某大型商业建筑消防设计     

王培玲 《中国勘察设计》2007,(9):105-107

大型商业建筑投资规模大,人员密集,一旦发生火灾,损失巨大,因此消防设计要慎之又慎。本文根据某大型商业建筑的特点,介绍了关于给排水和暖通专业的消防设计。  相似文献   

Using cumulative NOAA-AVHRR spectral indices for estimating fire danger codes in northern boreal forests     

《International Journal of Applied Earth Observation and Geoinformation》2007,9(3):335-342

In Canada, fire danger is rated by the Canadian forest fire danger rating system (CFFDRS). One of its components is the fire weather index (FWI) system, which has among others the drought code (DC). DC is used here as a surrogate of dead forest fuel moisture. DC values were computed from weather data acquired between 1993 and 1999 and compared to 10-day composite NOAA-AVHRR images acquired over Canadian northern boreal forests. They were yearly correlated with single compositing period and cumulative NDVI and surface temperature (ST) NOAA-AVHRR data. Correlations with cumulative spectral variables were stronger than with single compositing period variables and the best correlations occurred for the spring compositing periods (R between 0.57 and 0.80). Spring DC models using both single compositing period and cumulative spectral variables were established. Surface temperature-based indices were more often used in the models than NDVI-based indices. The models were stronger for dry or normal years than for wet years. Limitations and possible improvements of the models are discussed.  相似文献   

卫星火情探测灵敏度试验与火情遥感新探测通道选择     

戎志国  刘诚  孙涵  马轮基  卢乃锰  刘京晶  张玉香  钟仕全  张艳  张鹏  张甲珅  李亚君  张行清  马瑞升  王君华 《地球科学进展》2007,22(8):866-871

2005年10月在广西武鸣机场进行了一系列的人工火情测量试验。进行的100 m2与200 m2火场同步观测试验表明，在EOS TERRA、EOS AQUA和FY 1D等气象卫星遥感图像的人工火场区，中波红外通道均有明显的增温效应，达到了现行业务火情监测的判识标准，表明气象卫星1 km分辨率的中波红外通道完全可以遥感监测到小至200 m2、甚至100 m2完全燃烧的火场。分析BOMEM MR 154 FT高光谱仪测定的火情光谱特征，发现在中波4.34~4.76 μm光谱段的辐亮度比火情监测常用通道3.5~4.0 μm有更强的响应关系。通过初步的大气辐射传输计算，结果表明此波段似为卫星遥感探测火情更为敏感和有效的通道。  相似文献   

Climatic controls of Holocene fire patterns in southern South America     

Cathy Whitlock  Patricio I. Moreno 《Quaternary Research》2007,68(1):28-36

Holocene fire-climate-vegetation linkages are mostly understood at individual sites by comparing charcoal and pollen records with other paleoenvironmental proxy and model simulations. This scale of reconstruction often obscures detection of large-scale patterns in past fire activity that are related to changes in regional climate and vegetation. A network of 31 charcoal records from southern South America was examined to assess fire history along a transect from subtropic to subantarctic biomes. The charcoal data indicate that fire activity was greater than present at ca. 12,000 cal yr BP and increased further and was widespread at 9500 cal yr BP. Fire activity decreased and became more spatially variable by 6000 cal yr BP, and this trend continued to present. Atmospheric circulation anomalies during recent high-fire years show a southward shift in westerlies, and paleoclimate model simulations and data syntheses suggest that such conditions may have prevailed for millennia in the early Holocene when the pole-to-equator temperature gradients were weaker and annual temperatures were higher than present, in response to orbital-time-scale insolation changes.  相似文献   

Landform and Vegetation Change in the Greaves Creek Basin: An asymmetric hanging valley in the Blue Mountains,New South Wales     

P.M. Selkirk  D.A. Adamson  A.J. Downing 《The Australian geographer》2001,32(1):45-75

Greaves Creek has cut a hanging valley through the entire Triassic sandstone sequence near Blackheath in the western Blue Mountains, New South Wales. Downstream of Beauchamp Falls, it cuts into Permian strata in the Grose Gorge. The hanging valley has a valley-in-valley structure. The narrow inner valley is bounded by high cliffs and its floor is cut by a deep narrow slot canyon where stream incision has occurred without valley widening. The course of the creek is related to joint directions. Intense jointing, minor faulting and sapping influence the stability of cliffs but up to 30m of incision has occurred without valley widening in the slot canyon. Topographic asymmetry expressed as unequal slopes of the valley sides is related to differential insolation, erosion, vegetation cover, bioturbation and fire intensity. In the western Blue Mountains and elsewhere in the Sydney Basin asymmetric slopes occur in many other valley-ridge systems, particularly those whose long axes are oriented between about east-west and north-east-south-west. Vegetation structure and floristics within Greaves Creek valley are related to physiography of the valley and to aspect through their effects on fire, moisture availability, light availability, soil depth and temperature.  相似文献   

The effects of fire on the surface properties and seed germination in two shallow monoliths from a rangeland soil subjected to simulated raindrop impact and water erosion     

