STUDY ON INDEX SYSTEM OF ASSESSMENT OF PUBLIC DISASTER PERCEPTION IN THE WESTERN CHINA

The study on humanity response to global environment change is a new direction in the research of global change science, of which an important aspect is to study the adaptation strategies of human being to environ-mental changes in different regions. One reasonable and scientific adaptation strategy is based on not only scientific assessment of the impact of environmental change on society, but also correct estimation of the public perception of environmental change, whereas the research on the latter is terribly weak. This paper intends to understand the per-sonality difference in public perception of environment in the western China primarily by establishing the assessment index system of nation environmental perception and analyzing the results of questionnaire survey in some regions of Shaanxi Province. The conclusions are as follows: 1) The state of public perception of disaster is one of the founda-tions of constituting and enforcing reasonable adaptation strategy to environmental change. 2) The personality differ-ences of public perception of disaster appear as follows: female disaster perception is stronger than male.the order of disaster perception from strong to weak from the point of age characteristics is 20-30, 0-20, 40-50, 30-40, 50-60,60 year old or over in turns; the order of disaster perception from strong to weak from the point of educational char-acteristics is senior high school, college, illiterate, junior high school, primary school, in turns; the order of disaster perception from strong to weak from the point of occupation characteristics is student, farmer, teacher, worker and functionary, in turns; the order of disaster perception from strong to weak from the point of habitat characteristics is city, countryside, towns, and metrooolis in turns.     

Comprehensive drought monitoring in Yunnan Province,China using multisource remote sensing data

Development of drought monitoring techniques is important for understanding and mitigating droughts and for rational agricultural management. This study used data from multiple sources, including MOD13 A3, TRMM 3 B43, and SRTMDEM, for Yunnan Province, China from 2009 to 2018 to calculate the tropical rainfall condition index(TRCI), vegetation condition index(VCI), temperature condition index(TCI), and elevation factors. Principal component analysis(PCA) and analytic hierarchy process(AHP) were used to construct comprehensive drought monitoring models for Yunnan Province. The reliability of the models was verified, following which the drought situation in Yunnan Province for the past ten years was analysed. The results showed that:(1) The comprehensive drought index(CDI) had a high correlation with the standardized precipitation index, standardized precipitation evapotranspiration index, temperature vegetation dryness index, and CLDAS(China Meteorological Administration land data assimilation system), indicating that the CDI was a strong indicator of drought through meteorological, remote sensing and soil moisture monitoring.(2) The droughts from 2009 to 2018 showed generally consistent spatiotemporal changes. Droughts occurred in most parts of the province, with an average drought frequency of 29% and four droughtprone centres.(3) Monthly drought coverage during 2009 to 2014 exceeded that over 2015 to 2018. January had the largest average drought coverage over the study period(61.92%). Droughts at most stations during the remaining months except for October exhibited a weakening trend(slope 0). The CDI provides a novel approach for drought monitoring in areas with complex terrain such as Yunnan Province.     

Agricultural opportunity costs assessment based on planting suitability: a case study in a mountain county in southwest China

Payment for ecosystem services (PES) has become an increasingly popular means of ecosystem conservation. Opportunity cost is an important factor to increase the investment efficiency of PES projects. However, the distribution of opportunity cost is usually unclear in mountainous regions due to the obvious environment changes. In this study, we developed a framework to assess the distribution of agricultural opportunity costs in mountainous regions and applied this method to Baoxing County, a typical mountainous county in Sichuan Province of southwest China. Planting suitability of 17 crops was assessed based on agricultural statistics and natural conditions data within a GIS environment. Agricultural opportunity cost was quantified with a weighted summation of farmers’ willingness to cultivate and each crop’s opportunity cost. Finally, specific agricultural opportunity cost was obtained according to the spatial areas of the protection programs and land use status. The results showed that agricultural opportunity costs of PES in Baoxing County were estimated to be more than $30 million, with a mean of 400.85 $/ha. Agricultural opportunity costs in mountainous regions displayed some obvious spatial variation and areas with lower agricultural opportunity costs could be selected as priority areas for PES. Our findings revealed that the planting suitability evaluation can make agricultural opportunity costs mapping more reasonable. It will be helpful for the PES programs implementation in mountainous regions.     

