【作者】 李静；

【导师】 桑广书；

【作者基本信息】 浙江师范大学 ， 自然地理学， 2010， 硕士

【摘要】 黑河流域地处西北干旱内陆区,生态环境脆弱。近几十年来,随着人口的增加和社会经济的快速发展,流域生态环境退化严重。为了能够有效治理流域生态环境,需要对生态环境的历史演变进行研究,以找到其演变规律。因此,本文通过查阅大量历史文献和考古资料,结合流域各大水文站、气象站数据和统计资料,从水资源、绿洲、城镇聚落和人口演变四个方面研究了黑河流域生态环境的历史演变过程及演变规律,并据此为黑河流域生态环境治理及可持续发展提出建议。(1)水资源是黑河流域人类生存、发展的命脉,是导致流域生态环境演变的主要动力。自西汉以来,流域水资源由河流沿岸及下游三角洲逐渐向其四周、甚至向上游山区转移,由自然水系向人工水系转移。时间上,两汉、南北朝、唐朝中后期、元朝后期和明朝中期,流域水资源较丰富；魏晋、南北朝后期至初唐、五代十国、元朝前期和明朝前期,流域水资源较匮乏；宋朝、清朝及20世纪水资源量接近多年平均值。(2)作为黑河流域人民生存和发展的场所,绿洲的演变是流域生态环境演变的重要反映。流域绿洲发展的兴盛期主要集中在汉、魏晋、唐中叶、西夏时期以及明清以来,其他时期虽然也有发展,但总体上属于绿洲退缩期。空间上,流域绿洲最早出现于下游三角洲上,西汉以后溯源上迁,稳定于中上游的冲积、洪积扇平原,明清以来逐渐向上游地带转移,20世纪以后新绿洲出现,并不断扩大,最终连接成绿洲带,呈现出向流域四周放射扩大的趋势。(3)城镇聚落是黑河流域社会经济发展的产物,其兴起、发展及衰亡过程是流域生态环境演变的直接表现。流域城镇聚落建设发展的兴盛期主要集中于汉唐,衰落期主要集中于东汉末期、唐朝中后期,改革开放以后是流域城镇内部结构及规模发生变化的主要时期。空间上,流域城镇聚落最早形成发展于流域下游古居延绿洲上,经历了由河流下游向中上游发展的过程,并最终稳定于河流冲积洪积扇的中上部,形成今天的城镇分布格局。(4)人类活动是影响黑河流域生态环境演变的重要因素之一,人口数量是衡量黑河流域人类活动强度的重要指标。黑河流域在清朝以前人口密度一直都未突破干旱区发生沙漠化的人口“临界指标”,人类活动对生态环境荒漠化过程的影响较弱。自清朝中期以后至今,流域人口激增,超过了“临界指标”,人类活动加强,对流域生态环境的变化起到主导作用。(5)黑河流域生态环境演变主要表现为向绿洲化和荒漠化两个相反方向演变。西汉时期、隋朝前期和唐朝“安史之乱”之前,流域生态环境演变趋向绿洲化。东汉末期、魏晋南北朝时期、隋朝末期及唐朝“安史之乱”以后直至现在,流域生态环境演变趋向荒漠化,且荒漠化程度、范围逐渐扩大。空间上,流域生态环境的荒漠化趋势演变最早出现在下游天然绿洲上,然后逐渐向中游蔓延,最后扩散到流域上游山区地区,最终导致整个流域生态环境趋向荒漠化。(6)基于对黑河流域生态环境演变过程及演变规律的研究,提出黑河流域应保证流域水源区生态环境不遭到破坏、提高中下游水资源利用率,保护天然绿洲、调整流域产业结构,加快城市化进程和限制流域人口增长速度等建议,以改善流域生态环境并实现生态环境可持续发展。更多还原

