摘要
土壤湿度作为生态环境的关键因子,是土壤监测和生态环境变化的重要指标。本研究基于MOD11A2LST和MOD13A2 NDVI数据,通过温度干旱植被指数TVDI(Temperature Vegetation Dryness Index)、相关性分析和区域统计分析等数理统计分析方法对香日德-柴达木河流域植被生长季的土壤湿度时空分布特征及其影响因素进行分析。结果表明:(1)香日德-柴达木河流域2005年、2010年、2015年和2020年植被生长季TVDI平均值为0.61,最大值为2015年(0.64),最小值为2020年(0.58),年际TVDI值缓慢下降,但在2015年出现上升现象,研究区旱情不稳定且长期处于干旱等级。(2)不同等级土壤湿度的面积从大到小依次为干旱>极干旱>正常>湿润>极湿润,分别占研究区总面积的30.63%、25.77%、22.16%、16.44%、5.01%。(3)TVDI在空间分布上呈现出由西北向东南逐渐递减的趋势,具有明显的区域差异性。(4)TVDI值与海拔呈负相关关系,海拔每升高500 m,TVDI值减少0.11,TVDI值与平均气温呈正相关关系,与坡度和降水量之间不存在明显的相关性关系。
As a key factor of the ecological environment,soil moisture is an important indicator for soil monitoring and changes to the ecological environment.This study is based on MOD11A2 LST and MOD13A2 NDVI data,and used mathematical statistical analysis methods,including the temperature-vegetation dryness index(TVDI),correlation analysis,and regional statistical analysis.The temporal and spatial distribution of humidity characteristics and its influencing factors were analyzed.The average TVDI value in the vegetation growing season of the Xiangride-Qaidam River basin from 2005 to 2020 was 0.61;the maximum value was noted in 2015(0.64)and the minimum value occurred in 2020(0.58).The interannual TVDI value slowly decreased over time;however,it did increase in 2015.The drought situation in the study area was unstable,and remained at a drought level for an extended time period.The area corresponding to different soil moisture levels,in descending order,was as follows:drought>extremely arid>normal>humid>extremely humid,accounting for 30.63%,25.77%,22.16%,16.44%,and 5.01%of the total area,respectively.The spatial distribution of TVDI gradually decreased from northwest to southeast,with obvious regional differences.Moreover,the TVDI value had a negative correlation with altitude,decreasing by 0.11 for every 500 m increase in altitude.The TVDI was positively correlated with the average temperature,but had no obvious correlation with precipitation.
作者
程梦园
曹广超
赵美亮
刁二龙
何启欣
高斯远
邱巡巡
程国
CHENG Mengyuan;CAO Guangchao;ZHAO Meiliang;DIAO Erlong;HE Qixin;GAO Siyuan;QIU Xunxun;CHENG Guo(College of Geographical Science,Qinghai Normal University,Xining 810008,Qinghai,China;Qinghai Province Key Laboratory of Physical Geography and Environmental Process,Xining 810008,Qinghai,China;Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation,Ministry of Education,Xining 810008,Qinghai,China;Academy of Plateau Science and Sustainability,People’s Government of Qinghai Province&Beijing Normal University,Xining 810008,Qinghai,China)
出处
《干旱区研究》
CSCD
北大核心
2022年第2期615-624,共10页
Arid Zone Research
基金
青海省重大科技专项(2019-SF-A4-3)
青海省创新平台建设专项青海省自然地理与环境过程重点实验室项目(2020-ZJ-Y06)。
关键词
土壤湿度
温度植被干旱指数
相关性分析
香日德-柴达木河流域
soil moisture
temperature vegetation drought index
correlation analysis
Xiangride-Qaidam River Basin
