近31年嘉陵江流域生态环境质量时空演变及驱动因子探测

Spatiotemporal Variation of Ecological Environmental Quality and Its Response to Different Driving Factors in Jialing River Basin in Recent 31 Years

[目的]城镇化建设的持续推进给嘉陵江流域生态环境带来的压力日益增加,多方位、客观、准确、快速测算区域生态环境质量是生态学研究的一个重点。[方法]利用Landsat数据和耦合的绿度、湿度、干度和热度的遥感生态指数(remote sensing ecological index,RSEI),探究了1990—2020年不同时间段嘉陵江流域生态环境质量时空演变及其对人类活动、地形和气象变化的敏感性。[结果](1)生态环境质量整体呈变好趋势,RSEI线性变化倾斜率为0.0003/a。2003年之前嘉陵江流域生态环境变化较为稳定,2003年之后呈现先减小后增加的趋势。(2)50%以上区域的生态环境质量变化不明显。但1990—1995年陇南以北和达州以东地区生态环境质量呈退化趋势,平武部分地区呈改善趋势。1995—2000年遂宁零星分布有轻微退化趋势的区域。2005—2010年南充以南、广元以北等地区均呈轻微改善趋势。2010—2020年迭部地区均以轻微退化趋势为主。(3)生态环境质量受到人口和国内生产总值的影响程度随时间变化呈下降趋势,土地利用、海拔、坡度和降水在2015年之前对生态环境质量影响较小,2015年后对生态环境的影响呈增加趋势。气温和风速对生态环境影响力在1995年、2015年均出现突增。(4)地形因子和气象与土地利用因子之间的交互作用对嘉陵江流域生态环境质量的影响均较大,且任何两种因子的交互作用都大于单个因子对嘉陵江流域生态环境质量的影响。[结论]国内生产总值和任何两个因子间的交互作用对嘉陵江流域生态环境质量的影响最小。研究区在2015年前生态环境质量受到人类活动的影响较大,但在2015年之后受到自然因素的影响逐渐增加,但总体上其生态环境质量有所改善,得益于近年来该市对生态环境的关注与投入。

[Objective]The continuous promotion of urbanization has brought increasing pressure on the ecological environment of the Jialing River Basin.The multi-directional,objective,accurate and rapid measurement of regional ecological environment quality is a key point of ecological research.[Methods]Landsat data and the remote sensing ecological index(RSEI)coupled with greenness,humidity,dryness and heat were used to explore the temporal and spatial evolution of the ecological environment quality of the Jialing River basin and its sensitivity to human activities,topography and meteorological changes in different time periods from 1990 to 2020.[Results](1)The Jialing River Basin had been in a good trend in the past 31 years.The overall ecological environment quality had been improving,The slope rate of RSEI linear change was 0.0003/a.Before 2003,the ecological environment change in the Jialing River Basin was relatively stable,and after 2003,it showed a trend of decreasing first and then increasing.(2)The change of ecological environment quality in more than 50%of the region was not obvious.However,from 1990 to 1995,the ecological environment quality in the north of Longnan and the east of Dazhou showed a degradation trend,while some areas in Pingwu showed an improvement trend.From 1995 to 2000,there was the scattered areas with slight degradation trend in Suining.From^(2)005 to 2010,areas south of Nanchong and north of Guangyuan showed a slight improvement trend.From^(2)010 to 2020,the Diebu region has a slight degradation trend.(3)The impact of population and GDP on the quality of the ecological environment had a downward trend over time.Land use,elevation,slope and precipitation had a small impact on the quality of the ecological environment before 2015,and the impact on the ecological environment had an increasing trend after 2015.The impact of temperature and wind speed on the ecological environment increased sharply in 1995 and 2015.(4)The interaction between topographic factors and meteorological and land use factors had a greater impact on the ecological environment quality of the Jialing River Basin,and the interaction of any two factors was greater than the impact of a single factor on the ecological environment quality of the Jialing River Basin.[Conclusion]The interaction between GDP and any two factors has the least impact on the ecological environment quality of the Jialing River Basin.The ecological environment quality of the study area was greatly affected by human activities before 2015,but the impact of natural factors gradually increased after 2015.However,the overall ecological environment quality of the study area had improved,benefiting from the city′s attention and investment in the ecological environment in recent years.