摘要
以生态目标的确定为基础,通过建立目标参数与径流间的关系计算得到河道生态环境需水量.其中生态目标由关键期生态目标和时间变化目标2部分组成.考虑不同功能生态环境需水量间的兼容性,以最高等级为标准确定关键期生态目标.采用河道多年平均天然径流量年内时间变化率作为生态环境需水量时间变化目标.海河流域永定河官厅水库下游河道计算中,以生态、生产需水矛盾最突出的4月生物繁殖初始时期对流速的要求作为关键期生态目标,根据河道断面实测资料确定目标参数与径流间的关系.计算结果表明,最小、适宜以及理想等级年度生态环境需水量分别为1.56×108m3,5.97×108m3和11.02×108m3,分别占河道天然径流量的7.19%,27.51%和50.78%,年内汛期8月及春季生物繁殖期(4月～6月)需水量需分别达到年度总量的20%.
Based on the identifying the ecological objectives, environmental flows in river reaches is calculated after the relation between parameters of objectives, and river discharges is determined. The ecological objectives are determined in a two step process： the objective will be determined for the critical period of the year, then the temporal variation will be defined. Considering the compatibility between the different kinds of environmental flow requirements, the strictest objective is settled to be the ecological objectives for the critical period of the year. The temporal variation of the natural river discharge monthly is settled to be the temporal variation of ecological objectives. In the studies of the environmental flows in the river reaches downstream for Guanting reservoir in the Yongding River of Haihe River Basin, the requirements of velocities for spawning of the fish in April are regarded as the ecological objectives in the most critical period because this also is the period of highest water demand for irrigation. The relation between objectives and river discharge is identified using historical data at the river station. The results indicate that the minimum, medium and ideal lever of annual environmental flow requirements are 1.56×10^8m^3, 5.97×10^8m^3 and 11.02×10^8m^3, about 7.19% , 27.51% and 50.78% of the natural river discharge respectively. The ratio of water requirements monthly should be 20% in the flood period （Aug.） and be 20% in biological propagation period in spring （Apr. -Jun.）.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2005年第5期43-48,共6页
Environmental Science
基金
国家自然科学基金重点资助项目(50239020)
国家重点基础研究发展规划(973)项目(2003CB415204)
关键词
生态环境需水量
生态目标
河道
永定河
environmental flows
ecological objective
river reaches
Yongding River
