基于栅格的安徽省人居环境人文适宜性评价

新时期新型城镇化建设对适宜的人居人文环境提出了切实要求。运用GIS技术,基于夜间灯光遥感影像、交通矢量、兴趣点（POI）、统计年鉴等多源数据,以500 m×500 m栅格为基础单元,选取经济水平、交通通达、历史文化、公共服务等因子（权重分别为0.36、0.27、0.17、0.20）,采用综合指数法构建人居环境人文适宜性评价模型,定量评价2017年安徽省人居环境人文适宜性。结果表明：① 安徽省人居环境人文适宜性指数介于0.83~87.10之间,划分为高度适宜区、较高适宜区、中度适宜区、一般适宜区及临界适宜区5种类型区,以中度适宜区面积最大,占全省总面积68.72%,高度适宜区面积最小,仅占总面积的1.24%,整体呈现“多核心”、“条带式”空间分异格局;② 交通通达和公共服务是造成全省人居环境人文适宜性分异的主要因子,其指数均值在中度适宜区皆达到了94.18,且贡献率均值在各类型区均在34.00%以上;历史文化对较高及临界适宜区影响明显,贡献率均值分别为10.51%和11.93%;经济水平对高度适宜区的作用最显著,其贡献率均值高达22.02%;③ 全省近90.86%的人口集中分布在人居环境人文适宜性指数43.00~66.00之间,属于中度至较高适宜区的范围,人居环境人文质量与人口分布较为匹配。测评结果较为客观地反映了安徽省人居环境的人文本底。     

Land use regionalization of rural settlements in China

This paper compartmentalizes regional land use of rural settlements in China by employing a hierarchical clustering method.The statistic data are sourced from the National Bureau of Statistics of China(NBSC) and the data of land use change from the Ministry of Land and Resources of China(MLRC).The population of rural settlement decreases from the southeast to the northwest of China and the density of rural settlement decreases from the east to the west of China.Land-use scale of rural settlement,the proportion of one-storey houses and the average household area decrease from the north to the south of China.The ratio of area of cultivated land to rural settlement is high in the northeast and southwest of China but low in the southeast of China.The land use regionalization of rural settlement can be divided into four regions,namely:the northern region of China,Qinghai-Tibet,Yunnan-Guizhou,and the middle and eastern region of China.The northern region of China and the middle and eastern region of China can be further divided into nine sub-regions:Xinjiang,Northeast China,Ningxia and Inner Mongolia,North China,the south of the Changjiang(Yantze) River and Sichuan Basin,Jiangsu-Shanghai,South China,the Loess Plateau,and Guangxi.In consideration of the significant regional differences,it is proposed that different policies should be implemented regarding the utilization and management of rural settlements.     

雅鲁藏布江中游地区城乡居民点多尺度空间分异及自然因素影响分析

西藏高原土地面积广阔,但适宜人类居住的空间却高度集中于局部地区,其中雅鲁藏布江中游地区是西藏高原最重要的人口承载区。利用核密度、空间“热点”探测和地理探测器等方法,从“居民点斑块-样带-研究区全域”构成的点-线-面多尺度揭示了雅鲁藏布江中游地区城乡居民点的规模、形态和密度的空间分异特征,并分析了自然因素对城乡居民点空间分异的影响。结果表明：① 全域尺度上,雅鲁藏布江中游地区各乡镇居民点规模空间差异较大,基本形成以“彭措林乡-增期乡”为轴线的南北对称态势,居民点形态普遍规则,密度总体偏低;② 样带尺度上,仅有拉萨河样带的密度分布呈线性分布,雅鲁藏布江样带和湘曲-年楚河样带的规模、形态和密度以及拉萨河样带的形态和规模在各自方向上均呈现非线性分布,即居民点东西方向呈现分布规模和形态“两端大中间小”、分布密度“两端小中间大”的特征,而南北方向规模、形态和密度均呈现“南大北小”的特征;③ 斑块尺度上,居民点规模普遍较小,面积小于1000 m ²的数量高达19 099个,占比达到55.14%;斑块形态比较规则,形状为规则类型的数量有21 256个,占比为61.37%;分布密度整体偏低,全域仅为0.34个/km ²;④ 自然要素中,海拔对居民点规模和密度的影响最大,地势起伏度和河流邻近性对居民点形态影响显著,而降水量对居民点的规模、形态和密度影响均不显著。     