基于信息量模型的中国滑坡灾害风险区划研究

基于信息论发展起来的信息量模型是进行区域滑坡灾害风险评估的一种有效方法。GIS技术为滑坡灾害在不同模型条件下的风险评估提供了有效地技术支持。经过研究，开发出了基于MapGIS软件平台的滑坡灾害风险分析系统。在该系统支持下．采用信息量模型对中国范围内的滑坡灾害进行危险性分析。进而进行区域社会经济易损性分析。并在此基础上进行最终的滑坡灾害风险评估。     

西南矿区山体崩塌成因机制分析及防治对策

西南地区的矿区具有相似的地理、地质环境,通过四川芙蓉煤矿白岩崩塌的典型实例,对西南矿区山体崩塌的成灾环境进行调查研究,揭示了西南矿区山体崩塌的成因机制,并简要提出了对该煤矿开发与综合治理建议,指出了加强防治工作的紧迫性,强调开展系统工程防灾的重要性,并为该煤矿解决正常采掘接替及工作面的布置问题作出了科学的指导.     

Object-based classification of cloudy coastal areas using medium-resolution optical and SAR images for vulnerability assessment of marine disaster

Efficient and accurate access to coastal land cover information is of great significance for marine disaster prevention and mitigation. Although the popular and common sensors of land resource satellites provide free and valuable images to map the land cover, coastal areas often encounter significant cloud cover, especially in tropical areas, which makes the classification in those areas non-ideal. To solve this problem, we proposed a framework of combining medium-resolution optical images and synthetic aperture radar(SAR) data with the recently popular object-based image analysis(OBIA) method and used the Landsat Operational Land Imager(OLI) and Phased Array type L-band Synthetic Aperture Radar(PALSAR) images acquired in Singapore in 2017 as a case study. We designed experiments to confirm two critical factors of this framework: one is the segmentation scale that determines the average object size, and the other is the classification feature. Accuracy assessments of the land cover indicated that the optimal segmentation scale was between 40 and 80, and the features of the combination of OLI and SAR resulted in higher accuracy than any individual features, especially in areas with cloud cover. Based on the land cover generated by this framework, we assessed the vulnerability of the marine disasters of Singapore in 2008 and 2017 and found that the high-vulnerability areas mainly located in the southeast and increased by 118.97 km2 over the past decade. To clarify the disaster response plan for different geographical environments, we classified risk based on altitude and distance from shore. The newly increased high-vulnerability regions within 4 km offshore and below 30 m above sea level are at high risk; these regions may need to focus on strengthening disaster prevention construction. This study serves as a typical example of using remote sensing techniques for the vulnerability assessment of marine disasters, especially those in cloudy coastal areas.     

Water Requirements and Irrigation Scheduling of Spring Maize Using GIS and CropWat Model in Beijing-Tianjin-Hebei Region

Due to the over use of available water resources, it has become very important to define appropriate strategies for planning and management of irrigated farmland. In this paper, Beijing-Tianjin-Hebei (Jing-Jin-Ji) region was chosen as the case study area for its special political and economic status and its severe water problem. To achieve effective planning, the information about crop water requirements, irrigation withdrawals, soil types and climatic conditions were obtained in the study area. In the meantime, a GIS method was adopted, which extends the capabilities of the crop models to a regional level. The main objectives of the study are: 1) to estimate the spatial distribution of the evapotranspiration of spring maize; 2) to estimate climatic water deficit; 3) to estimate the yield reduction of spring maize under different rainfed and irrigated conditions. Based on the water deficit analysis, recommended supplemental irrigation schedule was developed using CropWat model. Compared to the rainfed control, the two or three times of supplemental water irrigated to spring maize at the right time reduced the loss of yield, under different scenarios.     

