Identification and distribution of 13003 landslides in the northwest margin of Qinghai-Tibet Plateau based on human-computer interaction remote sensing interpretation

The periphery of the Qinghai-Tibet Plateau is renowned for its susceptibility to landslides.However,the northwestern margin of this region,characterised by limited human activities and challenging transportation,remains insufficiently explored concerning landslide occurrence and dispersion.With the planning and construction of the Xinjiang-Tibet Railway,a comprehensive investigation into disastrous landslides in this area is essential for effective disaster preparedness and mitigation strategies.By using the human-computer interaction interpretation approach,the authors established a landslide database encompassing 13003 landslides,collectively spanning an area of 3351.24 km^(2)(36°N-40°N,73°E-78°E).The database incorporates diverse topographical and environmental parameters,including regional elevation,slope angle,slope aspect,distance to faults,distance to roads,distance to rivers,annual precipitation,and stratum.The statistical characteristics of number and area of landslides,landslide number density(LND),and landslide area percentage(LAP)are analyzed.The authors found that a predominant concentration of landslide origins within high slope angle regions,with the highest incidence observed in intervals characterised by average slopes of 20°to 30°,maximum slope angle above 80°,along with orientations towards the north(N),northeast(NE),and southwest(SW).Additionally,elevations above 4.5 km,distance to rivers below 1 km,rainfall between 20-30 mm and 30-40 mm emerge as particularly susceptible to landslide development.The study area’s geological composition primarily comprises Mesozoic and Upper Paleozoic outcrops.Both fault and human engineering activities have different degrees of influence on landslide development.Furthermore,the significance of the landslide database,the relationship between landslide distribution and environmental factors,and the geometric and morphological characteristics of landslides are discussed.The landslide H/L ratios in the study area are mainly concentrated between 0.4 and 0.64.It means the landslides mobility in the region is relatively low,and the authors speculate that landslides in this region more possibly triggered by earthquakes or located in meizoseismal area.

Temporal and Spatial Distribution Characteristics of Lightning Activity in the Pan-Pearl River Delta

Based on the lightning data acquired by a lightning imaging sensor(LIS)carried on the TRMM satellite from 1998 to 2013,the spatial distribution,seasonal,monthly,and diurnal characteristics of lightning activity in the Pan-Pearl River Delta were analyzed.The results show that in the Pan-Pearl River Delta,lightning activity was more in the south and less in the north.Near 23°N,lightning density was high from Guangdong and Guangxi to the southern edge of Yunnan.Lightning density weakened continuously as the latitude increased.Among the provinces in the Pan-Pearl River Delta,the maximum and average of lightning density in Hainan Province was greater than that of other provinces.Besides,the lightning activity showed obvious seasonal changes.In the whole year,lightning activity was the weakest in November and next February.Lightning activity in most areas of the Pan-Pearl River Delta was the strongest in August.The peak of lightning activity in most areas of the Pan-Pearl River Delta occurred from 12:00 to 20:00.Lightning activity was the weakest between 07:00 and 10:00 in most areas.

Temporal and Spatial Distribution of Elements in a Small Catchment, and Buffer Function of Wetland in Longgan Lake, China

Wetland is the conjunction of lake and terrene where human activities are concentrated. From the viewpoints of material transport and cycling in the terrene-lake system, wetland is the buffer where sand and mud, heavy metals, pollutants and nutrients are tarried. In this paper, we provide a case study based on the temporal and spatial distribution of elements in the Wangling River catchment, a small sub-catchment of Longgan Lake in the middle reaches of the Yangtze River. We have found that wetland can buffer major heavy metals such as Cr, Cu, etc. significantly, but has a little buffer function to some active elements such as Fe and Mn, which are always transported as solutions. Human activities not only influence the distribution of elements, but also weaken the buffer function of wetland. Intensive human activities in the Longgan Lake area in the past 70 years have been recorded in stream, wetland and lake sediments, especially the human activity events such as deforesting and reclaiming on a large scale in 1958 and the 1980’s. Human activities caused the increase of sedimentation rates since the 1950’s, as well as the increase of elements’ concentrations. The extensive use of fertilizers and pesticides since the 1960’s have led to the increase of total P concentrations. Increasing SO-2 emission accelerate the process of cation exchange in soil, and enhance the leaching of Mn out of soils. Permanent storing of water causes the soil gleyification that also intensifies the leaching of Mn. These are two major reasons for the obvious increase of manganese concentrations in recent 20 years in Longgan Lake. Intensive human activities since the 1950s’ have intensified the population in this region and thus destroyed the buffer function of wetland.

