Alleviating drought and water scarcity in the Mediterranean region through managed aquifer recharge

Drought and water scarcity can significantly impair the sustainable development of groundwater resources, a scenario commonly found in aquifers in the Mediterranean region. Water management measures to address these drivers of groundwater depletion are highly relevant, especially considering the increasing severity of droughts under climate change. This study evaluates the potential of managed aquifer recharge (MAR) to offset the adverse effects of drought and water scarcity on groundwater storage. Los Arenales aquifer (central Spain), which was unsustainably exploited for irrigation in the second half of the twentieth century, is employed as a case study. Two neighbouring zones within this aquifer are contrasted, namely, Los Arenales (LA) and Medina del Campo (MC). The primary difference between them in terms of water resources management is the wide-scale implementation of MAR systems in LA since the early 2000s. Several groundwater statistical methods are used. Groundwater-level trend analysis and average piezometric levels show in LA a faster recovery of aquifer storage and less susceptibility to drought compared to MC. On the other hand, standardised precipitation indexes and standardised groundwater level indexes of detrended groundwater-level time series, which do not include the effects of MAR, show that LA can be more negatively affected by drought and groundwater abstraction. The sharper recovery of piezometric levels in LA when considering MAR, and bigger drought impacts observed when the effects of this measure are removed, demonstrate that MAR can effectively alleviate the impacts of water scarcity and drought, providing an adaptation solution to climate change worldwide.

     

湖泊水质遥感研究进展

详述了湖泊遥感水质最新发展动态,如遥感水质模型的数学方法、与水质指标最敏感的波段以及TM、SPOT、MODIS、MERIS、AVHRR、CASI等传感器的适用情况,并分析了可能导致湖泊水质遥感模型误差的原因和解决办法。湖泊各项水质组分与光谱之间相互影响可认为是一种非常复杂的非线性关系,最适合用神经网络这样的黑箱模型来模拟。应当研究和选取敏感波段,用高光谱逐段分析与各种水质指标相关最密切的波段。湖泊水质遥感最终走向实用化必将其与水生态问题结合起来,作为一种监测手段,在水中藻类的时空分布、流域营养物质输送模型和湖泊水域水质模型等问题中得到广泛应用。我国学者使用超光谱数据源获得更为精确的监测成果还比较少,由于我国卫星可以用来进行水质遥感的波段比较宽,应当在新一代的资源环境卫星上加入更适合水质遥感的波段。     

二维平面非恒定流数学模型的遥感水位数据同化

为了在水流计算中定量化利用遥感水位数据,基于偏微分方程最优化控制理论建立了变分模型来融合二维平面非恒定流的数学模型和数据。根据遥感数据空间信息密集的特点,提出遥感水位数据同化的新算法。采用人工合成数据考察了面域遥感数据对于定常参数和时变两类参数的反演效果。试验结果表明,遥感数据提供的空间分布式信息有利于空间分布式参数的反演识别,而且通过引入考虑水面空间变化信息的附加项,可以改善观测信息的同化,更好地辨识时变参数(流量过程)。以Moselle河的RADARSAT卫星遥感水位数据检验了模型的实用性。     

基于综合营养状态指数的喀斯特高原湖泊富营养化研究

随着社会的进步和经济的不断发展,人类对地表的干扰程度逐年上升,我国大部分湖泊都受到了不同程度的污染,尤其是因氮、磷等营养物质所引起的湖泊富营养化,严重影响了湖泊水库水质及水体生态系统的平衡。喀斯特高原湖泊具有独特的生态环境与地理背景,其生态系统较为脆弱,破坏之后难以恢复。因此,对百花湖表层各理化指标进行监测,统计了2012～2016年间各月的理化参数,分析各指标的时空变化趋势,并运用综合营养状态指数评价法对百花湖进行综合评价,得出该水库2012～2016年的富营养化等级及其变化趋势,以期为百花湖污染提供综合防治的依据。     

新一轮二滩电站库区遥感调查

新一轮二滩电站库区遥感调查是在我国前20年滑坡、泥石流遥感调查技术方法基础上的一次革新。本文介绍了革新方法的数据源、工作平台、技术流程、及人机交互与自动分类相结合的遥感解译方法，并对获得的工作区滑坡、泥石流的数量、分布、特性及它们的环境背景作简要分析。     

