摘要
采用景观生态学理论和GIS空间分析技术,诊断1950年以来上海中心城区的河网水系变化特征,及其对水系连通性和城市水安全的影响。研究表明:(1)采用景观生态学方法中的廊道连接率、环路指数等连通性指标,较好地诊断了河网地区的高密度网状水系结构特征及其变化过程,四个典型河网连通指标之中,以环路指数对水系结构演变的响应较为敏感。(2)近70年来,上海中心城区河网密度下降了68.54%,消亡河道多为1 km长度以下末端村镇级河道,占总消亡河道的77.13%。(3)1994年之前区域水系连通性指标高于1,而此后开始低于1,河网水系环路指数剧烈下降,上海中心城区基本不再具有典型的网状水系结构特征。(4)河网萎缩导致水面率锐减和河网连通受阻,近70年来,雨水泵站排水能力增强与河网总长度和河网连通性变化均存在显著的响应关系,其中对河网总长度变化的响应更加明显。
The evolution characteristics of river system in the central urban area of Shanghai since 1950,and the evolution effects on water system connectivity and urban water safety are diagnosed by using the landscape ecological theory and GIS spatial analysis.The study shows that(1)the use of connectivity indexes of corridor connection rate and loop index in landscape ecological method can better diagnose the structural characteristics and evolution process of high—density network water system in river network areas.In the four typical river network connectivity indicators,the loop index is more sensitive to the evolution of the water system structure.(2)The river network density of the central urban area of Shanghai has declined by 68.54%in the recent 70 years.The most extinct rivers less than 1 km in length are the village-level rivers and are accounted for 77.13%of the total extinct rivers.(3)Before 1994,the connectivity index of regional river system was higher than 1.And then it started going below 1,and the loop index of river system decreased sharply.The central urban area of Shanghai basically no longer has the characteristics of the typical network river system structure.(4)The atrophy of river network leads to the sharp decrease of water surface rate and the obstruction of river network connection.In the recent 70 years,the enhanced drainage capacity of rainwater pumping stations has a significant response relationship with the total length of the river network and the change of river network connectivity,in which the response to the change in the total length of the river network is more obvious.
作者
吴玫玫
张森
王忠昊
赵军
WU Meimei;ZHANG Sen;WANG Zhonghao;ZHAO Jun
出处
《城市道桥与防洪》
2021年第6期137-141,M0012,M0013,共7页
Urban Roads Bridges & Flood Control
关键词
河网水系
演变
连通性
水安全
上海中心城区
river network system
evolution
connectivity
water safety
central urban area of Shanghai