C. J. Chartres  H. J. Mücher 《地球表面变化过程与地形》1989,14(5):407-417

This paper describes the methods used and some preliminary results of simulated erosion studies on soils with cryptogamic crusts from a semiarid rangeland environment. Two 0·3 m² shallow monoliths were collected from the upper 20 cm of a Typic Haplargid from the semiarid Australian rangelands and subjected to a range of rainfall intensities and durations representing potentially erosive summer and winter rainfall events. One of the monoliths was cleared of vegetation by a simulated low intensity bushfire. Macro- and micromorphological properties of the surface, as well as runoff and erosion losses, were measured during the experiment. Runoff and erosion losses were, as expected, greater for all conditions on the burned than on the unburned monolith. Intensive rainfall damaged the cryptogamic crust unprotected by vegetation by widening and deepening desiccation cracks around the cryptogams, and breaking away and dispersing larger soil fragments from the crack margins. The burned and eroded surfaces provided a much poorer environment for seed entrapment, germination, and growth than did the unburned surface.  相似文献   

A 14,300-year-long record of fire-vegetation-climate linkages at Battle Ground Lake, southwestern Washington   总被引：1，自引：0，他引：1  

Megan K. Walsh  Cathy Whitlock 《Quaternary Research》2008,70(2):251-264

High-resolution macroscopic charcoal analysis was used to reconstruct a 14,300-year-long fire history record from the lower Columbia River Valley in southwestern Washington, which was compared to a previous vegetation reconstruction for the site. In the late-glacial period (ca. 14,300-13,100 cal yr BP), Pinus/Picea-dominated parkland supported little to no fire activity. From the late-glacial to the early Holocene (ca. 13,100-10,800 cal yr BP), Pseudotsuga/Abies-dominated forest featured more frequent fire episodes that burned mostly woody vegetation. In the early to middle Holocene (ca. 10,800-5200 cal yr BP), Quercus-dominated savanna was associated with frequent fire episodes of low-to-moderate severity, with an increased herbaceous (i.e., grass) charcoal content. From the middle to late Holocene (ca. 5200 cal yr BP to present), forest dominated by Pseudotsuga, Thuja-type, and Tsuga heterophylla supported less frequent, but mostly large or high-severity fire episodes. Fire episodes were least frequent, but were largest or most severe, after ca. 2500 cal yr BP. The fire history at Battle Ground Lake was apparently driven by climate, directly through the length and severity of the fire season, and indirectly through climate-driven vegetation shifts, which affected available fuel biomass.  相似文献   

The Vegetation Resilience After Fire (VRAF) index: Development,implementation and an illustration from central Italy     

Marina Bisson  Alessandro FornaciaiAlessandro Coli  Francesco MazzariniMaria Teresa Pareschi 《International Journal of Applied Earth Observation and Geoinformation》2008

A suitable index is proposed to evaluate the natural short–medium-term recovery capability of vegetation in burnt areas. The study area covers 2450 km² in western Tuscany (Province of Pisa, Italy). This region is characterized by a typical Mediterranean climate and is subject to fire damage during the dry summer season. Damage is mitigated where a natural rapid regrowth of vegetation prevents soil erosion, supporting the return to a natural pre-fire state.  相似文献   

Annual growth zones in stems of Hypericum irazuense (Guttiferae) in the Costa Rican páramos     

Matthew T. Kerr  Sally P. Horn  Henri D. Grissino-Mayer  Lauren A. Stachowiak 《自然地理学》2018,39(1):38-50

The high peaks of the Cordillera de Talamanca in Costa Rica support shrub- and grass-dominated páramo ecosystems that experience stand-replacing wildfires. The dry season that facilitates these fires results in dormancy in plant growth and provides an opportunity to use dendrochronological analyses to determine ages of plants in burn sites to support studies of fire history and postfire vegetation recovery. This study investigates the formation of annual growth zones in stems of the common shrub Hypericum irazuense. Unlike other páramo shrubs, H. irazuense rarely resprouts following fire, instead recovering through seedling recruitment following seed dispersal from the unburned periphery. Laboratory analysis of 19 prepared cross sections from 15 stems shows that samples of H. irazuense from burned areas can provide an estimate of the minimum number of years since the previous fire, supporting earlier work based on field examination of stems. Including a time lag for seedling recruitment or resprouting refines that estimate. Counts of growth zones in most sections coincided with dates of the last known fires. The presence of annual growth zones in H. irazuense places the species within a relatively small group of woody Neotropical species for which annual rings or growth zones have been demonstrated.  相似文献   

Mapping fire regimes in China using MODIS active fire and burned area data     

《Applied geography (Sevenoaks, England)》2017

Relatively little is known about vegetation fire regimes in China. In this study, we investigated fire regime characteristics and their potential drivers, utilizing information extracted from the MODerate resolution Imaging Spectrometer (MODIS) satellite. Twelve fire regime variables were selected and computed on a regular grid over all of China, using MODIS burned area and active fire data during the period 2001 to 2016, to identify fire incidence and its inter-annual variability, seasonality, intensity, fire size distribution and vegetation types affected by fire. The variables were normalized and clustered to define six fire regimes with distinctive fire attributes. Results show that 78.6% of the land in China was affected by fire during the study period. The barren or sparsely vegetated lands of western China are nearly fire-free. Active fires were observed in Central China, but area burned was not detectable from MODIS. Forest fires in northeastern China are relatively large, infrequent, with a short fire season that peaks in non-winter seasons and higher inter-annual variability, implying a high likelihood of accidental causes. In contrast, forest fires in southern China are relatively small, frequent, with a long fire season that peaks in non-summer seasons, and lower inter-annual variability, suggesting regular use as a land management tool. Low inter-annual variability and low fire intensity were associated with cropland fires, whereas grassland fires generally exhibit the opposite traits. We have also discussed the potential drivers of each fire regime characteristics.  相似文献