【Abstract】 The Heihe River Basin located in northwest arid inland areas. Its ecological environment is fragile. With the increase of population and the rapid development of social economy, its ecological environment degenerated seriously in recent several decades. In order to effectively control the ecological environment, to study the historical evolution of the ecological environment and to find the rule of ecological environment evolution is necessary. Consequently, the paper studies about the historical evolution process and the evolution rule of Heihe River Basin’s ecological environment by consulting a large number of historical documents and archaeological materials, in combination with the hydrological and meteorological data. The study includes four aspects:water evolution, oasis evolution, towns and villages evolution and population evolution. The paper proposes suggestions for the sustainable development of ecological environment, according to the ecological environment evolution rule.(1) As the lifeblood of human survival and development, water is the main force to cause ecological environment evolution. Since the Han Dynasty, the water transferred along the river to the around, transferred from downstream delta to upstream mountains and transferred from natural water system to artificial water system. Water resource is rich during the Han Dynasty, the Northern and Southern Dynasties, the mid-late of Tang Dynasty, the late Yuan Dynasty and the middle of Ming Dynasty. It is scarce during the Wei and Jin Dynasties, the late Northern and Southern Dynasties, the early Tang Dynasty, the Five Dynasties, the early Yuan Dynasty and the early Ming Dynasty. It is close to the average during the Song Dynasty, the Qing Dynasty and the 20th century. (2) As the place of human survival and development, the evolution of oases is an important reaction to the ecological environment evolution. The prosperous period of oasis development is mainly focus on the Han Dynasty, the Wei and Jin Dynasties, the middle of Tang Dynasty, the Xixia Dynasty and since the Ming and Qing Dynasties. Oasis first appeared in the downstream delta, and then traced on the move and stayed in the alluvial fan and plains in the upper reaches of Heihe River since the Han Dynasty, gradually transferred to the upstream areas since the Ming and Qing Dynasties. Since the 20th century emerged new oasis, it expands unceasingly and finally connects into oasis belt. At last, oasis shows an expanding trend around the watershed.(3) Urban settlement is the product of socio-economic development of Heihe River Basin, its emergence, development and decline process is the direct manifestation of ecological environmental evolution. The prosperous period of urban settlements development mainly concentrated in the Han and Tang Dynasties, the decline period mainly concentrated in the late of Han Dynasty and the mid-late of Tang Dynasty. Since the reform and opening up, the internal structure of urban changed gradually. The urban settlements first appeared and developed on the Juyan ancient oasis in the downstream of Heihe River Basin, then developed from the downstream to the upstream, finally stable developed in the upper part of the alluvial fan and formed today’s urban distribution pattern.(4) The population is an important indicator to measure the intensity of human activity in Heihe River Basin. Before the Qing Dynasty, the population density has not beyond the "critical index" which can cause desertification in arid desert. The influence of human activities on the ecological environment desertification is weak. Since the mid-Qing Dynasty, the population density has beyond the "critical index", so human activities play a leading role to ecological environment change.(5) Desertification and oasis are two main behave of ecological environment evolution of the Heihe River Basin. Ecological environment evolution is trend to oasis during the Han Dynasty, the early Sui Dynasty and before the "Anshi War". Ecological environment evolution is trend to desertification during the late of Han Dynasty, the Wei and Jin Dynasties, the Northern and Southern Dynasties, the late of the Sui Dynasty and after the "Anshi War", and desertification degree and scope expand gradually. In the space, desertification first appeared on the natural oases in the downstream, then spread to the middle gradually, finally spread to upstream mountainous areas. As a result, it caused desertification in the whole basin.(6) Based on the thorough analysis about the rule of ecological environment evolution of the Heihe River Basin, the paper proposes suggestions for the sustainable development of ecological environment. The Heihe River Basin should protect the ecological environment in the upstream, should improve the utilization efficiency of water resources and protect the artificial oases while expanding the natural oases, should accelerate urbanization by adjusting the industrial structure, should limit the population growth rate, and so on.更多还原