Vulnerability of mountain glaciers in China to climate change

Mountain glaciers in China are an important water source for both China and adjoining countries, and therefore their adaptation to glacier change is crucial in relation to maintaining populations. This study aims to improve our understanding of glacial vulnerability to climate change to establish adaptation strategies. A glacial numerical model is developed using spatial principle component analysis(SPCA) supported by remote sensing(RS) and geographical information system(GIS) technologies. The model contains nine factorsdslope, aspect, hillshade,elevation a.s.l., air temperature, precipitation, glacial area change percentage, glacial type and glacial area, describing topography, climate, and glacier characteristics. The vulnerability of glaciers to climate change is evaluated during the period of 1961-2007 on a regional scale, and in the 2030 s and 2050 s based on projections of air temperature and precipitation changes under the IPCC RCP6.0 scenario and of glacier change in the 21 st century. Glacial vulnerability is graded into five levels: potential, light, medial, heavy, and very heavy, using natural breaks classification(NBC). The spatial distribution of glacial vulnerability and its temporal changes in the 21 st century for the RCP6.0 scenario are analyzed, and the factors influencing vulnerability are discussed. Results show that mountain glaciers in China are very vulnerable to climate change, and41.2% of glacial areas fall into the levels of heavy and very heavy vulnerability in the period 1961-2007. This is mainly explained by topographical exposure and the high sensitivity of glaciers to climate change. Trends of glacial vulnerability are projected to decline in the 2030 s and 2050 s, but a declining trend is still high in some regions. In addition to topographical factors, variation in precipitation in the 2030 s and 2050s is found to be crucial.

VULNERABILITY AND ADAPTATION OF CHINESE AGRICULTURE TO GLOBAL CLIMATE CHANGE

Global climate change is now widely recognized, although some uncertainties remain. Being sensitive to climatic conditions, agriculture will be influenced by climatic changes. The major effects can be generalized as changes in the geographical limits to agriculture, changes in crop yields and impacts on agricultural systems. Chinese agriculture is particularly sensitive to climatic change and variability. Given prospects for huge population increase and the already intense utilization of resources, there is a serious threat to China’s abilily to feed itself. Thus, adaptation and adjustment to climatic change are urgently in need of attention. Climate is inherently variable and uncertain. so researchers should recognize this reality of climate in assessing implication for agriculture. A variety of approaches are suggested to reduce food production’s when appraising the effect of climate change on vulnerability to climate.

Agricultural Vulnerability to Drought in China's Agro-pastoral Ecotone:A Case Study of Yulin City,Shaanxi Province

Agro-pastoral ecotone of northern China is the prominent area for agricultural production,but it is also the most typical ecological fragile area with frequent drought disasters.Taking Yulin City at Shaanxi Province in China as the case area,the paper aims to investigate the spatio-temporal changes of agricultural vulnerability to drought in China’s agro-pastoral ecotone in the period 2000 to2020.The results show that:1)the agricultural vulnerability to drought in Yulin City has shifted from high vulnerability in the period2000–2010 to low vulnerability in the period 2011–2020.2)There exist obvious spatio-temporal differences of the agricultural vulnerability to drought in Yulin City during the research period.3)Four sensitive events and 14 resilient events were identified in the research and the crops of Yulin had become more resilient to drought.Finally,the paper put forward with policy implications to make adaptive strategies of agriculture to climate change in China’s agro-pastoral ecotone in the future,e.g.,carrying out agricultural zoning based on agricultural production conditions,intensifying the construction of disaster prevention and relief system,and integrating with modern agricultural technology to develop new type agriculture.

