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B | 这标志着广东省历史上引水流量最大、输水线路最长、建设条件最复杂、总投资最高的跨流域引调水工程进入实施阶段。

C |     Researchers from China and the UK have solved the mystery surrounding Saccorhytus coronaries – a millimeter-long spiny creature that was found in 2017 and believed to have inhabited oceans 500 million years ago. The veil of mystery over the critter persisted for years, as the scientists could not locate the creature’s anus. Turns out – they should not have even tried.,The critter was originally determined to be a member of a deuterostomes group of animals - the ancestors to the modern vertebrates (including humans). However, scientists' latest research suggests that it actually belongs to another group called ecdysozoans – the predecessors of the modern spiders and various insects. As it turned out, the whole mishap happened over the creature's anus – or rather lack thereof.,Ecdysozoans normally have an anus and hence the critter was initially ruled not to belong to them. But, upon closer discovery using x-rays, scientists saw it resembles ecdysozoans internally more than the ancestors of the vertebrates.,Like them, Saccorhytus has a large mouth and also features tiny holes around it that served as bases for spines that kept the critter anchored in one place. Those holes also served as a source of confusion as they were originally believed to be gills – another mark of the proto-vertebrates.,'Ugliest I've Ever Seen': Fisherman Shares Pic of Mysterious Creature He Found in Australia29 June, 13:17 GMT,As to Saccorhytus' absence of anus, scientists are yet to find out what happened to it. One theory suggests that there was an even earlier representative of ecdysozoans that has not been discovered, but did not have an anus.,Another theory goes that Saccorhytus did not actually need one.,"It could be that it lost it during its own evolution - perhaps it didn't need one because it could just sit in one spot with one opening for everything," Emily Carlisle, one of the researchers, said.。水利部部长李国英表示，工程建成后，将进一步优化环北部湾城市群水资源配置格局，从根本上解决粤西地区水资源短缺问题，提升区域供水安全保障能力，对支撑粤西地区经济社会发展具有十分重要的意义。广东降水丰沛，为何还会缺水？水利部珠江水利委员会副主任易越涛介绍，粤西地区特别是雷州半岛，自古以来就以干旱闻名，沿海诸河多为中小河流，自然调蓄能力弱，丰枯变化大，工程性缺水问题突出。由于地表水匮乏，导致当地工农业过度开采地下水，又造成了地面沉降等问题。水资源也因此成为影响区域发展的限制因素。建设重大引调水工程，势在必行。2013年，珠江流域综合规划获国务院批复。“环北工程建成后，可长远解决粤西地区水资源承载能力与经济发展布局不匹配问题，大幅提高区域供水安全保障能力。”水利部规划计划司副司长乔建华介绍，环北部湾广东水资源配置工程总投资606亿元，是国务院确定的今年加快推进的55项重大水利工程之一。

D | 工程从西江干流取水，通过泵站加压提水，穿过云开大山，调水至雷州半岛，输水线路约500公里，覆盖人口超1800万人。据介绍，环北部湾广东水资源配置工程主要为城乡生活和工业生产供水，兼顾农业灌溉，同时也将为改善水生态环境创造条件。“工程建成后，受水区增供水量20.79亿立方米，其中，城乡生活和工业供水14.38亿立方米，农业灌溉供水6.41亿立方米。”易越涛说。此外，工程建成后可退减超采地下水5.66亿立方米，退还被挤占的生态环境用水1.85亿立方米。从西江到粤西，既有连绵的云开大山，又有平缓的滨海平原，既要连通10座水库，又要跨越诸多中小河流，其中不乏行业性甚至世界级技术难题。“针对设计、建设、运维各阶段的重点难点，我们依靠科技创新，聚焦重大技术难题科研攻关，充分论证，编制了《环北部湾广东水资源配置工程科研纲要》。”环北工程项目设计总工程师刘元勋说。珠江流域，水网密布。多年来，各项珠江治理工作不断推进。目前，流域累计建成江海堤防2.7万多公里、各类水库1.7万多座、各类蓄水工程14万多座，流域整体防洪能力有了显著提高，水资源配置和城乡供水体系基本完善。“作为国家水网的重要组成部分，环北部湾广东水资源配置工程的建成将进一步完善珠江流域水资源调配格局。

E | ”易越涛说，接下来，将接续全力做好环北部湾广东水资源配置工程各项工作，不断完善珠江流域水网，为粤港澳大湾区高质量发展提供有力的水安全保障。（经济日报记者 吉蕾蕾）返回搜狐，查看更多责任编辑：