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711.
岩溶地区人类活动的水文效应研究现状及展望   总被引:10,自引:1,他引:10  
在全球气候变化背景下,加之岩溶生态系统的脆弱性及敏感性,地表水与地下水交换迅速,岩溶水动力系统对人类活动及其造成的生态环境变化反馈敏感。岩溶地区人类活动导致的植被退化、石漠化等环境问题已对岩溶地区的水文水循环过程造成了严重影响,水资源问题已成为岩溶地区发展的重要限制因素。本文在对岩溶生态系统及水文环境特性分析的基础上,从土地利用变化的水文效应,人类活动对降水—径流的影响、岩溶水资源的开发利用、岩溶地下水污染及水文模型在岩溶地区的应用等方面,概述了岩溶地区人类活动水文效应的相关研究现状与不足,总结了未来岩溶地区人类活动水文效应的5个研究趋势,并探讨了研究中的重点及难点问题。  相似文献   
712.
Du  Yunyan  Tu  Wenna  Liang  Fuyuan  Yi  Jiawei 《地理学报(英文版)》2021,31(2):179-194
Mobile internet and wireless communication technologies have produced unprecedented location-aware data. Such big geospatial data can be used as a proxy measure of the ‘digital footprints' left by us on the planet and provide a valuable opportunity to understand the dynamic and short-term human disturbance on the nature at fine scales. This study investigated the spatiotemporal variations of human's digital footprints on the Qinghai-Tibet Plateau using smartphone-users-generated Tencent's location request data. The results showed that human's digital footprints cover less than 5% of Qinghai and Tibet, exhibiting either a U-shaped or an N-shaped temporal change pattern during the major festivals. Spatial changes of the digital footprints manifested a transition process from dispersion to concentration in Xining and Lhasa. Human disturbance assessment of seven large nature reserves on the plateau showed that the Qinghai Lake is the most disturbed one as shown by 14.6% of its area is stained with human digital footprints and the areal average of footprint intensity is 1.59, and the disturbance was significantly escalated during the National Day holiday. By contrast, the Qangtang and Hoh Xil are the least affected nature reserves with the two indices less than 1% and 0.1, respectively.  相似文献   
713.
Lanzhou Valley Basin is composed of two smaller diamond-shaped basins striking from NW to SE and including 6 river terraces. The lower terraces remaining even and smooth are main sites for city buildings. The main function of Lanzhou urban settlement is a ferry and transport centre. Lanzhou used to be an im-portant crossing site and post on the "silk road",and then became a transport and trade centre in Northwest China. In the middle part of the 17th century, Lanzhou became the capital of Gansu,a new province. The development process of Lanzhou urban settlement indicates that urban settlement is a system consisting of natural environment and human society based on the former.  相似文献   
714.
几十年来,个人申诉制度在联合国人权保护体系内和区域性人权机构都得到了不同程度的发展。个人申诉制度的确立和发展,无论是在理论上还是实践上,都是对传统国际法的一大突破。事实证明,个人申诉制度顺应了个人权利主体意识增强的趋势,是完善国际人权的监督和保护所不可缺少的。  相似文献   
715.
The influence of human activities on environment and climate change is the most conspicuous problem of the Loess Plateau, and it may be divided into two aspects: firstly, the excessive utilization of land by the human race causes the destruction of vegetation, and consequently large expanse of land is under desertification and the characteristics of the ground surface and the water and heat exchange on the ground surface have changed; secondly, the use of coal by industries produces a huge amount of carbon dioxide and trace elements, which enter into the atmosphere to cause air pollution.Data of 1951-1990 are collected from 69 meteorological stations on the Loess Plateau. After analysis, the decadal variations of temperature and rainfall in the last 40 years are obtained as follows: (1) In the arid zone of the north- west of the Loess Plateau, the increase in temperature is the largest. For the past 40 years, the annual mean temperature has increased 0.7-1.0 ℃ . In the semiarid zone of the middle part  相似文献   
716.
本文扼要介绍近期出现的绿色变革浪潮,提出绿色文化的概念,阐述绿色的价值、绿色文化的一般原则、绿色文化与其它文化的关系,初探绿色社区建设的构想。展示绿色未来,要正视以往由于人类对地理环境的偏见和人类中心主义所招致生态危机,重新调整和确立良好的人地关系。其对地球村的发展有深远意义。  相似文献   
717.
Results of palaeoecological studies involving pollen analytical, chemical and palaeomagnetic investigations on a 3 m core from Lough Doo, NE County Mayo, are presented. The record, which commences shortly after 7000 BP, shows a sharp Alnus expansion coinciding with a decline in Pius at 6400 BP, an elm decline taking place in the context of severe soil erosion and the final decline of Pinus occurring as the chemical record indicates onset of severe reducing conditions in the catchment. Pine becomes extinct at or shortly before 3200 BP in the context of increased farming activity and the expansion of blanket bog in the adjacent upland areas. A later feature (c. 1880 BP) is the expansion of Taxus to 7.1% of total pollen. On the basis of the palynological evidence, it is concluded that there were no major Neolithic Landnam phases, which contrasts sharply with the evidence for widespread woodland clearance and the laying out of extensive and regular field systems in the northern coastal part of County Mayo. In the upper part of the core a severe inversion of 14C dates is recorded. On the basis of the palaeomagnetic and pollen evidence this began at c. 1500 BP and is considered to have been initiated in the context of woodland clearance and a renewal in farming activity.  相似文献   
718.
A preliminary analysis of the primary health care delivery component of a small rural development project in Deurali, Nepal, suggests that personal relations between project personnel and their target population (e.g., implementors'sincerity and commitment to service) can overcome many cultural, geographical, and class-related social barriers to achieving project objectives. The Deurali medical staff's ability to combine their technical skills with sincerity, hard work, and commitment has made the Deurali project reasonably successful in meeting villagers'primary health care needs.  相似文献   
719.
Baxter  P. J.  Neri  A.  Todesco  M. 《Natural Hazards》1998,17(2):163-176
Volcanic eruptions increasingly present catastrophic natural risks with hundreds of millions of people now living in areas of active volcanism and major conurbations around active eruptive centres. Interdisciplinary studies in disaster reduction have an important role in volcanic emergency management through advancing our understanding of the physical impacts of eruptive phenomena and the causes of death and injury in explosive eruptions. Numerical modelling of pyroclastic flows, amongst the most destructive of eruptive phenomena, provides new opportunities to improve the evaluation of the potential destructiveness of volcanic events and their human impacts in densely populated areas. In this work, the results of numerical modelling of pyroclastic flow propagation at Vesuvius have been analysed in terms of the physical parameters (temperature, ash in air concentration, and dynamic pressure) that are most critical for human survival. Our numerical simulations of eruptions of Vesuvius indicate that a large area exists where total destruction may not be inevitable in small to medium scale events, a finding that has prompted us to explore further the implications for human survival as part of an interdisciplinary approach to disaster reduction. The lessons of modelling at Vesuvius should be integrated into civil protection plans for other urban centres threatened by volcanoes.  相似文献   
720.
Based on data from instrumental measurements, map comparison, sedimentological methods, historical literature analysis and 14C dating techniques, a data-base has been built to study the changing sedimentation rate of the lower Yellow River over the past 13,000 years. A striking increase of sedimentation rate with time has been revealed which reflects the effects of both global climatic change and human activities. The points in the plots can be fitted by several straight-line segments with different slopes, representing geological sedimentation, naturally accelerated sedimentation and anthropogenically accelerated sedimentation.  相似文献   
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