青藏高原高寒草地植被指数变化与地表温度的相互关系

为了解脆弱的高原生态环境对升温过程的响应, 利用1982-2006年国家标准地面气象站地表温度和GIMMS-NDVI数据集, 探讨了青藏高原高寒草地植被指数和地表温度的变化特征及其相互关系. 结果表明:1982-2006年, 高寒草地NDVI、地表温度整体均呈现增加趋势, 年均NDVI、生长季NDVI、年最大NDVI(NDVI_max)与年均地表温度、生长季地表温度的上升趋势分别为0.007 (10a)^-1、0.011 (10a)^-1、0.007 (10a)^-1与0.60 ℃·(10a)^-1、0.43 ℃·(10a)^-1; NDVI_max与地表温度显著相关的地区达70.49%. 但是高原地形、气候、水文环境的空间差异性导致高寒草地NDVI与地表温度的相关关系十分复杂. NDVI_max与年均地表温度的相关性最为显著; 在返青期和枯萎期, NDVI与地表温度均为显著正相关. 不同的植被覆盖条件下, NDVI对地表温度的响应不同:植被覆盖差以及退化严重的地区, NDVI_max与地表温度呈负相关性; 反之, NDVI_max与地表温度主要表现为正相关.     

黑龙江省漠河地区土地覆被与地表温度时空变化特征研究

以我国高纬度多年冻土区漠河县城区及郊区862 km²的区域为研究对象,基于RS和GIS技术对该区地表覆被变化和地表温度进行研究。结果表明：地表类型和地表温度反演结果与现场比对结果一致;从1988年到2015年,经过火灾后重建和城镇化发展,建设用地面积增加了11.33 km²;以2015年为例,冬季由于积雪覆盖,有79.02%的区域无植被覆盖,夏季有80.91%的区域为高植被覆盖。冬季地表温度和高程具有高度相关性,高程每升高100 m,地表温度平均升高2.27℃,表明该区地表温度也存在显著的逆温现象。该区城镇热岛效应全年存在,城镇区域地表温度高于全区平均值,夏季最显著,最高温差可达6.37℃。地表温度与NDVI具有明显的负相关关系;不同土地利用类型地表温度由低到高的顺序为水体-林地-草地-裸地-建筑用地。     

新疆冬春季积雪及温度对冻土深度的影响分析

利用新疆64个气象台站1960-2010年的气象资料,分析了新疆50 a来冻土深度的变化趋势,并讨论了温度（平均地温、平均气温）、降水（冬春季年降水、平均积雪深度）与冻土深度（平均冻土深度、最大冻土深度）的相关关系. 结果表明：以10 a时段的年代际变化分析,新疆50 a来平均冻土深度和最大冻土深度均呈明显减小趋势. 50 a来平均冻土深度全疆、北疆、南疆分别减小了约7 cm、10 cm、4 cm,最大冻土深度则分别减小了约11 cm、16 cm、9 cm. 新疆50 a来平均气温和平均地温均呈波动上升趋势,且与冻土深度均有着良好的相关性,其与平均冻土深度的相关系数分别达到了-0.67、-0.77,与最大冻土深度的相关系数也分别达到了-0.51、-0.65,地温与气温的上升对应着冻土深度的减小. 新疆冬春季年降水与冻土深度有着较好的相关性,其与平均冻土深度、最大冻土深度的相关系数分别达到了-0.40、-0.37. 新疆的平均积雪深度与冻土深度也有着一定的弱相关,其原因与积雪对地面的保温作用有关.     

Groundwater flow and solute transport at the Mourquong saline-water disposal basin, Murray Basin, southeastern Australia

Saline groundwater and drainage effluent from irrigation are commonly stored in some 200 natural and artificial saline-water disposal basins throughout the Murray-Darling Basin of Australia. Their impact on underlying aquifers and the River Murray, one of Australia's major water supplies, is of serious concern. In one such scheme, saline groundwater is pumped into Lake Mourquong, a natural groundwater discharge complex. The disposal basin is hydrodynamically restricted by low-permeability lacustrine clays, but there are vulnerable areas in the southeast where the clay is apparently missing. The extent of vertical and lateral leakage of basin brines and the processes controlling their migration are examined using (1) analyses of chloride and stable isotopes of water (²H/¹H and ¹⁸O/¹⁶O) to infer mixing between regional groundwater and lake water, and (2) the variable-density groundwater flow and solute-transport code SUTRA. Hydrochemical results indicate that evaporated disposal water has moved at least 100 m in an easterly direction and that there is negligible movement of brines in a southerly direction towards the River Murray. The model is used to consider various management scenarios. Salt-load movement to the River Murray was highest in a "worst-case" scenario with irrigation employed between the basin and the River Murray. Present-day operating conditions lead to little, if any, direct movement of brine from the basin into the river. Electronic Publication     