Assessing the vulnerability of ecosystems to climate change based on climate exposure, vegetation stability and productivity

Background: Global warming has brought many negative impacts on terrestrial ecosystems, which makes the vulnerability of ecosystems one of the hot issues in current ecological research. Here, we proposed an assessment method based on the IPCC definition of vulnerability. The exposure to future climate was characterized using a moisture index(MI) that integrates the effects of temperature and precipitation. Vegetation stability, defined as the proportion of intact natural vegetation that remains unchanged under changing climate, was used together with vegetation productivity trend to represent the sensitivity and adaptability of ecosystems. Using this method, we evaluated the vulnerability of ecosystems in Southwestern China under two future representative concentration pathways(RCP 4.5 and RCP 8.5) with MC2 dynamic global vegetation model.Results:(1) Future(2017–2100) climate change will leave 7.4%(under RCP 4.5) and 57.4% of(under RCP 8.5) of areas under high or very high vulnerable climate exposure;(2) in terms of vegetation stability, nearly 45% of the study area will show high or very high vulnerability under both RCPs. Beside the impacts of human disturbance on natural vegetation coverage(vegetation intactness), climate change will cause obvious latitudinal movements in vegetation distribution, but the direction of movements under two RCPs were opposite due to the difference in water availability;(3) vegetation productivity in most areas will generally increase and remain a low vulnerability in the future;(4) an assessment based on the above three aspects together indicated that future climate change will generally have an adverse impact on all ecosystems in Southwestern China, with non-vulnerable areas account for only about 3% of the study area under both RCPs. However, compared with RCP 4.5, the areas with mid-and highvulnerability under RCP 8.5 scenario increased by 13% and 16%, respectively.Conclusion: Analyses of future climate exposure and projected vegetation distribution indicate widespread vulnerability of ecosystems in Southwestern China, while vegetation productivity in most areas will show an increasing trend to the end of twenty-first century. Based on new climate indicators and improved vulnerability assessment rules, our method provides an extra option for a more comprehensive evaluation of ecosystem vulnerability, and should be further tested at larger spatial scales in order to provide references for regional, or even global, ecosystem conservation works.

Assessing ecological vulnerability in western China based on Time-Integrated NDVI data

Arid and semi-arid areas are the most vulnerable regions to climate change. Clear understanding of the effects of climate change on ecosystems in arid and semi-arid regions and the ecosystem vulnerability is important for ecosystem management under the background of climate change. In this study, we conducted a vulnerability assessment on various ecosystems from 1982 to 2013 in western China with large areas of arid and semi-arid lands based on the Time-Integrated Normalized Difference Vegetation Index （TINDVI） data and climate data. The results indicated that grasslands were the most vulnerable ecosystem to climate change in western China, especially for those in Tibetan Plateau. Croplands in oases were not vulnerable to climate change compared to rain-fed croplands in semi-arid regions （e.g. Gansu and Inner Mongolia）, which was attributed to the well-developed drip irrigation technology in oases. Desert and Gobi ecosystems were slightly vulnerable to climate change during the past several decades. The assessment results, as revealed in this study, can provide a reference for taking appropriate actions to protect the ecosystems in western China.

Vulnerability of an inland river basin water resource system under the background of future accelerated glacier melt: A case of Yarkent River Basin in arid Northwest China

Water resources of inland river basins of arid Northwest China will be profoundly affected by future accelerated glacier melt. Based on scenarios of climate warming, accelerated glacier melt and socioeconomic development in the future, vulnerability of the Yarkent River Basin water resources for 2010-2030 is evaluated quantitatively using the indicator of water deficiency ratio. Results show that the quantity of the basin＇s water resources will continuously increase over the next 20 years, mainly due to the effect of climate warming and accelerated glacier melt. But, in the next 10 years, the basin will have a deficient water status, and the water resource system will be quite vulnerable. This is due to an increased water demand from rapidly increasing socioeco- nomic development and a lack of low water-use efficiency in the near future. After about 2020, water supply will outstrip demand, greatly relieving the basin＇s water deficient due to increased water resources and the advancement of water-saving technology. Contrast to the hypothetical situation of unchanged glacier melt, climate wanning and resulting accelerated glacier melt may play a role in relieving the supply-demand strain to some extent.

