基于景观格局的西南山区耕地生态风险研究
赵 馨1,2,3, 周忠发1,2,3, 朱 孟1,2,3, 王玲玉1,2,3, 吴 跃1,2,3

(1.贵州师范大学 喀斯特研究院/地理与环境科学学院, 贵阳 550001; 2.贵州省喀斯特山地生态环境国家重点实验室培育基地, 贵阳 550001; 3.国家喀斯特石漠化防治工程技术研究中心, 贵阳 550001)

石漠化耕地; 生态风险; 分层分级; 景观格局; 西南地区

Research on Ecological Risk of Karst Rocky Desertification Cultivated Land Based on Landscape Pattern
ZHAO Xin1,2,3, ZHOU Zhongfa1,2,3, ZHU Meng1,2,3, WANG Lingyu1,2,3, WU Yue1,2,3

(1.School of Geography and Environmental Science/Institute of Karst Science, Guizhou Normal University, Guiyang 550001, China; 2.State Key Laboratory Incubation Base for Karst Mountain Ecology Environment of Guizhou Province, Guiyang 550001, China; 3.State Engineering Technology Institute for Karst Desertification Control, Guiyang 550001, China)

rocky desertification farmland; ecological risk; hierarchical classification; landscape pattern; southwest China

备注

为探究西南山区复杂地形地貌下不同类型耕地景观生态风险差异性,探索不同石漠化环境下耕地的发展情况。选取2013—2017年息烽县遥感影像,利用深度学习进行耕地提取,并根据石漠化程度对耕地进行分类。综合考虑外部胁迫、土壤污染胁迫、农户干扰等不同风险源,计算了不同类型耕地景观生态风险。结果 表明:(1)5年间息烽县耕地共减少8 149 hm2,其中,2015年喀斯特旱地减少占比29%,2017年喀斯特旱地减少占比96%,通过计算各类耕地景观指数看出,息烽县各类耕地景观破碎度、分离度与面积变化呈反比,景观优势度与面积变化呈正比。(2)各类耕地景观自然损失度和生态风险概率的空间及时间变化,导致息烽县耕地景观生态风险程度主要表现为西南处于低风险,南北中部地区处于高风险。时间尺度上耕地景观生态风险平均值表现为2015年>2013年>2017年,分别为0.186,0.118,0.112。(3)通过灰色关联矩阵分析得出,息烽县各类耕地景观风险受到城镇发展和农村现代化影响明显,且2015年关联度低于其余年份。研究发现,不同程度石漠化下的耕地生态风险存在差异性。

In order to explore the differences in landscape ecological risks of different arable land types under complex terrain in the Southwest Mountainous Area, and explore the development of cultivated land under different rocky desertification environments, we selected remote sensing images of Xifeng County in the period 2013—2017, used deep learning to extract, and classified the cultivated land according to rock desertification grades. Integrally considering different risk sources such as external stress, soil pollution stress, and farmers' interference, we calculated the ecological risks of different types of cultivated land landscape. The results showed that:(1)the cultivated land in Xijing County had decreased by 8 149 hm2 in the past five years; among which the karst dry land decreased by 29% in 2015, and the karst dry land decreased by 96% in 2017; it could be seen that the fragmentation and separation of various cultivated land landscapes in Xifeng County were inversely proportional to area changes, and the degree of landscape dominance was directly proportional to area changes by calculating the index of various cultivated land landscapes;(2)the spatial and temporal changes in the natural loss and ecological risk probability of various types of cultivated land landscapes had resulted in the ecological risk of cultivated land landscapes in Xifeng County with low risk in the southwest and high risk in the north and south; the average ecological risk of cultivated land landscape on the time scale decreased in the order: 2015>2013>2017, which were 0.186, 0.118, and 0.112, respectively;(3)based on the grey correlation proof analysis, it was concluded that the risk of various cultivated land landscapes in Xifeng County was significantly affected by urban development and rural modernization, and the correlation in 2015 was lower than in other years. This study found that the ecological risk of cultivated land under different levels of rocky desertification was different.