海河流域NDVI对气候变化的响应研究

以海河流域为研究区,利用8 km分辨率AVHRR/NDVI数据和气象资料,逐像元对1981-2000年时段的流域NDVI值、年降水量和年均气温的变化率进行分析,计算了NDVI和年降水量、年均气温的相关关系.结果表明,1981-2000年时段内,海河流域年降水量变化总体呈现北部和南部增加,中部减少的趋势,其变化范围在-8...     

土壤湿度信息遥感研究

土壤湿度是农业生产与应用过程中非常重要的因素,决定农作物的水分供应状况.本文利用MODIS产品数据获取的归一化植被指数(NDVI)和陆面地表温度(Ts)构建Ts-NDVI特征空间,根据温度植被干旱指数(TVDI)的研究原理与方法,对研究区2010年5～8月份土壤湿度分布情况进行遥感监测.结合气象数据与土壤墒情资料对局部...     

华东地区气温变化对居住建筑能源消耗的影响研究

基于1961-2007年华东478个测站和2010-2039年RegCM3模式模拟的日平均气温资料,分析了华东采暖度日和制冷度日时空变化特征及其与气温变化的关系。结果表明,1961-2007年期间,华东采暖度日呈先增加后减少的变化趋势,制冷度日则呈先减少后增加的变化趋势。在2010-2039年期间,华东采暖度日将继续减...     

岚县近54年气候变化特征分析

利用吕梁高海拔山区代表站岚县气象观测站1957年-2010年的气温、年（季）降水量、年日照时数、年蒸发量等地面气象资料,应用线性趋势函数分析法进行了统计分析。结果表明：岚县年平均气温呈上升趋势,冬季增温最显著;降水量的变化总体上呈减少趋势,降水量的减少主要是夏季降水减少所引起。年日照时数有明显的下降趋势,年蒸发量则缓慢增加。     

Bacterioplankton dynamics along the gradient from highly eutrophic Pearl River Estuary to oligotrophic northern South China Sea in wet season: implication for anthropogenic inputs

Bacterioplankton abundance (BA) and biomass (BB) from the eutrophic Pearl River Estuary (PRE) to the oligotrophic northern South China Sea (NSCS) were studied in the wet season. BA was significantly higher (p < 0.05) in PRE (12.51 ± 3.52 × 10⁸ cells L⁻¹), than in the continental shelf neritic province (CSNP, 4.95 ± 2.21 × 10⁸ cells L⁻¹) and in the deep oceanic province (OP, 3.16 ± 1.56 × 10⁸ cells L⁻¹). Nutrient-replete PRE waters (DIN > 100 μM and PO₄ > 1 μM) resulted in high chl a and BB, whereas nutrient-depleted offshore waters (DIN <5 μM and PO₄ < 0.5 μM) had low biomass. Temperature (>26 °C) was not the controlling factor of BA. BB was significantly correlated with chl a biomass both in PRE and NSCS. The bacteria to phytoplankton biomass (BB/PB) ratio increased clearly along the gradient from near-shore PRE (0.15) to offshore CSNP (0.93) and deep OP (2.75), indicating the important role of small cells in the open ocean compared to estuarine and coastal zones.     

凌云县麻竹种植的气象条件分析

根据麻竹的生物学特性,结合凌云县1971～2000年30a的气候资料进行分析,得出：凌云县造林季节温度适宜．旺长期和出笋期水分条件充分,地形、土壤符合种植条件,是种植麻竹理想的区域,但个别年份干旱、雨涝和低温冻害等是影响麻竹生长和产量的不利因素,应加以防范,以达到充分利用当地气候资源,提高麻竹产量和品质及进一步推广发展...     

Structure of gravel beaches and their relationship to tidal range

The height of accretionary gravel beaches, determined by the vertical distance between the large sphere zone at the seaward margin and the large disc zone at the landward margin, is determined mainly by tidal range. As the beach builds seaward, this height translates into thickness and so the complete thickness of gravel beach accumulations is a good indicator, in the geological record, of tidal range. Beaches with a small tidal range have the zone between the large discs and the large spheres compressed and sometimes steepened. These beaches are characterized mainly by cusps and berms, both of which yield steeply dipping, seaward building, cross‐strata. Beaches built by large, persistent waves generally have a steep profile, whereas those with small wave height appear to have a shallow profile. Cusps generally have extremely well‐sorted gravels, often in an openwork fabric and with a landward crown of coarse gravel that may grade seaward into shape‐sorted, gently dipping gravels. Berms, which may extend for hundreds of metres along the coast, comprise, in section, very well‐sorted cross‐stratified gravels that may intermittently build seaward for a distance >15 m. Extensive selection pavements typify beaches with a high tidal range and comprise sheets of gravel which are well‐sorted and dip at comparatively low angles towards the sea. These selection pavements form beds that, in section, can be >50 m in seaward length; they grow from clasts, supplied to them from swash or backwash, and which are selected by the fabric of the existing sheet. In some cases, the selection pavements can be very mature having only a specific clast shape and size remaining. Total preservation of the beach sequence in the geological record is more likely to take place in areas of rapid deposition of sediments, such as the marine fringes to a fan delta.     

Quantitative estimates of temperature and precipitation changes over the last millennium from pollen and lake-level data at Lake Joux, Swiss Jura Mountains

This paper presents quantitative climate estimates for the last millennium, using a multi-proxy approach with pollen and lake-level data from Lake Joux (Swiss Jura Mountains). The climate reconstruction, based on the Modern Analogue Technique, indicates warmer and drier conditions during the Medieval Warm Period (MWP). MWP was preceded by a short-lived cold humid event around AD 1060, and followed by a rapid return around AD 1400 to cooler and wetter conditions which generally characterize the Little Ice Age (LIA). Around AD 1450 (solar Spörer minimum), the LIA attained a temperature minimum and a summer precipitation maximum. The solar Maunder minimum around AD 1690 corresponded at Joux to rather mild temperatures but maximal annual precipitation. These results generally agree with other records from neighbouring Alpine regions. However, there are differences in the timing of the LIA temperature minimum depending on the proxy and/or the method used for the reconstruction. As a working hypothesis, the hydrological signal associated with the MWP and LIA oscillations at Lake Joux may have been mainly driven by a shift around AD 1400 from positive to negative NAO modes in response to variations in solar irradiance possibly coupled with changes in the Atlantic meridional overturning circulation.     

阿坝-简阳地学剖面深部温度及热结构

在青藏高原东部到四川盆地这两个构造单元进行了稳态钻孔温度测量和岩石热导率测试,确定了相应钻孔的大地热流数据.应用这些可靠的热流数据,对横穿这两个构造单元的阿坝-简阳地学断面进行了2-D温度场研究,获得其深部热结构的认识.模拟结果显示,松潘-甘孜地块地表为高热流区域,达到80～110 mW/m2,四川盆地地表为中低热流区...     

Block-supported cataclastic flow within the upper crust

Recent work from portions of the Sevier fold-thrust belt that have deformed primarily within the elastico-frictional regime, demonstrates that cataclastic flow can be subdivided into two types: matrix- and block supported. The two types may operate simultaneously within the same deforming material. However, their activity can vary spatially, temporally and across scales. Although block-supported cataclastic flow is a critical process in upper crustal deformation, it continues to be largely ignored and/or misunderstood, primarily because established concepts and definitions for cataclastic flow are chiefly based on matrix-supported cataclastic flow. Here, block-supported cataclastic flow is examined to better understand cataclastic flow in general and to explore its relationship with matrix-supported cataclastic flow.