青藏高原城乡建设用地和生态用地转移时空格局

青藏高原作为中国重要的生态环境保护地,城镇化和生态环境的变化受到广泛关注。本文基于1990-2015年土地利用数据,进行生态用地和城乡建设用地之间的转移分析,通过核密度以及标准差椭圆分析进行空间转移强度的定性研究。结果表明：① 1990-2015年青藏高原生态用地显著地向城乡建设用地转移,是城乡建设用地向生态用地转移量的54.6倍,其中2000-2005年和2010-2015年是用地转移的热点时期;② 城乡建设用地与生态用地之间的转换在空间上呈现逆向状态,生态用地向城乡建设用地的转移分布逐渐从青藏高原的周边区域向腹地蔓延;城乡建设用地向生态用地的转移最初出现在青藏高原的腹地,逐渐向外围扩张;③ 生态服务功能越大的生态用地,越容易被人类占用,随之发生用地类型的转移,侵占后的土地很难反向转移为具有高生态服务功能的生态用地。     

内蒙古自治区人居环境综合适宜性评价及空间优化

科学评价区域人居环境适宜性,是开展国土空间开发适宜性评价的前提,对提高区域资源环境承载能力,促进人与自然和谐发展至关重要。本文以内蒙古自治区为案例,基于栅格尺度从自然与人文2个方面对人居环境适宜性进行评价;将适宜性因子作为城乡建设用地扩展的限制条件,采用MCR模型对城乡建设用地进行模拟,提出区域人居环境空间优化方案,主要结论有：水文与气候条件对内蒙古自治区人居环境的整体限制作用较强;内蒙古自治区人居环境临界适宜与不适宜区占比最高,达到52.8%;高度适宜区占比最低为9%,主要分布在前套平原及西辽河平原,全区人居环境适宜性水平整体偏低。内蒙古自治区城乡建设用地人居环境比较适宜与高度适宜区占绝对优势,适宜比例超过73%,从适宜性空间分布来看,南部整体优于北部,东部整体优于西部,地带性特征明显。内蒙古自治区城乡人居环境不适宜与临界适宜主要表现为自然条件不适宜及对自然保护区的不合理占用。内蒙古自治区城乡建设用地模拟结果显示远期呼包地区一体化连片趋势明显,内蒙古自治区可逐步形成以呼包鄂都市区、赤通都市区为主体,以文化特色鲜明、公共设施完善的中心城镇及中心乡村为依托,以人居环境不适宜区为间隔,城乡融合的人居环境空间格局。     

2010-2015年中国生物多样性保护优先区域人类干扰程度评估

生物多样性是人类赖以生存与发展的基础。中国生物多样性保护优先区域集中分布着中国绝大多数的生物物种,如何保护好这些区域的生态系统和生物多样性,是实现可持续发展急需解决的问题。本文基于2010年和2015年的2期土地利用/覆被数据,应用人类干扰指数,分析了中国生物多样性保护优先区域人类干扰的程度及变化。结果表明：① 2015年中国生物多样性保护优先区域人类干扰程度以微度和轻度为主,15个优先区处于微度干扰,占优先区总面积的84.10%,13个处于轻度干扰,占优先区总面积的6.65%;华北平原黄土高原区和华东华中丘陵平原区人类干扰程度较高,而西南高山峡谷区、蒙新高原荒漠区和青藏高原高寒区人类干扰程度很低;② 2010-2015年,占优先区总面积84.54%的区域人类干扰程度基本持衡,人类干扰程度发生增加和下降的面积大致冲抵,生物多样性保护优先区域整体变化不大,华南低山丘陵区和东北山地平原区人类干扰程度较高,且升幅超过1%,华北平原黄土高原区降幅最大,为0.15%;③ 人类干扰程度较高且变化幅度大的区域,主要受经济发展对生态系统干扰及土地利用程度加深的影响,对农田、居民点及工矿交通用地的需求增加,退耕还林等部分生态工程实施有利于减少人类对生态系统的干扰程度。总体上看,全国32个生物多样性保护优先区域整体上人类干扰程度较低且变化幅度较小,且人类干扰程度高的区域分布较集中,说明国家生态保护各项政策与措施的实施对生物多样性保护起到了良好的促进作用,有利于生物多样性的保护。     

