Characteristics and laws of MODS coupling relation in arid zone under global change

Global change has influenced the distribution pattern and spatio-temporal changes of resources in arid zone, and has restrained the land use and land cover change, which is shown by water-heat state, landscape structure, climate effect, and human activities. The above-mentioned characteristics have a close coupling relation with the mountain-oasisdesert system （MODS）. The climate in Central Asia arid zone is warm and wet, which is different from that in northern China which takes a tendency of aridity, and the mechanism has restricted the characteristics and laws of MODS. Systematic interface characteristics and process, especially the formation, transformation and consumption laws of water resource reflect directly MODS＇s response to global change in arid zone. Spatio-temporal pattern, dynamic change, scale change and coupling mode of MODS reflect the ecology mechanism between the systems and within the systems.     

北京应主动适应干旱

北京境内有100多条河流．其中2／3水质达不到水功能规划要求，育一半以上属于连农田灌溉部不能用的劣五类水。为什么北京现在拥有官厅．密云两大巨型水库．利用了永定河水．潮白河水却越来越缺水？为了北京的可持续发展．有哪些方面是需要转变或改进的？本文作者从北京的历史，现实出发。探讨了北京的缺水现状．并提出了”北京应主动适应千旱“的论点。[编者按]     

怎样种好旱地小麦？

一、深浅轮耕。以土蓄水 深耕可打破犁底层，增加透水性和蓄水量，并能促进根系下扎和扩大根系吸收范围，提高水肥利用率。但深耕一定要因地、因时制宜，一般宜在整地早、降水多、墒情足的年份深耕，耕深22～25厘米，耕后耙实、耢平。在少雨干旱年份宜浅耕。实践证明，旱地小麦遇足墒深耕一年后，可浅耕2-3年。     

气候变化对农业生态环境的影响

近年来,人们惊呼气候出现了异常,全球很多地方80年代以来气温增高,而亚、美、非各大洲又大范围降水减少,干旱严重,农作物减产。我们所处的海滦河流域亦出现了类似现象。本文正是针对这些情况,对于气候变化对农业生态环境的影响进行初步探讨。     

西北地区的干旱环境与沙漠化

本文分析了我国西北地区的干旱环境条件、变化趋势以及河西走廊河流下游地区的沙漠化状况，提出了值得重视和进一步深入研究的干旱地区植被恢复生态机制问题以及进行沙漠化防治的对策，对于西部开发战略的实施和西部地区的生态环境建设具有一定指导意义。