基于Landsat时间序列遥感数据的华北平原农田火烧迹地检测与制图     

张素梅  杜惠琳  刘良  白翔宇  冯凯东  赵红梅 《地理科学》2020,40(1):149-157

以河南省漯河市、周口市和驻马店市交界处为研究区,基于2000年10月~2011年12月间的101幅图像,采用谐波模型和断点识别算法拟合Landsat时间序列实现对过火像元的检测,并将结果与目视解译结果、MODIS火烧迹地产品MCD64A1检测结果对比进行精度分析。结果表明：① 随着燃烧面积指数BAI (Burned Area Index)异常值阈值增大,焚烧火点误判误差减小,漏判误差增大,火烧迹地制图的总体精度先增大后减小;② 当BAI异常值阈值2.9×RMSE（Root Mean Square Error）时,该方法总体精度达到最高93.25%,MCD64A1产品总体精度为70.25%;③ 本文算法的漏判误差和误判误差相对平衡,而MCD64A1产品的漏判误差远大于误判误差。研究表明,相比MODIS火烧迹地产品数据,Landsat时间序列火烧迹地法可更有效地检测农田火烧迹地。  相似文献   

Stress value in earthquake 2003 Dayao Ms6.1 source region     

Xiaofeng Xu  Yongge Wan  Huilin Wang 《地震学报(英文版)》2011,(4):343-350

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Mechanism of Underground Fluid Injection Induced Seismicity and Its Implications for CCS Projects   总被引：2，自引：0，他引：2  

Wei Xiaochen  Li Qi  Xing Huilin  Li Xiaying  Song Ranran 《地球科学进展》2014,29(11):1226-1241

CO₂ capture and storage projects must consider the potential possibility ofinjection induced seismicity. Moderate earthquakes and strong earthquakes may endanger human life and property, and even felt earthquakes and microquakes also pose a threat to seal integrity of CO₂ reservoir and increase the risk of leakage. Underground fluid injection induced seismicity usually happens in some geoengineering projects such as waste fluid disposal, EOR and EGS, and it occurs when fluid is injected along the fault. Therefore, it can be studied through stress analysis. The density of supercritical CO₂ is smaller than water, which may develop density flow in the deep strata or water-rock interactions in pre-existing structures, and cause the variation in permeability and pressure to induce a seismic activity. In this paper, we reviewed the mechanism of underground fluid injection induced seismicity with the focus of CCS, combined with fluid injection projects and seismic monitoring analysis in both commercial scale and experimental scale, to investigate its impact on the integrity of the cap rock of the reservoir. Finally, we summarized the appropriate site selection, injection methods and monitoring programs to prevent the occurrence of induced seismicity.  相似文献   

Application of a Degree-Day Model for Determination of Mass Balance of Urumqi Glacier No. 1, Eastern Tianshan, China     

吴利华  李慧林  王林 《中国地质大学学报(英文版)》2011,(4)

In order to verify the feasibility and stability of a degree-day model on simulating the long time series of glacier mass balance, we apply a degree-day model to simulate the mass balance of Urumqi Glacier No. 1 for the period 1987/1988-2007/2008 based on temperature and precipitation data from a nearby climate station. The model is calibrated by simulating point measurements of mass bal-ance, mass balance profiles, and mean specific mass balance during 1987/1988-1996/1997. The opti-mized parameters are obt...  相似文献   

Comparison of speleothem δO records from eastern China with solar insolation, ice core and marine records: Similarities and discrepancies on different time scales     

Naijung Wan  Weiling Chung  Hong-Chun Li  Huilin Lin  Teh-Lung Ku  Chuan-Chou Shen  Daoxian Yuan  Meiliang Zhang  Yushi Lin 《Journal of Asian Earth Sciences》2011,40(6):1151

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1960年以来中国天山冰川面积及气候变化   总被引：11，自引：3，他引：8  

王圣杰  张明军  李忠勤  王飞腾  李慧林  李亚举  黄小燕 《地理学报(英文版)》2011,21(2):263-273

Based on the statistics of glacier area variation measured in the Chinese Tianshan Mountains since 1960,the response of glacier area variation to climate change is discussed systematically.As a result,the total area of the glaciers has been reduced by 11.5% in the past 50 years,which is a weighted percentage according to the glacier area variations of 10 drainage basins separated by the Glacier Inventory of China (GIC).The annual percentage of area changes (APAC) of glaciers in the Chinese Tianshan Mountains is 0.31% after the standardization of the study period.The APAC varies widely for different drainage basins,but the glaciers are in a state of rapid retreat,generally.According to the 14 meteorological sta-tions in the Chinese Tianshan Mountains,both the temperature and precipitation display a marked increasing tendency from 1960 to 2009 at a rate of 0.34℃·(10a)-1 and 11 mm·(10a) -1,respectively.The temperature in the dry seasons (from November to March) increases rapidly at a rate of 0.46℃·(10a)-1,but the precipitation grows slowly at 2.3 mm·(10a)-1.While the temperature in the wet seasons (from April to October) grows at a rate of 0.25℃·(10a)-1,but the precipitation increases at 8.7 mm·(10a)-1.The annual and seasonal climatic trends ac-celerate the retreat of glaciers.  相似文献   

