Evaluating value of natural landscapes in China

Natural landscapes consist of the natural substances, environment, and phenomena, all of which provide many benefits to people, including a sense of place, sightseeing, relaxing, and recuperating. However, the economic value of natural landscapes has only been recognized in recent decades, and the resulting large-scale decline and degradation of ecosystems now severely threatens the sustainable provision of their services to society. There is an emerging consensus that natural capital should be incorporated into the current socioeconomic accounting system. Many studies valuated natural resources at local and regional scales, but there are very few empirical studies at a national level. To provide a benchmark for natural landscape management on a national scale, we use the travel cost method(TCM) and the contingent valuation method(CVM) to determine the economic value and the spatial distribution of natural landscapes across China. Our results show that the total economic value of China′s natural landscape was 9.75 × 10~(11) U.S. dollars(USD) in 2012. Of this value, the highest proportion was in the eastern and southwestern regions of China, which accounts for 23.7% and 18.3%, respectively. The provinces of Guangdong, Sichuan, Yunnan, Inner Mongolia, and Heilongjiang were the top five in terms of the largest number of natural landscapes and largest economic values. Together, these five provinces accounted for 32.9% of the total number of natural landscapes and 29.4% of the total economic value in 2012. We believe this study will increase awareness of the value of natural landscapes, and more importantly provide a scientific basis for resolving conflicts between development and resource conservation.     

Territorial suitability assessment and function zoning in the Jiuzhaigou earthquake-stricken area

An earthquake in the Jiuzhaigou area caused numerous secondary disasters, such as rolling stones, land collapse, landslides and debris flow, which badly affected the safety of human settlements and influenced the spatial layout of the post-disaster reconstruction. Therefore, carrying out assessments of land and identifying a suitable zone for human habitats were very important. This research creates the territorial suitability assessment and function zoning conceptual model in the earthquake-stricken area, and the new methods of the territorial suitability evaluation system were used to divide the spatial functional zones of the earthquake stricken area, which provide a theoretical guidance and decisionmaking basis for the reconstruction of the disaster area. The results showed that:(1) The Jiuzhaigou earthquake-stricken area comprises of an ecological area that has a high level of importance to the ecosystem. In the earthquake-stricken area, 65% of national land is at an altitude of 3000-4000 m, and therefore not suitable for a high level of intensive reconstruction, but reconstructed in an eco-friendly manner.(2) The zone suitable for reconstruction comprises mainly of the river valley and the flat terrain of western parts. The land with low suitability is mainly located on steep terrain, such as highmountains and low gullies. The geographic and geomorphic conditions limit the spread of a suitable reconstruction zone.(3) The earthquake-stricken area mainly comprises of a tourism industry gathering area, population gathering area, agriculture and animal husbandry development area, and ecological preservation area with areas of 76 km^2, 44 km^2, 1591 km^2 and 7512 km^2, respectively. Scientifically zoning the reconstruction areas using scientific evaluation may provide guidance for the location of reconstruction sites.     

Deep-sea geohazards in the South China Sea

Various geological processes and features that might inflict hazards identified in the South China Sea by using new technologies and methods.These features include submarine landslides,pockmark fields,shallow free gas,gas hydrates,mud diapirs and earthquake tsunami,which are widely distributed in the continental slope and reefal islands of the South China Sea.Although the study and assessment of geohazards in the South China Sea came into operation only recently,advances in various aspects are evolving at full speed to comply with National Marine Strategy and‘the Belt and Road’Policy.The characteristics of geohazards in deep-water seafloor of the South China Sea are summarized based on new scientific advances.This progress is aimed to aid ongoing deep-water drilling activities and decrease geological risks in ocean development.     