NPP vulnerability of the potential vegetation of China to climate change in the past and future

Using the Integrated Biosphere Simulator, a dynamic vegetation model, this study initially simulated the net primary productivity（NPP） dynamics of China＇s potential vegetation in the past 55 years（1961–2015） and in the future 35 years（2016–2050）. Then, taking the NPP of the potential vegetation in average climate conditions during 1986–2005 as the basis for evaluation, this study examined whether the potential vegetation adapts to climate change or not. Meanwhile, the degree of inadaptability was evaluated. Finally, the NPP vulnerability of the potential vegetation was evaluated by synthesizing the frequency and degrees of inadaptability to climate change. In the past 55 years, the NPP of desert ecosystems in the south of the Tianshan Mountains and grassland ecosystems in the north of China and in western Tibetan Plateau was prone to the effect of climate change. The NPP of most forest ecosystems was not prone to the influence of climate change. The low NPP vulnerability to climate change of the evergreen broad-leaved and coniferous forests was observed. Furthermore, the NPP of the desert ecosystems in the north of the Tianshan Mountains and grassland ecosystems in the central and eastern Tibetan Plateau also had low vulnerability to climate change. In the next 35 years, the NPP vulnerability to climate change would reduce the forest–steppe in the Songliao Plain, the deciduous broad-leaved forests in the warm temperate zone, and the alpine steppe in the central and western Tibetan Plateau. The NPP vulnerability would significantly increase of the temperate desert in the Junggar Basin and the alpine desert in the Kunlun Mountains. The NPP vulnerability of the subtropical evergreen broad-leaved forests would also increase. The area of the regions with increased vulnerability would account for 27.5% of China.

东北黑土区农业干旱脆弱性及其应对策略研究——以黑龙江省为例

为揭示东北黑土区农业干旱脆弱性的时空演化过程与特征,本研究以黑龙江省为例,从暴露水平、敏感程度和适应能力的视角,构建了农业干旱脆弱性评价模型,解析了2000—2020年黑龙江省水稻、玉米、大豆的干旱脆弱性的时空演进过程与特征。结果显示:2000—2011年农业干旱事件频发,其中有8个敏感事件和11个韧性事件,2011年以后再无农业干旱事件发生,2011—2020年水稻、玉米和大豆的干旱脆弱性较2000—2010年分别下降了46.14%、51.50%和38.53%;受作物生育需水量与地区降水不匹配的影响,大豆、水稻的干旱脆弱性相对较高。研究表明,黑龙江省农业干旱脆弱性总体呈先增强后减弱的演进趋势,呈北高南低和东西高、中部低的空间分布格局。基于该结果,本研究提出了旨在提升东北黑土区农业适应气候变化韧性的政策及措施建议。

Ecosystem vulnerability of China under B2 climate scenario in the 21st century

This paper applies climate change scenarios in China based on the SRES assumptions with the help of RCMs projections by PRECIS (providing regional climates for impacts studies) system introduced to China from the Hadley Centre for Climate Prediction and Research at a high-resolution (50 km×50 km) over China. This research focuses on B2 scenario of SRES. A biogeochemical model "Atmosphere Vegetation Integrated Model (AVIM2)" was applied to simulating ecosystem status in the 21st century. Then vulnerability of ecosystems was assessed based on a set of index of mainly net primary production (NPP) of vegetation. Results show that climate change would affect ecosystem of China severely and there would be a worse trend with the lapse of time. The regions where having vulnerable ecological background would have heavier impacts while some regions with better ecological background would also receive serious impacts. Extreme climate even would bring about worse impact on the ecosystems. Open shrub and desert steppe would be the two most affected types. When the extreme events happen, vulnerable ecosystem would extend to part of defoliate broad-leaved forest, woody grassland and evergreen conifer forest. Climate change would not always be negative. It could be of some benefit to cold region during the near-term. However, in view of mid-term to long-term negative impact on ecosystem vulnerability would be enormously.

