【作者】 张晓伟；

【导师】 沈冰； 莫淑红；

【作者基本信息】 西安理工大学 ， 水文学及水资源， 2006， 硕士

【摘要】 石羊河流域是河西走廊三大内陆河流域之一。由于水资源过度开发,形成中游经济发展挤占下游用水,下游发展依赖超采地下水,因而造成地下水位持续大幅度下降,导致水质恶化、植被退化、土地沙化、绿洲萎缩等,这些都直接威胁着绿洲的存亡。石羊河流域已成为西北地区生态环境退化的典型。因此分析石羊河流域水资源现状,寻求水资源合理利用模式和外调水规模,这对石羊河流域的经济发展有着重要的现实意义,同时也为中央和各级地方政府制定河西走廊及西北地区战略方针提供科学依据。本论文结合实际生产课题,通过分析得出以下主要结论和认识:(1)根据石羊河流域存在的主要问题,选择民勤红崖山灌区和金昌市作为外调水的受水区。(2)流域出山口径流年际变化不大,出山径流存在减少趋势且具有持续性。出山口各条河流分别具有22年、14年、10年等周期。基于组合预测的思想将灰色理论、自记忆模型、BP神经网络相结合对受水区供水系统年径流进行拟合,结果较为理想。同时对供水系统不同水平的年径流进行了预测。(3)建立了人口预测的GM(1,1)模型。(4)对受水区生态需水量进行了计算,得出:民勤红崖山灌区生态需水量为1.93×108m3,金昌市灌区为0.068×108m3。同时汇总了受水区不同水平年的需水量与供水量。(5)根据受水区高、中、低线不同发展水平,按照基本节水定额和强化节水定额进行水资源供需平衡分析,建议:2010年民勤红崖山灌区按照强化节水定额采取低线发展,金昌市灌区采取低线发展,市区采取中线发展方案,这样受水区水资源量,供需基本平衡。2020年受水区应采取强化节水定额低线发展,需外调水量为5.71×108m3,其中民勤灌区为3.637×108m3,金昌市为2.073×108m3。(6)对受水区不同水平年适宜规模进行了计算,表明在有外调水的情况下,民勤红崖山灌区通过退耕保持耕地灌溉面积60万亩,在适宜的发展规模之内,对于金昌市灌区,规划中规划的65.36万亩灌溉耕地面积也在适宜的规模,但由于其林草所占比例过小,建议再退耕3.36万亩,还林还草,使其保持在适宜的发展规模之内。如果没有外调水,2020年民勤红崖山灌区水资源量,将不能维持绿洲现有规模及经济水平;金昌市灌区则需退耕7.6万亩,才能保障灌区现有农业经济水平。更多还原

【Abstract】 The Shiyang River basin is one of three big inland river basins in Hexi Corridor, Gansu. Because of overdevelopment of water resources, vicious circle was resulted, which appear as the development on middle reaches occupies the downstream water, the downstream development occupies the ecology water, the conflict of supply and demand is severe day by day. The groundwater is over exploited seriously in Minqin, which brings about decline of water table continuously and causes water quality deterioration, the vegetation degenerates, the land desertification and the oasis shrinks. The survival of Minqin oasis has been threatened. The Shiyang River Basin has become the typical region of ecological environment degenerates in Northwest China. Therefore, it is of practical significance to analyze present situation of water resources in Shiyang River Basin, to seek the reasonable used pattern and water diversion quantity from other watersheds. At the same time, it also provides the scientific basis for the central and all levels of local authority to make strategic policy for Hexi Corridor, Gansu and for northwest China. The main conclusions and understands through analysis were obtained by the study, as follows:(1) According to the existed problems in the Shiyanghe River Basin, the Minqin Hongyashan irrigation district and Jinchang city were selected as reception area.(2) The annual runoff at mountain-pass gauging stations does not change acutely, but have remarkable reduction tendency and persistence. The rivers have the 22 year, 14 year, 10 year, and 9 years periods separately. Based on the combination forecast thought, the grey theory, self-memory model and the BP neural network were used to predict the annual runoff of the water supply system, the result is rather ideal.(3) The GM(1,1) model was established to predict the population increase.(4) The ecological water requirement in the reception region was obtained: the ecological water requirement in Minqin Hongyashan irrigation district is 1.93×108m3 and the Jinchang irrigation district is 0.068×108m3. And the total water demand and supply at different water years were sum up.(5) Based on development of higher, middle, lower level in the reception region, andaccording to the basic and intensified quota of the water saving, the balance of water supply and demand were analyzed. Based on the analysis, it was suggested that in 2010, Minqin Hongyashan irrigation district adopt the lower level of development according to intensified water saving quota, and also the Jinchang irrigation district, the urban district adopt the median level of development, and such the reception region water balance of supply and demand would be retained. In 2020, if the reception regions adopt intensified water saving quota and lower level of development, they would need the quantity of water diversion from other watersheds of 5.71×108m3, of which Minchin irrigation district 3.637×108m3, Jinchang 2.073×108m3.(6) Based on calculation of suitable scale of reception region, it was indicated that 60×104 mu irrigated farmland in Minqin Hongyashan irrigation district would be suitable. And in Jinchang irrigation district 65.36×104 mu irrigated farmland is suitable, but the proportion of forestry and grass land is too low, and it was suggested that it had better return 3.36×104 mu farmland to forestry and grass land for making the reception region in the suitable scale. If there is no water diverted into the area, it would not be maintain the existed scale and economic development level due to short of water for the Minqin Hongyashan irrigation district. The Jinchang irrigation district would return 7.6×104 of farmland into grassland, in order to keep the agro-economy maintaining the existed economic level as nowadays.更多还原