Integrated rockfall hazard and risk assessment along highways: An example for Jiuzhaigou area after the 2017 Ms 7.0 Jiuzhaigou earthquake,China

This work addresses the integrated assessment of rockfall(including landslides) hazards and risk for S301, Z120, and Z128 highways, which are important transportation corridors to the world heritage site Jiuzhai Valley National Park in Sichuan, China. The highways are severely threatened by rockfalls or landslide events after the 2017 Ms 7.0 Jiuzhaigou earthquake. Field survey(September 14-18 th, 2017, May 15-20 th, 2018, and September 9-17 th, 2018), unmanned aerial vehicle(UAV), and satellite image identified high-relief rockfalls and road construction rockfalls or landslides along the highway. Rockfall hazard is qualitatively evaluated using block count, velocity, and flying height through a 3D rockfall simulation at local and regional scales. Rockfall risk is quantitatively assessed with rockfall event probability, propagation probability, spatial probability, and vulnerability for different block volume classes. Approximately 21.5%, 20.5%, and 5.3% of the road mileage was found to be subject to an unacceptable(UA) risk class for vehicles along S301, Z120, and Z128 highways, respectively. Approximately 20.1% and 3.3% of the road mileage belong to the UA risk class for tourists along Z120 and Z128 highways, respectively. Results highlighted that high-relief rockfall events were intensively located at K50 to K55(Guanmenzi to Ganheba) and K70 to K72(Jiudaoguai to Shangsizhai Village) road mileages along S301 highway and KZ18 to KZ22(Five Flower Lake to Arrow Bamboo Lake) road mileages, KZ30(Swan Lake to Virgin Forests), and KY10.5 kilometers in Jiuzhai Valley. Rockfalls in these locations were classified under the UA risk class and medium to very high hazard index. Road construction rockfalls were located at K67(Jiuzhai Paradise) and K75–K76 kilometers along S301 highway and KZ12 to KZ14(Rhino Lake to Nuorilang Waterfall), KZ16.5 to KZ17.5(Golden Bell Lake), KY5(Lower Seasonal Lake), and KY14(Upper Seasonal Lake) kilometers along Z120 and Z128 highway in Jiuzhai Valley. Rockfalls in these areas were within a reasonable practicable risk to UA risk class and very low to medium hazard index. Finally, defensive measures, including flexible nets, concrete walls, and artificial tunnels, could be selected appropriately on the basis of the rockfall hazard index and risk class. This study revealed the integration between qualitative rockfall hazard assessment and quantitative rockfall risk assessment, which is crucial in studying rockfall prevention and mitigation.     

Assessment of prospective hazards resulting from the 2017 earthquake at the world heritage site Jiuzhaigou Valley,Sichuan, China

On August 8, 2017, a Ms = 7.0 magnitude earthquake occurred in the Jiuzhaigou Valley, in Sichuan Province, China(N: 33.20°, E: 103.82°). Jiuzhaigou Valley is an area recognized and listed as a world heritage site by UNESCO in 1992. Data analysis and field survey were conducted on the landslide, collapse, and debris flow gully, to assess the coseismic geological hazards generated by the earthquake using an unmanned aerial vehicle(UAV), remote-sensing imaging, laser range finders, geological radars, and cameras. The results highlighted the occurrence of 13 landslides, 70 collapses, and 25 potential debris flow gullies following the earthquake. The hazards were classified on the basis of their size and the potential property loss attributable to them. Consequently, 14 large-scale hazards, 30 medium-sized hazards, and 64 small hazards accounting for 13%, 28%, and 59% of the total hazards, respectively, were identified. Based on the variation tendency of the geological hazards that ensued in areas affected by the Kanto earthquake(Japan), Chi-chi earthquake(Taiwan China), and Wenchuan earthquake(Sichuan China), the study predicts that, depending on the rain intensity cycle, the duration of geological hazard activities in the Jiuzhaigou Valley may last over ten years and will gradually decrease for the following five to ten yearsbefore returning to pre-earthquake levels. Thus,necessary monitoring and early warning systems must be implemented to ensure the safety of residents,workers and tourists during the construction of engineering projects and reopening of scenic sites to the public.     

基于物联网的九寨沟智慧景区管理

从"数字景区"到"智慧景区"是景区可持续发展面临的新机遇与挑战.本文从景区管理的需求出发,探讨了建设基于物联网的"智慧景区"的必要性,设计了基于物联网新技术的"智慧景区"框架,探讨了基于服务架构的景区智能化管理模式,结合智慧九寨沟的建设,实现了基于在RFID,IP摄像头、移动执法智能终端和数据中心组成的景区物联网基础上的"智慧景区"游客分流应用功能,实践了物联网技术在智慧景区建设中的应用.     