Changes in the supply and demand potentials of China's glacier water resources in the 21st century:Spatiotemporal mismatches and combined effects

China's glacier water resources(GWRs)are not only indispensable suppliers of fresh water for humans living in large domestic areas but also affect the water supply to downstream neighbouring countries.Therefore,it is crucial to systematically evaluate the spatiotemporal(mis-)matches between the supply and demand potentials of China's GWRs and the combined supply and demand effects in the 21st century to enable regional sustainable development.To facilitate such research,in this study,we first regionalized the importance of China's GWRs in terms of the supply potential and downstream human dependence to reveal the spatial(mis-)matches between supply and demand potentials.Then,changes in the service potential of glacier meltwater and in population dynamics,as well as their temporal(mis-)matches and associated opportunities and risks,were further assessed at the river basin scale.The results showed that GWR plays an important role in 4 of 16 macroscale glacier-fed basins(i.e.,Tarim,Junggar,Ili,and Zangxi)and 11 of 37 subbasins within the China region due to higher supply potential and demand potential in those basins.The importance of China's GWRs increases dramatically when taking the demand potential of downstream countries into account,especially in the Ganges and Indus river basins.The peaks in meltwater runoff from the most glacierized basins of the eastern Tianshan Mountains,eastern Qilian Mountains,and southeastern Tibetan Plateau of China occur slightly earlier than the projected peak population(around 2030)under the mid-range Shared Socioeconomic Pathway(SSP245),leading to a compound risk in terms of decreasing meltwater supply and increasing human dependence at the end of the 2020s.However,the peak meltwater is expected to occur later than the peak population in the Tarim,Qiangtang Plateau,and Qaidam basins.The opportunities offered by the increase in meltwater can relieve the water resource pressure for those populations under water-stressed conditions.Greater attention should also be paid to water shortage risks in the transboundary river basins,especially in the Indus and Ganges basins,because the peak meltwater within China is generally expected to occur sooner than the projected peak population of downstream countries.This study provides an effective planning and decision-making basis for the full utilization of China's GWRs and adaptation when glacier runoff declines.

中国冰川脆弱性现状评价与未来预估

冰川的脆弱性是指冰川对气候变化的脆弱性.基于科学性与实际相结合的原则、全面性与主导性原则、可比性原则、可操作性原则,以气候变化脆弱性的暴露度、敏感性与适应能力三要素为标准,遴选构建了我国冰川脆弱性评价指标体系.使用中国1961-2007年594个站点的年平均气温和590个站点的年降水量资料、中国第一、二次冰川编目数据,借助RS与GIS技术平台,使用空间主成分方法,构建了冰川脆弱性指数模型,在区域尺度上综合评价了中国冰川脆弱性的现状.基于IPCC A1B气候情景下气温和降水量变化预估数值、21世纪冰川变化预估数据,对2030年代和2050年代的冰川脆弱性进行了初步预估.依据自然分类法,将冰川脆弱性分为潜在脆弱、轻度脆弱、中度脆弱、强度脆弱与极强度脆弱5个等级.结果表明:从现状看,中国冰川对气候变化很脆弱,约92%的冰川作用区存在不同程度的脆弱性,而且强度脆弱区和极强度脆弱区面积占研究区总面积的41%;情景和动态上,2030年代和2050年代仍有约80%的冰川作用区存在不同程度的脆弱性,但整体上冰川脆弱性呈减弱趋势,局部地区冰川仍处于强度和极强度脆弱状态.冰川脆弱性是多因素综合影响的结果,在现状情况下,冰川脆弱程度主要取决于冰川的地形暴露和冰川对气候变化的敏感性;2030年代和2050年代除地形因素之外,降水量变化上升成为冰川脆弱程度的关键影响因素.在未来气候持续变暖情况下,冰川脆弱性不增反降,冰川对气候变化的敏感性降低可能是主要原因.

