共查询到20条相似文献，搜索用时 144 毫秒
1.
对与水生生物生存栖息相关的河流底质、水深、水温、流速、水质等生态因子进行研究。提出水生生物的栖息地适合度模型,从生物生存栖息地影响角度对河流治理工程进行科学的评价。以长江珍稀动物中华鲟为研究对象,通过对影响中华鲟的各种生态因子的统计研究,分析整理出适宜其生存繁殖的河流水温、水深、底质、流速、含沙量及食卵鱼10个因子的临界指标,得出了这些因素的适合度曲线。发展了适合评价长江中华鲟栖息地的适合度方程,并用12组实测数据对模型进行了修改验证,提出了适合评价长江中华鲟栖息地适合度模型。 相似文献
2.
建立三维水动力学模型分析中华鲟产卵栖息地水力因子的时空分布和中华鲟产卵时的适宜水力特性,为设计最佳的生态调度方案提供科技支撑。研究结果表明,中华鲟产卵栖息地的上产卵区水深和流速的变化主要受流量影响,涡量的变化主要受地形影响;中华鲟产卵前需要高流量脉冲刺激产卵。坝下与隔流堤之间流速和涡量值的大小与波动远大于其他区域,均值为2.4 m/s和11 m2/s。产卵栖息地水体表层、中层和底层的流速和水平涡量分布格局相似,均是在上产卵区值较大,空间分布多样性高。水体中层垂向涡量的值远大于底层和表层。产卵栖息地水体表层、中层和底层水力分布特征为中华鲟繁殖提供了有利的水力条件,体现出中华鲟对产卵栖息地不同功能区的自主选择性。 相似文献
3.
4.
根据春汛期水生态系统的特点,应用河道内流量增量法,选用二维河流模型River2D,建立栖息地与流量变化的动态关系,进而应用Mann-Kendall方法,开发基于栖息地突变分析的生态需水阈值模型。以第二松花江支流辉发河五道沟断面附近河段为例,选择松花江流域分布较为广泛的鲤鱼作为对象物种,以流速和水深两个因素表征鱼类栖息地,利用1956～2000年45年的春汛期月径流资料,判定鱼类栖息地在1970年开始发生了突变。在突变前加权可用面积95%的置信区间范围为275.5～915.7m2/km,对应的流量范围为58.8～121.1m3/s,并将其作为研究区春汛期间的生态需水阈值。春汛发生在冰封期刚刚结束的时段,适宜的春汛期生态需水能够提高生态系统多样性,对于鱼类等水生生物乃至于整个生态系统都有重要的生态意义。 相似文献
5.
结合物理栖息地模拟模型的水力学与栖息地模型,以黄河干流兰州-石嘴山河段为研究样区及该河段的关键鱼种黄河鲤鱼为对象物种,以流速及水深二水力学因子进行研究,推求该研究样区兰州、安宁渡、下河沿、青铜峡和石嘴山五断面对象物种的流量与权重可使用面积的关系。通过对上述各断面1975-1985年汛前共11年生态、水文及断面资料的分析计算,归纳出研究断面汛前适合的生态流量分别为195、220、220、220、175 m3/s,计算结果在Tennant法界定的生态流量范围之内。 相似文献
6.
河流景观生态学已成为河流科学研究与应用的新范式,但国内研究还颇为不足。从河流景观生态学发展的逻辑必然性、主要进程、基本内容与重要理论等方面进行了总结。结果显示,多尺度跨学科整体论河流认识要求和景观尺度上处理河流问题的实践需求共同推动河流景观生态学的迅速发展,其中心议题是河流物理景观系统与生物系统在不同等级尺度上的结构、格局与功能过程,尤其重视物理景观与不同等级生物系统的相互作用关系,对河流景观多尺度等级性、高动态性和有向性等突出性质的认识已取得重要理论发展。指出当前面临5个方面的核心议题亟需取得突破:改进和统一河流景观分类系统、河流景观跨尺度研究、河流景观方法对经典河流生态理论的再认识、河流景观机理与模拟、河流景观对气候变化与区域土地利用/覆被变化的响应研究。 相似文献
7.