青藏高原冰雪消融区岩漠动态变化遥感监测研究现状与展望

青藏高原作为地球第三极增温明显,相关研究多集中于青藏高原冰雪动态,很少关注冰雪消融后岩漠的变化。岩漠通过地气相互作用影响着全球气候变化的区域差异。本文通过梳理青藏高原冰雪、冰雪消融区、岩漠动态变化遥感监测方法体系,着重分析了各遥感数据来源及提取方法的优缺点和适用性,并对基于遥感技术条件下青藏高原冰雪动态监测、冰雪消融区岩漠动态变化监测的数据来源、研究方法与技术进行了总结。目前,青藏高原冰雪动态变化遥感监测数据来源多样、研究方法成熟,而冰雪消融区岩漠动态变化遥感监测尚未形成系统研究。在人为干扰不明显背景下,青藏高原冰雪消融区岩漠的动态变化,在一定程度上也可作为对冰雪变化遥感监测的补充。     

A comprehensive evaluation of tourism climate suitability in Qinghai Province, China

Qinghai Province is an important component of the Qinghai-Tibet Plateau in China. Scientific evaluation of the suitability of Qinghai’s climate for tourism can contribute to overcoming obstacles posed by climate on sustainable tourism development in Qinghai Province, including disparities between the low and high seasons, high altitude health concerns, and weather events. A tourism climate suitability evaluation model of the Qinghai-Tibet Plateau is constructed (Tourism Climate Suitability Index, or TCSI), and tourism climate suitability is comprehensively evaluated for Qinghai Province from climate data from 1960 to 2009. Results show that: (I) There is clear distributional characteristics of spatial-temporal variability of TCSI values in Qinghai Province. (II) Tourism climate suitability in Qinghai Province has significant seasonal and regional differences. The year is divided into a very suitable period (July and August), suitable tourism periods (from April and October), less suitable periods (From Nov to Mar). June to August is the most suitable tourism period in Qinghai. Qinghai Province is divided into five levels of tourism climate suitability: most suitable regions, very suitable regions, suitable regions, less suitable regions, and unsuitable region. (III) The key factor which influences regional differences in tourism climatic suitability is atmospheric oxygen. And the key factors which chiefly influence seasonal differences of tourism climate suitability are temperature and humidity, the wind chill factor, and barrier weather.     

基于LSTM神经网络的青藏高原月降水量预测

青藏高原的降水量预测不仅为该地区水资源合理规划利用提供依据,同时对中国及周边国家气候变化研究有着重要的意义。论文利用1990—2016年青藏高原降水量数据,采用长短期记忆神经网络（LSTM）对青藏高原月降水量进行预测,主要包括：① 使用青藏高原86个测站1990—2013年的月降水资料,预测各个测站2014—2016年的月降水量,并与传统的RNN、NAR、SSA和ARIMA预测模型相比,平均决定系数R²分别提高了0.07、0.15、0.13和0.36,均方根误差（RMSE）和平均绝对误差（MAE）表现更低;② 分析了降水量预测精度的空间分布特征,将各模型的R²在青藏高原地区内插值,分析R²的空间分布特征,发现所有模型降雨稀少的干旱地区和降雨多的湿润地区R²较低,在气候稳定、降水规律性明显的地区R²较高,且LSTM模型R²≥0.6的空间范围远大于传统模型;③ 分析了不同预测长度对各模型预测精度的影响,发现所有模型会随着预测长度增加而预测精度降低,但在不同的预测长度下LSTM预测的RMSE值都低于其他模型。     

Assessing suitability of rural settlements using an improved technique for order preference by similarity to ideal solution

Land suitability assessment is a prerequisite phase in land use planning; it guides toward optimal land use by providing information on the opportunities and constraints involved in the use of a given land area. A geographic information system-based procedure, known as rural settlement suitability evaluation (RSSE) using an improved technique for order preference by similarity to ideal solution (TOPSIS), was adopted to determine the most suitable area for constructing rural settlements in different geographical locations. Given the distribution and independence of rural settlements, a distinctive evaluation criteria system that differed from that of urban suitability was established by considering the level of rural infrastructure services as well as living and working conditions. The unpredictable mutual interference among evaluation factors has been found in practical works. An improved TOPSIS using Mahalanobis distance was applied to solve the unpredictable correlation among the criteria in a suitability evaluation. Uncertainty and sensitivity analyses obtained via Monte Carlo simulation were performed to examine the robustness of the model. Daye, a resource-based city with rapid economic development, unsatisfied rural development, and geological environmental problems caused by mining, was used as a case study. Results indicate the following findings: 1) The RSSE model using the improved TOPSIS can assess the suitability of rural settlements, and the suitability maps generated using the improved TOPSIS have higher information density than those generated using traditional TOPSIS. The robustness of the model is improved, and the uncertainty is reduced in the suitability results. 2) Highly suitable land is mainly distributed in the northeast of the study area, and the majority of which is cultivated land, thereby leading to tremendous pressure on the loss of cultivated land. 3) Lastly, 12.54% of the constructive expansion permitted zone and 8.36% of the constructive expansion conditionally permitted zone are situated in an unsuitable area, which indicates that the general planning of Daye lacks the necessary verification of suitability evaluation. Guidance is provided on the development strategy of rural settlement patches to support decision making in general land use planning.     

