半干旱流域水热变化规律及植被响应  

Water and thermal conditions variation and the vegetation response at semi-arid Basin

作　　者：方青青 张思远 王国强[2] 王运涛 段利民[3] 刘廷玺[3] 姚继平 FANG Qingqing;ZHANG Siyuan;WANG Guoqiang;WANG Yuntao;DUAN Limin;LIU Tingxi;YAO Jiping(School of Water Conservancy and Hydropower Engineering,North China Electric Power University,Beijing 102206,China;College of Water Sciences,Beijing Normal University,Beijing 100875,China;The College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China;The School of Ecology and Environment,Inner Mongolia University,Hohhot 010021,China)

机构地区：[1]华北电力大学水利与水电工程学院,北京102206 [2]北京师范大学水科学研究院,北京100875 [3]内蒙古农业大学水利与土木建筑工程学院,呼和浩特010018 [4]内蒙古大学生态与环境学院,呼和浩特010021

出　　处：《生态学报》2024年第16期7198-7212,共15页Acta Ecologica Sinica

基　　金：国家重点研发计划项目(2021YFC3201203);国家自然科学基金项目(52209017);中国博士后自然科学基金项目(2022M711135)。

摘　　要：近年来,水热条件显著变化下植被变绿现象发生在我国诸多半干旱流域,尽管发挥了增汇减碳效用,但也加剧了水资源量的短缺。研究水热变化下植被响应有助于理解植被⁃水资源平衡机制,对流域水资源可持续利用与生态保护有重要意义,是国际性的前沿科学问题。但鲜有研究聚焦植被动态对水热变化的周期性和阶段性响应特征,导致植被变绿和水资源利用的协同机制尚不清晰。将海拉尔河流域中上游作为研究区域,利用趋势分析、小波周期分析等方法分析了1980—2012年海拉尔河流域水热变化特征,从整体趋势和动态过程两个维度探讨了水热变化下植被在时空尺度上的响应原因及影响。结果表明:(1)空间上,年均降水量自西(草原)向东(森林)增加,气温减少;相对于草原区,森林区呈现径流量、植被NDVI大,升温慢、降水降幅大的特点。(2)时间上,流域年均降水和径流量分别以10mm/10a和19.3mm/10a的趋势减小;年均气温和生长季NDVI分别以0.65℃/10a和0.003—0.006/10a显著上升,表现出水热条件的暖干化抑制径流量(“抑流”)和促进植被生长的特征(“促长”),甚至在1998年后,降水回升和气温升高趋于平缓,仍表现出“抑流”和“促长”的特征,体现了水热影响的累积性。(3)整体趋势方面,降水和气温在6.9a、径流和植被NDVI分别在13.8、9.8a存在周期性。植被整体变化趋势主要受温度主导,而植被变绿是径流衰减的重要因素;动态过程方面,径流动态变化和周期性规律主要受降水控制,而植被动态变化和周期性规律受到降水、气温等的综合影响,且响应过程受到累积效应的作用。研究结果提高了对半干旱流域植被和水资源协调关系的认识,可为植被管理与水资源利用提供有效依据。Recently,most semi⁃arid basins in China have experienced vegetation greening under significant water and thermal conditions changes,which has exacerbated the shortage of water resources despite the positive effect of increasing carbon sinks and reducing carbon emissions.The study of vegetation response under variations of water and thermal conditions can help to understand the mechanism of the balance between the hydrological processes and vegetation pattern and is of great significance for the sustainable utilization of water resources and ecological protection.However,few studies have focused on the time⁃periodic and segmented response mechanisms of vegetation dynamics to variations of water and thermal conditions,resulting in unclear mechanisms of trade⁃off between vegetation greening and water resources.This study analyzed the varied trends of water and thermal conditions and discussed the spatio⁃temporal response of vegetation from two points:overall trends and varied processes at the upper and middle Hailar River Basin from 1980 to 2012 by using trends and wavelet period analysis.The results show that:(1)spatially,the average annual precipitation increased and the temperature decreased from west(grassland)to east(forest).Compared with the grassland area,the runoff and the Normalized Difference Vegetation Index(NDVI)in the forest area showed larger,and indicated slower warming and larger precipitation declining.(2)Temporally,the average annual precipitation and the runoff slightly decreased with a trend of 10 mm/10 a and 19.3 mm/10 a,respectively;the average annual temperature and NDVI in the growing season increased significantly with a trend of 0.65℃/10 a and 0.003-0.006/10 a,respectively.The results suggested that warming and drying inhibited the runoff and increased the vegetation growth,even in the context of precipitation increased and smooth increasing trend of temperature after 1998,showing the accumulative effect of water and thermal.(3)The periodicity of precipitation,temperature,runoff a

关 键 词：水热条件 径流变化 植被响应 水分胁迫 

分 类 号：Q948[生物学—植物学] P333[天文地球—水文科学]