具有软弱基座的逆向岩质斜坡形成演化机理研究

通过地质分析及数值模拟分析,研究青川县一个下部具有软弱基座、上部为硬质岩体的大型逆向层状岩质斜坡的变形破坏。得出其演化的地质力学模式为压致蠕变、拉裂、倾倒型。即软弱基座的压缩蠕变引起上部硬质岩体拉裂和弯曲,最终导致斜坡后缘拉张开裂而前缘压缩弯曲的倾倒式变形。     

广饶县蔬菜基地生态地质环境研究

为了解广饶县蔬菜基地生态地质环境质量,通过对水、土环境质量现状进行调查,重点研究了四大蔬菜基地的生态地质环境特征,结果表明四大蔬菜基地生态环境质量相对较好,蔬菜质量也达到无公害标准。发现在花官乡及稻庄镇存在土壤硒元素富集区,大蒜及芹菜中硒元素含量也较高,对引导当地绿色高效生态农业发展具有重大意义。     

中国镍矿预测类型及主要战略接续区

为了充分展示和利用全国镍矿预测的思路及其主要成果,本文根据矿产预测类型的划分标准,将镍矿划分为岩浆型镍-铜硫化物矿、风化壳型镍矿和海相沉积型镍-钼-钒矿3种类型,并系统总结了各矿产预测类型的基本特征、成矿规律、利用现状、预测要素和预测方法。在此基础上,对中国镍矿从成矿地质背景、地球化学特征、矿床分布密集程度、成矿强度以及资源潜力方面进行了分析与综合,结合矿床类型特点,提出了喀拉通克、觉罗塔格、北山、辽吉、龙首山、祁曼塔格、墨江—金平和宝坛等8个战略接续区,用以指导镍矿找矿工作部署。     

大陆坡脚确定原则与方法

大陆坡脚是大陆边缘的一个重要地形特征,是沿海国扩展其大陆架权利和划定其200海里以外大陆架外部界限的基础,也是大陆架界限委员会审议沿海国划界案时特别关注的重要技术参数。《联合国海洋法公约》第76条大陆架制度的制定源于典型的被动大陆边缘。但由于全球大陆边缘的多样性和复杂性,特别是后期构造活动、沉积作用对大陆边缘的改造与影响,海底地形地貌异常复杂多变,导致大陆坡脚的识别非常困难。加上各沿海国为获得最大范围的外大陆架,对大陆坡脚的相关规定进行有利于自己的解释,使得大陆坡脚的确定成了外大陆架划界中一个颇具争议的热点问题。本文基于对《联合国海洋法公约》和《大陆架界限委员会科学和技术准则》对大陆坡脚的规定,结合不同类型大陆边缘的地质特征和各沿海国划界实践,对陆坡基部区的确定、坡度变化最大之点的选取以及相反证明规则的适用性等问题进行了探讨。     

气候变化背景下尼雅河流域生态基流研究

流域生态基流是河流生态系统健康稳定的关键,以新疆尼雅河流域为研究区域,根据民丰县气象站1958—2018年的气象数据与尼雅河4个水文监测断面1978—2018年的水文数据,运用趋势拟合、Tennant法、相关性分析和回归模型等分析流域气候变化、确定生态基流并探究其时空分异与保证率变化,揭示生态基流对气候变化的响应。结果表明：61 a来流域气温以0.22 ℃·(10a)^-1的速度增加,年降水量以3.8 mm·(10a)^-1的速度增加;尼雅水库、八一八渠首、尼雅水文站和尼雅渠首的年生态基流推荐值分别为：1.989 m³·s^-1、2.188 m³·s^-1、1.755 m³·s^-1、1.702 m³·s^-1;生态基流年际最大值出现在2010年,最小值在1980年,年内最大值在7月,最小值在1月或12月;空间上表现为上游高下游低,以八一八渠首处最高,尼雅渠首处最低;各站多年平均生态基流保证率分别为：50%、45%、50%、45%,且表现出汛期明显高于非汛期;逐年、逐月生态基流与气温、降水量均在0.01水平上显著相关,但在春夏季对气温敏感,秋冬季对降水量敏感,各水文监测断面的回归模型耦合效果相似,流域整体回归方程R²=0.365,且生态基流对气候变化响应具有整体性和衰减性。研究结果可为尼雅河流域生态调水和水生态修复提供参考。     

地温测报质量与信息规则库的关系

对我国现有的气温和0～320cm各个层次的地温进行了比较和综合分析,揭示出了地温的垂直变化规律,阐述了地面气象业务软件参数设置里"规则库"与台站数据质量控制结果的密切关系。在此基础上介绍了自动气象站的观测员和预审员如何及时发现和判定一系列异常数据正误的方法。结果利于帮助有关工作人员了解地温的变化特点和规律,及时分析、判定、发现异常数据。     

Calculating the Climatology and Anomalies of Surface Cloud Radiative Effect Using Cloud Property Histograms and Cloud Radiative Kernels