Water quality assessment of benthic diatom communities for water quality in the subalpine karstic lakes of Jiuzhaigou,a world heritage site in China

Jiuzhaigou, characterized by its magnificent waterscapes and subalpine karstic features, is both a World Heritage Site and a World Biosphere Reserve in southwestern China. In recent years, this unique ecosystem has shown signs of stress due to increasing tourism activities within the reserve. The various routine methods, which monitor physical and chemical properties, do not fully reflect water quality in the subalpine and alpine lakes, while the indicators using aquatic organisms to evaluate the water quality or status of the subalpine lakes are poorly reported. Thus, in this study, benthic diatoms from multiple habitats in Jiuzhaigou were sampled and assessed for water quality monitoring. Canonical Correspondence Analysis (CCA) showed that the canonical coefficients for elevation, water temperature and total nitrogen on the first Canonical Correspondence Analysis axis were -0.84, 0.78 and -0.53, respectively, environmental variables associated with the distribution patterns of benthic diatoms. The dominance of diatom taxa indicative of nutrient enrichment indicates a clear trend toward eutrophication in the Pearl Shoal and Colorful Lake, two of the sites mostly visited by tourists. It was observed that the effect of the type of substratum on diatom community composition is not significant in subalpine lakes. The most dominant species in Jiuzhaigou lakes are the genera Achnanthes, Fragilaria, Cymbella, Cocconeis, Diatoma and Denticula. In combination with dominant and sensitive species in the benthic diatom communities, CCA and CA methods can be used to evaluate the impact of human activities on subalpine karstic lakes. The dominance of diatom taxa is indicative of nutrient enrichment and the results of CCA and CA indicate a clear trend toward eutrophication in the Pearl Shoal and Colorful Lake, two of the sites mostly visited by tourists.     

Estimation on Aesthetic Value of Tourist Landscapes in a Natural Heritage Site： Kanas National Nature Reserve, Xinjiang, China

Most world natural heritage sites are designated partly by reason of their prominent aesthetic values in accordance with Article Ⅶ of World Natural Heritage Convention.In this paper, the aesthetic values of Kanas National Nature Reserve, which has potential for such designation, was analyzed quantitatively using scenic beauty estimation(SBE).The landscapes of 19 representative scenic spots in the Kanas National Nature Reserve in summer and autumn were selected as the objects of evaluation.The contributions of different landscape factors to the aesthetic value of the Kanas National Nature Reserve were revealed using a multivariate quantitative model.The main factors affecting the aesthetic value were waterscapes, vegetation, mountains, folk culture and the tourist environment.The t-test and F-test results are extremely significant.According to the results, some suggestions were given for conserving the landscapes in the Kanas National Nature Reserve.     

关于规划环评指标体系建设的建议

提出了进行规划环评的指标体系：即规划内容、规划选址、规划布局、规划配套的环保和公共设施、环境容量、预测评价、环保措施等7个指标，并对规划环评的意义、内容、组织实施等方面进行了介绍，以实例论述了气象部门在进行规划环评时的优势所在。     

鲜水河断裂跨断层异常与九寨沟地震关联性探讨

提取巴颜喀拉地块东部边界鲜水河断裂、龙门山断裂及边界附近西秦岭构造区跨断层灰色关联度指标曲线,根据1999~2007年、2009~2015年及2015~2017年GPS速度场数据计算所得的鲜水河断裂、龙门山断裂及塔藏断裂剖面变化,通过对比分析寻找地块边界断裂活动的共性特征。结果表明,2009年巴颜喀拉地块东部出现显著的SE向加速运动,之后数年一直维持这种高速特性,汶川8级地震的发生调整了该地区的应力状态,有利于芦山7级地震及九寨沟7级地震的发生;2015~2017年巴颜喀拉地块东部在维持高速运动和高应力状态基础上继续增速变化,地块边界鲜水河断裂2016~2017-07跨断层观测数据显示的显著拉张加速变化与九寨沟地震有一定关联,具中期背景性预测意义。     

Seismogenic fault and topography control on the spatial patterns of landslides triggered by the 2017 Jiuzhaigou earthquake

