气候变化下长江中下游水稻灌溉需水量时空变化特征   总被引：12，自引：0，他引：12       下载免费PDF全文

王卫光  彭世彰  孙风朝  邢万秋  罗玉峰  徐俊增 《水科学进展》2012,23(5):656-664

选择长江中下游单季中稻为研究对象,结合45个气象站1961~2010年逐日气象资料,基于统计降尺度模型(SDSM),生成HadCM3气候模式A2和B2两种情景下各站点参考作物腾发量和降水数据。基于联合国粮食及农业组织(FAO)推荐的作物系数法,并考虑有效性降雨和不同地区深层渗漏量,分析历史和未来的水稻灌溉需水时空变化特征。结果表明:过去50年,除了太湖流域以外的长江中下游大部分区域的参考作物腾发量和水稻需水量都呈显著下降趋势,而显著下降的水稻灌溉需水量主要位于鄱阳湖流域;未来两种情景下,参考作物腾发量、水稻需水量和水稻灌溉需水量均值都呈下降趋势,但水稻灌溉需水量降幅最小;水稻需水量和水稻灌溉需水量在长江中下游地区的变化趋势具有明显的空间异质性,水稻需水量大幅减少的区域由太湖流域向汉江和洞庭湖流域扩展。未来水稻灌溉需水量减少的区域主要分布在太湖流域、汉江流域东部和洞庭湖流域北部,并随时间推移呈扩大趋势。  相似文献   

用应用需求数据库评估卫星观测能力     

黄富祥  董超华  张文建 《气象科技》2007,35(1):119-122

卫星应用需求分析是气象卫星规划和研制十分关键的第一步。为了搞好21世纪的全球气象卫星发展规划,WMO和CEOS从1996年开始征集全球对地观测卫星的应用需求和建立卫星需求数据库,创立了国际通行的RRR程序方法,建立了全球对地观测卫星应用需求数据库。文章介绍了WMO/CEOS卫星应用需求数据库的RRR程序方法和数据库的部分内容,着重介绍和评述了建立卫星应用需求数据库以及基于卫星需求数据库进行卫星观测能力定量评估的方法,为中国气象卫星应用需求数据库的建设创造有利条件。  相似文献   

黑龙江省基础测绘需求的预测分析     

王威  唐艳丽  李蔚  刘铁健 《地理信息世界》2000,(3)

基础测绘工作有着广泛的社会需求，其需求量与国民经济建设发展密切相关，某些基础测绘产品已进入衰退期，应采取及时推出新产品策略。  相似文献   

Using hydrologic and hydraulically derived geometric parameters of perennial rivers to determine minimum water requirements of ecological habitats (case study: Mazandaran Sea Basin—Iran)     

Alireza Shokoohi  Yang Hong 《水文研究》2011,25(22):3490-3498

This paper studies one of the most important problems of dry countries that are confronted with water deficit and the competition of rivals to allocate water. Some common methods have been investigated for computing the minimum water requirement to save a river's biological activity. After a discussion of the currently used method in Iran (the Tenant Method), the application of some other methods, which are known as Hydraulic and Hydrological Methods, is illustrated. The case study is a river in the northern part of Iran and this research addresses the critical situation of this river in near future regarding the planned anthropogenic alteration and its consequences. It has been shown that the application of environmental water allocation methods that have no background in a region could be misleading. The first proposed method is the Texas Method, in which flexibility in water allocation helps to develop an integrated river management paradigm in the study area. The second preferred method is a Hydraulic Method, by which the implementation of morphological parameters or flow geometrical properties could sustain physical habitat within an acceptable range in terms of depth, width, velocity, and bed shear stress. In the case study, the Maximum Curvature Method was superior to the Slope Method. The investigation revealed that using a widely recommended slope of 1 for the discharge‐wetted perimeter function can lead to an overestimated and unacceptable discharge. The Tenant Method in respect to minimum environmental flow requirement yielded the weakest result, and it has been illustrated that its application might impose irrecoverable shock to the ecosystem. The Flow Duration Curve Method (the Q₉₅ Method), in spite of its subjectivity, showed more compatibility with the river's condition in comparison with the Tenant Method. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

