干旱年澜沧江小湾水库典型消落带植被制图及其空间分布分析  

Vegetation Mapping and Analysis of Its Spatial Distribution in Typical Water LevelFluctuating Zone of Xiaowan Reservoir on Lantsang River in Drought Year

作　　者：江维薇 朱颂 肖衡林 Jiang Weiwei;Zhu Song;Xiao Henglin(School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan,Hubei 430068,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,武汉430068

出　　处：《水土保持通报》2022年第1期240-249,共10页Bulletin of Soil and Water Conservation

基　　金：国家重点研发计划项目“大型水库消落带生态系统演替规律及恢复技术”(2016YFC0502208);湖北省自然科学基金项目(2020CFB409);湖北省自然科学基金重点类项目(2020CFA046);国家自然科学基金项目(42101375,52078195)。

摘　　要：[目的]调查研究干旱年澜沧江小湾库区消落带植被自然恢复现状,为消落带植被恢复和维护等相关研究提供本底资料和参考。[方法]以2019年消落带典型区域固定样地调查为依托,综合运用无人机遥感、GNSS定位和GIS空间分析,于2020年7月进行干旱年复位调查,绘制研究区消落带植被分布图,定量刻画干旱年研究区消落带植被自然恢复的物种组成、面积、覆盖率、沿地形梯度分布特征,并与2019年非干旱年进行对比分析。[结果]研究区消落带统计植物共14种,为一年生或多年生草本植物,其中狗牙根、习见蓼、柳叶菜、藿香蓟为优势物种,分别占植被总面积的85.62%,4.22%,3.72%,3.12%。狗牙根在消落带高,中,低段比例分别为50.21%,9.94%,39.85%;柳叶菜有95.53%分布于高段;藿香蓟有54.48%分布于中段;87.22%的习见蓼分布于中段和低段。绝大多数植物偏好生长于25°以下缓坡消落带,而柳叶菜在坡度60°以下均覆盖良好。消落带植被受到地形因子的影响中:最近邻水体距离>高程>坡度>坡向。旱情导致植被年度退化59.75%,集中体现在消落带中下部,习见蓼大量枯萎退化。[结论]消落带上半部相对于下半部植被恢复更稳定,优势物种的稳定性明显优于非优势物种,其中狗牙根和习见蓼耐淹性较好,而狗牙根相对于习见蓼表现出了更强的耐旱性和恢复稳定性;干旱胁迫和淹水胁迫对消落带植被的空间分布有显著影响,并且,在干旱年,前者的影响略大于后者。[Objective]The natural restoration of vegetation in the water level fluctuating zone(WLFZ)of the Xiaowan Reservoir on Lantsang River during a drought year were investigated to provide background information and a reference for studies related to the restoration and maintenance of vegetation in the area.[Methods]Based on a fixed sample site survey in a typical area of WLFZ in 2019,a drought year reset survey was conducted in July 2020 using a combination of unmaned aerial vehicle(UAV)remote sensing,GNSS positioning,and GIS spatial analysis to map the distribution of vegetation in WLFZ in the study area;quantitatively portray the species composition,area,cover,and distribution characteristics along a topographic gradient of vegetation in WLFZ in the drought year;and conduct a comparative analysis with the non-drought year of 2019.[Results]A total of 14 species of plants were counted,all of which were annual or perennial herbs.Cynodon dactylon,[HJ]Polygonum plebeium,Epilobium hirsutum,and Ageratum conyzoides were the dominant species,accounting for 85.62%,4.22%,3.72%,and 3.12%of the total vegetation area,respectively.The proportions of C.dactylon in WLFZ were 50.21%,9.94%,and 39.85%in sections H,M,and L(high,medium,and low),respectively;95.53%of E.hirsutum was distributed in section H;54.48%of A.conyzoides was distributed in section M;and 87.22%of P.plebeium was distributed in sections M and L.Most plants preferred to grow on gentle slopes below 25°in WLFZ,while E.hirsutum covered well on slopes less than 60°.Vegetation in WLFZ was influenced by topographic factors:distance to the nearest neighboring water body>elevation>slope>aspect.Drought resulted in an annual degradation of 59.75%of the vegetation,concentrated in the middle and lower parts of WLFZ,where a large amount of P.plebeium withered.[Conclusion]Vegetation recovery was more stable in the upper half of the zone than in the lower half,and the dominant species were significantly more stable than the non-dominant species,with C.dactylon and P.plebeium being

关 键 词：消落带 3S技术 干旱年 无人机遥感 小湾水库 澜沧江 

分 类 号：X87[环境科学与工程—环境工程] TV697.42[水利工程—水利水电工程]