基于GF-2影像西藏桑耶地区岩性-构造遥感解译

西藏桑耶地区位于青藏高原中南部,区内切割强烈,地势陡峻,属于高山峡谷区。为提高区域地质调查野外工作效率,在调查中率先开展了遥感解译研究。在充分收集已有资料的基础上,通过对GF-2卫星数据进行预处理和影像增强,结合野外验证建立了各地质要素的遥感解译标志,实现了区内不同地层岩性、侵入岩、断裂和褶皱等地质要素的提取,最终编制了研究区1:5万遥感地质解译图,为区域地质调查提供了数据支撑。结果表明: 各地质要素在GF-2数据上均有良好反映,完全满足1:5万尺度的遥感地质解译和编图的需要,充分显示出该卫星数据在区域地质调查等工作中具有良好的应用前景。     

Assessing soil erosion in Mediterranean karst landscapes of Lebanon using remote sensing and GIS

Maps showing the potential for soil erosion at 1:100,000 scale are produced in a study area within Lebanon that can be used for evaluating erosion of Mediterranean karstic terrain with two different sets of impact factors built into an erosion model. The first set of factors is: soil erodibility, morphology, land cover/use and rainfall erosivity. The second is obtained by the first adding a fifth factor, rock infiltration. High infiltration can reflect high recharge, therefore decreasing the potential of surface runoff and hence the quantity of transported materials. Infiltration is derived as a function of lithology, lineament density, karstification and drainage density, all of which can be easily extracted from satellite imagery. The influence of these factors is assessed by a weight/rate approach sharing similarities between quantitative and qualitative methods and depending on pair-wise comparison matrix.The main outcome was the production of factorial maps and erosion susceptibility maps (scale 1:100,000). Spatial and attribute comparison of erosion maps indicates that the model that includes a measure of rock infiltration better represents erosion potential. Field investigation of rills and gullies shows 87.5% precision of the model with rock infiltration. This is 17.5% greater than the precision of the model without rock infiltration. These results indicate the necessity and importance of integrating information on infiltration of rock outcrops to assess soil erosion in Mediterranean karst landscapes.     

遥感技术在内陆水体水质监测中的应用

内陆水体水质遥感监测是基于经验、统计分析或水质参数的光谱特征,选择遥感波段数据与地面实测水质参数数据进行数学分析,建立水质参数反演算法实现的。简要介绍了内陆水体水质监测中遥感应用研究的发展和现状,阐述了水质遥感监测原理与方法、常用的遥感数据和几种主要水质参数的遥感监测进展,讨论了目前遥感在水质监测应用中存在的问题和未来该领域研究的重点。     

全国边海防地区基础地质遥感调查

为满足全国边海防地区经济建设与国防建设对地质信息的需求,自2011年起,中国地质调查局国土资源航空物探遥感中心(简称航遥中心)联合全国相关地调中心与省级地质调查研究院、行业地质调查部门、高等院校和边海防地区国防建设应用与研究等24家单位,利用遥感技术快速获取了东北、西北、西南和南海三沙等边海防重点地区95万km²基础地质、工程地质、水文地质、矿产地质以及地质灾害等9类地质专题信息,编制了32类1:5万与1:25万服务于经济建设和国防建设的地质应用专题图件,形成了边海防地区遥感地质调查技术体系、共享数据库和应用成果,解决了边海防地区地质调查工作难点问题,创新了军民融合地质调查方式。该文围绕“全国边海防地区基础地质遥感调查”的目标任务,阐述了实施的技术路线和取得的成果,并对未来的工作进行了展望。     

Assessment of impervious surface growth in urban environment through remote sensing estimates

The fast growth in population and expansion of urban built area has led to the transformation of the natural landscape into impervious surfaces. Remote sensing-based estimate of impervious surface area (ISA) has emerged as an important indicator for the assessment of water resources depletion in urban areas and developed a correlation between land-use change and their potential impact on urban hydrology. In the present work, a remote sensing-based Impervious Surface Area (ISA) was carried out for New Okhla Industrial Development Authority (NOIDA) city, one of the fastest growing cities in National Capital Region (NCR) of India. The impervious surface area (ISA) of NOIDA was calculated for the years 2001, 2007 and 2014 using multi-temporal LANDSAT thermal data by applying linear spectral mixing analysis (LSMA) techniques to monitor the growth rate of impervious surface. The results observed by analysis of multi-temporal satellite images show an extreme temporal change in the growth of ISA in the city. The ISA observed for the year 2001 is 28 sq.km; in 2007, its increase was 48 sq.km and was 132 in 2014. The results were observed from this work through the use of satellite data which is very important for water resource management, planning and prediction of ISA impact on hydrology.     

Understanding the occurrences of fault and landslide in the region of West-Cameroon using remote sensing and GIS techniques

Natural Hazards - Remote sensing was used to visualize the West region with the purpose of investigating recent natural hazards observed in this area. Various approaches used based on...     