Jiuzhaigou National Park, located in northwest plateau of Sichuan Province, is a UNESCO World Heritage Site, and one of the most popular scenic areas in China. On August 8, 2017, a Mw 6.5 earthquake occurred 5 km to the west of a major scenic area, causing 25 deaths and injuring 525, and the Park was seriously affected. The objective of this study was to explore the controls of seismogenic fault and topographic factors on the spatial patterns of these landslides. Immediately after the main shock, field survey, remote-sensing investigations, and statistical and spatial analysis were undertaken. At least 2212 earthquake-triggered landslides were identified, covering a total area of 11.8 km~2. Thesewere mainly shallow landslides and rock falls. Results demonstrated that landslides exhibited a close spatial correlation with seismogenic faults. More than 85% of the landslides occurred at 2200 to 3700 m elevations. The largest quantity of landslides was recorded in places with local topographic reliefs ranging from 200 to 500 m. Slopes in the range of ~20°-50° are the most susceptible to failure. Landslides occurred mostly on slopes facing east-northeast(ENE), east(E), east-southeast(ESE), and southeast(SE), which were nearly vertical to the orientation of the seismogenic fault slip. The back-slope direction and thin ridge amplification effects were documented. These results provide insights on the control of the spatial pattern of earthquake-triggered landslides modified by the synergetic effect of seismogenic faults and topography.     

2017-08-08四川九寨沟MS7.0地震对周边区域应力影响

基于2017年九寨沟M_S7.0地震破裂模型及区域均匀分层粘弹性地壳模型,计算此次地震引起的周边地区同震及震后库仑应力变化,讨论地震对周边若干活动断层的影响。结果表明,此次地震增加了虎牙断裂北段发震破裂区两端的库仑应力,最大同震库仑应力增量为148 kPa,在很大程度上超过地震应力触发阈值10 kPa,震后50 a内破裂区两端的库仑应力有所增强,但增量较小,仅在3~5 kPa左右;虎牙断裂南段同震库仑应力增量较小,在3 kPa左右,震后50 a内应力基本无变化;塔藏断裂带西北段的同震应力增量在5～33 kPa之间,在大部分区域超出应力触发阈值,震后应力有所加强,但是增量较小(约为3 kPa)。库仑应力加载有可能增加以上活动断层的地震危险性,需加强监测。地震对雪山断裂带西段(以虎牙断裂与雪山断裂交叉点为界)的影响较小,其同震库仑应力最大增量仅在6.15 kPa左右,未超过地震应力触发阈值。同时,地震还减小了雪山断裂带东段、白龙江断裂舟曲段、岷江断裂北部以及龙日坝断裂北部地区的库仑应力,可能短时间内减小了这些地区的地震危险性;而对距离震中较远(150 km以外)的地区(如青川断裂)影响十分微弱,其同震与震后应力变化可忽略不计。     

Surface ozone in Jiuzhaigou National Park, eastern rim of the Qinghai-Tibet Plateau, China

Located in southwestern China, Jiuzhaigou National Park is one of the most popular tourism destinations in China, famous for its unique aquatic ecosystems and beautiful forests. However, plants in the park may be at high ozone risk as a result of the intensive use of diesel tour buses in the park. In addition, Jiuzhaigou is close to a region with relatively high regional anthropogenic NO x emissions. During the growing season, also the peak season of tourism, we measured ozone concentration at two sites within the Park and these were: Jiuzhaigou Bureau (JB) and Long Lake (LL). The results indicate that ozone concentrations were not high enough to cause foliar injury during the monitoring period, although the risk of ozone to plants was higher in spring than in summer and autumn. Diurnal ozone cycles at JB and LL displayed significantly higher ozone concentrations in the daytime than in the nighttime, suggesting photochemical production of ozone during the day and ozone deposition during the night as a result of the nocturnal boundary layer. In parallel with the seasonal change of background surface ozone in the Northern Hemisphere, maximum daily 8-h average ozone concentration (MDA8) and daily ozone concentration decreased from spring to autumn at the two sites. This temporal variation in Jiuzhaigou was most likely associated with the downward mixing of ozone-rich air from the free troposphere, because all the high-ozone events (MDA8 > 70.0 ppb) were observed in spring and ozone-rich air from the free troposphere was the dominant cause. In summary, our data suggest that ozone concentrations in Jiuzhaigou were more affected by the regional-scale of background pattern in air quality and meteorological conditions than by local tourist activities.     