成昆铁路北段粘性泥石流浆体流变参数的时间效应     

赵惠林 《山地学报》1990,(2)

对成昆铁路北段一些粘性泥石流浆体所作的剪切试验结果表明,流变参数[含:表观粘度η和屈服应力(极限静切力)τ]随时间推移而变化。粘性泥石流浆体的流变参数具有时间依赖效应,随剪切时间推移而递增。粘性泥石流浆体呈现出反触变性的流变行为,随时间推移而变稠,就此越发变得不易流动。  相似文献   

数据源对大地水准面精度的影响分析     

李新法  陈永立  马会林 《测绘通报》2011,(6):36-38

组合法是目前我国省市进行大地水准面精化普遍采用的方法。通过对大地水准面精化时所用到的各种数据源进行分析,探讨各数据源对大地水准面精度的影响,并提出提高大地水准面精度的办法。  相似文献   

肺痨康对COPD模型大鼠脏器系数的影响     

王冬梅  王丽  贾慧琳 《应用海洋学学报》2019,35(4):144-145

目的：观察肺痨康对慢性阻塞性肺疾病（chronic obstructive pulmonary disease，COPD）模型大鼠脏器系数的影响，探究其对COPD模型大鼠是否具有治疗作用及其作用机制。方法：将60只SD雄性大鼠适应性喂养1周后随机分为空白组、模型组、地米塞松组及肺痨康高、中、低剂量组，采用香烟烟熏（CS）+脂多糖（LPS）气管内滴注复合因素法建立COPD大鼠模型，于造模第15天开始，肺痨康低、中、高剂量组分别予肺痨康药液0.1405、0.281、0.843ml/（kg·d）灌胃，地塞米松组予地塞米松每天每只0.054mg灌胃，空白组、模型组予相应体积0.9%氯化钠注射液灌胃，每天1次。灌胃14d后处死、取材、称重并计算相关脏器系数。结果：与模型组比较，地塞米松组、肺痨康高剂量组能不同程度地降低肺脏系数（P<0.01），提高脾脏系数和胸腺系数（P<0.01，P<0.05），肺痨康中、低剂量组能提高胸腺系数（P<0.01）。结论：肺痨康高剂量可减轻模型大鼠肺脏的炎症反应并增强其免疫力。  相似文献   

近50 年来天山地区典型冰川厚度及储量变化   总被引：8，自引：2，他引：6  

王璞玉  李忠勤  李慧林  吴利华  金爽  周平 《地理学报》2012,67(7):929-940

冰川储量变化与冰川水资源量变化以及冰川对河川径流的贡献量密切相关。在GPR-3S技术支持下, 本研究基于雷达测厚数据、不同时期的高分辨率遥感影像、地形图及实测资料, 分析了天山三个典型地区四条代表性冰川近期厚度及储量变化特征, 并通过对比探讨了造成变化差异的可能原因。结果表明, 1962-2006 年乌鲁木齐河源1 号冰川厚度平均减薄0.15m a^-1, 冰储量亏损26.2×10⁶ m³, 冰川末端平均退缩3.8 m a^-1;博格达峰南坡的黑沟8 号冰川在1986-2009 年间, 冰舌平均减薄0.57 m a^-1, 冰储量损失了25.5×10⁶ m³, 末端平均退缩11.0 m a^-1;位于博格达峰北坡的四工河4 号冰川在1962-2009 年间冰舌平均减薄0.32 m a^-1, 冰储量亏损14.0×10⁶ m³, 末端平均后退8.0 m a^-1;1964-2008 年间, 托木尔峰青冰滩72 号冰川冰舌平均减薄0.22 m a^-1, 由此至少造成冰储量亏损14.1×10⁶ m³, 末端退缩达40.0 m a^-1。对比分析显示, 青冰滩72 号冰川消融退缩最为强烈, 黑沟8 号冰川次之, 与乌鲁木齐河源1 号冰川、科其喀尔冰川相差不大, 稍大于四工河4 号冰川和哈密庙尔沟冰川。这种差异可能与区域气候变化和冰川物理特征有直接关系。  相似文献