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Evaluating Reference Crop Evapotranspiration (ETo) in the Centre of Guanzhong Basin—Case of Xingping & Wugong, Shaanxi, China  [PDF]
Hussein I. Ahmed, Junmin Liu
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.55055
Abstract: In this paper, the Penman-Monteith method was applied to evaluate the reference crop evapotranspiration. A reliable estimation of the reference evapotranspiration (ETo) is of critical importance and required accurate estimates to close the water balance. The aim of this paper is estimating the reference evapotranspiration (ETo) as preliminary to use for groundwater modeling in the area. Based on FAO-Penman-Monteith method, ETo calculator software was applied. Meteorological data within this study were obtained from two gauges stations (Xing ping and Wu gong) and available literatures. The results indicated that the values of ETo for a period (1981-2009)29 yearsin two stations approximately the same. Specifically, is ranged between 0.4 - 6.9 mm /day, 0.4 - 6.7 mm/day and the average value is 2.6 mm/ day, 2.6 mm/day in Xing ping and Wu gong respectively. In addition, the maximum values were occurred in summer season (May, June and July). The result also found that the correlation coefficient ≈ 1. Moreover, “ETo” was increasing by recent years. The reference crop evapotranspiration for some crops were calculated.
Class A pan coefficients (Kp) to estimate daily reference evapotranspiration (ETo)
Sentelhas, Paulo C.;Folegatti, Marcos V.;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2003, DOI: 10.1590/S1415-43662003000100018
Abstract: the class a pan coefficient (kp) has been used to convert pan evaporation (eca) to grass-reference evapotranspiration (eto), an important component in water management of irrigated crops. there are several methods to determine kp values, using wind speed, relative humidity and fetch length and conditions. this paper analyses the following methods to estimate kp values: doorenbos & pruitt (1977); cuenca (1989); snyder (1992); pereira et al. (1995); raghuwanshi & wallender (1998); and fao/56 (allen et al., 1998). the estimated values of kp and the observed kp, obtained from the relationship between eto measured in a weighing lysimeter and eca measured in a class a pan, were compared by regression analysis. the same routine was adopted to evaluate eto estimates with the different kp values. the results showed that all methods to estimate kp did not predict it well, with low correlation (r2< 0.2), which resulted in estimates of eto with high dispersion (r2< 0.8). the best kp methods to estimate eto were pereira et al. (1995) and cuenca (1989), both presenting high efficiency. the use of an arbitrary and constant kp (0.71) to estimate eto, produced the same precision and accuracy as the estimates of kp based on pereira and cuenca methods. this fixed value is a practical and simple option to convert eca into eto, but this value must be calibrated for each place under different climatic conditions.
Comparative study of reference crop evapotranspiration (ETo) by different energy based method with FAO 56 Penman-Monteith method and at New Delhi, India  [PDF]
Ram Karan Singh,P.S.Pawar
International Journal of Engineering Science and Technology , 2011,
Abstract: The use of FAO 56 Penman-Monteith method for reference evapotranspiration (ETo) calculations to get crop water requirement has been recommended globally because it provides good results under wide range of climatic conditions. In absence of reliable data required for this method various other methods viz.FAO 24 Radiation, Priestley-Taylor, Blaney-Criddle, Hargreaves, Turc, Makkink and Pan Evaporation are used commonly. Main objective of this study is to evaluate performance of these seven commonly used energy based methods based on their daily ETo predictions compared to FAO 56 Penman-Monteith method predicted ETo and lysimetric ETc under prevailing climatic conditions of New Delhi. Use of Maize (Zea mays L.) crop lysimeter ET along with other meteorological parameters for seventeen carefully selected crop seasons ranging from 1976 to 2006 had done for performance evaluation. Statistical indicators used to evaluate performance were regression coefficient (R2), least root mean square difference (RMSD), mean bias error (MBE) and t-statistics.It can be concluded from the overall study that Priestley-Taylor and FAO 24 Blaney-Criddle method can be used for ETo predictions under wide range of climatic conditions when limited data is available or non reliability of data.