Seismic response of cracking features in Jubao Mountain during the aftershocks of Jiuzhaigou Ms7.0 earthquake

Jiuzhaigou is a world-heritage site located in the plateau area of Northwest Sichuan Province,China. Serious slope failures in the epicentral area were triggered by the Ms7.0 Jiuzhaigou earthquake occurred on August 8, 2017. The source areas of the hazards are usually concentrated near ridge crests,revealing the possible occurrence of ground motion amplification phenomena. To explore the role of the amplification of ground motions in the formation of earthquake-triggered slope failures, two seismometers were installed, on the next day after the main shock, at the bottom of the slope of Jubao Mountain near the seismogenic fault. The two monitoring sites are located at elevations of 1414 m(J1) and 1551 m(J2, the top of the mountain). Five aftershocks were recorded by the monitoringinstruments. We compared the mean levels of the peak ground acceleration(PGA) observed at different locations, and investigated the directional variations in the shaking energy by analyzing the polar diagrams of the Arias intensity(Ia). Then, in order to identify the directional resonance phenomenon and their frequencies and amplification coefficients, we examined the horizontal-to-vertical spectral ratio(HVSR) and the standard spectral ratio(SSR). Polar diagrams of the Arias intensity(Ia) indicated that the site response of Jubao Mountain showed a pronounced directivity(in the EW direction) with shaking maxima near the hill top oriented orthogonally to the elongation of the relief. We observed an obvious resonance phenomenon at site J2 at relatively low frequencies(2.5-9 Hz) and very weak spectral amplifications at site J1 at high frequencies(5-15 Hz), which suggested that the predominant frequency of monitoring site J2 was obviously attenuated and that the difference in the spectra was related to the influences of the local-scalesite conditions of the whole mountain. The results of spectral ratio analyses(HVSR and SSR) showed that the direction of resonance was concentrated around an EW orientation, and the amplification factors near the hill top were larger than 2. It suggests that geologic factors also play a significant role in the anisotropic amplifications affecting the tops of slopes besides the topographic effects.     

Quantitative assessment of impacts of climate and economic-technical factors on grain yield in Jilin Province from 1980 to 2008

Climate change is one of the most important challenges threatening agricultural grain yield and food security. Determining the factors influencing grain yield in Jilin Province and the weights of their contribution are a very important task, because Jilin Province is an important agriculture base in China. In this study, the accumulation factor sequence evaluating data method was used to analyze the climate and economic-technical factor contribution weights to grain yield and grain yield changes in each city of Jilin Province. Climate yield was also estimated to study the climate effect on the grain yield, and it was calculated in two ways:an improved algorithm and a traditional quadratic method. The results show that the climate and economic-technical factors have different contribution weights to grain yield in different cities in Jilin Province. The contribution weight of the climate factor to grain yield was 0.212-0.349, while that the economic-technical factor was 0.651-0.788. Furthermore, the changes of the climate factor contributing to grain yield changes accounted for 0.296-0.546, and the changes of the economic-technical factor accounted for 0.454-0.704. The weights of climate and economic-technical factor contributing to grain yield are very different between the eastern and western cities in Jilin Province, but their weights contributing to the grain yield change are similar in these cities. In general, the amount of fertilizer used per hectare (FUPH) is the main factor affecting grain yields and yield changes from 1980 to 2008. It is noted that when the FUPH growth rate stabilized after 1995, the effects of the climate factor on the grain yield become more obvious than before. The improved algorithm is effective for estimating climate yield in Jilin Province, and the climate yields were mostly between-500 kg/ha and 500 kg/ha, and showed a slightly rising trend in most cities.     