Applications of remote sensing in geology

Geologie en Mijnbouw -     

应用多光谱遥感信息反演干旱区浅水湖泊水深

选取位于中国北方干旱区的湖泊乌梁素海为研究区,基于2002-2004年的LandsatTM数据以及同期实测水深数据,根据水深遥感原理,通过1次,2次,3次实测水深数据与遥感影像反射率及其组合之间的相关关系,选取五变量,三变量,二变量及一变量的非对数及对数模型进行湖泊水深估值,继而通过误差分析及模型对比,最终确定出3次实测数据五变量非对数模型作为乌梁素海的最优估值模型。该模型利用多光谱组合确定水深的估值模式,克服了单光谱信息难以综合反映沉水植物、芦苇、水色及底质空间变化的困难,符合干旱区浅水湖泊的特性,结果可为干旱区其它浅水湖泊水深反演提供新的思路和参考。     

遥感多指标评价模型在高原地区给水站选址中的应用

为满足藏北高原地区给水站快速选址的需求,从该区气象水文、地质环境和地貌条件出发,对给水站选址的遥感多指标评价模型进行了优化,减小了模型复杂度和遥感信息提取的工作量。采用模糊评价算法对各指标进行规范化,构建高原地区给水站选址多指标评价模型; 采用加权合成算法计算给水站选址评估指数。研究区实地勘查表明,选址评估指数的验证结果与理论分析结果一致,该模型在高原地区给水站选址中具有较好的应用效果。     

卫星遥感监测ET方法及其在水管理方面的应用

概述了利用遥感技术监测流域蒸发(ET)用于流域水管理的研究,利用卫星遥感监测ET比传统地面监测ET方法具有更高的经济合理性和实用性;通过遥感监测的ET,不仅可以对农业用水效率、灌溉系统性能作出更符合实际的评价,还可服务于流域水资源管理和区域水资源利用规划。随着信息技术的快速发展,卫星遥感监测ET的方法在水管理方面的应用前景广阔,我国应加强对该技术的研究和应用。     

Developments in budget remote sensing for the geosciences

Acquiring outcrop, landform or other surface topography data in the field for the geosciences has always been challenging. Accessibility is often a problem, time is usually limited and an ideal spatial and temporal coverage often has to be compromised to be more manageable. However, emerging technologies, and some re-inventions of rather older ones, can overcome many of these constraints in a very exciting and budget-friendly manner. This article briefly introduces and reviews four major recent developments in budget remote sensing, specifically the use of blimps, kites, drones or UAVs (including quadcopters), and structure from motion (SFM) software. Both scientific and applied case studies are given and some possibilities for future studies are highlighted. Overall, the potential for these technologies to revolutionise the geosciences is clear and should be opportunistically embraced by scientists, resource and hazard managers and educators alike.     

基于地表水循环遥感观测的黑河流域水平衡分析

流域内水循环各环节的水量及其时空分布是不断变化的,掌握流域水循环与水平衡状况是进行流域水资源合理开发利用的重要基础。以2000—2019年黑河流域水文显著变化期为研究时段,综合应用TRMM与GPM卫星观测的降水量、遥感估算的蒸散发量等数据并结合气象站点、水文站点等观测数据,对流域降水、蒸散发与径流等水循环要素的水平衡进行了分析。结果表明:祁连山区是主要产流区,向中游年均下泄水量约为45.11×108 m3。其中,消耗于中游的年均量约为29.92×108 m3,约占66%;补充下游的年均量约为15.19×108 m3,约占34%。民乐—张掖盆地是黑河中游水资源消耗的主要区域,年均消耗的上游来水和当地降水量达43.97×108 m3,约占中游消耗量的75%;中游农田蒸散发年均消耗水量约20.3×108 m3,占总消耗量的35%;上游区降水量增加是黑河干流出山口径流量增加的主因,对径流量增加的贡献率为96%,导致年均径流增加0.35×108 m3,潜在蒸散发对径流增加几乎没有贡献。根据目前黑河干流上游径流量变化与中游水资源消耗现状,如果未来水文周期变化导致上游径流减少,中下游用水矛盾凸显的风险较大。地表水循环遥感观测可作为流域水平衡分析的方法之一,分析流域地表水水资源的空间分布状况、揭示水资源变化趋势与原因,支撑水资源合理配置,陆面实际蒸散发是水平衡分析不确定性的主要来源,准确估测不同类型下垫面实际蒸散发量是提升分析可靠性的关键。基于互补相关的陆面实际蒸散发估算方法相对简单,但其中用于计算湿环境蒸散发量的Priestley-Taylor公式中乘性经验系数受地形影响空间变异很大,区域上采用统一数值会对结果造成不可忽视的影响。