陕西关中地区苹果园苹果全爪螨对4种杀螨剂的抗药性评估
Resistance Monitoring of Panonychus ulmi from Apple Orchards to Four Acaricides in Guanzhong
 [PDF]

张旭东,武荣祥,赵奇,苏小计,陈茂华
- , 2017, DOI: 10.3969/j.issn.1001-7461.2017.02.33
Abstract: 为明确陕西省关中地区苹果园苹果全爪螨(Panonychus ulmi)田间种群对4种常见杀螨剂的抗药性现状,并指导该螨的田间药剂防治。采用玻片浸渍法,对采自陕西兴平、礼泉、淳化、扶风和凤翔5个地区苹果园苹果全爪螨田间种群进行毒力测定,并分析其相对抗性水平。结果表明,礼泉种群对阿维菌素和噻虫嗪LC50值最低,分别为0.041 mg?L-1和58.578 mg?L-1,凤翔种群对哒螨灵和三唑锡LC50值最低,分别为11.202 mg?L-1和96.181 mg?L-1;各田间种群对阿维菌素的相对抗性倍数为1.11~1.88倍,对哒螨灵的相对抗性倍数为1.36~3.61倍,对噻虫嗪的相对抗性倍数为1.11~3.14倍,对三唑锡的相对抗性倍数为1.84~2.43倍。总之,不同地区苹果全爪螨田间种群对药剂抗性水平不同,兴平种群对哒螨灵和凤翔种群对噻虫嗪的致死中浓度明显高于其他4个地区,田间实际防治过程中应根据各地实际情况有针对性地进行用药。
The aims of this study were to investigate the resistance levels of the field populations of Panonychus ulmi (Koch) collected from the apple orchards in Guanzhong (central area of Shaanxi Province,China) to four kinds of acaricides,and to provide guidance for chemical control of P.ulmi.The slide-dip method was used to test the toxicity,the apple orchards were located in Xingping,Liquan,Chunhua,Fufeng and and Fengxiang.The P.ulmi population from Liquan showed the lowest LC50 to abamectin (0.041 mg?L-1) and thiamethoxam (58.578 mg?L-1),and the population from Fengxiang showed the lowest LC50 to pyridaben (11.202 mg?L-1) and azocyclotin (96.181 mg?L-1).The field populations of P.ulmi had different relative resistance to different acaricides,with the relative resistance ratios of 1.11-1.88 to abmectin,1.36-3.61 to pyridaben,1.11-3.14 to thiamethoxam,and 1.84-2.43 to azocyclotin.In a word,the relative resistance levels to four acaricides varied within populations of P.ulmi from different locations.Xingping population showed the highest LC50 value to pyridaben,and Fengxiang population showed the highest LC50 value to thiamethoxam.Our results suggested that the application of acaricides should be varied significantly with the populations of P.ulmi from different locations
零售肉品中产气荚膜梭菌的检测与定型:以陕西关中地区为例
Detection and typing of Clostridium perfringens from retail meat in Guanzhong,Shaanxi
 [PDF]

姜艳芬,王清爱
- , 2016,
Abstract: 【目的】检测陕西关中地区肉品中的产气荚膜梭菌,并进行血清型和产气荚膜梭菌肠毒素(CPE)基因型鉴定,初步掌握该地区肉品中产气荚膜梭菌的污染状况。【方法】从陕西西安、杨凌、武功等地的超市、农贸市场、肉食品小摊随机采集新鲜生熟鸡、猪肉及其制品,共计314份,经细菌分离纯化、染色镜检、生化试验和单重PCR检测确定分离菌株为产气荚膜梭菌,应用多重PCR检测分离菌株的血清型并进行cpe毒素基因检测。【结果】样品中产气荚膜梭菌检出率为45.86%,且均为A型cpe产气荚膜梭菌,其中熟肉制品、生鲜肉检出率分别为50.91%和43.14%;鸡肉、猪肉检出率分别为53.06%和33.90%。【结论】陕西关中地区的肉品中存在产气荚膜梭菌污染,建议针对可能引起产气荚膜梭菌污染和大量繁殖的环节采取更有效的预防措施。
【Objective】To understand the contamination and distribution of Clostridium perfringens (C.perfringens)in raw or cooked retailed meat in Guanzhong,Shaanxi,C.perfringens strains were isolated from collected retailed meat samples,and serotyped using established multi-PCR.【Method】A total of 314 samples including fresh raw meat (chicken and pork),cooked chicken claws,sausage and preserved pork were purchased randomly from supermarkets,farmer’s markets and food stands in Xi’an,Yangling and Wugong.Samples were isolated and purified as suspect C.perfringens strains.The isolates of C.perfringens were then confirmed using Gram staining,biochemical test,PCR amplification and serotyped by the developed multiplex PCR and genotyped by cpe gene detection.【Result】The isolation rate of C.perfringens was 45.86% and all isolates were classified as cpe type A.C.perfringens identification rates in cooked meat samples and raw fresh meat samples were 50.91% and 43.14%,while the rates in chicken and pork were 53.06% and 33.90%,respectively.【Conclusion】This study demonstrated the presence of C.perfringens in meat products in Guanzhong,Shaanxi,and it is suggested to take more effective preventive measures to control contamination and mass proliferation of C.perfringens