A semi‐analytical solution of surface flow and subsurface flow on a slope land under a uniform rainfall excess

A new approach is proposed to analyze the surface flow and subsurface flow passing over a pervious ground under a uniform rainfall excess. The flow field is divided into two regions that are called water layer and soil layer. To figure out the hydraulic behavior of overland flow on an inclined plane under a rainfall event, the simplified Navier–Stokes equations are employed for the surface water flow, and the flow inside the soil layer is porous media flow, which is governed by Biot's (1956, 1962) theory of poroelasticity. The velocity distribution of overland flow is nonzero at the ground surface. The relation between water depth and slope length was developed first. The profile of surface water flow was then found backwards from the downstream end of the flow section by the Runge–Kutta method. After that, the flow velocity and flow discharge of each layer could also be obtained via the water depth. Finally, the variation of fluid shear stress inside the soil layer is also discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

Heat flow and destabilized cratons: a comparative study of the North China,Siberian, and Wyoming cratons

Heat has a close relation to cratonic stability. We reconstructed the thermal history of the eastern North China, Wyoming, and Siberian cratons by using xenolith and thermal indicator data, and then the thermal lithospheric thickness in geological time was calculated by combining the crustal structural and thermal parameters. Researches from three cratons demonstrate that heat-flow values of the eastern North China Craton (eNCC) and Wyoming Craton (WC) have increased exceeding 20 mW/m² in the Meso-Cenozoic and the thermal lithospheric thickness has decreased by >100 km because of the cratonic destabilization. However, the thermal history variation of the Siberian Craton (SC) is small, ~5 mW/m², the lithosphere has remained stable and it has experienced relatively little lithospheric thinning <100 km. The differences of the cratonic thermal regime are related to the breakup of the Pangea supercontinent. Destabilized cratons on active continental margin are directly affected by plate subduction. Stable cratons in the interior of the supercontinents are directly affected by the upwelling of superplumes and that may result in lithospheric thinning. Differences in the thermal evolutions of cratons provide new geothermal evidence for the different thermal regimes associated with the breakup of the Pangea supercontinent.     

北京城区2000—2014年地表温度反演及因素分析

传统的城市温度监测方法周期长、效率低,而利用热红外遥感影像进行城区温度监测的方法具有准确、简便、实用等优点。基于Landsat TM、ETM+、OLI遥感影像数据,应用辐射传输方程法对北京城区（东城区、西城区、宣武区、崇文区、朝阳区、海淀区和丰台区7个区域）2000—2014年夏季地表温度的空间分布和时间变化进行分析及温度反演,结果显示,高温区分布有一定的规律,降雨情况、植被覆盖度的变化以及城区规划都是北京城区温度变化的重要影响因素。研究结果可为减缓北京的热岛效应提供依据。     

济阳坳陷地幔热流和深部温度

济阳坳陷深部地热状况对于分析岩石圈深部结构特征、探索该盆地形成和演化的地球动力学过程具有重要意义.依据济阳坳陷最新的钻探资料和深部地球物理探测结果, 按沉积盖层、上、中、下地壳4层结构, 建立了分别代表该区凹陷部位和凸起及斜坡带上的2种地壳结构模型.通过多道能谱分析, 测试了区内4 3块岩心样品的放射性元素U、Th、40K含量, 统计得出了济阳坳陷沉积盖层的平均生热率为(1.40±0.26) μW/m3.在研究大地热流分布的基础上, 结合济阳坳陷地壳各岩层放射性生热率, 采用“剥层”法, 从地表开始, 由浅到深逐步扣除各层段所提供的热量, 得到了济阳坳陷的地幔热流.并且采用相似的方法, 利用一维稳态热传导方程, 分析了地壳上地幔顶部的温度状况.结果表明, 济阳坳陷的地幔热流约为38.4~39.2 mW/m2, 占整个地表总热流量的5 8%;地幔顶部温度约为602~636℃.与世界上其他各类地质构造单元相比, 济阳坳陷无论是地幔热流值或其与地表热流之比值都是比较高的, 其深部地热状态具有介于稳定地区和构造活动区之间的特点.      