Formation mechanism of a rainfall triggered complex landslide in southwest China

This case study is about a landslide that occurred after 4 days of heavy rainfall,in the morning of June 29,2012,in Cengong County,Guizhou Province of China,geographical coordinated 108°20′-109°03′E,27°09′-27°32′N,with an estimated volume of 3.3×106 m3.To fully investigate the landslide process and formation mechanism,detailed geotechnical and geophysical investigations were performed including borehole drilling,sampling,and laboratory tests coupled with monitoring of displacement.Also,a combined seepage-slope stability modeling was performed to study the behavior of the landslide.After the heavy rainfall event,the sliding process started in this area.The landslide development can be divided into different parts.The man-made fill area,spatially distributed in the south side of the landslide area with low elevations,slid first along the interface between the slope debris and the strongly weathered bedrock roughly in the EW direction.Consequently,due to severe lateral shear disturbance,the slope in the main sliding zone slid next towards the SW direction,along the sliding surface developed within the strongly weathered calcareous shale formation located at a depth of 25-35 m.This means it was a rainfall triggered deep-seated landslide.Finally,retrogressive failure of a number of upstream blocks occurred,which moved in more than one direction.The initial failure of the man-made fill area was the‘engine’of the whole instability framework.This artificial material with low permeability,piled up in the accumulation area of surface and sub-surface and destroyed the drainage capacity of the groundwater.The numerical modeling results agreed with the analysis results obtained from the laboratory and field investigations.A conceptual model is given to illustrate the formation mechanism and development process of the landslide.     

Hazard assessment of landslide disaster using information value method and analytical hierarchy process in highly tectonic Chamba region in bosom of Himalaya

The present study is focused on a comparative evaluation of landslide disaster using analytical hierarchy process and information value method for hazard assessment in highly tectonic Chamba region in bosom of Himalaya. During study, the information about the causative factors was generated and the landslide hazard zonation maps were delineated using Information Value Method (IV) and Analytical Hierarchy Process (AHP) using ArcGIS (ESRI). For this purpose, the study area was selected in a part of Ravi river catchment along one of the landslide prone Chamba to Bharmour road corridor of National Highway (NH-154A) in Himachal Pradesh, India. A numeral landslide triggering geoenvironmental factors i.e. slope, aspect, relative relief, soil, curvature, land use and land cover (LULC), lithology, drainage density, and lineament density were selected for landslide hazard mapping based on landslide inventory. Landslide hazard zonation map was categorized namely “very high hazard, high hazard, medium hazard, low hazard, and very low hazard”. The results from these two methods were validated using Area Under Curve (AUC) plots. It is found that hazard zonation map prepared using information value method and analytical hierarchy process methods possess the prediction rate of 78.87% and 75.42%, respectively. Hence, landslide hazard zonation map obtained using information value method is proposed to be more useful for the study area. These final hazard zonation maps can be used by various stakeholders like engineers and administrators for proper maintenance and smooth traffic flow between Chamba and Bharmour cities, which is the only route connecting these tourist places.     

黑碳在全球气候和环境系统中的作用及其在相关研究中的意义

燃烧形成的黑碳粒子进入大气中可影响辐射平衡,导致全球气候变暖,其沉降在河流、湖泊、海洋、土壤等环境中对全球生物地球化学循环起到重要的作用,成为当前国际地球科学研究的热点问题。综述了黑碳的定义及排放、沉降、降解过程,并总结了其在现在及过去环境和气候系统中的重要作用与研究意义。黑碳是全球惰性有机碳库的重要组成部分,在全球慢速碳循环中发挥潜在作用。因其具有很强的吸光特性,它在区域气候变暖过程中扮演重要角色。沉降在不同地质载体中的黑碳难以降解,可以保存几百万年,为地质历史时期古气候和古环境重建研究提供重要信息。海洋沉积物过去数百万年的黑碳记录指示了天然火的演化信息,晚第四纪黄土剖面黑碳也指示了天然火的变化信息,最近千年的湖泊和冰芯黑碳记录既反映了天然火的信息,也指示人类活动的信号。未来黑碳研究应进一步关注标准测量方法,以真正理解黑碳在全球气候与环境系统中的作用。     

Susceptibility assessment of landslides caused by the wenchuan earthquake using a logistic regression model