Temporal and Spatial Characteristics of Lightning Activity in Huai'an during 2011-2014

Based on the monitoring data of lightning activity in Huai'an from 2011 to 2014,the temporal and spatial distribution of lightning activity and lightning density were analyzed. The results show that positive and negative lightning activity in Huai'an had obvious seasonal variations and diurnal variations during 2011-2014. The month changes of positive and negative lightning activity had a single peak and valley,while the diurnal variations of both positive and negative lightning activity had double peaks and valleys. The high-value areas of ground flash density in Huai'an had obvious randomness. Seen from the spatial distribution of annual average of ground flash density,lightning activity was mainly distributed in Xuyi County,Jinhu County and Huai'an District.

Long-term agricultural activity affects anthropogenic soil on the Chinese Loess Plateau

Anthropogenic activities largely influence the soil quality of agricultural fields and the composition of soil. Samples of typical anthropogenic Loutu soil in the Guanzhong area of the Loess Plateau, Shaanxi Province, China were collected and measured for soil compaction, bulk density, total organic carbon（TOC）, active organic carbon（AOC）, and soil enzyme activities to investigate spatial variations in soil quality. The results indicate that soil compaction and bulk density increased with increasing distance from the farm village, whereas soil TOC, AOC, and soil enzyme activities firstly increased and subsequently decreased with increasing distance from the farm village. All of the tested parameters presented clear concentric distribution. Vertically, soil compaction and bulk density in the topsoil were lower than those in the subsoil, but all other tested parameters in the topsoil were significantly higher than those in the subsoil. In addition, there was a significant positive correlation between organic carbon content and enzyme activities, confirming that the spatial distribution of Loutu soil characteristics has been affected by long-term anthropogenic activities to some extent. The results of this study imply that the use of farmyard manure and appropriate deep plowing are important and effective ways to maintain and improve soil quality.

Statistical study of “trunk-like” heavy ion structures in the inner magnetosphere

We present a statistical study of“trunk-like”structures observed in He+and O+in the inner magnetosphere.The main characteristic of these structures is that the energy of the peak flux decreases earthward.Using observations from the Helium Oxygen Proton Electron(HOPE)instrument onboard Van Allen Probe A,we identify the trunks observed from November 2012 to June 2019 and obtain the universal time,L shell,magnetic local time(MLT),and energy information of each trunk’s root and tip.We then investigate the behavior of trunks in terms of their frequency of occurrence,temporal evolution,spatial and energy distribution,and trunk dependence on different geomagnetic indices.We find that(1)the trunks are always located at L=1.5−4.0 and have a preferential location mainly concentrated at MLT=18−24,(2)the sector within MLT=14−16 is a forbidden zone without trunk roots,and(3)the energy of He+ trunks is the largest near dusk and gradually decreases in the counterclockwise direction,whereas the energy of O+ trunks is relatively evenly distributed with MLT and L.The differences between He+ and O+ trunks are probably due to the different charge exchange and Coulomb collision lifetime.The dependence on different geomagnetic indices indicates that the trunk structures occur more frequently during relatively quiet periods.

