基于遥感技术的兖济滕矿区采煤沉陷区现状及动态变化特征

利用遥感技术,对兖济滕矿区2000-2010年的采煤沉陷区动态变化进行了研究,结果表明,2010年,兖济滕矿区累计沉陷面积为88．43km^2,占整个矿区面积的3．53％。10年来,沉陷区面积呈直线上升趋势,由2000年的57．37km^2,增加到2010年的88．43km^2,平均年增沉陷地面积约为3．45km^2。采用遥感手段,在大范围内,可以较直观、准确地确定采煤沉陷区的范围、面积、形态、动态变化等特征,可为沉陷区的综合治理提供科学依据。     

新疆渭干河流域土壤盐渍化时空变化及成因分析

以1985 年渭干河流域土壤普查数据、1998 年Landsat TM影像和2008 年CBERS影像为数据源, 通过人机交互解译方式获取3 个时期土壤盐渍化分布状况, 然后采用GIS空间分析方法对23 年来土壤盐渍化时空变化特征进行分析。结果表明:①1985-2008 年, 总趋势是随着流域灌区和耕地面积的扩大, 盐渍化耕地也随之增加, 土壤盐渍化耕地面积由13.32×10⁴hm²增至13.78×10⁴hm²。②流域土壤盐渍化现象普遍, 主要分布在绿洲的下部边缘地带, 河流中下游、地势平缓低洼等区域, 盐渍化耕地在绿洲内部呈条形状分布, 在绿洲外围呈片状分布。③河道、渠系和水库渗漏、耕作制度不合理、土地不平整和气候变化等多种因素导致渭干河流域土壤盐渍化扩大, 但在局部地区由于生态恢复和改良利用措施, 使得土壤盐渍化面积也有缩减。     

Manmade Vulnerability of the Cancun Beach System: The Case of Hurricane Wilma

Climate change and resultant coastal erosion and flooding have been the focus of many recent analyses. Often these studies overlook the effects of manmade modifications to the coastline which have reduced its resilience to storm events. In this investigation, we integrate previous reports, historical photo analysis, field work, and the application of numerical models to better understand the effects of Wilma, the most destructive hurricane to affect Cancun, Mexico. Huge waves (of significant height, >12 m), long mean wave periods (>12 s), devastating winds (>250 km/h), and powerful currents (>2 m/s) removed >7 million cubic meters of sand from the Cancun beach system, leaving 68% of the sub‐aerial beach as bedrock, and the rest considerably eroded. Numerical simulations show that the modifications to the barrier island imposed by tourist infrastructure have considerably increased the rigidity of the system, increasing the potential erosion of the beach under extreme conditions. If there were no structural barriers, a series of breaches could occur along the beach, allowing exchange of water and alleviating storm surge on other sections of the beach. If the effects caused by anthropogenic changes to Cancun are ignored, the analysis is inaccurate and misleading.     

Structure and seasonal changes in atmospheric boundary layer on coast of the east Antarctic continent

The temperature, humidity, and vertical distribution of ozone in the Antarctic atmospheric boundary layer（ABL） and their seasonal changes are analyzed, by using the high-resolution profile data obtained during the International Polar Year 2008 to 2009 at Zhongshan Station, to further the understanding of the structure and processes of the ABL. The results show that the fre- quency of the convective boundary layer in the warm season accounts for 84% of its annual occurrence frequency. The frequency of the stable boundary layer in the cold season accounts for 71% of its annual occurrence frequency. A neutral boundary layer ap- pears rarely. The average altitude of the convective boundary layer determined by the parcel method is 600 m; this is 200 to 300 m higher than that over inland Antarctica. The average altitude of the top of the boundary layer determined by the potential tempera- ture gradient and humidity gradient is 1 200 m in the warm season and 1 500 m in the cold season. The vertical structures of ozone and specific humidity in the ABL exhibit obvious seasonal changes. The specific humidity is very high with greater vertical gradi- ent in the warm season and very low with a lesser gradient in the cold season under 2 000 m. The atmospheric ozone in the ABL is consumed by photochemical processes in the warm season, which results in a slight difference in altitude. The sub-highest ozone center is located in the boundary layer, indicating that the ozone transferred from the stratosphere to the troposphere reaches the low boundary layer during October and November in Antarctica.     

Boundary shift of potential suitable agricultural area in farming-grazing transitional zone in Northeastern China under background of climate change during 20th century

Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded： 1） The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2） The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3） The western and eastern boundaries of the suitable agricul~re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.     