The impact of catastrophic natural disaster on land-use changes of Qingping town and the selection of suitable land for settlement construction

A Ms 8.0 large earthquake occurred in Sichuan,China on May 12,2008(hereafter called 5.12 Earthquake),and then a large debris flow happened in the quake-hit Qingping Township of Mianzhu county on August 13,2008(hereafter called 8.13 Debris Flow).The influence of two disasters on the changes in land use were analyzed by using highresolution aerial photos and satellite remote sensing images taken before and after the 5.12 Earthquake and 8.13 Debris Flow,the selection of suitable construction land were studied by learning experiences and lessons from the selection of resettlement areas and through field surveys and with land use transfer model and analytical model in combination with RS and GIS.The results showed that the influence of the 5.12 Earthquake on ecological environment was far greater than that of the 8.13 Debris Flow;there were more salient conflicts between population and land after the earthquake.Sites for post-disaster reconstruction should not be in disaster-prone areas or in gully-facing areas.Suitable land for settlement construction in I-1~I-5 low-hazard zones is optimal settlement areas for post-disaster reconstruction.     

2017年四川九寨沟MS7.0地震震前地壳密度变化特征

基于紧凑约束最小二乘优化反演算法,利用2014~2017年地表重力变化观测成果,反演得到2017年九寨沟MS7.0地震前震中及周边地区的地壳三维密度变化。结果表明：1）在震中及周边地区出现大范围的重力变化,并沿张掖-西宁-九寨沟一带形成最大值达9 μGal的重力变化梯度带;2） 地壳密度变化量随深度增加而增大,其中在45 km附近达到最大,为0.2 g/cm3;3） 震中及邻区范围内形成密度变化的正负四象限分布（2014-04~2017-04）,其表现的物质运移方向呈左旋走滑式分布,与震源机制解基本一致。据此推断,在震前产生了与地震孕育相关的深部构造运动,而强震易发生在物质运移汇聚地方。     

九寨沟Ms7.0地震的InSAR观测及断层破裂研究

为提高九寨沟2017-08-08 MS7.0地震的InSAR同震形变场精度,厘清发震断层的构造形态及形成机制,对形变区相干系数进行统计分析并确定相干性阈值,利用GACOS对形变场进行大气校正,再根据余震分布和地质背景确定发震断层的基本形状,最后基于Okada弹性半空间位错模型反演发震断层的滑动分布。改正后的InSAR同震形变场显示,视线向最大下沉为25 cm,最大抬升为10 cm,分别位于震中西北和东南,形变长轴为北西向,主要形变区位于发震断层西部。改正后的InSAR形变场残差均方根较改正前小,最大滑动量为0.9 m,平均滑动角为-0.5°,破裂主要集中在地下1~20 km范围内,矩震级为6.5,与USGS和GCMT等机构的结果一致。研究表明,利用GACOS改正九寨沟InSAR同震形变场对提高形变场精度具有一定的作用,反演断层滑动分布的结果较改正前差别不明显,发震断层的属性与虎牙断裂北段的性质基本一致。结合余震重定位结果可以推断,发震断层为虎牙断裂的北向延伸部分,此次地震事件为巴颜喀拉地块南东向扭转与华南地块碰撞的结果,中下地壳粘性流体的差异分布是导致虎牙断裂倾角变化的主要原因。     

Tectonic control on slow-moving Andean landslides in the Colca Valley,Peru

The Colca Valley in the Central Andes is a region characterized by the occurrence of large slow-moving landslides and a high level of seismic activity.In this study,we aimed to determine passive and active tectonic control on the formation of selected five large landslides in the Colca Valley and to assess geohazard associated with these features.For that purpose,we performed a post-landslide field survey,applied remote sensing techniques,and obtained eyewitness accounts.Recently,the need to understand mass movement processes in this region is even higher due to the establishment of the Colca y Volcanes de Andagua Geopark(Colca and Andagua Volcanoes Geopark).Our results suggest that the studied landslides usually represent a complex failure mechanism,dominated by translational sliding or rotational displacements,commonly associated with the formation of horst-and-graben like structures.We found a spatial correlation between the distribution of landslides and inherited fault network.The head scarps appear to be limited by the WNW-to NW-striking faults,whereas the lateral extent of some of the reported features seems to be connected with the NNE-striking normal faults,common in both,the Mesozoic strata and the Pleistocene-Holocene deposits.