摘要
水土流失是影响区域生态安全的重要因素,深入了解区域降雨侵蚀时空异质性有利于更有针对性地实施水土保持措施。基于重庆市32个国家级气象站点2009-2022年逐小时降雨数据,应用降雨侵蚀力简易模型计算了研究区内不同生态功能区的降雨侵蚀力和侵蚀密度的时空分异性。结果表明:(1)各生态功能区的降雨侵蚀力和侵蚀密度年际变化的标准差为340.01~687.17 MJ·mm/(hm^(2)·h)和0.15~0.21 MJ/(hm^(2)·h·a),变异系数为0.16~0.25和0.05~0.08;年内分布表现为夏季最高,冬季最低,其中夏季降雨侵蚀力占比50.78%~55.72%;侵蚀密度作为非共识性指标,在揭示侵蚀风险方面比降雨侵蚀力更为敏感。(2)在年际变化中,降雨侵蚀力的年均值高值区主要分布在大巴山生态屏障区和三峡库区核心区生态涵养区的部分区域,低值区位于丘陵谷地生态品质提升区;年降雨侵蚀力最大值出现在2021年大巴山生态屏障区的城口县,达4 676.44 MJ·mm/(hm^(2)·h),最小值出现在2011年丘陵谷地生态品质提升区的永川区,仅806.25 MJ·mm/(hm^(2)·h);季节尺度上,春季高值区发生在武陵山生态屏障区,夏、秋时段的高值区出现在大巴山生态屏障区和三峡库区核心区生态涵养区以中山地貌为主的区域,冬季整体变化较弱。(3)降雨侵蚀密度的空间分布特征表明,高值区分布在大巴山生态屏障区,低值区分布在大娄山生态屏障区;季节尺度上的高值区存在空间差异,春季高值区发生在武陵山生态屏障区,夏季高值区发生在大巴山生态屏障区和丘陵谷地生态品质提升区的部分区域,秋、冬季高值区发生在三峡库区核心区生态涵养区。
Rainfall erosion plays a critical role in influencing regional ecological security.Detailed understanding the spatial and temporal heterogeneity of regional rainfall erosion is conducive to more targeted implementation of soil and water conservation measures.This study utilized hourly rainfall data from 32 national meteorological stations in Chongqing spanning from year 2009 to 2022 to examine the spatiotemporal variability of rainfall erosivity and erosion density within ecological environmental management units.The results showed that:(1) The standard deviation of inter-annual changes in rainfall erosivity and erosion density across various ecological functional zones ranged from 340.01 to 687.17 MJ·mm/(hm~2·h) and 0.15 to 0.21 MJ/(hm~2·h·a),with a coefficient of variation of 0.16 to 0.25 and 0.05 to 0.08,respectively.The distribution was uneven throughout the year,with the highest values occurring in summer and the lowest in winter.Summer rainfall erosivity accounted for 50.78% to 55.72% of the total,indicating its significant impact on erosion risks compared to other seasons.As a non-consensus index,erosion density is more sensitive than rainfall erosivity in revealing erosion risk.(2) In terms of spatial distribution,high annual average values of rainfall erosivity were concentrated in the Daba Mountain ecological barrier zone and part of the Three Gorges reservoir area core ecological conservation zone,while low values were found in the ecological quality improvement zone of hilly valleys.The maximum annual rainfall erosivity occurred in 2021 in Chengkou County,within the Daba Mountain ecological barrier zone,reaching 4 676.44 MJ·mm·/(hm~2·h).The minimum value was recorded in 2011 in Yongchuan District,located in the ecological quality improvement zone of hilly valleys,at only 806.25 MJ·mm·/(hm~2·h).For seasonal scale,the high-value area was located in the Wuling Mountain ecological barrier zone in spring,while during summer and autumn,they were distributed in the Daba Mountain ecological barrier zone and the middle mountain part of the Three Gorges reservoir area core ecological conservation zone.However,the variation in winter was relatively insignificance.(3) The characteristics of spatial distribution of erosion density indicated that high annual average values were concentrated in the Daba Mountain ecological barrier zone,while low values were in the Daloushan ecological barrier zone.There were seasonal spatial differences.As discussed,high-value zones in spring occurred in the Wuling Mountain ecological barrier zone.In summer,the high-value zones present in Daba Mountain ecological barrier zone and parts of the ecological quality improvement zone of hilly valleys.While the high-value zones shifted to the Three Gorges reservoir area core ecological conservation zone during autumn and winter seasons.
作者
龙训建
李天阳
罗宏森
叶琰
叶勇
张钰欣
王子衿
LONG Xunjian;LI Tianyang;LUO Hongsen;YE Yan;YE Yong;ZHANG Yuxin;WANG Zijin(College of Resources and Environment,Southwest University,Chongqing 400715,China;High School Affiliated to Southwest University,Chongqing 401120,China)
出处
《西南大学学报(自然科学版)》
北大核心
2025年第6期162-174,共13页
Journal of Southwest University(Natural Science Edition)
基金
国家自然科学基金青年基金项目(42107347)
重庆市技术创新与应用发展专项(CSTB2023TIAD-KPX0075)。
关键词
水土保持
降雨侵蚀力
侵蚀密度
生态功能区
soil and water conservation
rainfall erosivity
erosion dentist
ecological function regionalization
