all farmers depend on timely and adequate rainfall for crop production and husbandry, as only 2 percent of cultivated area is equipped for irrigation. Thus, climate variability and change will have an increasing impact on agricult...

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