The Wenchuan earthquake on May 12, 2008 caused numerous collapses, landslides, barrier lakes, and debris flows. Landslide susceptibility mapping is important for evaluation of environmental capacity and also as a guide for post-earthquake reconstruction. In this paper, a logistic regression model was developed within the framework of GIS to map landslide susceptibility. Qingchuan County, a heavily affected area, was selected for the study. Distribution of landslides was prepared by interpretation of multi-temporal and multi-resolution remote sensing images (ADS40 aerial imagery, SPOT5 imagery and TM imagery, etc.) and field surveys. The Certainly Factor method was used to find the influencial factors, indicating that lithologic groups, distance from major faults, slope angle, profile curvature, and altitude are the dominant factors influencing landslides. The weight of each factor was determined using a binomial logistic regression model. Landslide susceptibility mapping was based on spatial overlay analysis and divided into five classes. Major faults have the most significant impact, and landslides will occur most likely in areas near the faults. Onethird of the area has a high or very high susceptibility, located in the northeast, south and southwest, including 65.3% of all landslides coincident with the earthquake. The susceptibility map can reveal the likelihood of future failures, and it will be useful for planners during the rebuilding process and for future zoning issues.     

An assessment of the climatic suitability of Afriski Mountain Resort for outdoor tourism using the Tourism Climate Index(TCI)

Tourism Climatic Indices(TCIs) are widely used in the global North to quantify the climatic suitability of a destination for tourism. Only one such study has been conducted in southern Africa to date. It is in a chronic shortage of research on tourism and climate change in the southern hemisphere. This study presents the application of the TCI in Lesotho, calculated for the eastern Lesotho Highlands. The region has an emerging tourism sector, which primarily comprises outdoor activities.These include hiking, horse-riding, music festivals,mountain biking, cultural visits, sightseeing, and at the Afriski lodge, skiing and snowboarding. These activities are reliant on climatic conditions that are conducive to the activity taking place, prolonged periods outdoors, and tourist satisfaction of the activity. Climate is a major determinant of both the length of season for these activities and the timing of peak tourist arrivals. Rising temperatures and changes in relative humidity and precipitation pose real threats to hiking, sightseeing and snow tourism at Afriski. The reliance of tourism in the region on specific climatic conditions for successful tourism prompted the use of the TCI. TCI results classify the eastern Lesotho Highlands as having.good‘ climatic conditions with an overall TCI score of 64 for the period 2012-2017. Monthly TCI scores for the easternLesotho reveal a bimodal-shoulder, meaning the peak climatic conditions are in the regional summer months(December to February). This conflicts with the peak tourist seasons of summer and winter, which align with South African school holidays, and the timing of the most profitable tourism activity(skiing)which occurs during the winter months of June, July and August. Lesotho is landlocked by South Africa.TCI analysis for South Africa reveals more suitable climatic conditions for tourism than Lesotho, with significantly higher scores of 80-89.     

Assessing the impacts of climate change and anthropogenic activities on vegetation in southwest China

The topography and geomorphology of southwest China are complex, and the intensity of human activities not balanced. The impact of climate change and anthropogenic activities on vegetation shows temporal and spatial differences. Therefore, we used normalized difference vegetation index(NDVI)to analyze the impact of climate change and anthropogenic activities on vegetation in four provinces and municipality in the southwest China from 2000 to 2015. The results showed that(1) NDVI increased 0.004–...     

Effects of loose deposits on debris flow processes in the Aizi Valley,southwest China

Loose deposits, rainfall and topography are three key factors that triggering debris flows.However, few studies have investigated the effects of loose deposits on the whole debris flow process.On June 28, 2012, a catastrophic debris flow occurred in the Aizi Valley, resulting in 40 deaths.The Aizi Valley is located in the Lower Jinsha River,southwestern Sichuan Province, China. The Aizi Valley debris flow has been selected as a case for addressing loose deposits effects on the whole debris flow process through remote sensing, field investigation and field experiments. Remote sensing interpretation and laboratory experiments were used to obtain the distribution and characteristics of the loose deposits, respectively. A field experiment was conducted to explore the mechanics of slope debris flows, and another field investigation was conducted to obtain the processes of debris flow formation, movement and amplification. The results showed that loose deposits preparation, slope debris flow initiation,gully debris flow confluence and valley debris flow amplification were dominated by the loose deposits.Antecedent droughts and earthquake activities may have increased the potential for loose soil sources in the Aizi Valley, which laid the foundation for debris flow formation. Slope debris flow initiated under rainfall, and the increase in the water content as well as the pore water pressure of the loose deposits were the key factors affecting slope failure. The nine gully debris flows converged in the valley, and the peak discharge was amplified 3.3 times due to a blockage and outburst caused by a large boulder. The results may help in predicting and assessing regional debris flows in dry-hot and seismic-prone areas based on loose deposits, especially considering large boulders.     