考虑分布式电源时空相关及电动汽车充电负荷分布特性的有源配电网概率潮流

目前分布式电源(distribution generation,DG)和电动汽车(electric vehicle,EV)充电负荷等随机变量接入电力系统时时空特性考虑不足,会导致概率潮流计算偏离实际。因此该文提出了考虑DG时空相关及EV分布特性的有源配电网概率潮流模型。首先,利用场景生成建立时空相关的风电、光伏出力概率模型;然后,考虑路网约束和用户心理,建立考虑EV时空分布特性的负荷概率模型;最后,以Nataf变换结合奇异值分解处理相关性输入变量,运用三点估计法对概率潮流进行计算,通过Cornish-Fisher级数拟合得到累积分布函数。以IEEE-33节点系统进行测试,利用所提模型分析了DG时空相关性和EV分布特性对配电网潮流的影响。结果表明DG时空相关性主要影响系统的波动性,EV分布特性主要影响系统的运行特性。该文研究可为新型配电网的安全运行提供理论指导。

基于时间维度的城市公园人群活动研究——以深圳文心公园、四海公园、荔香公园为例

文章以时间、空间和人群活动为切入点,对深圳市南山区文心公园、四海公园、荔香公园的人群活动情况展开了调研,对时间维度下城市公园人群活动的人群构成特征、空间分布特征、活动变化特征进行了分析,解析了影响城市公园活动人群活动的因素。最后,基于调研和分析的结果,对城市公园的设计如何适应不同时段下不同人群的活动需要提出了建议。

西安市创新活动空间分布特征及影响因素研究——基于多尺度地理加权回归

文章以专利申请数据表征创新活动,将其分为知识型、生产型创新活动两类,通过核密度分析法、空间自相关分析法、标准差椭圆、DBSCAN聚类等方法从总体和分类别两大层面分析和探究西安市创新活动的空间分布特征,得出其创新活动空间分布具有规律性分异、差异化集聚、选择性依赖三大特征的结论。在此基础上,利用多尺度地理加权回归模型,选取相关影响因素进一步分析创新活动的空间分异特征,最终得出创新主体驱动创新活动、环境配置吸引创新活动、知识借用激励创新活动的结论。

河南省非物质文化遗产的空间分布特征及旅游活化机制研究

河南省丰富的非物质文化遗产是中原文明源远流长的见证。从空间分布和旅游活化机制的视角考察非物质文化遗产,有助于了解其空间分布特征,探究其活化路径。基于实地调研与文献资料,系统阐述了河南省18个地市的非物质文化遗产旅游活化现状,基于GIS分析了河南省非物质文化遗产的空间分布特征,借助SPSS软件分析了非物质文化遗产与旅游发展之间的关系,归纳总结了非物质文化遗产的旅游活化机制。研究发现:河南省非物质文化遗产类型差异化特征显著;国家级非物质文化遗产和省级非物质文化遗产在空间上表现为非均衡性,多呈团状和带状分布。基于此,提出了河南省非物质文化遗产的旅游活化机制。

Differences in distributions, assembly mechanisms, and putative interactions of AOB and NOB at a large spatial scale

Ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) play crucial roles in removing nitrogen from sewage in wastewater treatment plants (WWTPs) to protect water resources. However, the differences in ecological properties and putative interactions of AOB and NOB in WWTPs at a large spatial scale remain unclear. Hence, 132 activated sludge (AS) samples collected from 11 cities across China were studied by utilizing 16S rRNA gene sequencing technology. Results indicated that Nitrosomonas and Nitrosospira accounted for similar ratios of the AOB community and might play nearly equal roles in ammonia oxidation in AS. However, Nitrospira greatly outnumbered other NOB genera, with proportions varying from 94.7% to 99.9% of the NOB community in all WWTPs. Similar compositions and, hence, a low distance–decay turnover rate of NOB (0.035) across China were observed. This scenario might have partly resulted from the high proportions of homogenizing dispersal (~13%). Additionally, drift presented dominant roles in AOB and NOB assembling mechanisms (85.2% and 81.6% for AOB and NOB, respectively). The partial Mantel test illustrated that sludge retention time and temperature were the primary environmental factors affecting AOB and NOB communities. Network results showed that NOB played a leading role in maintaining module structures and node connections in AS. Moreover, most links between NOB and other microorganisms were positive, indicating that NOB were involved in complex symbioses with bacteria in AS.