8.
9.
针对拟建鄱阳湖水利枢纽工程对地下水影响问题,选择赣江三角洲为代表区,采用资料收集、野外调查、统计分析和数值模拟等方法进行研究。依据地质钻探资料、地下水与河流动态关系、区域数字高程模型,结合鄱阳湖历史形成与演化过程确定研究区边界条件,运用GMS模拟软件建立了研究区地下水三维运动模型。依据推荐的枢纽调度方案,利用数值模型计算枢纽运行后对地下水运动影响的时空变化规律。结果表明:枯水年份影响大,距离河流、坝址近的地方影响大,反之亦然。影响幅度范围0~2m,地下水径流交替因此减弱,丰水年份土壤潜育化面积增加9.3%。 相似文献
10.
在总结水生态屏障研究历程的基础上,对水生态屏障的概念进行了探讨,提出了水生态屏障的定义。从河流、湖泊、水库3种主要水生态屏障类型说明水生态屏障的主要功能及适宜宽度研究进展,并从生态学、水文学、地理学、遥感学的技术应用评述了水生态屏障宽度的界定方法。目前,对水生态屏障适宜宽度的标准还缺乏统一的认识,流域尺度下水库生态屏障适宜宽度的界定是水生态屏障宽度界定面临的难点问题,提出综合水文学、生态学、环境科学及地形、遥感、地理信息等多学科理论及技术手段构建流域尺度的生态水文模型是界定水生态屏障及其水库生态屏障适宜宽度的有效方法。 相似文献
11.
12.
Assessment of ecological flow rate by flow duration and environmental management class in the Geum River, Korea 总被引：1，自引：1，他引：0
This study attempted to analyze flow duration in a basin using a method to estimate environmental flow developed by the International Water Management Institute, and simulate the effects of runoff characteristics unique to a river and flow variability due to basin developments on aquatic ecosystems. To do so, KModSim, a simulation model for basin-wide water distribution, was used to assess flow duration in the Geum River basin, one of the four major river basins in Korea, by environmental management class (EMC). Flow duration curves by EMC at Sutong and Gongju sites were derived on the basis of natural flow in the Geum River basin. As a result, they were found to be consistent with the results of previous studies. Time series of mean monthly flow data by EMC were plotted together with those of simulated flow data by reservoir operation scenario; Sutong and Gongju points both showed flow behaviors corresponding almost to “A” in EMC. In addition, the characteristics of habitats by species of fish were identified through monitoring fish habitat at the Sutong site, so that optimal ecological flow rate was estimated. For this purpose, relations between flow discharge and weighted usable area for Coreoleuciscus splendidus and Pseudopungtungia nigra were projected using physical habitat simulation system, and EMCs consistent with flow duration curves (estimated taking in-stream flow) were assessed. The results or findings reported in this study are expected to serve as basic data for making a plan to efficiently monitor and manage aquatic ecosystems in the Geum River basin. 相似文献
13.
对水流模拟的发展历史进行了总结,指出阻碍水流模拟发展的主要问题,提出克服这些瓶颈问题的方法是将智能科学与水利科学交叉融合,实现水流的智能模拟。据此,介绍了水流智能模型理论,结合遗传算法、模糊逻辑、元胞自动机、混沌分析理论、人工神经网络、专家系统、数据挖掘等智能理论和技术,对水流智能模拟的实现途径作了探讨,并指出建造一个优秀的水流模拟智能系统的关键是联合运用各种智能方法,认为智能化是当前水流模拟发展的新方向,水流智能模型将是水利科学的一种新的研究途径,并将在研究水流问题上具有广阔的应用前景。 相似文献
14.
15.
