We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angl...We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners＇ cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.展开更多
为分析城镇土地利用及路网形态对过境公路交通事故的影响程度,以北方某市G503、G302、G334、G203、S514等5条公路沿线的33个城镇为研究对象,通过对城镇路网建模获取拓扑特征参数,采用兴趣点(point of interest,POI)计算土地利用强度与...为分析城镇土地利用及路网形态对过境公路交通事故的影响程度,以北方某市G503、G302、G334、G203、S514等5条公路沿线的33个城镇为研究对象,通过对城镇路网建模获取拓扑特征参数,采用兴趣点(point of interest,POI)计算土地利用强度与土地混合利用程度,采用随机森林模型分析自变量对过境公路交通事故的影响程度,并通过负二项回归分析自变量与过境公路交通事故的相关性。结果表明:随机森林模型中的城镇POI数、过境公路介数中心性、过境公路节度、城镇节点数、土地混合利用程度的特征权重分别为0.62、0.14、0.11、0.07、0.06,城镇POI数对过境公路交通事故的影响最大,过境公路介数中心性与节点数对过境公路交通事故有一定影响,城镇节点数、土地混合利用程度对过境公路交通事故的影响较弱;在负二项回归方法下,过境公路介数中心性、城镇POI数与过境公路交通事故显著正相关,城镇节点数、过境公路节度和土地混合利用程度与过境公路交通事故的相关性不显著。随机森林模型结论与负二项回归分析结论接近,随机森林模型对自变量的非加和性与非线性特点适应较好,适用于交通事故致因分析。控制城镇规模、合理规划城镇路网对减少过境公路交通事故风险和提高交通安全有重要意义。展开更多
文摘We investigated forest road networks and forestry operations before and after mechanization on aggregated forestry operation sites. We developed equations to estimate densities of road networks with average slope angles, operational efficiency of bunching operations with road network density, and average forwarding distances with operation site areas. Subsequently, we analyzed the effects of aggregating forests, establishing forest road networks, and mechanization on operational efficiency and costs. Six ha proved to be an appropriate operation site area with minimum operation expenses. The operation site areas of the forest owners＇ cooperative in this region aggregated approximately 6 ha and the cooperative conducted forestry operations on aggregated sites. Therefore, 6 ha would be an appropriate operation site area in this region. Regarding road network density, higher-density road networks increased operational expenses due to the higher direct operational expenses of strip road establishment. Therefore, road network density should be reduced to approximately 200 m.
文摘为分析城镇土地利用及路网形态对过境公路交通事故的影响程度,以北方某市G503、G302、G334、G203、S514等5条公路沿线的33个城镇为研究对象,通过对城镇路网建模获取拓扑特征参数,采用兴趣点(point of interest,POI)计算土地利用强度与土地混合利用程度,采用随机森林模型分析自变量对过境公路交通事故的影响程度,并通过负二项回归分析自变量与过境公路交通事故的相关性。结果表明:随机森林模型中的城镇POI数、过境公路介数中心性、过境公路节度、城镇节点数、土地混合利用程度的特征权重分别为0.62、0.14、0.11、0.07、0.06,城镇POI数对过境公路交通事故的影响最大,过境公路介数中心性与节点数对过境公路交通事故有一定影响,城镇节点数、土地混合利用程度对过境公路交通事故的影响较弱;在负二项回归方法下,过境公路介数中心性、城镇POI数与过境公路交通事故显著正相关,城镇节点数、过境公路节度和土地混合利用程度与过境公路交通事故的相关性不显著。随机森林模型结论与负二项回归分析结论接近,随机森林模型对自变量的非加和性与非线性特点适应较好,适用于交通事故致因分析。控制城镇规模、合理规划城镇路网对减少过境公路交通事故风险和提高交通安全有重要意义。
