Spatial variation and driving mechanism of soil organic carbon components in the alluvial/sedimentary zone of the Yellow River

Alluviation and sedimentation of the Yellow River are important factors influencing the surface soil structure and organic carbon content in its lower reaches. Selecting Kaifeng and Zhoukou as typical cases of the Yellow River flooding area, the field survey, soil sample collection, laboratory experiment and Geographic Information System(GIS) spatial analysis methods were applied to study the spatial distribution characteristics and change mechanism of organic carbon components at different soil depths. The results revealed that the soil total organic carbon(TOC), active organic carbon(AOC) and nonactive organic carbon(NOC) contents ranged from 0.05–30.03 g/kg, 0.01–8.86 g/kg and 0.02–23.36 g/kg, respectively. The TOC, AOC and NOC contents in the surface soil layer were obviously higher than those in the lower soil layer, and the sequence of the content and change range within a single layer was TOCNOCAOC. Geostatistical analysis indicated that the TOC, AOC and NOC contents were commonly influenced by structural and random factors, and the influence magnitudes of these two factors were similar. The overall spatial trends of TOC, AOC and NOC remained relatively consistent from the 0–20 cm layer to the 20–100 cm layer, and the transition between high-and low-value areas was obvious, while the spatial variance was high. The AOC and NOC contents and spatial distribution better reflected TOC spatial variation and carbon accumulation areas. The distribution and depth of the sediment, agricultural land-use type, cropping system, fertilization method, tillage process and cultivation history were the main factors impacting the spatial variation in the soil organic carbon(SOC) components. Therefore, increasing the organic matter content, straw return, applying organic manure, adding exogenous particulate matter and conservation tillage are effective measures to improve the soil quality and attain sustainable agricultural development in the alluvial/sedimentary zone of the Yellow River.     

全球增暖下我国旱涝灾害可能情景的初步研究

在全球变暖的情况下,我国东南沿海、西南、西北、内蒙古和东北部分地区,洪涝灾害可能增加;而黄河中游以南和华北平原干旱可能增加.这一变化特征与本世纪暖期降水分布变化,以及与CO_2倍增情况下气候模似结果基本一致.     

新疆某水库大坝变形监测方法研究

结合新疆克拉玛依三座坝线均长达5km左右的平原水库,介绍了由于地质环境影响大坝沉降和位移而建立变形监测控制网、观测方法、数据分析处理以及工作中的一些方法和经验.     

低本底液闪仪计算机控制系统的改进

新研制改进的低本底液闪计算机控制系统，具有数据获取和数据处理、实时能谱测量、谱显示选取工作点以及测量中断后继续测量等功能，从而使液闪仪的自动化和智能化程度得到了进一步提高。     

甘宁青地区强震孕育的深部电性和力学环境

以200多点次的大地电磁测深资料和6条人工地震测深剖面的资料为根据，结合重力测量和地热流观测资料，分析研究了甘肃、宁夏和青海地区的强震孕育的深部环境。认为强震孕育在增厚的低阻层的顶部，低速层的上方以及介质在横向上电性和力学性质均剧烈变化的环境之中。这些条件的实质是在地应力作用下纵、横向地层变形不一致，在这不协调之处极有利于应力集中。     

水库水体生态系统数值模拟模型及其应用──以丹江口水库为例

介绍了水库生态系统模拟模型,对水库生态变化过程及其数学模拟方法进行了分析.采用1995年的水文、气象、水库调度资料、入库河流水质及水库初始水质资料模拟了该年度丹江口水库水体生态逐日变化过程.     

Anisotropy of the apparent resistivity variation rate near the epicentral region for strong earthquakes

IntroductionThe geo-electrical anisotropy before earthquake is of special significance for the prediction of earthquake location and for the research on crustal stress status near the epicentral region. The anisotropy has been studied from various aspects (CHEN, et al, 1983; QIAN, et al, 1985, 1996; LU, et al, 1990a; MAO, et al, 1995; RUAN, et al, 1999). But the anisotropic phenomena presented by geo-electrical data are not practically satisfactory and not clear as compared with the res…     

DISTRIBUTIONS AND HYDROLOGICAL CHARACTERISTICS OF TROPICAL CYCLONE RAINSTORMS AND FLOODS IN CHINA

I.horoductionPleNorthwestPacificOceanisti1elnostfrequentlyaffeCtedareaoftropicalcyclone(TC).AboLIt36percentTCoftheworldoccurinffosarea[2],andthenumberofTCWhichlandedonChinawiti1n1akimumwindforcescalesoverlOisabout35percentofti1atintheeastemcoastalcoLUitriesofAsia[l].BothrainstormsandfloodsMide,theidriuenceofTCareheaVyinChina,suchastherainfalldePthof2749mm/3datXinliao,Taiwanandpeakdischargeof44,6oOm'/satHuanggo(55,42okn'),YalujiangRjver.Therefore,TCisanimportantfaCtorforflooddisas…     

星载激光光斑影像激光指向变化探测法

地面光斑足印的定位精度高度依赖于激光指向角的测量精度,星载激光光斑质心提取及其变化规律对激光指向角的分析具有重要的意义。本文基于ICESat/GLAS的激光剖面阵列（laser profile array,LPA）影像数据,首先利用灰度一阶矩阵法提取LPA的质心,精度优于0.3个像素,LPA相对定位精度优于0.11个像素。其次利用傅里叶变换和傅里叶级数拟合对LPA质心坐标的变化进行周期探测和建模分析,结果表明,激光光斑影像的质心坐标存在1.83×10^-4 Hz、3.36×10^-4 Hz、5.19×10^-4 Hz和6.71×10^-4 Hz 4个明显的周期变化,拟合结果的相关性R²达到了0.86,拟合精度可达0.4″,优于0.13个像素,得到了较好的结果。可为我国的高分七号和后续的卫星激光测高数据处理提供参考。     

2016年度呼图壁地下天然储气库对周缘微地震活动性的影响

呼图壁储气库是中国目前存储量最大的天然气储气库,位于新疆准噶尔盆地南缘,北天山山前坳陷带内的呼图壁背斜上.储气库靠近百万人口大城市乌鲁木齐,气库的注放气活动对其周缘地震活动的长期影响是事关生产和生活的重要安全问题.本文以呼图壁储气库为中心,在86.5°E—87.5°E,43.5°N—44.5°N的范围内,基于新疆维吾尔自治区地震局在该区域建立的密集流动台阵数据,应用模板匹配滤波技术对2016年全年的波形数据进行搜索识别,检测到遗漏地震事件151个,完善扩充了原有地震目录,使得该区域完备震级由1.1降到约0.7.通过分析新目录中404个地震的时空分布规律,我们发现2016年,即气库建成第三年以后,储气库的气压变化依然会影响周缘地区的地震活动.当储气库的气压增大到超过约22 MPa的阈值后,较小的气压波动也会导致该区域地震活动性明显增强;气压变化对距储气库中心最远约40 km范围内区域的地震活动存在较为明显的影响.