Yang Yang Zhonghua Wang Xuelian Wang Changsen Zhao Chunbin Zhang Tianli Pan 《地球科学进展》2020,35(5):513-522
With the socio-economic development, water demand has increased, resulting in river environment flow often not being met. As an important indicator of river ecosystem, environment flow plays a key role in maintaining the sustainability of the ecosystem. This study fully considered the biological needs of river ecosystems, used food web models (Ecopath) to identify key species of fish, determined the ecological flow velocity, combined the river sections, and used the Adapted Ecological Hydraulic Radius Method (AEHRA) to calculate the environment flow. Based on the calculation results of the environment flow, the River2D model was used to simulate the river flow, and the environment flow satisfaction rate of the river was calculated. The calculation results show that the environment flow of each river in the flood season can be satisfied, and the environment flow of most rivers in the non-flood season cannot be satisfied, and the satisfaction rate is extremely low, which causes the ecosystem health to be destroyed. Therefore, ecological regulation of rivers during non-flood seasons should be strengthened to meet river environment flow. The new method for calculating the environment flow of the river provided in this paper can provide a method for aquatic ecological restoration, and the research results can provide important scientific basis for the aquatic ecological restoration and management of rivers in Jinan. 相似文献
16.
E. H. Imam S. A. El Baradei 《International Journal of Environmental Science and Technology》2009,6(2):315-324
This research studies the impact of water level control structures on self-assimilative capacity of rivers and on fish habitat. Constructing a water level control structure in a river reach will alter its hydraulics as well as its water quality, thermal regime and fish habitat. A mathematical model is developed to simulate river hydraulics, water quality, temperature and fish habitat. Diurnal dissolved oxygen concentrations are investigated to show their impact on fish. A case of a Nile River reach was studied to investigate the impact of the existence of the Esna barrage on the water quality and fish in its upstream reach. The barrage has negative impacts on the upstream self-assimilative capacity of the rivers. The waste load that the river could absorb was only 54 % (at low flow) and 78 % (at high flow) of the entire load if no barrage was present. Including in the simulation of the effects of photosynthesis and respiration, the above mentioned percentages were raised to 54 % and 91 %, respectively. Although water level control structures have negative impacts on the upstream self-assimilative capacity of the rivers, they have positive effect on downstream dissolved oxygen concentrations due to reaeration that happens across them. Downstream dissolved oxygen concentration increased by 6 % from its upstream concentration value. The barrage has a positive effect on fish habitat in the upstream section. The weighted usable area of Tilapia fish is doubled in case of barrage existence. The barrage causes a slight decrease in water temperature that reaches an average of 0.13 degree in the month of June. 相似文献
17.
18.
河道潜流带是河水与地下水交互作用的关键过渡区,具有高度的动态性和敏感性,频繁的水力交换易引发其内部的生物地球化学反应,并对河流生态安全产生重要影响。为提高河道潜流交换水动力监测结果的真实性和有效性,介绍渗流、水压、溶质、温度等监测方法及其适用性,归纳河床和河岸的监测点布设参数和不同监测手段的数据采集频率,系统总结河段、河床及河岸的潜流交换理论与计算方法,探讨导致潜流监测结果不确定的因素。针对现有监测方法的不足和未来研究的发展方向,提出今后需加强多方法联合监测和多技术集成的应用,开展河岸侧向潜流监测及不确定性分析等工作,为潜流带水文-生物地球化学过程耦合机制研究提供可靠数据。 相似文献
19.
随着对地卫星遥感技术的发展,微波遥感监测为径流模拟提供了新途径。目前,基于被动微波遥感亮度温度的河道径流模拟方法亟待深入探索。本文基于M/C信号法,利用新一代高精度被动微波亮温数据集在中国典型流域进行河道径流模拟,探讨该方法的适用性,分析断面河宽、平均流量、控制面积、植被覆盖度、高程、土地覆盖/利用类型、气候类型等地形地貌和水文气象因素对模拟效果的影响。结果表明:在中国七大流域61个典型站点中,决定系数R2 ≥ 0.5的站点占比超过59.0%,41.0%的站点纳什效率系数ENS ≥ 0.5;位于西南诸河流域的站点模拟效果最佳,尤其在青藏高原地区;高程、平均流量、气候类型以及断面河宽是影响模拟效果的主要因素;站点位于高原山地气候下的小型河流一般模拟效果更佳,本文方法相对更适用。研究成果可为河道径流模拟提供研究思路,为微波遥感的水文应用提供切实指导。 相似文献