干旱地区

Zinc deficiency and drought are two major factors limiting crop growth and development in calcareous soils of North China.

我国北方地区石灰性土壤上缺锌与干旱限制因子同时存在，影响作物生长和产量提高。

When it rains in the Petén, mosquitoes swarm in such clouds that today's Maya have to drive them away with greasy smoke from torches burning cohune palm nuts. In the dry season, the heat bakes the swampy bajos , or bottomlands, the rivers fall, and drought threatens.

佩滕地区一旦下雨，蚊子便如鸟云般成群涌现，现在的玛雅人就必须以火炬燃烧羽叶棕榈果实，用带油脂的烟驱赶它们，到了干季，热气炙烤着遍布沼泽的洼地；河川水位降低，干旱随时会降临。

Images of deglaciation, thawing tundra, coastal inundation, early bloom, drought, and dying coral bring the headlines on global warming to life. Images are available on global change themes in Antarctica, Alaska, coastlines, England, oceans, polar thaw, temperate zone, tropics, and weather. Copyright notices are conspicuously posted.

"全球变暖观察"是美国蓝色地球联盟的一个研究项目，该网站提供了有关全球变暖的图片和说明，包括冰川消退、苔原消失、海平面上升、干旱、珊瑚死亡等，这些图片通过不同的专题保存，比如地区、事件、温度带等。

But most people reckon that the most likely explanation is that it was started by natural causes. For Southern California is an arid, desert landscape that was almost uninhabited for centuries.

但是大多数人认为大火最可能是自然燃起的，因为几百年来南加利福尼亚就是一片干旱而又几乎无人居住的沙漠地区。

First, select four kinds of main risks source from bigly celebrate the main risk in region source, namely the flood, drought, sand-dust weather and petroleum pollution accident, etc. According to the different a request for to habitat, study this 19 kinds of landscapes ecosystem type of the Regional induce for 7 kinds of ecosystems system: Then the marsh of bulrush, lakes and reservoirs , salt alkali wasteland, prairie, island form wood, farmland, town. The difference is proceeded by characteristic according to each type ecosystem to the analysis of four kinds of main risks source, including the certain risk all rate, delimiting the space distribute, analyzing the risk strength to the receptor etc. At proceed the revelation the different from endanger to analyze the inside, this text borrows ecosystem index number that this index sign to reflect primarily habitat the ecosystem meaning of the type of habitat the different from position, with weak an index number to show the destructibility of the habitat, from but compute each ecosystem that is lost by ecosystem system an index number.

首先，从大庆地区主要的风险源中遴选出四种主要的风险源，即洪涝、干旱、沙尘天气和石油污染等；依据不同生物类群对生境的要求，将本研究区域的19种景观生态类型归纳为7种生态系统：即芦苇沼泽、湖泡库渠、盐碱荒地、草甸草原、岛状林、农田、城镇；对四种主要风险源的进行分析，包括确定风险概率，划定空间分布，对风险受体的作用强度分析等；在进行暴露和危害分析中，本文主要借生态指数这一指标来反映不同生境类型的生态意义和地位，以脆弱度指数来体现不同生境的易损性，从而计算出各受体生态系统的生态损失度指数；由于各主要风险物质对风险受体的作用强度是不同的，对形成区域性生态风险的作用大小也有差异，因此本文采用层次分析法对主要生态风险物质进行综合评价，并把判断矩阵排序权值的合理计算问题归为—非线性化问题，并提出用基于遗传算法(GA[5])的层次分析模型进行权重分析；进行风险表征，即综合前面两个阶段的信息，对环境中风险的性质和强度以及风险评价过程中不确定性问题进行分析与描述，并划分出五级生态风险区；最后，根据划分的五级生态风险区的特征，分别提出针对各生态风险区的生态风险管理对策。

In some cases disease and drought have decimated livestock numbers which has constrained the use of draft animal s.

在某些地区，疾病和干旱导致牲畜成批死亡，限制了畜力的使用。

In the interior, and even in parts of the temperate south-east - inland from the Great Dividing Range - droughts are commonplace, and years can pass without a drop of rain.

在内陆，甚至在气候温和的东南部部分地区，干旱非常普遍，有时几年都不下一滴雨。

And scientists concerned about climate change believe it will cause more drought in many areas in the future.

和科学家关注气候变化相信这将造成更多的干旱，许多地区在未来的。

Parts of China are suffering their worst drought in 50 years.

中国的一些地区正在面临着50年来最严重的干旱。

It is important to reseach the precipitation series and the drought forecasting of this area.

因此，对该地区降水序列的研究以及对干旱的预测尤显重要。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