华蓥山中段地区地下水资源量评价   总被引：1，自引：1，他引：0  

康小兵  罗声  许模  刘宏 《中国岩溶》2018,37(4):527-534

四川华蓥山中段地区水流失比较严重,供需矛盾突出,水环境持续恶化,不但影响到居民正常的生产和生活,而且严重影响了该地区国民经济的建设和发展。通过野外调查和综合分析现场收集的资料,总结出华蓥山中段地区地下水资源量流失情况:该区每年流失的水资源量约为0.914 4亿m3,且华蓥山褶皱西翼水流失总量大于东翼,而西翼北端是区内水流失量最严重的区域,其水资源量流失的影响因素主要为气候、社会发展及人类活动等。   相似文献   

Spatiotemporal change patterns of urban lakes in China’s major cities between 1990 and 2015     

Cong Xie  Leiguang Wang  Xing Fang  Wenzhi Liao 《International Journal of Digital Earth》2018,11(11):1085-1102

China has experienced unprecedented urbanization in the past decades, resulting in dramatic changes in the physical, limnological, and hydrological characteristics of lakes in urban landscapes. However, the spatiotemporal dynamics in distribution and abundance of urban lakes in China remain poorly understood. Here, we characterized the spatiotemporal change patterns of urban lakes in China’s major cities between 1990 and 2015 using remote-sensing data and landscape metrics. The results showed that the urban lake landscape patterns have experienced drastic changes over the past 25 years. The total surface area of the urban lakes has decreased by 17,620.02?ha, a decrease of 24.22%, with a significant increase in the landscape fragmentation and a reduction in shape complexity. We defined three lake-shrinkage types and found that vanishment was the most common lake-shrinkage pattern, followed by edge-shrinkage and tunneling in terms of lake area. Moreover, we also found that urban sprawl was the dominant driver of the lake shrinkage, accounting for 67.89% of the total area loss, and the transition from lakes to cropland was also an important factor (19.86%). This study has potential for providing critical baseline information for government decision-making in lake resources management and urban landscape design.  相似文献   

Development of groundwater favourability map using GIS-based driven data mining models: an approach for effective groundwater resource management     

Kehinde Anthony Mogaji  Hwee San Lim 《国际地球制图》2018,33(4):397-422

The development of groundwater favourability map is an effective tool for the sustainability management of groundwater resources in typical agricultural regions, such as southern Perak Province, Malaysia. Assessing the potentiality and pollution vulnerability of groundwater is a fundamental phase of favourability mapping. A geographic information system (GIS)-based Boolean operator of a spatial analyst module was applied to combine a groundwater potentiality map (GPM) model and a groundwater vulnerability to pollution index (GVPI) map, thereby establishing the favourable zones for drinking water exploration in the investigated area. The area GPM model was evaluated by applying a GIS-based Dempster–Shafer–evidential belief function model. In the evaluation, six geoelectrically determined groundwater potential conditioning factors (i.e. overburden resistivity, overburden thickness, aquifer resistivity, aquifer thickness, aquifer transmissivity and hydraulic conductivity) were synthesized by employing the probability-based algorithms of the model. The generated thematic maps of the seven hydrogeological parameters of the DRASTIC model were considered as pollution potential conditioning factors and were analysed with the developed ordered weighted average–DRASTIC index model algorithms to construct the GVPI map. Approximately 88.8 and 85.71% prediction accuracies for the Groundwater Potentiality and GVPI maps were established using the reacting operating characteristic curve method and water quality status–vulnerability zone relationship scheme, respectively. Finally, the area groundwater favourability map (GFM) model was produced by applying a GIS-based Boolean operator on the Groundwater Potentiality and GVPI maps. The GFM model reveals three distinct zones: ‘not suitable’, ‘less suitable’ and ‘very suitable’ zones. The area analysis of the GFM model indicates that more than 50% of the study area is covered by the ‘very suitable’ zones. Results produce a suitability map that can be used by local authorities for the exploitation and management of drinking water in the area. The study findings can also be applied as a tool to help increase public awareness of groundwater issues in developing countries.  相似文献   

Examining human heat stress with remote sensing technology     

Yang Song 《地理信息系统科学与遥感》2018,55(1):19-37

Heat stress as an environmental hazard which can seriously affect productivity, health, or even survival of individuals has long been studied. Despite the endeavors that have been made to address the issue quantitatively with various heat stress indices, they are often measured at scatter sites. This research devotes to revealing human heat stress within continuous space with remote sensing technology. The study began with the retrieval of dry-bulb temperature from land surface temperature (LST) with empirical models. As wet-bulb temperature was calculated from dry-bulb temperature and relative humidity, discomfort index (DI) as an indicator of heat stress was revealed for the study area at 1 km spatial resolution for three summer days. Results indicated that DI can be derived within continuous space with remotely sensed data, and its spatial distribution can be dramatically affected by relative humidity. Further comparison between DI and LST indicated that LST as a widely utilized indicator of surface thermal condition fails to address human heat stress as environmental factors such as relative humidity are not taken into account.  相似文献   