Causes of geothermal fields and characteristics of ground temperature fields in China

There are many arguments on energy sources and main controlling factors of geothermal fields, so a systematic study on the distribution of ground temperature fields shall be necessary. In this paper the thermal conduction forward method of geothermal field is used to simulate cooling rate of abnormal heat sources and heat transfer of the paleo-uplift model. Combined with a large number of geothermal field exploration cases and oil exploration well temperature curves of domestic and foreign, the following conclusions are drawn:(1) According to the magmatic activity time, the magmatism activities are divided into two categories: Magma active areas(activity time 500 000 years) and weak/magma inactive areas(activity time 500 000 years). The latter has a fast cooling rate(the cooling time of the magma pocket buried around 10 km is less than 200 000 years) after it has intruded into the shallow layer and it has no direct contribution to modern geothermal fields;(2) China belongs to a weak/magma inactive area such as Tengchong region and Qinghai-Tibet region because the chronological data of these regions show that its magma activity time is more than 500 000 years;(3) The temperature of most geothermal fields can be obviously divided into three segments in the vertical direction: A high geothermal gradient segment(Segment H) at the surface, then a low geothermal gradient segment(Segment L) at a secondary depth, and finally a lower temperature segment(Segment D) at a deeper depth. The temperature isoline presents a mirror reflection relation on the temperature profile, indicating that geothermal field is dominated by heat conduction, rather than having an abnormally high temperature "heat source" to provide heat;(4) Near-surface(0-5 km) materials' lateral heterogeneity caused by tectonic movement shall probably be the main controlling factor of ground temperature fields.     

江汉盆地钻井地温测量和大地热流分布

盆地的稳态温度是分析地温场和大地热流的基础,是盆地构造热演化的必要前提。本文根据最新获得的9口钻井的稳态温度数据和124块岩石热导率,结合已有资料对江汉盆地地温梯度和大地热流进行了系统分析。结果显示江汉盆地热流41.9～60.9 mW/m~2,平均52.3mW/m~2,盆地总体表现为较低的大地热流,反映了中新生代以来构造活动逐渐减弱,盆地不断冷却的结果;从盆地内热流分布看,热流分布南高北低,反映了江汉盆地构造活动的不均一性。     

Causes of geothermal fields and characteristics of ground temperature fields in China

There are many arguments on energy sources and main controlling factors of geothermal fields, so a systematic study on the distribution of ground temperature fields shall be necessary. In this paper the thermal conduction forward method of geothermal field is used to simulate cooling rate of abnormal heat sources and heat transfer of the paleo-uplift model. Combined with a large number of geothermal field exploration cases and oil exploration well temperature curves of domestic and foreign, the following conclusions are drawn: (1) According to the magmatic activity time, the magmatism activities are divided into two categories: Magma active areas (activity time < 500 000 years) and weak/magma inactive areas (activity time > 500 000 years). The latter has a fast cooling rate (the cooling time of the magma pocket buried around 10 km is less than 200 000 years) after it has intruded into the shallow layer and it has no direct contribution to modern geothermal fields; (2) China belongs to a weak/magma inactive area such as Tengchong region and Qinghai-Tibet region because the chronological data of these regions show that its magma activity time is more than 500 000 years; (3) The temperature of most geothermal fields can be obviously divided into three segments in the vertical direction: A high geothermal gradient segment (Segment H) at the surface, then a low geothermal gradient segment (Segment L) at a secondary depth, and finally a lower temperature segment (Segment D) at a deeper depth. The temperature isoline presents a mirror reflection relation on the temperature profile, indicating that geothermal field is dominated by heat conduction, rather than having an abnormally high temperature “heat source” to provide heat; (4) Near-surface (0-5 km) materials’ lateral heterogeneity caused by tectonic movement shall probably be the main controlling factor of ground temperature fields.     

青藏高原东部春季感热通量与我国东部气温的年际关系

利用ERA-Interim提供的地表感热、环流场资料和1979-2013年753站中国春季气温观测资料探讨了青藏高原（以下简称高原）东部春季感热通量与我国东部气温的关系。春季高原东部感热与我国东部气温在年际变化上存在密切的相关关系。去除9年滑动平均以后的SVD第一模态结果表明,当高原东部感热出现南弱（强）北强（弱）时,对应我国东北和华南地区的气温异常偏低（高）。当春季高原感热呈现南负北正的分布时,高层200 hPa上,高纬东风异常减弱背景西风有利于冷空气的南下,加之副热带西风急流显著增强,有利于东北地区形成气旋性环流。中低层环流场上,我国北方地区上空为一深厚的东北冷涡所控制,从对流层低层到高层,均呈现较强的气旋式环流分布。一方面,它引导西伯利亚冷空气南下,造成我国东北地区气压异常减弱,气温异常偏低;另一方面,其西侧北风异常阻滞了华南地区上空的背景西南风,不利于暖气流的输送。进一步分析得出,与PC1相关的南北温度差值场上,东亚地区上空从低纬到高纬呈现“负-正-负”的分布形势,有利于副热带西风急流在我国上空的显著增强。气旋中心上暖下冷的结构,导致位涡显著发展并向低层伸展、侵入,增强了对流层中低层的气旋性环流。气旋中心整个对流层为深厚的异常干空气,湿度负值中心与冷中心相对应,表明干冷空气异常下传发展。干侵入使得冷涡加强发展,维持了异常气旋性环流,导致春季东北、华南地区的异常降温。虽然前冬Nino3.4区海温与春季感热相关较好,但其对我国东部春季气温影响并不显著。     