1971—2010年气候变化对河南省主要作物需水量的影响     

周迎平  胡正华  崔海羚  陈书涛  师丽魁 《南京气象学院学报》2013,5(6):515-521

以小麦、玉米、棉花、花生等主要农作物为研究对象,选取河南省12个气象站点1971—2010年的气象资料,采用联合国粮农组织（FAO）推荐的Penman-Monteith公式计算参考作物生育期内需水量,分析其生育期需水量变化规律.结果表明：河南省多个地区需水量的年内分布,都在6月达到全年的最高值,在11或12月降至全年的最低值;需水量最大的是棉花,其次是小麦、花生和玉米;近40年,棉花、小麦、花生和玉米的需水量都表现为减少趋势.通过分析各气象因子与需水量的相关性发现：平均风速与作物需水量显著正相关,由于平均风速大幅下降,从而在很大程度上抵消了因其他气象因子变化引起的需水量增加趋势,造成主要作物生育期需水量的减少.  相似文献   

钉镶首饰的设计与Rhino建模技法     

周汉利 《地质科学译丛》2011,(4):53-60

Rhino是一款功能强大的专业三维造型设计软件,广泛地应用于各种行业的设计领域。在珠宝首饰设计方面,国外应用Rhino设计珠宝首饰已较普遍,在我国的应用则处于发展初期。因此,研究和介绍Rhino设计珠宝首饰的技法,对于普及Rhino在我国珠宝首饰设计中的应用具有重要的意义。根据对Rhino在珠宝首饰设计中的应用研究体会,以设计精度要求很高的钉镶首饰为例,介绍了钉镶首饰的结构和设计要求,并结合两种简单典型的钉镶首饰模型实例,详细讲解采用Rhino进行精确的钉镶首饰设计的建模技法,供珠宝首饰设计人员和学习者参考。  相似文献   

Studies on the phosphorus requirement and proper calcium/phosphorus ratio in the diet of the black sea bream (Sparus macrocephalus)     

Liu Jingke  Li Maotang  Wang Keling  Wang Xincheng  Liu Jianking 《中国海洋湖沼学报》1993,11(2):130-134

An expriment on the phosphorus requirement and the proper Ca/P ratio in the diet of the black sea bream using the phosphorus gradient method (with casein as basic diet, sodium dihydrogen phosphate as source of phosphorus, and calcium lactate as source of calcium) showed that growth was greatly affected by the diet's phosphorus content and Ca/P ratio. Inadequate phosphorus in the diet resulted in slow growth and poor food conversion ratio (FCR). Analyses of the fish body showed it contained a high level of lipid but a low level of moisture, ash, calcium and phosphorus. The optimal values of phosphorus and Ca/P ratio in the black sea bream diet are 0.68% and 1∶2 respectively. Phosphorus in excess of this optimum value resulted in slow growth or even death. The results of this experiment clearly indicated that phosphorus is the principal mineral additive affecting black sea bream growth. Contribution No. 1972 from the Institute of Oceanology, Academia Sinica.  相似文献   

SELENIUM REQUIREMENT OF SHRIMP PENAEUS CHINENSIS     

田玉川  刘发义 《中国海洋湖沼学报》1993,11(3):249-253

Penaeus chinensis were reared in fibreglass tanks for the study of their selenium requirements. The shrimp were fed semipurified diets containing graded levels of selenium, and weight gains, activities of glutathione peroxidase (GSH-Px) and selenium contents in muscle and hepatopancreas were determined. Weight gain and GSH-Px activity were the highest when the shrimp were fed diet containing 20 mg/kg selenium; Good linear correlation was found between GSH-Px activities and selenium contents in the diets, and the number of healthy shrimp. The experiment showed that 20 mg/kg selenium in the diet is optimal for the shrimp and that GSH-Px activity can be an important biochemical index of the selenium nutrition status of the animal.  相似文献   

地震信息网自适应网络安全技术模型研究   总被引：1，自引：0，他引：1  

刘云华  刘治  单新建  李卫东 《地震研究》2011,34(1):96-101

对地震信息网存在的一些安全隐患做了初步调研,在此基础上,提出了自适应网络安全模型及法规、技术和管理三种因素相互配合的防御体系,使网络安全以合理代价控制在可以接受的范围内.  相似文献   

GIS数据应用体系框架研究     

刘瑜  徐爱锋  张洪艳 《测绘与空间地理信息》2011,34(2):157-158,161

当前的理信息系统(Geographic Information System,GIS)数据应用体系框架在数据更新、数据与需求一致性、数据质量保证等方面存在不少实际问题,在分析上述问题的基础上,探讨了具体的解决方法,构建了完整的GIS数据应用体系框架,为GIS工程建设和运行提供了理论依据和更具操作性的实践经验.  相似文献