风场是影响林火蔓延行为最关键的因素之一。许多林火发生在地形复杂多变的山区,会产生复杂的局部风场。为探究动态风场对林火蔓延预测的影响,以“3·30”西昌泸山森林火灾为研究对象,利用WRF(weather research and forecasting)模...风场是影响林火蔓延行为最关键的因素之一。许多林火发生在地形复杂多变的山区,会产生复杂的局部风场。为探究动态风场对林火蔓延预测的影响,以“3·30”西昌泸山森林火灾为研究对象,利用WRF(weather research and forecasting)模式模拟动态风场,并与林火蔓延模型耦合。分别将模拟风场和均一风场分别输入林火蔓延模型,基于林火蔓延过程中实际火场范围数据,分析动态风场对林火蔓延模型预测结果的影响。结果表明,耦合WRF模式和林火蔓延模型考虑了分辨率更高、且更为准确的局部风场,能够实现对森林火灾蔓延的动态模拟。预测得到的火场范围和均一风场相比,与实际范围具有更高的相似度。展开更多
Background： An examination of the distribution of ancient charcoal kiln sites in the forest landscape seems to be worthwhile, since general trends in the selection of suitable kiln site locations in the past might be...Background： An examination of the distribution of ancient charcoal kiln sites in the forest landscape seems to be worthwhile, since general trends in the selection of suitable kiln site locations in the past might become obvious. In this way forest landscape elements with a more intense usage by charcoal burning can be identified. By doing this, we can expect to gain information on the former condition and tree species composition of woodland. Investigations on the spatial distribution of charcoal kiln sites in relation to landscape attributes are sparse, however, probably due to the high on-site mapping effort. The outstanding suitability of LiDAR-derived digital terrain models （DTMs） for the detection of charcoal kiln sites has been recently proved. Hence, DTM-based surveys of charcoal kiln sites represent a promising attempt to fill this research gap. Methods： Based on DTM-based surveys, we analyzed the spatial distribution of charcoal kiln sites in two forest landscapes in the German federal state of Hesse： Reinhardswald and Kellerwald-Edersee National Park. In doing so, we considered the landscape attibutes ＂tree species composition＂, ＂water supply status＂, ＂nutrient supply status＂, ＂soil complex classes＂, ＂altitude＂, ＂exposition＂, and ＂inclination＂. Results： We found that charcoal kiln sites were established preferably on hillside locations that provided optimal growing and regeneration conditions for European beech （Fagus sylvatico） due to their acidic brown soils and sufficient water supply. These results are in line with instructions for the selection of appropriate kiln site locations, found in literature from the 18th to the 19th century. Conclusions： We conclude that there were well-stocked, beech-dominated deciduous forest stands in northern Hesse before 1800, particularly at poorly accessible hillside locations. These large stocks of beech wood were utilized by the governments of the different Hessian territories through the establishment of ironworks and hammer mills. Our argumentation is well in line with findings which underline that not all Hessian forests were overexploited in the 18th century. Frequently repeated complaints about ＂wood shortage＂ seemed to be more a political instrument than reality, not only in Hesse, but all over Europe. Consequently, a differentiated assessment of woodland conditions in proto-industrial times is strictly advised, even if contemporary sources draw a dark picture of the historic situation.展开更多
文摘风场是影响林火蔓延行为最关键的因素之一。许多林火发生在地形复杂多变的山区,会产生复杂的局部风场。为探究动态风场对林火蔓延预测的影响,以“3·30”西昌泸山森林火灾为研究对象,利用WRF(weather research and forecasting)模式模拟动态风场,并与林火蔓延模型耦合。分别将模拟风场和均一风场分别输入林火蔓延模型,基于林火蔓延过程中实际火场范围数据,分析动态风场对林火蔓延模型预测结果的影响。结果表明,耦合WRF模式和林火蔓延模型考虑了分辨率更高、且更为准确的局部风场,能够实现对森林火灾蔓延的动态模拟。预测得到的火场范围和均一风场相比,与实际范围具有更高的相似度。
文摘Background： An examination of the distribution of ancient charcoal kiln sites in the forest landscape seems to be worthwhile, since general trends in the selection of suitable kiln site locations in the past might become obvious. In this way forest landscape elements with a more intense usage by charcoal burning can be identified. By doing this, we can expect to gain information on the former condition and tree species composition of woodland. Investigations on the spatial distribution of charcoal kiln sites in relation to landscape attributes are sparse, however, probably due to the high on-site mapping effort. The outstanding suitability of LiDAR-derived digital terrain models （DTMs） for the detection of charcoal kiln sites has been recently proved. Hence, DTM-based surveys of charcoal kiln sites represent a promising attempt to fill this research gap. Methods： Based on DTM-based surveys, we analyzed the spatial distribution of charcoal kiln sites in two forest landscapes in the German federal state of Hesse： Reinhardswald and Kellerwald-Edersee National Park. In doing so, we considered the landscape attibutes ＂tree species composition＂, ＂water supply status＂, ＂nutrient supply status＂, ＂soil complex classes＂, ＂altitude＂, ＂exposition＂, and ＂inclination＂. Results： We found that charcoal kiln sites were established preferably on hillside locations that provided optimal growing and regeneration conditions for European beech （Fagus sylvatico） due to their acidic brown soils and sufficient water supply. These results are in line with instructions for the selection of appropriate kiln site locations, found in literature from the 18th to the 19th century. Conclusions： We conclude that there were well-stocked, beech-dominated deciduous forest stands in northern Hesse before 1800, particularly at poorly accessible hillside locations. These large stocks of beech wood were utilized by the governments of the different Hessian territories through the establishment of ironworks and hammer mills. Our argumentation is well in line with findings which underline that not all Hessian forests were overexploited in the 18th century. Frequently repeated complaints about ＂wood shortage＂ seemed to be more a political instrument than reality, not only in Hesse, but all over Europe. Consequently, a differentiated assessment of woodland conditions in proto-industrial times is strictly advised, even if contemporary sources draw a dark picture of the historic situation.
