许晓露, 郝利娜, 刘汉湖,等.平山造城工程下的延安新区河网水系演变[J].河南理工大学学报（自然科学版）,2022,41(4):72-79.

XU X L, HAO L N, LIU H H, et al.Evolution of river network system in the mountain excavation and city construction in Yan’an New District[J].Journal of Henan Polytechnic University(Natural Science) ,2022,41(4):72-79.

平山造城工程下的延安新区河网水系演变

许晓露1, 郝利娜1,2, 刘汉湖1, 赵美龄1, 孟田1, 蒋川东1

1.成都理工大学 地球科学学院，四川 成都610059;2.成都理工大学 地质灾害防治与地质环境保护国家重点实验室，四川 成都 610059

摘要:为了探讨造城工程对河网水系演变的影响等，以延安新区平山造城工程区为例，基于 2009 ，2013和2017年的DEM数据，分别提取相应时相的水系，选取河流长度、河网密度、河流发育系数和河流弯曲系数等指标，分析延安新区平山造城工程前后河网水系的演化特征，探讨平山造城工程对河网水系演变的影响。结果表明：（1）2009—2017年，研究区内水系的长度和河网密度呈下降趋势，河流总长度减少了 16.88 km，河网密度减少了 0.051 km/km²，其中 Ⅲ 级河流减幅最大，减少了 13.38 km；（2）从水系结构特征看，延河的河流弯曲系数从1.67下降至 1.64，河流的自然特性减弱， Ⅱ，Ⅲ 级河流发育系数下降，Ⅲ 级河流发育系数远低于 Ⅱ 级河流的，降幅也更大；（3）随着平山造城工程项目建设，许多细小河流被填埋甚至消失，支流衰减，河流结构受到干扰，自然调蓄能力减弱，使得在极端降雨等事件下遭受洪涝等自然灾害的风险增大。

关键词:平山造城;延安新区;河网水系;水系演变

doi:10.16186/j.cnki.1673-9787.2020090078

基金项目:中国博士后科学基金资助项目（2020T130074，2017M622982）；国家自然科学基金资助项目（41702358，41771444， 41790445）

收稿日期:2020/09/18

修回日期:2020/12/18

出版日期:2022/07/15

 Evolution of river network system in the mountain excavation and city construction in Yan’an New District

XU Xiaolu1, HAO Lina1,2, LIU Hanhu1, ZHAO Mailing1, MENG Tian1, JIANG Chuandong1

1.College of Earth Sciences，Chengdu University of Technology， Chengdu 610059 ， Sichuan， China;2.State Key Laboratory of Geohazard Prevention and Geoenvironment Protection，Chengdu University of Technology，Chengdu  610059,Sichuan, China

Abstract: In order to to study the influence of city construction on river network system, taking the mountain excavation and city construction project in Yan’an New District as an example,based on DEM data in 2009，2013 and 2017 ,the river net with different time series was extracted respectively. The river length , drainage density ,tributary development index and river bending index were selected to analyze the evolution process of river network system before and after the mountain excavation and city construction project for Yan’an New District. The results showed that:(1) From 2009 to 2017,the river length and the drainage density in the study area showed a downward trend, with the total river length decreasing by 16.88 km and the drainage density de creasing by 0.051 km/km². The Ⅲ river net reduced 13.38 km. (2) From the perspective of the structural of the river net system ,the river bend index of the Yanhe river droped from 1.67 to 1.64, and the natural characteristics of the river weaken. Both II and Ⅲ river net index decreased. The river development levels of the Ⅲ river net was far lower than the Ⅱ river network. (3) With the development of the mountain excavation and city construction project, many tiny river valleys have been buried or even disappeared, and tributaries have been attenuated ,river structure has been disturbed, resulting in the decline of the natural storage capacity to extreme rainfall events which might trigger floods and geological disasters has been increased.

Key words:mountain excavation and city construction;Yan’an New District;river network system;water system evolution

平山造城工程下的延安新区河网水系演变_许晓露.pdf