Climate Change and its Impacts on the Winter Wheat Yield in Wugong Region of Shaanxi Province
Hao Ding,Zhi-Nong Wang,Hu-Jun Shang,You-Gong Zhang
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2012.3668.3676
Abstract: Understanding the impacts of climate change on the Winter wheat yield in Wugong region is important for effectively making relevant countermeasures and policy. Based on the monthly weather data and Winter wheat yield data in Wugong station from 1935-2010, the Mann-Kendall Method, Rescaled Range Analysis Method (R/S), Straight Line Slipping Average Simulating Method and Path Analysis Method were adopted to study the changing tendency of the main meteorological factors, the aridity-humidity as well as the impacts of climate change on the winter wheat yield in Wugong region. The results have shown that the minimum temperature had an increasing trend, the wind speed, hours of sunshine and ET0 were all gradually decreasing, they have come to a remarkable level; SPI was dropped, the climate trended to be drought gradually. Hurst indexes of ET0 and SPI (annual value and winter wheat growth period) were all >0.5 which will appear to be the persistent trend in the future. The minimum temperature increasing trend had the most powerful comprehensive determined ability on winter wheat yield; the maximum temperature was the major limited weather factor of the Winter wheat yield increasing. However, the negative impact of climate change on the winter wheat production in Wugong region can be mitigated to some extent by some technological innovations.
Biological records of paleoclimate and paleoenvironment changes from Guanzhong area, Shaanxi Province during the last glacial maximum
Xiangxu Xue,Weijian Zhou,Jie Zhou,J. Head,A. J. T. Jull
Chinese Science Bulletin , 2000, DOI: 10.1007/BF02887417
Abstract: We have collected a suite ofPaleoloxodon naumanni-Coelodonta antiquitatis fossils from a river terrace profile between Xi’an and Xianyang cities in Guanzhong Area, Shaanxi Province. A detailed examination of the fossils, together with14C determinations and pollen analyses, have enabled us to reconstruct preliminary features of climate and environment changes and their evolutionary processes, within the last glacial maximum (LGM): about 20 ka ago, the climate was basically cool and wet, and was favourable for the existence ofPaleoloxodon naumanni-Coelodonta antiquitatis fauna. This was followed by a cold, dry phase which was no longer suitable for this type of faunal suite, causing the death of a large number of mammalian assemblages. The available evidence indicates the existence of cold-dry and cool-wet climate and environment fluctuations during the LGM. The cool-wet stage within the LGM reflects a Heinrich event occurring in the high latitude areas, proving the existence of a teleconnection between polar-high latitude areas and the Loess Plateau.