中国西部冰川对近期气候变暖的响应

中国冰川主要分布在青藏高原及周边地区,在这一广大的区域内分布有冰川46377条。研究表明,中国西部变暖显著,1950年代以来平均气温上升0.2℃/10a,其中1990年代是近千年中最暖的10年;同时,1950s以来西北各省的降水量增加了约18%。为认识这一气候变化对中国西部冰川的影响,利用遥感和地理信息系统方法,获取了近50a来5000多条冰川的变化状况。结果表明,中国西部82.2%的冰川处于退缩状态,冰川面积减少了4.5%,同时也有一些冰川处于前进状态。此外,近数十年中国西部冰川变化表现出明显的区域差异,青藏高原中部和西北部地区的冰川相对稳定,而高原周边山区的冰川物质亏损严重,处于加速退缩状态。

中国冻土对气候变化的脆弱性

冻土的脆弱性是指冻土对气候变化的脆弱性,是冻土易受气候变化,尤其是温度变化不利影响的程度.研究冻土对气候变化的脆弱性是提高对自然生态系统、工程系统、生态-社会-经济系统对冻土变化影响的脆弱性的认知,科学适应冻土变化诸种影响的前提和基础.基于科学性与实际相结合的原则、全面性与主导性原则、可操作性原则,以暴露度、敏感性与适应能力为标准,遴选构建了我国冻土脆弱性评价指标体系.借助RS与GIS技术平台,使用空间主成分方法,构建了冻土脆弱性指数模型,在区域尺度上综合评价了冻土的脆弱性.依据自然分类法,将冻土脆弱性分为潜在脆弱、轻度脆弱、中度脆弱、强度脆弱与极强度脆弱5级.结果表明:总体上我国冻土以中度脆弱为主,但青藏高原多年冻土对气候变化尤为脆弱;冻土脆弱性具有显著的地域分布特点,青藏高原、西部高山、东北多年冻土区脆弱性相对较高,季节冻土区相对较低.与季节冻土相比,多年冻土对气候变化更脆弱.在当前升温幅度条件下,冻土脆弱程度主要取决于冻土的地形暴露与冻土对气候变化的适应能力.

东北地区湿地的水文景观分类及其对气候变化的脆弱性

湿地对气候变化的脆弱性取决于湿地在水文景观中所处的位置。笔者简单介绍了水文景观的基本理论 ,从水文景观视角对东北地区的典型湿地进行了分类 ,并依据水文景观特征将东北地区的湿地所发育的景观分为冰蚀地貌、山地沟谷、河口三角洲、滨海低洼地、河漫滩、阶地洼地和古河道洼地、山前洼地、湖泊及其湖泊边缘洼地和半干旱、半湿润平原低湿洼地等类型 ,并将发育于各类景观中的湿地对气候变化的脆弱性划分出低度脆弱性、低 -中度脆弱性、中 -高度脆弱性。

气候变化对中国东部季风区水资源脆弱性的影响评价

将耦合暴露度、灾害风险、敏感性与抗压性的脆弱性评估模型应用于中国东部季风区水资源脆弱性评价,从水资源供需平衡角度分析了气候变化对东部季风区水资源脆弱性的影响。结果表明,2000年气候条件下,我国东部季风区接近90%的区域水资源处于中度脆弱及以上状态。其中水资源中度和高度脆弱区域约占全区的75%,极端脆弱区域接近15%。中国北方海河、黄河、淮河和辽河流域的水资源脆弱性最高。未来气候变化影响将加剧水资源脆弱性的风险,不同RCP排放情景下2030年代我国东部季风区水资源中度脆弱及以上区域面积有明显的扩大,极端脆弱区域将达到20%-25%。由于未来需水的进一步增加,中国北方水资源脆弱性的格局并未发生根本变化,而南方东南诸河等区域将面临可能发生的水危机。

全球气候变化影响下中国森林的脆弱性分析

本文对全球气候变化影响下中国森林的脆弱性作了初步研究。首先讨论了适应性、敏感性和脆弱性的概念及其评价方法：其次介绍了中国森林脆弱性的评价指标。脆弱性的分析通常包括适应性和敏感性，或现实的脆弱性及未来的脆弱性两部分内容，前者主要分析现实影响森林生态系统自身调节与恢复能力的各种因素，后者主要分析未来气候变化影响下可能造成的脆弱性。现实的脆弱性指标主要包括林地质量、林龄结构、薪材供应以及森林灾害四类指标。未来的脆弱性指标主要包括类型变化、生产力变化以及森林火险三类指标。将各类指标综合，即可得到综合指标；最后，根据所能获得的资料初步计算分析了中国森林的脆弱性分布。