Contrasting water–rock interaction behaviors of antimony and arsenic in contaminated rivers around an antimony mine,Hunan Province,China     

《Chemie der Erde / Geochemistry》2021,81(2):125748

Although antimony (Sb) and arsenic (As) exhibit similar geochemical behavior and toxicity in the environment, growing evidence suggests that their water–rock interaction behavior in contaminated rivers is quite different. Twenty-nine river water samples were collected between September and November 2018 from contaminated rivers around an antimony mine in Hunan Province, China. The concentrations of As and Sb were inversely proportional to the water flow distance. The rates and magnitudes of Sb decrease were more prominent than those of As. Silicate mineral dissolution from rocks such as silicified limestone increased the As and Sb concentration of in-mine-district (IMD) water. Dissolution of carbonate minerals, ion exchange, and competitive adsorption were the major water–rock interactions, resulting in rapidly decreasing As and Sb concentration in IMD direct impacted water and IMD indirect impacted water. The behaviors of As and Sb during water–rock interaction were dissimilar for areas dominated by carbonate and silicate minerals.  相似文献   

The evolution of the terrestrial-terminating Irish Sea glacier during the last glaciation     

Richard Christopher Chiverrell  Geoff Stephen Powell Thomas  Matthew Burke  Alicia Medialdea  Rachel Smedley  Mark Bateman  Chris Clark  Geoffrey A. T. Duller  Derek Fabel  Geraint Jenkins  Xianjiao Ou  Helen Marie Roberts  James Scourse 《第四纪科学杂志》2021,36(5):752-779

Here we reconstruct the last advance to maximum limits and retreat of the Irish Sea Glacier (ISG), the only land-terminating ice lobe of the western British Irish Ice Sheet. A series of reverse bedrock slopes rendered proglacial lakes endemic, forming time-transgressive moraine- and bedrock-dammed basins that evolved with ice marginal retreat. Combining, for the first time on glacial sediments, optically stimulated luminescence (OSL) bleaching profiles for cobbles with single grain and small aliquot OSL measurements on sands, has produced a coherent chronology from these heterogeneously bleached samples. This chronology constrains what is globally an early build-up of ice during late Marine Isotope Stage 3 and Greenland Stadial (GS) 5, with ice margins reaching south Lancashire by 30 ± 1.2 ka, followed by a 120-km advance at 28.3 ± 1.4 ka reaching its 26.5 ± 1.1 ka maximum extent during GS-3. Early retreat during GS-3 reflects piracy of ice sources shared with the Irish-Sea Ice Stream (ISIS), starving the ISG. With ISG retreat, an opportunistic readvance of Welsh ice during GS-2 rode over the ISG moraines occupying the space vacated, with ice margins oscillating within a substantial glacial over-deepening. Our geomorphological chronosequence shows a glacial system forced by climate but mediated by piracy of ice sources shared with the ISIS, changing flow regimes and fronting environments.  相似文献   

基于多源遥感影像的长春市城市建成区提取     

王博帅  蒲东川  李婷婷  牛雪峰 《吉林大学学报(地球科学版)》2021,51(4):1284-1294

夜光遥感影像记录的城市灯光与人类活动密切相关,已广泛应用于城市信息提取。珞珈一号作为新一代夜光遥感数据源,比以往的夜光数据具有更高的空间分辨率和光谱分辨率,可以更清晰地表达城市建成区范围和内部结构。本文利用珞珈一号夜光遥感影像,通过人类居住指数（human settlement index, HSI）、植被覆盖和建筑共同校正的城市夜光指数（vegetation and build adjusted nighttime light urban index, VBANUI）及支持向量机（support vector machine, SVM）监督分类3种方法对长春市城市建成区进行提取,并与利用NPP/VIIRS（suomi national polar-orbiting partnership/visible infrared imaging radiometer suite）夜光遥感影像、采用同样方法得到的结果对比。结果显示：本文提出的VBANUI提高了传统植被覆盖校正的城市夜光指数（vegetation adjusted nighttime light urban index, VANUI）的提取精度,使用珞珈一号夜光遥感影像通过VBANUI提取的城市建成区结果最优,其Kappa系数为0.80,总体分类精度为90.74%;使用珞珈一号和NPP/VIIRS夜光遥感影像通过HSI按最佳阈值提取城市建成区的Kappa系数分别为0.75和0.72,总体分类精度分别为88.27%和86.54%;复合数据的SVM监督分类法中Landsat-NDBI、Landsat-NDBI-VIIRS、Landsat-NDBI-LJ和Landsat-NDBI-LJlog的Kappa系数分别为0.602、0.627、0.643和0.681,总体分类精度分别为81.11%、81.52%、82.25%和84.48%。研究结果表明：3种提取方法下,均为使用珞珈一号夜光遥感影像的结果优于使用NPP/VIIRS夜光遥感影像的结果,证明相比于NPP/VIIRS夜光遥感影像,珞珈一号夜光遥感影像更适用于城市尺度的建成区范围提取。  相似文献   