鄂尔多斯盆地中生代晚期以来大地热流的变化及其对生态环境格局和演变的影响

鄂尔多斯盆地的西北部、东北部和南部三个区域现今大地热流平均值分别为56．3、67．3和65．3mW／m^2，对应的生态环境格局也有明显的差异。研究表明，大地热流每增加4～5mW／m^2可使年均地表温度升高约l℃，使最低月均地表温度升高2。C以上。鄂尔多斯盆地东北部的平均大地热流比西北部高出11mW／m^2，东北部年均地表温度可能比西北部高出2～3℃，其最低月均地表温度可能比西北部高出4～6℃。西北部的大地热流平均值已经低于维持地表生态系统延续所需大地热流的临界值(57mW／m^2)，其自然生态系统整体上已经处于脆弱境地；东北部和南部的大地热流均大于57mW／m^2，自然生态系统均尚较稳健。东北部的沙漠化可能是风沙侵入的结果，其生态应该是可以恢复的。整个西北部作为一个整体看，72万年以前大地热流就已衰减到临界值以下，区域生态系统渐趋脆弱，开始整体上向荒漠化演变。     

The permafrost regime in the Mackenzie Delta,Beaufort Sea region,N.W.T. and its significance to the reconstruction of the palaeoclimatic history

Observed depths to the base of the ice-bearing permafrost (!BPF) as determined from geophysical well-log and survey information in the Mackenzie Delta and offshore Beaufort Sea continental shelf show significant variation. Depths range from over 700m beneath the northeastern portion of Richards Island and the adjacent offshore region to the north, to less than 100m in the modern Mackenzie Delta and offshore Mackenzie Bay regions. Along the Tuktoyaktuk Peninsula, permafrost thicknesses exceed 600m but tend to thin to less than 100m in a southeasterly direction. The wide variation in the thickness and distribution of permafrost is due in part to differences in the subsurface deltaic lithologies and to the complexity of the past surface temperature history, exhibited, for example, by fluctuations of the mean annual ground temperature. Geological cross-sections showing variation in the Tertiary and Upper Cretaceous deltaic sequences indicate a good correlation with the permafrost distribution. In particular, where the sand and gravel units of the Iperk and Kugmallit Sequences predominate, permafrost is thick owing to the high thermal conductivities of the ice-rich sediments. Conversely, where the low thermal conductivity shales and mudstones of the Richards Sequence are present, permafrost is accordingly thinner. Numerical models of permafrost aggradation in the Mackenzie Delta region suggest that Early and Late Wisconsinan surface temperatures were of the order ?18°C. A mid-Wisconsinan rise in temperature to approximately ?8°C, similar to mean surface temperature today, is also indicated. This proposed palaeoclimate is sufficient to account for the observed maximum permafrost thicknesses in the region.     

Heat flow and crustal thermal structure in the Late Archaean Closepet Granite batholith,south India

The Late Archaean Closepet Granite batholith in south India is exposed at different crustal levels grading from greenschist facies in the north through amphibolite and granulite facies in the south along a ∼400 km long segment in the Dharwar craton. Two areas, Pavagada and Magadi, located in the Main Mass of the batholith, best represent the granitoid of the greenschist and amphibolite facies crustal levels respectively. Heat flow estimates of 38 mW m⁻² from Pavagada and 25 mW m⁻² from Magadi have been obtained through measurements in deep (430 and 445 m) and carefully sited boreholes. Measurements made in four boreholes of opportunity in Pavagada area yield a mean heat flow of 39 ± 4 (s.d.) mW m⁻², which is in good agreement with the estimate from deep borehole. The study, therefore, demonstrates a clear-cut heat flow variation concomitant with the crustal levels exposed in the two areas. The mean heat production estimates for the greenschist facies and amphibolite facies layers constituting the Main Mass of the batholith are 2.9 and 1.8 μW m⁻³, respectively. The enhanced heat flow in the Pavagada area is consistent with the occurrence of a radioelement-enriched 2-km-thick greenschist facies layer granitoid overlying the granitoid of the amphibolite facies layer which is twice as thick as represented in the Magadi area. The crustal heat production models indicate similar mantle heat flow estimates in the range 12–14 mW m⁻², consistent with the other parts of the greenstone-granite-gneiss terrain of the Dharwar craton.     