脉冲驱动等离子体射流中活性粒子空间分布规律

为探究大气压脉冲驱动等离子体射流中活性粒子空间分布特性,采用同轴双环等离子体射流反应器,在外施脉冲激励驱动下,研究各活性粒子在不同电离段的特征峰相对强度沿轴向空间的变化规律。结果表明:在脉冲激励等离子体射流所有测量点位均能检测到NO、OH、N_(2)、N_(2)^(+)、He等活性粒子特征峰,其中以OH、N_(2)、N_(2)^(+)粒子所对应的发射光谱谱带及特征峰较为显著;在高压电极和接地电极之间的电场驱动电离段,活性粒子NO、OH、N_(2)的特征峰相对强度在靠近高压电极和接地电极区域较高,而在两电极中间的区域相对强度较低,不同激发能级He、N_(2)^(+)特征峰相对强度沿气流方向逐渐降低;在接地电极至反应器管口的半开放离子激发段,活性粒子NO、OH以及不同能级N_(2)、N_(2)^(+)、He特征峰的相对强度轴向分布呈现出随着气流方向逐渐降低的趋势;在反应器管口至等离子体射流末端区域的开放离子激发段,活性粒子OH、NO与不同能级He特征峰的相对强度轴向分布随气体流动方向逐渐减弱,不同能级N_(2)、N_(2)^(+)特征峰的相对强度呈现出先增后减的规律,为脉冲驱动等离子体射流能量传递过程与反应机理的深入研究提供支撑。

1977—2020年沂蒙山区极端气温时空变化特征分析

【目的】为深入掌握全球变暖背景下沂蒙山区极端气温事件及复合极端高温事件的动态演变特征,以期为预防区域性灾害提供理论参考。【方法】根据1977—2020年沂蒙山区的逐日气温资料,利用线性拟合、Mann-Kendall突变检验法、Morlet复小波分析等方法,对沂蒙山区极端气温事件及昼夜复合高温的时空变化特征进行了分析,并探讨了极端气温指数对全球变暖停滞现象的响应特征及发生持续性昼夜复合高温事件时的环流特征。【结果】结果表明:(1)近44年,沂蒙山区暖指数(TN90、TX90、SU25)呈上升趋势,冷指数(TN10、TX10、FD0)呈现下降趋势,具有昼夜不对称性,昼夜温差缩小,促使昼夜复合高温事件的发生。(2)极端气温指数突变时间大多出现在20世纪90年代和二十一世纪初期,突变时间上冷指数早于暖指数,突变后极端气温暖事件的发生频率增加,极端气温冷事件的发生频率减少;昼夜复合高温事件以2012为界,前期波动不明显,高发于2012—2020年;各极端气温指数及昼夜高温事件均在1998—2012年间响应了全球变暖停滞现象。(3)沂蒙山区西部地区为暖夜日数(TN90)、暖昼日数(TX90)以及昼夜复合高温事件的增速显著高值区。(4)沂蒙山区夏季昼夜复合高温事件在2012—2020年持续性较强,南压高压异常偏北偏东,中层副热带高压异常西伸是影响沂蒙山区持续昼夜复合高温的环流机制。【结论】综上,研究区将延续暖化趋势,沂蒙山西部为极端气温事件及复合极端高温事件的高发区域且在近些年增温显著,应重点关注以上地区长历时高强度增温在城市规划、人类健康和农业生产等方面产生的影响,及时制定适应气候变化的策略和措施,促进沂蒙山区生态环境和社会经济的可持续发展。

Spatial distribution of phosphorus forms in sediments with different distances to the estuary of the Dianchi Lake,China

Effects of human activity on the distribution of phosphorus(P)forms were investigated for the sediments and porewaters in Daqinghe Estuary of Dianchi Lake,China.The concentrations of total P(TP),inorganic-P(IP),and organic-P(Org-P),and the ratio of iron-bound P(Fe-P)/calcium-bound P(Ca-P)in the sediments decreased with the increasing distance from the sampling site to the estuary.This is probably due to the flocculant materials,e.g.,ferric and aluminous salts,usually being added in the wastewater treatment processes.The concentration of ammonia in the sediment porewaters significantly decreased with the increasing distance from the sampling site to the estuary.Both concentrations of total nitrogen and nitrogen in the sediment porewaters decreased to some content with the increasing distance from the sampling site to the estuary.However,the concentrations of nitrate,dissolved total P(DTP),and TP did not have strong relationship with the distances from the sampling sites to the estuary.Pollution load and water quantity also had an important influence on the concentrations of P in sediments and its interstitial water in estuary sedimentary area.

