延安市地质灾害与影响因素耦合分析

Coupling Analysis between Geological Disasters and Influence Factors in Yan’an

受地形地貌、气象水文、地层岩性、植被类型及人类工程活动等的影响,延安市地质灾害频发。以延安市2018年地质灾害普查数据为基础资料,对延安市各县(区)的地质灾害进行统计分析,深入探讨地质灾害分布规律及其与各影响因素的耦合关系,结果表明:①88. 89%的地质灾害集中发生于海拔800~1 400 m的黄土丘陵区,94. 90%的崩塌发生坡度大于50°的范围内,92. 33%的滑坡集中发生于20°~50°的范围内;②86. 28%的崩塌为黄土崩塌,滑坡均为黄土型滑坡,地质灾害集中发育于年均降雨量510~530 mm及590 mm以上的区域;③地质灾害沿水系、道路两侧一定范围内呈带状分布;④人类工程活动对地质灾害影响深远,62. 39%的崩塌及73. 42%的滑坡分布于人口密度大于200人/km^2的区域,53. 64%的崩塌及66. 30%的滑坡分布于栽培植物区。研究结果可为延安市地质灾害防治提供参考依据。

Geological disasters occurred frequently in Yan’an due to the influence of topography,meteorology,hydrology,lithology,vegetation types and human activities. The distribution laws of geological disaster and its coupling relationship with influencing factors were obtained through the statistical analysis on the geological disaster of each county( district) that based on the 2018 geological disaster census data of Yan’an. The results show these as follows.①88. 89 % of geological disasters mainly occurred in loess hilly areas at the altitude range of 800 ~1 400 m,94. 90% of the collapses of slopes were greater than 50° and 92. 33% of landslides occurred in the range of 20°~ 50°;② 86. 28% of the collapses were loess collapse and the landslides were all loess landslide. Geological disasters were concentrated in areas with an average annual rainfall of 510 ~ 530 mm and above 590 mm;③geological disasters were distributed along the both sides of water systems and roads;④human engineering activities had a profound impact on geological disasters,62. 39% of the collapses and 73. 42% of the landslides were distributed with the population density of more than 200 person/km^2,53. 64% of the collapses and 66. 30% of the landslides were distributed in the areas with cultivated plants. The results can provide references for the geological disasters prevention in study area.