水利水电技术（中英文）

【目的】城市化建设的持续推进给南渡江流域生态带来的压力日益增加，但目前关于南渡江流域生态环境质量变化特征及不同环境因子变化对其影响情况仍未达成共识。基于综合指标评价南渡江流域生态环境及其驱动因子对维护南渡江流域经济发展—生态环境平衡的决策制定至关重要。【方法】采用耦合了区域绿度、湿度、干度和热度特征的遥感生态指数(remote sensing ecological index,RSEI)探究了1991—2021年南渡江流域生态环境质量时空动态，并分析了不同环境因子、地形因子和土地利用变化对南渡江流域生态环境质量的影响情况。【结果】结果表明：(1)南渡江流域1991—2021年间生态环境质量均呈上升趋势，2005年为突变年，且上游增加最快，中游次之，下游最慢。1991—2005年和2012—2021年生态环境质量呈下降趋势的面积显著大于呈上升趋势的面积，2006—2011年两者面积相差不大。(2)未来一段时间内南渡江流域除儋州市和定安县部分区域生态环境质量以改善趋势为主，其它区域生态环境质量将以下降趋势为主。(3)2005年之前和2012年之后的RSEI变化主要由热度指数变化引起，但在2006—2011年间主要由热度指数和干度指数变化引起，绿度和湿度指标对其影响较小。(4)海拔对生态环境质量变化速率随地形因子变化无显著变化，但其变化的波动性随海拔和坡度的增加均呈增加趋势，且上游最敏感，中游次之，下游最后。【结论】南渡江流域在生态环境维持与治理方面政策的大方向是有效的，绝大部分区域生态环境质量都在提升，少部分地区略有降低，应有针对性地进行政策调整，改善生态环境质量。

[Objective]The continuous promotion of urbanization has brought increasing pressure on the ecology of Nandu River Basin, but there is still no consensus on the change characteristics of ecological environment quality in Nandu River Basin and the impact of different environmental factors on it. It is very important to evaluate the ecological environment of Nandu River basin and its driving factors by using comprehensive indexes for the decision making of maintaining the balance between economic development and ecological environment of Nandu River Basin.[Methods]Therefore, this paper used the remote sensing ecological index(RSEI) coupled with regional greenness, humidity, dryness, and heat characteristics to explore the spatial-temporal dynamics of ecological environment quality in Nandu River Basin from 1991 to 2021. The effects of different environmental factors, topographic factors, and land use change on the ecological environment quality in Nandu River Basin were investigated.[Results]The result showed as follows:(1) The ecological environment quality of the Nandu River Basin showed an increasing trend from 1991 to 2021. The year of 2005 was a sudden change year, and the increase was the fastest in the upper reaches, followed by the middle reaches, and the slowest in the lower reaches. During 1991—2005 and 2012—2021, the area with declining trend was significantly larger than that with increasing trend, and there was no significant difference between the two areas during 2006—2011.(2) In the future, except Danzhou City and Ding'an County, the ecological environment quality in some regions of Nandu River Basin will mainly improve, while the ecological environment quality in other regions will mainly decrease.(3) The changes of RSEI before 2005 and after 2012 were mainly caused by the changes of heat index, but the changes of heat index and dryness index during 2006—2011 were mainly caused by the changes of greenness index and humidity index.(4) Elevation has no significant change in the rate of change of eco-environmental quality with the change of topographic factors, but its fluctuation trend increases with the increase of elevation and slope, and the upper reaches are the most sensitive, followed by the middle reaches, and the lower reaches are the last.[Conclusion]The policy direction of ecological environment maintenance and management in Nandu River Basin is effective, and the ecological environment quality in most regions is improving, while a few regions are slightly decreasing. Targeted policy adjustments should be made to improve the ecological environment quality.