种植方式对当归田土壤酶活性时空分布的影响

在当归道地产区设置起垄覆膜穴栽(LS)、膜侧开沟斜栽(MC)和露地开沟斜栽(LD)3种种植方式,分析比较不同种植方式生育期内0~10 cm、10~20 cm、20~30 cm耕层土壤酶活性的时空变化特性,以期探明种植方式对土壤酶活性的影响,为全面评估当归覆膜技术体系提供理论依据。结果表明,生育期内脲酶活性呈先上升后下降的趋势,移栽后120 d达到峰值,LS和MC方式较LD方式分别提高了41.00%和36.69%,其活性随土层加深逐渐降低;蔗糖酶活性呈先上升后下降的趋势,移栽后120 d达到峰值,LS和MC方式较LD方式分别提高了46.40%和45.90%,其活性随土层加深逐渐降低;过氧化氢酶活性呈先上升后下降的趋势,移栽后90 d达到峰值,LS和MC方式较LD方式分别降低了8.46%和7.70%,其活性基本随土层加深逐渐增加;磷酸酶活性呈先上升后下降的趋势,移栽后150 d达到峰值,LS和MC方式较LD方式分别提高了48.56%和40.37%,其活性随土层加深逐渐降低。除过氧化氢酶外,覆膜方式同一生育期不同耕层土壤酶活性均高于露地方式,但覆膜方式间差异不显著。因此,覆膜种植可显著提高当归根系层水解酶活性,但对氧化还原酶具有显著抑制作用,酶活性分布具有明显的垂直分层现象。

秦皇岛近岸海域剩余环境容量研究

以秦皇岛近岸海域为研究区域,通过GIS对COD、无机氮、活性磷酸盐进行插值,再与目标浓度对比后获得剩余环境容量。通过分析,研究区域COD、无机氮、活性磷酸盐总环境容量剩余量分别为2362.322 t、146.340 t、31.639 t。各因子剩余环境容量均呈现东北偏高,西南偏低的趋势,其中无机氮、活性磷酸盐西南局部区域出现超标现象,无机氮、活性磷酸盐超标区域面积占比分别为13.2%,3.04%。

我国国家工业遗产空间分布特征与系统活化策略

以我国196个国家工业遗产为研究对象,运用最邻近指数、网格维数和核密度对国家工业遗产空间分布类型、均衡性和集聚性特征进行分析。研究发现,我国国家工业遗产在空间上呈现出集聚分布、线性分布、区域分布不均衡等总体特征,且其在长三角、环渤海、成渝等地区集聚程度最高,在山西南部、黑龙江南部和福建沿海等地集聚程度次之。再针对国家工业遗产的空间分布特征,从“全域均衡—区域协作—单体活化”三个层面提出我国国家工业遗产的系统活化策略,即以政府公布为主导推动工业遗产全域均衡保护、加强部门协作构建区域整体活化机制、结合个体保护现状采用分级分类的利用模式。