中国海洋经济发展的时空差异及其动态变化研究

中国海洋经济近年来快速发展,但地区差异明显。以沿海11个省市区为研究对象,从时间与空间2个角度,运用变差系数及加权变差系数来表现1996~2010年沿海省市经济发展的差异程度,结果表明中国沿海省市海洋经济成倍增长,总体差异在波动中减小;采用区位熵、洛伦兹曲线及基尼系数对海洋产业结构及其空间布局演化进行分析,得出海洋产业结构向高级阶段演进,海洋产业集聚规模有所减弱,各产业趋于均衡发展;具有资源属性的海洋产业集聚程度最高,海洋第三产业集聚程度降低;利用主成分分析法对沿海省市的海洋经济发展进行综合评价将其分为3个梯队;使用R/S分析法对沿海地区差异情况进行预测,显示未来差距有增大的趋势。最后从提高海洋资源开发能力、提高海洋经济发展质量等角度提出了具体建议。     

陕西省碳足迹时空变化研究

为了解近年来陕西省碳足迹的状况,采用《2006年IPCC国家温室气体清单指南》和中国《省级温室气体编制指南》推荐的方法测算了陕西省及其各市的碳足迹。结论如下：1995~2009年,陕西省碳足迹从4 129.38×10⁴t上升到22 460.23×10⁴t,增加了443.91%。从空间上全省碳足迹可分为3类：陕南始终为负值;陕北和渭南市较高;关中除渭南市以外的地区较低。14 a间全省人均碳足迹由1.18 t增加到5.95 t;各市人均碳足迹,陕北较高,关中较低,陕南为负值。全省碳足迹密度从2.00 t/hm²增高到10.90 t/hm²。陕西省的人均和单位面积的碳足迹远高于应对全球气候变化的目标,但空间上差异很大。以2009年为例,全省人均碳足迹是应对全球气候变化目标的2.98倍,而陕北则超过10倍,高于美国;关中为1.29~4.57倍。全省2009年碳足迹密度是应对全球气候变化目标的4.89倍;渭南、咸阳、西安3市高达9.63~16.95倍;榆林、铜川、延安和宝鸡4市为3.54~7.10倍;陕南植被的固碳作用消除了当地的碳排放外,还有剩余碳汇,但尚不能抵消陕北及关中的较高的碳足迹,因此总体看,对气候变化有负面影响,陕西的碳减排任务仍较重。     

Human influence, plant landscape evolution and climate inferences from the archaeobotanical records of the Wadi Teshuinat area (Libyan Sahara)

Central Sahara rock shelters offer an early and middle Holocene environmental reconstruction. This paper summarises palynological research carried out within a multidisciplinary archaeological research project on the Wadi Teshuinat area (Tadrart Acacus Mts., in south-western Fezzan, Libya). The sites were occupied by hunter-gatherer and pastoralist cultures. On-site pollen data, treated as a single ‘regional site’, showed that different pollen stratigraphies and flora characterised the past phases. Plant macro-remains also helped to understand local plant exploitation and landscape evolution. Pollen spectra showed the following climate oscillations: wet and cool (approx. 8800–8250 cal. BC), dry and warm (approx. 7920–7520 cal. BC), wet (approx. 7550–7200 cal. BC), dry (approx. 6340–6210 cal. BC—geoarchaeological evidence), wet and warm (approx. 6250–4300 cal. BC, including a wetter and warmer phase at approx. 5500–4600 cal. BC); dry and warm (approx. 4250–2900 cal. BC); drier and warm (approx. 2900–1600 cal. BC, up to the present). Since the early Holocene, both climatic and anthropic factors have played an important and strictly interconnected role in transforming the environment. Thus, while subsistence strategies were adjusting to climatic and environmental changes, the plant landscape was also being slowly and continuously shaped by humans.     

Geomorphic evidence of major sea-level fluctuations during marine isotope substage-5e, Cape Cuvier, Western Australia

A detailed geomorphologic and morphostratigraphic investigation of raised marine terraces at Cape Cuvier, Western Australia, reveals two morphologically distinct units. A lower, well-developed accretional reef terrace between 3 and 5.5 m above MLWS (mean low-water springs; hereafter denoted as “+”) represents an extended interval of stable sea level. An upper erosional terrace and incipient coralgal rim between + 8.5 to 10.5 m represents a brief sea-level stillstand at this higher elevation. These features suggest the lower and upper terraces developed during discrete sea-level events. In an attempt to better define the timing of emplacement of each marine unit, 20 coral samples collected along vertical and lateral reef growth axis from both terraces were analysed with U-series dating. Unfortunately, all coral samples exhibited elevated δ²³⁴U_initial values, suggesting that pervasive uptake of ²³⁴U-enriched uranium and ²³⁰Th thorium had occurred. Despite the shortcomings of absolute dating, a succession of events can be resolved though morphostratigraphic relationships. Comparison of the facies relationships, coral growth, and morphostratigraphic features between the lower and upper terraces indicates that an early to mid MIS 5e stillstand at + 3 to 5 m was followed by a late rise to + 8.5 to 10.5 m. This agrees with an emerging global view of MIS 5e sea-level history derived from stable carbonate platforms, rejecting the hypothesis that these higher sea-level benchmarks are an artefact of localized tectonic processes.     

乾安县40年气候变化的分析

利用东北地区月平均气温、降水量、蒸发量等资料,计算了宁夏季气温和降水的相关系数,表明东北地区西部复季气温与降水量呈显著负相关.从年代际变化的分析中得知,20世纪90 年代暖干趋势明显,其中以乾安最为突出.分析乾安及其邻近测站蒸发量的年代际变化,表明乾安的夏季蒸发量上升趋势明显,并远大于其他测站,对环境的不良影响加重,而存下垫面条件较好一些的区域,夏季蒸发量呈下降趋势.乾安县未来复季气温仍为上升趋势,降水量存总体平均值之下呈旱.涝交替变化.