Cloud radiative kernels (CRK) built with radiative transfer models have been widely used to analyze the cloud radiative effect on top of atmosphere (TOA) fluxes, and it is expected that the CRKs would also be useful in the analyses of surface radiative fluxes, which determines the regional surface temperature change and variability. In this study, CRKs at the surface and TOA were built using the Rapid Radiative Transfer Model (RRTM). Longwave cloud radiative effect (CRE) at the surface is primarily driven by cloud base properties, while TOA CRE is primarily decided by cloud top properties. For this reason, the standard version of surface CRK is a function of latitude, longitude, month, cloud optical thickness (τ) and cloud base pressure (CBP), and the TOA CRK is a function of latitude, longitude, month, τ and cloud top pressure (CTP). Considering that the cloud property histograms provided by climate models are functions of CTP instead of CBP at present, the surface CRKs on CBP-τ histograms were converted to CTP-τ fields using the statistical relationship between CTP, CBP and τ obtained from collocated CloudSat and MODIS observations. For both climate model outputs and satellites observations, the climatology of surface CRE and cloud-induced surface radiative anomalies calculated with the surface CRKs and cloud property histograms are well correlated with those calculated from surface radiative fluxes. The cloud-induced surface radiative anomalies reproduced by surface CRKs and MODIS cloud property histograms are not affected by spurious trends that appear in Clouds and the Earth's Radiant Energy System (CERES) surface irradiances products.     

The Significant Role of Radiosonde-measured Cloud-base Height in the Estimation of Cloud Radiative Forcing

The satellite-based quantification of cloud radiative forcing remains poorly understood, due largely to the limitation or uncertainties in characterizing cloud-base height (CBH). Here, we use the CBH data from radiosonde measurements over China in combination with the collocated cloud-top height (CTH) and cloud properties from MODIS/Aqua to quantify the impact of CBH on shortwave cloud radiative forcing (SWCRF). The climatological mean SWCRF at the surface (SWCRF_SUR), at the top of the atmosphere (SWCRF_TOA), and in the atmosphere (SWCRF_ATM) are estimated to be ?97.14, ?84.35, and 12.79 W m^?2, respectively for the summers spanning 2010 to 2018 over China. To illustrate the role of the cloud base, we assume four scenarios according to vertical profile patterns of cloud optical depth (COD). Using the CTH and cloud properties from MODIS alone results in large uncertainties for the estimation of SWCRF_ATM, compared with those under scenarios that consider the CBH. Furthermore, the biases of the CERES estimation of SWCRF_ATM tend to increase in the presence of thick clouds with low CBH. Additionally, the discrepancy of SWCRF_ATM relative to that calculated without consideration of CBH varies according to the vertical profile of COD. When a uniform COD vertical profile is assumed, the largest SWCRF discrepancies occur during the early morning or late afternoon. By comparison, the two-point COD vertical distribution assumption has the largest uncertainties occurring at noon when the solar irradiation peaks. These findings justify the urgent need to consider the cloud vertical structures when calculating the SWCRF which is otherwise neglected.     

Mineralogical controls on element dispersion in regolith over two mineralised shear zones near the Peak, Cobar, New South Wales

Effective exploration for polymetallic ore deposits in the Cobar region is hampered by incomplete knowledge of the mineralogical controls on element dispersion in the different regolith-landform settings throughout the area. A detailed mineralogical and geochemical study of regolith profiles over two major mineralised shear zones in a strongly weathered but dominantly erosional setting has delineated the important host minerals for a range of base metal cations. Iron oxides/oxyhydroxides, particularly goethite and to a much lesser extent hematite, are major hosts for Pb, Cu, and Zn as substituted/adsorbed cations and as constituents of associated or intergrown minerals, probably including members of the jarosite–alunite group. Correlations between elements and major regolith minerals suggest that goethite is also a host phase for As, Bi and Sb. Minor manganese minerals, including lithiophorite and cryptomelane group minerals, also host base metals in appreciable amounts. No clear association was found between gold and any particular secondary mineral. It is likely that gold is present largely as elemental gold particles associated with a range of minerals.Sampling strategies for geochemical exploration in variably leached and stripped regolith in the Cobar area should take into account the relative abundance of goethite and manganese oxides/oxyhydroxides within the profiles and overlying lag. Goethite would appear to be the preferred sampling medium for base metals. Highly ferruginous lag has a high proportion of hematite with variable maghemite and very low manganese oxide contents. Most of the base metal content in this surface material is strongly bound to the crystalline oxides/oxyhydroxides. More work is required to understand the effects of surface transformation of goethite to hematite and maghemite on the mobility and distribution of base metal cations in soil and ferruginous lags.     

GIS地形分析模型库管理系统的设计与实现

GIS地形分析中模型数量庞大、存储样式多种多样,因此,实现对模型资源的有效管理是基于GIS进行地形分析的关键技术.文中通过对GIS地形分析模型库的研究,提出GIS地形分析模型库管理系统的设计思想和总体框架,并开发系统原型,提高模型的可重用性,基本满足GIS地形分析模型管理的需要.