陕西榆林风沙滩区全新世气候和环境变迁

榆林长城沿线处于环境变化敏感带,其风沙滩区沉积剖面的磁化率和粒度分析结果显示,该区全新世早期11 500~10 000 a BP随着全球气候的逐渐转暖,磁化率、黏粒和粉沙含量逐渐增高;全新世中期的10 000~4 500 a BP气候相对比较湿润,植被覆盖度增大,风沙活动减弱,地表沉积物当中粉沙和黏土成分含量显著增大,风化成壤作用增强,地表发育沙质弱古土壤;全新世中期后段的4 500~3 000 a BP期间,气候以比较温和湿润为主,但在4 200~4 000 a BP出现一个气候干旱事件,风沙活动强烈;近3 000 a以来,气候显著干旱化,波动频繁,地表风沙沉积物显著变粗,表现出有5次沙漠扩张。该区生态环境演化、人文历史变迁基本上是自然因素与人为活动综合作用的结果,以自然演化为主,近代人为因素对环境变化起着加强和放大作用。     

中国气候舒适度时空分布特征分析

气候舒适度对人类活动和地区适宜性评价等研究具有重要意义,而温湿指数是气候舒适度评价的一项重要指标。传统的温湿指数计算都是基于站点数据,无法获取大尺度区域舒适度的时空变化特征。本文利用2005—2018年MODIS地表温度、大气可降水量数据,结合地理加权回归方法对经典温湿指数模型进行改进,计算并分析中国年均和月均气候舒适度时空演变特征。结果如下：① 采用GWR方法进行地表温度和气温的拟合,拟合精度（Adjusted R²=0.9~0.98,RMSE=0.14~1.89 ℃）较为理想,说明采用LST、NDVI、DEM作为自变量的地理加权回归分析,能够较精确地拟合地面气温;② 2005—2018年年均温湿指数统计结果表示,云南省累计舒适月数最多,高达167个月,中部省份相对于东南沿海省市舒适时期较多,最高舒适月数差值可达到41个月。中国年均舒适度空间分布规律基本保持一致,除新疆、西藏和东北的部分区域以外,舒适度空间呈现从南到北,舒适度等级由舒适变寒冷。从舒适度等级面积变化情况看,2005—2018年全国舒适度等级呈现由寒冷变舒适的趋势;③ 2018年全年舒适面积最大的月份为5月,其次为10月,不舒适月份集中在1月和7月,全国呈现极冷或极热。春季和秋季空间分布特征较为相似,呈现由东南到西北逐渐递减的趋势;除青藏高原地区外,夏季和冬季呈现由南到北递减趋势。舒适区域主要集中在低纬、中海拔地区。     

Modelling spatial variation in the treatment costs of nonpoint source pollution in mountainous regions of southwest China

Non-point source(NPS) pollution is considered to be one of the main threats of the aquatic environment. Mountainous regions are particularly important water sources for urban areas. The various driving factors of NPS pollution such as terrain, precipitation, and vegetation type in mountainous regions show clear spatial heterogeneity. Consequently, the management systems required for NPS pollution in mountainous regions are complex. In this study, we developed a framework to estimate and map the treatment costs for NPS pollution in mountainous regions and applied this method in Baoxing County, a typical mountainous county in Sichuan Province of southwest China. The export levels of total nitrogen(TN) and total phosphorus(TP) in Baoxing County were estimated using the water purification model in InVEST(Itegrated Valuation of Ecosystem Services and Tradeoffs) tool. NPS pollutant treatment costs were calculated based on the level of pollutants exports, water yield, water quality targets, and treatment costs of NPS pollutants per unit mass. The results show that at the watershed level the amounts of TN and TP exported in Baoxing County were below threshold limits. However, at the sub-watershed level, TN and TP excesses of 291.64 and 2.96 tons per year were found, respectively, with mean TN and TP treatment costs of 6.58 US$/hm~2 and 0.35 US$/hm~2. Appraising pollution treatment cost intuitively reflects the overall expenditure in NPS pollution reduction from an economic perspective. This study provides a foundation for the implementation of Payment for Ecosystem Service(PES) and the prevention and control of NPS pollution.     