Integrating CART algorithm and multi-source remote sensing data to estimate sub-pixel impervious surface coverage: a case study from Beijing Municipality,China

The sub-pixel impervious surface percentage(SPIS) is the fraction of impervious surface area in one pixel,and it is an important indicator of urbanization.Using remote sensing data,the spatial distribution of SPIS values over large areas can be extracted,and these data are significant for studies of urban climate,environment and hydrology.To develop a stabilized,multi-temporal SPIS estimation method suitable for typical temperate semi-arid climate zones with distinct seasons,an optimal model for estimating SPIS values within Beijing Municipality was built that is based on the classification and regression tree(CART) algorithm.First,models with different input variables for SPIS estimation were built by integrating multi-source remote sensing data with other auxiliary data.The optimal model was selected through the analysis and comparison of the assessed accuracy of these models.Subsequently,multi-temporal SPIS mapping was carried out based on the optimal model.The results are as follows:1) multi-seasonal images and nighttime light(NTL) data are the optimal input variables for SPIS estimation within Beijing Municipality,where the intra-annual variability in vegetation is distinct.The different spectral characteristics in the cultivated land caused by the different farming characteristics and vegetation phenology can be detected by the multi-seasonal images effectively.NLT data can effectively reduce the misestimation caused by the spectral similarity between bare land and impervious surfaces.After testing,the SPIS modeling correlation coefficient(r) is approximately 0.86,the average error(AE) is approximately 12.8%,and the relative error(RE) is approximately 0.39.2) The SPIS results have been divided into areas with high-density impervious cover(70%–100%),medium-density impervious cover(40%–70%),low-density impervious cover(10%–40%) and natural cover(0%–10%).The SPIS model performed better in estimating values for high-density urban areas than other categories.3) Multi-temporal SPIS mapping(1991–2016) was conducted based on the optimized SPIS results for 2005.After testing,AE ranges from 12.7% to 15.2%,RE ranges from 0.39 to 0.46,and r ranges from 0.81 to 0.86.It is demonstrated that the proposed approach for estimating sub-pixel level impervious surface by integrating the CART algorithm and multi-source remote sensing data is feasible and suitable for multi-temporal SPIS mapping of areas with distinct intra-annual variability in vegetation.     

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.     

三北工程区植被恢复对土壤风蚀的影响及植被恢复潜力研究

三北地区是我国重要的生态屏障,分析2000—2019年三北防护林体系建设工程（简称：三北工程）区植被恢复时空变化状况,厘定人类活动与气候要素对植被恢复的贡献,探究植被恢复对土壤风蚀影响,评估植被恢复潜力空间,可为三北防护林体系建设工程未来规划管理和科学施策提供参考。本文在选取植被覆盖度和植被净初级生产力表征植被恢复状况基础上,利用地面数据,结合模型模拟,定量评估了2000—2019年三北防护林体系建设工程区植被恢复程度及其对土壤风蚀的影响,并对植被恢复潜力进行探究。研究结果表明：① 2000—2019年植被恢复程度高、较高的面积,占总面积的35.29%和13.16%,主要分布在黄土高原区及北部区域和风沙区与东北华北平原农区的部分地区。人类活动与气候因素对植被恢复贡献率为10.45%和89.55%;② 土壤风蚀以轻度侵蚀和微度侵蚀为主,呈逐年下降趋势,剧烈侵蚀面积减少了66.45%,防风固沙服务得到进一步提升。植被恢复程度与土壤风蚀模数呈负相关关系,植被恢复程度较好有助于降低土壤风蚀模数;③ 三北工程区森林、草地和荒漠生态系统仍有8.16%的恢复潜力,内蒙古高原北部部分地区、哈顺戈壁北部和准噶尔盆地西北部及周边区域、黄土高原南部部分区域存在较大恢复潜力。     