Biological records of paleoclimate and paleoenvironment changes from Guanzhong area, Shaanxi Province during the last glacial maximum
XUE Xiangxu,
XUE Xiangxu
,ZHOU Weijian (

科学通报(英文版) , 2000,
Abstract: We have collected a suite ofPaleoloxodon naumanni-Coelodonta antiquitatis fossils from a river terrace profile between Xi’an and Xianyang cities in Guanzhong Area, Shaanxi Province. A detailed examination of the fossils, together with14C determinations and pollen analyses, have enabled us to reconstruct preliminary features of climate and environment changes and their evolutionary processes, within the last glacial maximum (LGM): about 20 ka ago, the climate was basically cool and wet, and was favourable for the existence ofPaleoloxodon naumanni-Coelodonta antiquitatis fauna. This was followed by a cold, dry phase which was no longer suitable for this type of faunal suite, causing the death of a large number of mammalian assemblages. The available evidence indicates the existence of cold-dry and cool-wet climate and environment fluctuations during the LGM. The cool-wet stage within the LGM reflects a Heinrich event occurring in the high latitude areas, proving the existence of a teleconnection between polar-high latitude areas and the Loess Plateau.
近代关中种植业结构的商品化选择与隐性危机应对
Commercialization and Latent Crisis Response of Guanzhong Farming Structure Since 20th Century
 [PDF]

,,樊志民
- , 2017,
Abstract: 陕西关中是旱作农业发展最具代表性的地区,近代以来关中种植业从小农经济逐步过渡到商品化经济,在种植业结构商品化选择的过程中,既体现出社会经济的进步与发展,也存在着农业种植形势严峻、粮食供求失衡、农业生产风险递增、种植业结构优化延缓等一系列的隐性危机,分析其成因,主要源于耕地资源流失严重、农民忽视粮食作物种植、种植结构存在盲目性以及劳动力外流等因素。针对关中区域化农业种植特点,提出应发挥关中有机旱作优势、加强粮价保护机制、提高农地征用价格,有效控制非农建设用地规模以及建立粮食品种精细化产业结构等有效应对隐性危机的解决方案,以达到关中地区种植业良性发展的目标。
As the ancient capital of thirteen dynasties, Guanzhong in Shaanxi is the most representative area of agricultural development in China. Since the modern times, the farming in Guanzhong area has transited from the peasant economy to commodity economy gradually. During the commercializing process of farming structure, the social economy has been improved and developed along with a series of latent crisis and other consequences such as severe situation of farming, imbalance of grain supply, increased risk of farming and delay of farming structure optimization. The analysis of the crisis cause finds that the latent crisis mainly results from arable land loss, neglecting of farming, blind planting selection and the trends of farmer’s non-agricultural employment and concurrently industry management. In this study, based on the farming characters in Guanzhong area, effective solutions for latent crisis are proposed to protect the virtuous farming development in Guanzhong area. The solutions include utilizing the advantage of organic dryland farming in Guanzhong area, enhancing the grain price protection, raising the expropriation price of agrarian land, controlling the scale of non-farming construction and establishing a refined farming structure.
Geospatial interpolation of reference evapotranspiration (ETo) in areas with scarce data: case study in the South of Minas Gerais, Brazil  [cached]
Mateus Ricardo Nogueira Vilanova,Silvio J. C. Sim?es,Isabel C. B. Trannin
Ambiente e água : An Interdisciplinary Journal of Applied Science , 2012,
Abstract: The reference evapotranspiration is an important hydrometeorological variable; its measurement is scarce in large portions of the Brazilian territory, what demands the search for alternative methods and techniques for its quantification. In this sense, the present work investigated a method for the spatialization of the reference evapotranspiration using the geostatistical method of kriging, in regions with limited data and hydrometeorological stations. The monthly average reference evapotranspiration was calculated by the Penman-Monteith-FAO equation, based on data from three weather stations located in southern Minas Gerais (Itajubá, Lavras and Po os de Caldas), and subsequently interpolated by ordinary point kriging using the approach "calculate and interpolate." The meteorological data for a fourth station (Três Cora es) located within the area of interpolation were used to validate the reference evapotranspiration interpolated spatially. Due to the reduced number of stations and the consequent impossibility of carrying variographic analyzes, correlation coefficient (r), index of agreement (d), medium bias error (MBE), root mean square error (RMSE) and t-test were used for comparison between the calculated and interpolated reference evapotranspiration for the Três Cora es station. The results of this comparison indicated that the spatial kriging procedure, even using a few stations, allows to interpolate satisfactorily the reference evapotranspiration, therefore, it is an important tool for agricultural and hydrological applications in regions with lack of data.
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