中国东部季风区水资源脆弱性评价

以中国东部季风区的八大流域为例,从水资源供需安全的角度,对2000年水资源状况和未来气候变化情景下的水资源脆弱性进行了评价。结果表明:海河流域是中国水资源的严重脆弱区,黄河和淮河均处于高度脆弱状态,辽河流域、松花江流域、长江流域、东南诸河和珠江流域绝大部分地区处于中度脆弱状态;未来气候变化使得中国东部季风区八大流域的水资源脆弱性均明显加重,黄淮海流域均上升到严重脆弱状态,对气候变化极度敏感,必须采取相应措施来积极应对气候变化对流域水资源的不利影响。

区域土地生产潜力对全球气候变化的响应评价——以中国北方农牧交错带中段为例

由于气候变化的不确定性,尤其由于区域对气候变化响应评价工作直接关系到区域气候变化对策的制定和区域发展,进行针对气候变化的响应研究比气候变化的影响评价研究更具现实意义。气候变化对区域土地利用会产生一系列的影响,这种影响作用下的区域的反应-相应的变化、必要的适应性调整和适应能力-即是对气候变化的响应。以敏感度和适应能力度量的脆弱性作为衡量区域对气候变化响应的指标,增强了不同研究工作的比较性,正在日益为有关学者接受,并在全球开始研究工作。本文对应用脆弱性理论进行区域气候变化响应研究做了有益的探索。选择气候变化的时间、空间变化明显的中国北方农牧业交错带的中段作为研究案例,分别对农牧业土地生产潜力相对气候变化的敏感度和区域对气候变化的适应能力进行了定量和半定量的计算与评价,从这两个方面给出脆弱性的表述作为对研究区域土地生产潜力对全球气候变化的响应评价。

中国冰川变化对气候变化的响应程度研究

理清冰川变化对气候变化的响应程度、揭示响应度的空间变化规律,是开展冰川变化预估及其对社会经济影响程度量化研究的基础。使用1958-2010年西部地区150个气象站点的夏季平均气温和年降水量资料、中国第一、二次冰川编目数据,通过夏季平均气温和年降水量变化趋势值定量反映气候变化,以冰川面积变化率表征冰川变化,借助GIS技术平台,采用参照对比方法,从宏观层面研究了中国西部冰川变化对气候变化的响应程度。依据等分分类法(Equal Interval),将响应程度分为极低度响应、低度响应、中度响应、高度响应、极高度响应5级。结果表明:中国冰川变化对气候变化的响应方式与程度不同,对夏季平均气温变化表现为正响应,而对年降水量变化主要表现为负响应,冰川分布区年降水量增加带来的冰川积累量增多不足以抵消因温度升高而增加的消融量,升温是中国西部冰川快速退缩的主导性因素。就整体而言,冰川变化对夏季平均气温变化的响应程度相对较低,但局部地区冰川变化对温度变化高度敏感,响应程度高与极高。不同类型冰川的变化对夏季平均气温变化的响应程度亦不同,海洋型冰川的变化以中高度响应为主,极大陆型冰川的变化主要呈现极低、低响应程度,而大陆型冰川变化的响应程度呈两级化。

通过综合指数法评价中国能源部门的气候变化适应能力

气候变化必然影响能源部门,能源部门必须采取措施适应未来的气候。在此之前,需要了解目前中国能源部门对气候变化的适应情况。故通过一个综合指数评估中国能源部门在2000-2017年对气候变化的适应情况。为建立一个综合指数,先确定了三个子指标:反应性适应指标、预测性适应指标、计划性适应指标,通过标准化处理、确定权重、指标汇总,最终得到气候变化适应指数(CCAI)。结果表明,中国能源部门在2000-2010年提出了反应性适应方案,其系统脆弱性较高;2010年后,出现了预期性的适应情景,即脆弱性是中等的。总体来看,中国能源部门从系统脆弱性较高的反应性适应情景到脆弱性中等的预期性适应情景,取得了一定的进展,且该部门正在为计划性适应情景奠定基础。