典型黑土区农业流域土壤侵蚀-沉积对土壤养分和酶活性的影响

研究农业流域土壤侵蚀—沉积对土壤养分和酶活性的影响可为土壤侵蚀退化评价提供重要科学依据。选择典型薄层黑土区的宾州河流域为研究区,在流域上游、中游和下游各选取2个代表性坡面,基于137 Cs示踪技术估算土壤侵蚀—沉积速率,分析流域和坡面尺度土壤侵蚀—沉积对土壤养分(有机质、全氮和速效磷)和土壤酶活性(转化酶、脲酶和碱性磷酸酶)的影响。结果表明:(1)土壤侵蚀速率在流域上游最大,分别是流域中游和下游的1.9,11.2倍;坡面尺度上土壤侵蚀速率在坡中部最大,分别是坡上部和坡下部的1.3~2.6,2.8~12.2倍。(2)在流域尺度上,土壤有机质空间分布与土壤侵蚀速率空间分布呈相反的变化趋势,土壤全氮和速效磷含量在流域下游皆大于流域中游;坡面尺度上土壤有机质、速效磷含量、转化酶、脲酶和碱性磷酸酶活性均表现为坡下部>坡中部,说明农地土壤侵蚀降低土壤养分含量和酶活性。(3)流域沉积区土壤沉积速率对土壤有机质、速效磷含量、脲酶和碱性磷酸酶活性有显著影响。(4)土壤有机质和速效磷含量对土壤脲酶和碱性磷酸酶活性有显著影响,表明土壤侵蚀—沉积引起的土壤养分再分布是造成土壤酶活性空间分异的重要原因。

近10年三门湾海域表层沉积物重金属含量变化及来源解析

为了解三门湾海域表层沉积物重金属的含量和分布特征,本研究对三门湾海域2019年82个站位海域表层沉积物中的Cu、Pb、Zn、Cd、Cr、As及Hg共7种重金属元素的含量进行测定,并对比10年前的数据,分析了元素含量的变化情况,追溯了其主要物质来源。结果表明,三门湾海域表层沉积物中Cu、Zn、Pb、Cd、Cr、As、Hg的平均质量浓度分别是31.33、96.46、29.86、0.116、91.54、13.09、0.06 mg/kg,Cu、Cr的含量相对较高。与2009年相比,2019年三门湾海域表层沉积物Cu、Zn与Cd的含量大体上保持一致,Pb、Cr与As的含量有所上升,Hg的含量显著降低。沉积物重金属含量由近岸向外海依次降低,高值区主要集中在蛇蟠水道口、力洋港与健跳镇附近。运用主成分分析与因子分析对重金属物质来源进行解析的结果表明,重金属物质的来源与人类活动的影响密切相关。

松嫩平原芦苇湿地土壤酶活性剖面分布特征及其微生物养分限制指示作用

土壤酶的催化作用是土壤有机质分解的限制性步骤,控制着湿地生态系统的物质循环。为揭示松嫩平原芦苇湿地土壤酶活性剖面分布特征,于2021年8月采集扎龙、莫莫格、牛心套保和向海芦苇湿地0-15、15-30、30-45、45-60、60-75 cm土壤样品,分析土壤碳、氮、磷循环相关的酶活性剖面分布特征及其主要影响因子。结果表明:不同湿地土壤β-1,4-葡萄糖苷酶(BG)、纤维二糖水解酶(CBH)、β-1,4-N-乙酰氨基葡萄糖苷酶(NAG)、酸性磷酸酶(AP)和多酚氧化酶活性(PPO)均随土壤深度增加逐渐降低,表层(0-15、15-30 cm)土壤酶活性均显著高于深层(45-60、60-75 cm)。随着土壤深度的增加,各湿地土壤C꞉N酶化学计量比整体呈现逐渐升高的趋势,而土壤N꞉P酶化学计量比呈逐渐降低的趋势。冗余分析发现,土壤总磷、含水率、总碳和溶解性有机碳是影响松嫩平原芦苇湿地土壤酶活性及酶化学计量比的关键因子。通过皮尔森相关性分析,进一步验证得知土壤C꞉N、N꞉P与土壤C꞉N和N꞉P酶化学计量比呈显著正相关,然而,土壤pH与BG、NAG和PPO活性显著负相关。土壤酶化学计量比的矢量分析和土壤碳、氮、磷化学计量比的阈值分析均表明松嫩平原芦苇湿地土壤氮元素含量相对较低,微生物存在一定程度的氮限制,且随土壤深度增加,氮限制逐渐加剧。该研究明确了松嫩平原芦苇湿地土壤酶活性剖面分布特征及酶化学计量比对微生物养分限制的指示作用,为明确湿地土壤碳、氮、磷循环过程及养分调控提供了重要的科学依据。