青藏高原初春积雪的多尺度变化与北大西洋海温的关系

青藏高原冬、春季积雪变化影响东亚甚至全球春、夏季的环流及气候异常。利用中国西部环境与生态科学数据中心提供的中国雪深长时间序列数据集,美国大气海洋局提供的全球逐月扩展重建海表温度,以及欧洲中期天气预报中心提供的逐月再分析数据,对青藏高原初春（3、4月）积雪的多尺度变化与北大西洋海表温度的关系进行了研究。结果表明,初春青藏高原雪深异常与初春北大西洋关键区海温异常有显著的负相关关系。当初春关键区海温正（负）异常时,初春高原中部偏北腹地地区、东南部地区积雪深度减少（增加）;初春北大西洋关键区海温异常通过激发下游青藏高原上空大气波列以及波作用通量异常来影响高原局地区域的温度和垂直运动,从而影响降雪的产生和积雪的累积。该结果为青藏高原初春积雪的多尺度变化及其影响提供了依据。     

中俄原油管道工程(漠河大庆段)沿线气温、地表和浅层地温年际变化特征

分析了中俄原油管道(漠河-大庆段)沿线自建站至2005年的月平均气温和地温观测资料,并通过插补建立了1961—2005年漠-大沿线各站各季及年平均温度资料完整序列.结果表明:各站年平均气温具有很好的相关性,近40多年年平均气温在20世纪60年代最低,70年代略有回升,80年代后气温逐渐升高,进入90年代后期升温有所减缓;沿线各站的年平均地表温度也是20世纪70年代最低,70年代进入80年代升温最明显.气温升温最显著的是冬、春季,升温率分别达到0.71℃.(10a)-1和0.48℃.(10a)-1,夏季升温率只有0.27℃.(10a)-1.年平均气温和地表温度的升温率分别为0.45℃.(10a)-1和0.27℃.(10a)-1,气温的升温比地表温度要快.年平均地表温度要比年平均气温高,深层地温的变化趋势与气温基本一致,在位相上有1～2a的差异.     

广东阳江盆地遥感数据地温反演及地热异常靶区圈定

地热能是一种安全、清洁、稳定的可再生能源,广东阳江地区的地热资源开发潜力巨大,但研究程度较低。热红外遥感技术能够高效地圈定地热异常区并对隐伏断裂进行预测,笔者等选取研究区landsat8遥感数据,通过分析地表温度、地热异常点及人类活动的关系,利用大气校正方法对该区潜在的地热异常进行了预测。在排除人为热影响下得到高温地热异常区9处,排除湖泊水域以及海拔的影响下得到低温地热异常区4处。在此基础上,利用地表温度与归一化植被指数计算研究区的温度植被干旱指数值（TVDI）,预测可能存在的隐伏断裂23 处。最后结合岩性、断裂构造有效地圈定了5处地热靶区,主要分布在研究区西南区域和新洲镇附近。研究结果有助于预测阳江地区具有开发前景的地热异常区、识别圈定具有勘探意义的靶区以及预测隐伏断裂,对该区后续地热资源的进一步研究具有重要的意义。     

雅鲁藏布江大拐弯入口段泥石流特征及应对措施

雅鲁藏布江大拐弯入口段活动的地质构造、特殊的地形与气候条件酿就了暴雨泥石流及冰川泥石流等地质灾害。近60a来,则隆弄冰川泥石流曾两度摧毁直白村;鲁霞-德阳段暴雨泥石流的洪积扇已经深入雅鲁藏布江中,该段河道处于半阻塞状态。两处地点的泥石流对上下游村庄、城镇及设施带来严重威胁。依据地貌调查及室内DEM定量分析,了解泥石流地质灾害的空间分布特征及其成因,对前人认为则隆弄冰川泥石流堰塞雅鲁藏布江造成上游回水成湖淹没米林、林芝等地的观点提出了新的看法;米林、林芝古淹没事件可能是对多地点泥石流爆发的响应。对米林—加拉一线不同地点不同类型的泥石流灾害可能造成的不良环境效应进行评估后提出几点应对措施。