禹城市农村居民点空间分布模式和景观格局

以禹城市农村居民点为研究对象,基于禹城市2000和2017年遥感影像解译数据,综合运用GIS、景观生态学及统计学理论与方法,分析了2000年与2017年禹城市乡村聚落的景观格局指数和空间演变特征。结果表明:禹城市两个时期农村居民点在空间分布特征上存在显著差异,与2000年相比,2017年禹城市农村居民点分布更加聚集;从聚集程度来看,禹城市农村居民点聚集的态势不够显著,这与禹城市当地的自然环境有密切的关系;禹城市农村居民点总体用地规模和数量虽然在减少,但部分居民点用地规模增加明显,居民点有集聚发展的态势,同时禹城市农村居民点斑块形态由复杂化向规则化转变。     

全球温升1.5℃和2.0℃情景下中国降雨诱发地质灾害危险性和人口暴露度评估研究

气候变化情景下极端降水事件的频次和强度预估呈增加趋势,这会导致全球部分地区极端降雨诱发地质灾害风险的增加。本文基于中国降雨诱发地质灾害易发性模型和不同地貌分区的累积事件降雨量-降雨历时阈值曲线,采用最新的CMIP6全球气候模式多模式集合结果,基于全球温升目标情景的视角,从地质灾害空间易发性和发生频次两方面,探讨温升情景下中国地质灾害危险性的可能变化及其对暴露人口的潜在影响。结果表明,CMIP6多模式集合预估的多年平均降水在温升1.5℃和2.0℃情景下相比基准时期可能增加5.4%～9.5%,导致中等至极高地质灾害易发区范围预估增加0.33%～0.74%,由于预估的极端降水事件增加,地质灾害发生频次预估增加7.0%～11.2%,进一步综合未来人口空间分布,潜在地质灾害暴露人口可能增加6.20亿人次（18.90%）和4.26亿人次（12.97%）。各地貌分区未来情景下地质灾害危险性预估增加且存在显著的空间异质性,温升2.0℃情景下中等至极高易发性范围相比基准时期增加0.71%～1.28%,地质灾害发生频次预估增加1.2%～15.6%,其中,青藏高原区地质灾害危险性增加最明显。综合考虑未来人口...     

Impacts of land use change on landscape patterns in mountain human settlement: The case study of Hantai District(Shaanxi,China)

Mountain area is an important geographical unit of land,and its ecology is sensitive and fragile.Over the past few decades,human activities have caused dramatic changes in land use in mountainous areas,which caused changes in landscape patterns and impacts on the ecological environment.It is unknown how the mechanism of land use affects the landscape pattern at different scales.The Hantai District,a typical human settlement in the mountain area in Shaanxi,China,was chosen as the study area.Based on the remote sensing images,the mathematical models and landscape indexes were adopted to evaluate the impact of land use change from 1998 to 2017 on the landscape pattern at different scales,and its main driving forces were analyzed.The results showed that the urbanized land expanded largest from 15.39%to 24.30%,and cultivated land experienced the largest decline from 43.54%to 35.35%.Changes in land use have made the patch morphology of most land types developed from a natural random to a sawtooth shape,and its spatial pattern evolved from a ruleset to a fragmented expansion.This reflects the continuous strengthening of human intervention in the process of regional development.Under the jurisdiction of Hantai District,the biggest change in landscape pattern is in Hanzhong City and Qili Town.The improved economy and increasing population and urbanization rate were the main factors that cause these changes.This research could provide necessary information for understanding the evolution mechanism of land resources in mountainous human settlements for mountainous areas with significant geomorphic differentiation.     