中国地下水资源演变趋势及影响因素分析   总被引：1，自引：0，他引：1       下载免费PDF全文

陈飞  徐翔宇  羊艳  丁跃元  郦建强  李原园 《水科学进展》2021,31(6):811-819

中国地下水资源发生了显著变化,全面摸清地下水资源演变趋势及其影响因素是治理和管理地下水资源的基础。基于全国水资源调查评价、中国水资源公报等资料,对中国60余年来地下水资源的演变规律与影响因素进行了系统分析。结果表明：全国地下水资源量总体稳定,但区域演变趋势差异明显,海河区、辽河区、黄河区呈明显衰减态势;地下水补给结构发生重大变化,由自然补给演变为自然与人工补给并存的模式;地下水排泄结构发生巨大变异,由天然排泄逐渐演变为以人工排泄为主。海河区、松花江区、黄河区、西北诸河区等区域地下水补给排泄关系严重失衡,超采问题突出;降水变化、下垫面条件改变、人类活动干扰是地下水资源变化的主要原因。  相似文献   

人类从哪里来？——（4）人类演化与古地理、古环境和古气候变化     

季强  季燕南  吴文盛 《江苏地质》2021,45(1):1-7

详细介绍了8 Ma以来全球气候变化的规律,研究表明地球上主要发生过3次冷气候事件：第一次冷气候事件大约发生在距今7 Ma,一股强烈的干冷气流刮过欧洲大陆,穿越赤道地区直达非洲大陆,使得原始森林开始萎缩,面积的缩小导致古猿与人类发生演化分异;第二次冷气候事件大约发生在距今4.2 Ma,那时干冷气候持续发展,非洲大陆的原始森林进一步萎缩,并逐渐演化为稀树草原,出现了南方猿人和傍人;第三次冷气候事件大约发生在距今2.3 Ma,全球气候变化波动较大,冷-暖气候交替发育,地球上出现了真正意义上的人（人属）,并逐渐演化成现代人。根据目前的研究,人类的起源和演化与古地理、古环境和古气候变化密切相关,人类演化历史大致可分为7个时期：撒海尔猿人—原初猿人时期、地居猿人时期、南方猿人—傍人时期、能人—鲁道夫人时期、匠人—直立人时期、先驱人—海德堡人时期和智人时期。  相似文献   

关键元素与生命健康:中国耕地缺硒吗?   总被引：1，自引：0，他引：1  

王学求  柳青青  刘汉粮  胡庆海  吴慧  王玮 《地学前缘》2021,28(3):412-423

地球上的生命和非生命都是由自然界已发现的92种化学元素组成的,通过全国土壤地球化学基准值与人体血液元素含量对比研究,发现血液中40~50种化学元素平均值与土壤地球化学基准值的分布高度一致,表明这些关键元素与生命息息相关。近年大家持续关注的硒(Se)元素是人体必需的微量元素,缺乏会产生健康风险,但摄入过量也会导致中毒,因此被称为健康窗口元素。过去研究认为,中国耕地缺硒是造成健康危害的原因之一。本文通过对全国3 382个网格化点位土壤采样,获得Se的地球化学基准值和空间分布数据,发现中国贫硒国土面积,按照世界卫生组织推荐值(0.1 mg/kg)和中国规范(0.125 mg/kg)计算,分别占21.1%和31.6%;适宜区(0.125~0.40 mg/kg)面积大约555万km²,占国土面积约57.1%;富硒区(>0.40 mg/kg)面积达110万km²,占国土面积约11.2%。贫硒国土主要分布在青藏高原和内蒙古局部地区,而中国9大平原的粮食主产区耕地总体上不缺硒,其中珠江三角洲平原、广西平原、成都平原、长江中下游平原是富硒区(>0.40 mg/kg),华北平原、东北平原、三江平原、关中平原是硒边缘区-适量区(0.125~0.40 mg/kg),只有河套平原是缺硒区(<0.125 mg/kg)。根据覆盖全国的网格化土壤采样分析结果,发现低硒带呈不连续的片状分布于内蒙古东部至青藏高原一带,与传统认为“低硒带分布于东北三省至西南云贵高原”不完全一致。硒的空间分布模式主要受地质背景、岩石类型、土壤类型和自然地理景观控制。  相似文献