紫禁城排水系统评估方法比较研究

紫禁城排水系统主要用于雨水排放,该系统已经历经六百余年,至今仍能正常使用。排水系统评估是紫禁城排水系统保护与研究工作的关键。本文采用推理公式法和管网水力模型法对紫禁城排水系统的开展评估评估,首先介绍了两种研究方法的基本原理,之后分别选取典型区域作为评估案例进行论述,最后又对两种方法进行比较分析,论述两种评估方法的特点及适用条件。

基于灰云聚类模型的城市排水系统韧性评估及应用研究

针对城市排水系统的韧性评估问题,提出一种基于灰云聚类模型的评估方法。首先,从抵抗、预警、适应和恢复四大属性建立涵盖经济、社会、生态环境、组织制度及系统自身5个维度的评估指标体系;其次,基于可变模糊云和正态云模型进行指标量化;再次,利用拉格朗日乘数法确定指标权重;最后,引入灰云聚类模型实现城市排水系统韧性评估。实例结果表明:西安市排水系统综合韧性等级为Ⅳ级,5个维度韧性等级分别为Ⅰ、Ⅳ、Ⅲ、Ⅱ和Ⅳ级,四大属性韧性等级分别为较低、较高、高和较高韧性。研究结果可为当前西安市排水系统韧性提升与投资管理提供一定的参考。

Subsurface Drainage Impact Assessment-in Ibshan, Egypt

This paper aims to mitigate the impacts of subsurface drainage system in Ibshan, Egypt on the environment. For studying and analyzing these impacts, data are collected concerning before and after the installation of the subsurface drainage system. The environmental impacts are set to be crops yields, salinity, and water table depth. Concerning crops yields, five crops are identified to study the effect of the subsurface drainage system on their productivity. Regarding salinity, the saline areas are investigated pre and post the subsurface drainage system. For the water table depth, the ground water table depths are reviewed before and after the subsurface drainage system. Also, the DRA1NMOD-S computer program is employed to determine the effect of the subsurface drainage system on the water table depth. It is concluded that the environmental impacts of the subsurface drainage system in Ibshan area are very good. The yields of five crops increased from 7% to 38%, 16.4% of saline areas are improved, and the ground water table depth is reduced by 10%. Also, an equation is obtained to predict the percentage decrease of ground water table depth according to the laterals spacing of the subsurface drainage system.