AN ASSESSMENT OF LAND USE CHANGES IN FUQING COUNTY OF CHINA USING REMOTE SENSING TECHNOLOGY

Fuqing County of southeast Chian has witnessed significant land use changes during the last decade.Re-mote sensing technology using multitemporal Landsat TM images was used to characterize land use types and to monitor land use changes in the county.Two TM scenes from 1991and 1996 were used to cover the county and a five-year time period.Digital image processing was carried out for the remotely sensed data to produce classified images.The images were further processed using GIS software to generate GIS databases so that the data could be further spatially analyzed taking the advantages of the software.Land use change areas were determined by using the change detection technique.The comparison of the two classified TM images using the above technologies reveals that during the five study years,a large area of arable lands in the county has been lost and deforestation has taken place largely because of the dramatic in-crease in built-up land and orchard.The conclusive statistical information is useful to understand the processes,causes and impacts of the land use changes in the county.The major driving force to the land use changes in the county ap-peared to be the rapid economic development.The decision makers of the county have to pay more attention to the land use changes for the county‘s sustainable development.     

中国耕地变化区的气候背景对比分析

研究我国耕地变化区的气候背景,对于了解耕地资源的生产能力,评价耕地占补平衡政策的实施效果,实现耕地资源保护和粮食安全等具有重要意义。本文在分析全国耕地空间变化的基础上,从年平均气温、年降水量和日照时数三个方面,研究耕地增加区和减少区的气候背景,并将其进行比较和分析,以期为国家保护耕地资源和发展农业生产等提供建议。研究结果表明,20世纪80年代末至2008年4个时段,耕地减少区比耕地增加区的年平均气温高0.45~1.05℃,年降水量高56.77~79.59mm,年日照时数少45.80~98.83h。耕地显著减少区比耕地显著增加区的年平均气温高0.81~1.85℃,年降水量高85.69~305.26mm,年日照时数少86.96~207.85h。在四个时段中,我国耕地重心逐渐北移且海拔升高。若海拔高度不变,耕地增加区比耕地减少区北移0.5-1个纬度,耕地显著增加区比耕地显著减少区北移1-2个纬度;若纬度不变,耕地增加区比耕地减少区,海拔升高100~200m,耕地显著增加区比耕地显著减少区,海拔升高150~350m。随年份增加,耕地增加区和显著增加区与耕地减少区和显著减少区在水分条件上的差别越来越大。这些结论对于研究我国粮食生产能力、评价耕地占补平衡、调整产业布局等具有重要意义。     

Geometrical feature analysis and disaster assessment of the Xinmo landslide based on remote sensing data

At 5:39 am on June 24, 2017, a landslide occurred in the village of Xinmo in Maoxian County, Aba Tibet and Qiang Autonomous Prefecture(Sichuan Province, Southwest China). On June 25, aerial images were acquired from an unmanned aerial vehicle(UAV), and a digital elevation model(DEM) was processed. Landslide geometrical features were then analyzed. These are the front and rear edge elevation, accumulation area and horizontal sliding distance. Then, the volume and the spatial distribution of the thickness of the deposit were calculated from the difference between the DEM available before the landslide, and the UAV-derived DEM collected after the landslide. Also, the disaster was assessed using high-resolution satellite images acquired before the landslide. These include Quick Bird, Pleiades-1 and GF-2 images with spatial resolutions of 0.65 m, 0.70 m, and 0.80 m, respectively, and the aerial images acquired from the UAV after the landslide with a spatial resolution of 0.1 m. According to the analysis, the area of the landslide was 1.62 km2, and the volume of the landslide was 7.70 ± 1.46 million m3. The average thickness of the landslide accumulation was approximately 8 m. The landslide destroyed a total of 103 buildings. The area of destroyed farmlands was 2.53 ha, and the orchard area was reduced by 28.67 ha. A 2-km section of Songpinggou River was blocked and a 2.1-km section of township road No. 104 was buried. Constrained by the terrain conditions, densely populated and more economically developed areas in the upper reaches of the Minjiang River basin are mainly located in the bottom of the valleys. This is a dangerous area regarding landslide, debris flow and flash flood events Therefore, in mountainous, high-risk disaster areas, it is important to carefully select residential sites to avoid a large number of casualties.