SAFETY ANALYSIS OF WATER RESOURCES AND ECO-ENVIRONMENT IN SHIYANG RIVER BASIN

来源 :Chinese Geographical Science | 被引量 : 0次 | 上传用户:epwangke96
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the water crises occurred in the 1970s, problems caused by continuous decrease of water resources have been becoming serious year by year and eco-environment crisis occurred as a consequence. Up to now, 10 380ha of irrigated lands have been abandoned due to sand coverage and water shortage in the basin. Ground water was over exploded in Wuwei and Minqin because of water shortage. Ground water table in many places dropped under 5m (which is the ecology water table level), thus about 3000ha of Elaeagnus angustifolia forest come to dead and another 5800ha become feeble, and wind-drift sand near the oasis become alive. According to the current situation, if water utilization scope was not enlarged, a water transfer volume of 600×106m3/a from other areas will be suitable to keep water resources and eco-environment safety in the basin, and also 70×106m3/a will be left as spare water. Under this condition the water resources and eco-environment of the basin can reach the critical safety line of 2.032×109m3/a; or if 180×106m3 of water can be transferred from other areas, the water resources can reach the safety warning line of 1.732×109m3/a. The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the water crises occurred in the 1970s, problems caused by of water resources have been established serious year by year and eco-environment crisis occurred as a consequence. Up to now, 10 380ha of irrigated lands have been abandoned due to sand coverage and water shortage in the basin. Ground water was over exploded in Wuwei and Minqin because of water shortage. Ground water table in many places dropped under 5m (which is the ecology water table level), thus about 3000ha of Elaeagnus angustifolia forest come to dead and another 5800ha become feeble, and wind-drift sand near the oasis become alive. According to the current situation, if water utilization scope was not enlarged, a water transfer volume of 600 × 106m3 / a from other areas will be suitable to keep water resources and eco-environment safety in the basin, and also 70 × 106m3 / a will be left as spare water. Under this condition the water resources and eco-environment of the basin can reach the critical safety line of 2.032 × 109m3 / a ; or if 180 × 106m3 of water can be transferred from other areas, the water resources can reach the safety warning line of 1.732 × 109m3 / a.
其他文献
1989年9月22日是民主德国杰出的图书馆学家赫尔斯塔·孔策诞生80周年。为了表彰他半个多世纪献身图书馆事业所创造的功勋,学习和发扬他所倡导的学说和思想,许多国家都在出版
越南印象涌动热潮没有寒风凛冽、冰封雪飘,却有树木葱郁、花草芳菲——地处北回归线以南的越南12月初依然生机盎然。川流不息的摩托车,鳞次栉比的临街小楼,热火朝天的开发区
血清胆固醇和/或甘油三酯水平的升高常常与冠心病的发生有关,不过,脂类差异的起因,及其作为与冠心病统计学相关的基础的生理关系仍不清楚。比较那些在一次心脏病发作后幸存
历时 4年多的EUROPA ,即培哚普利在稳定型冠心病患者中降低心血管事件的欧洲试验的结果在欧洲心脏学会第 2 5届年会上正式公布。EUROPA主要是评价ACE抑制剂培哚普利减少不伴
60年代以来,放射性核素用于甲状腺功能检查,已逐步由(放射性核素)引入体内的方法发展为体外示踪法。1959年 Hamolsky 氏首先报道了体外红细胞摄取~(131)I—T_3作为甲状腺功
郑宅古镇位于浦江县东部,北依仙华山,南临浦阳江,镇内有白麟溪蜿蜒而过。郑宅因郑姓家族聚居,故而得名。北宋元符年间,郑氏三兄弟自遂安迁往白麟溪畔承恩里,成为郑氏始祖。南
29例晚期血吸虫病患者分别作了TSH、T_4、T_5放射免疫测定以及~(125)I—T_5血浆结合比值测定,其中4例患者作 TRH 兴奋试验。结果血清 T_4、TSH、~(125)I-T_5血浆结合比值以及
本文用放射免疫测定法,检测50例类风湿性关节炎患者和15例有渗出液的骨关节病患者的血清和滑膜液中铁蛋白,结果在全部滑膜液标本中均可检出铁蛋白。滑膜液中铁蛋白浓度在骨
1961年Clarke等报导第1例以来,已有许多嵌合型Down综合征被注意到。作者报告1例初孕妇所生的男孩,于孕期头3个月曾作过两次静脉肾盂撮影。分娩时疑为 Since Clarke et al r
随着科学技术的迅猛发展,人们生存的社会已不再是传统的农业社会或工业社会,而是一个崭新的信息社会。图书馆则是这个社会中收集、整理、加工和传递文献情报的信息机构,为使