多源30 m分辨率土地覆被数据在蒙古高原的一致性分析和精度评价

蒙古高原土地覆被的变化表征着区域内生态环境的变化,许多环境问题的研究依赖于准确的土地覆被信息。因此,评估当前全球土地覆被数据在区域尺度上的准确性非常重要。本文以蒙古高原为研究区,从构成相似性、类型混淆程度、空间一致性、绝对精度4个方面,分析了GlobeLand30、GLC_FCS30和FROM_GLC 3种30m高分辨率全球土地覆被数据的一致性和准确性。结果表明：① 3种土地覆被数据都显示,草地和裸地是蒙古高原的主要土地覆被类型,任意2种数据的面积序列相关系数都优于0.95;② 3种土地覆被数据中完全一致的区域占蒙古高原总面积的61.87%,主要集中在土地表面异质性低的区域;③ GLC_FCS30数据的总体精度（78.33%）最高,GlobeLand30数据的总体精度（76.85%）次之,FROM_GLC数据的总体精度（75.86%）最低;林地、草地、水体和裸地在3种土地覆被数据中的精度较高（75%以上）,灌丛、湿地等地类的精度较低（50%以下）。因此,对蒙古高原土地覆被进行全要素研究时,可以综合考虑选择总体精度最高的GLC_FCS30数据。对特定地类研究的用户,可参考3种土地覆被数据的分类精度有针对性的进行选择。本文可为蒙古高原相关研究选择合适的土地覆被数据提供参考。     

基于多源数据的地表覆盖制图与分析——以广东省广州市为例

地表覆盖数据是关于土地利用信息的重要来源,在地理国情监测、气候变化研究、生态环境评估等方面发挥着重要的作用。本文以广东省广州市作为研究区域,利用OSM数据结合FROM-GLC数据和Landsat-8遥感影像数据,对研究区域地表覆盖进行分类并完成地表覆盖制图。实验结果表明,利用OSM数据进行地表覆盖制图结果总体精度较高,具有可用性,但是OSM数据空白区域占比较大,有数据区域个别要素数量较少,在参考选取样本时,样本代表性不够高,部分类型的地表覆盖分类精度较低。     

An Estimation of Ground Ice Volumes in Permafrost Layers in Northeastern Qinghai-Tibet Plateau,China

The ground ice content in permafrost serves as one of the dominant properties of permafrost for the study of global climate change, ecology, hydrology and engineering construction in cold regions. This paper initially attempts to assess the ground ice volume in permafrost layers on the Qinghai-Tibet Plateau by considering landform types, the corresponding lithological composition, and the measured water content in various regions. An approximation demonstrating the existence of many similarities in lithological composition and water content within a unified landform was established during the calculations. Considerable knowledge of the case study area, here called the Source Area of the Yellow(Huanghe) River(SAYR) in the northeastern Qinghai-Tibet Plateau, has been accumulated related to permafrost and fresh water resources during the past 40 years. Considering the permafrost distribution, extent, spatial distribution of landform types, the ground ice volume at the depths of 3.0–10.0 m below the ground surface was estimated based on the data of 101 boreholes from field observations and geological surveys in different types of landforms in the permafrost region of the SAYR. The total ground ice volume in permafrost layers at the depths of 3.0–10.0 m was approximately(51.68 ± 18.81) km~3, and the ground ice volume per unit volume was(0.31 ± 0.11) m~3/m~3. In the horizontal direction, the ground ice content was higher in the landforms of lacustrine-marshland plains and alluvial-lacustrine plains, and the lower ground ice content was distributed in the erosional platforms and alluvial-proluvial plains. In the vertical direction, the volume of ground ice was relatively high in the top layers(especially near the permafrost table) and at the depths of 7.0–8.0 m. This calculation method will be used in the other areas when the necessary information is available, including landform type, borehole data, and measured water content.     

青藏高原月NDVI时空动态变化及其对气候变化的 响应

青藏高原脆弱的高寒植被对外界干扰十分敏感,使其成为研究植被对气候变化响应的理想区域之一。青藏高原气候变化剧烈,在较短的合成时间研究气候变化对植被的影响十分必要。因此,本文利用GIMMS NDVI时间序列数据集,研究了1982-2012年青藏高原生长季月尺度植被生长的时空动态变化,探讨了其与气温、降水量和日照时数等气候因子的响应关系。结果表明：在区域尺度上,除8月外,其他各月份植被均呈增加趋势,显著增加多发生在4-7月和9月;大部分月份的NDVI增加速率随着时段的延长显著减小,表明NDVI增加趋势放缓;在像元尺度上,月NDVI显著变化的区域多呈增加趋势,但显著减少范围的扩张多快于显著增加。4月和7月植被生长主要是受气温和日照时数共同作用,6月和9月受气温的控制,而8月则主要受降水量的影响。长时间序列NDVI数据集的出现为采用嵌套时段研究植被生长变化趋势奠定了前提,而植被活动变化趋势的持续性则有助于形象表征植被活动变化过程、深入理解植被对气候变化的响应和预测植被未来生长变化趋势。由此推测,青藏高原月NDVI未来增加趋势总体上趋于缓和,但在像元尺度显著变化的区域趋于增加。