不同非空间模拟方法下CLUE-S模型土地利用预测——以秦淮河流域为例   总被引：4，自引：0，他引：4  

卞子浩  马小雪  龚来存  赵静  曾春芬  王腊春 《地理科学》2017,37(2):252-258

基于快速城镇化背景下秦淮河流域土地利用历史状况,选择CLUE-S模型对其2020年土地利用情况进行模拟预测。分别使用线性回归、Markov模型、灰色GM（1,1）模型预测CLUE-S模型非空间模块的土地利用需求量,再嵌入CLUE-S中得到3种预测结果,对预测结果进行比较。另外设定“自然发展”情景与考虑规划政策影响的“优化格局”情景,模拟2020年不同情景下秦淮河流域土地利用格局情况,并进行景观格局分析。结果表明：线性回归模型、Markov模型、灰色GM（1,1）模型的Kappa指数分别为0.866、0.849、0.867,3种方法均满足模型精度要求;自然发展情景中2020年水域、水田、林地、城镇用地、旱地面积相对于2010年分别变化21.5%、-15.3%、-9.0%、51.5%、-28.9%,而优化格局情景下水域、水田、林地、城镇用地、旱地面积分别变化3.1%、-1.6%、10.8%、6.3%、-10.6%,相比于自然发展情景,优化情景土地利用状况更符合保护基本农田、增加生态用地连通性、提高雨水下渗能力以及缓解城市热岛效应的要求,为后期土地利用规划提供了依据。  相似文献   

Computing a hierarchy favored optimal route in a Voronoi-based road network with multiple levels of detail     

Zhenghua Hu  Guofeng Wang  Jiye Wang  Lingkui Meng 《International journal of geographical information science》2017,31(11):2216-2233

This paper introduces a robust method for computing the optimal route with hierarchy. We convert a planar road network into its Voronoi-based counterpart with multiple levels of detail (LoDs), which is subsequently assigned travel times that are estimated for different times of day using taxicab trajectory data. On the basis of this network structure, we model the path-finding process in travel, as the optimal route with hierarchy is computed in a ‘coarse-to-fine’ manner. In other words, the route is iteratively constructed from roads in a low LoD network to roads in a high LoD network. To confirm the efficiency and effectiveness of our method, comparative experiments were conducted using randomly selected pairs of origins/destinations in Wuhan, China. The results indicate that our travel lengths are on average 12% longer than those computed by the Dijkstra algorithm and 15% shorter than those computed by the hierarchical algorithm (in ArcGIS). Our travel times are on average 29% longer than those computed by the Dijkstra algorithm and 31% shorter than those computed by the hierarchical algorithm (in ArcGIS). Hence, we argue that our method is situated in terms of performance between the Dijkstra algorithm and the hierarchical algorithm (in ArcGIS). Moreover, road usage patterns confirm that our algorithm is cognitively equivalent to the hierarchical algorithm (in ArcGIS) by favoring high-class roads and outperforms the Dijkstra algorithm by avoiding choosing low-class roads. Computationally, our method outperforms the Dijkstra algorithm but is on the same level as the hierarchical algorithm (in ArcGIS) in terms of efficiency. Therefore, it has the potential to be used in real-time routing applications or services.  相似文献   

MODES月预测产品在贵州的释用     

李忠燕  严小冬  张娇艳  白慧  吴战平 《气象科技》2017,45(6):1058-1064

基于符号一致率评分(Pc)法,对多模式解释应用集成预测系统(MODES)的6种模式产品开展贵州85站2要素月预测释用,根据评估结果进一步采用等权平均方案和最优方案对6种模式产品展开2012—2015年48个月的回算统计。分析表明:不同的模式产品的预报性能各不相同,其中ECMWF的模式产品的预测性能较NCC和NCEP来说相对较高;模式产品释用时,最优方案的预报评分均高于其它6个模式产品的Pc评分平均值,且最优方案的预报评分高于等权平均方法的预报评分;回算结果,无论是气温还是降水,最优方案的Pc评分均都高于省级发布的月预测产品评分,这说明利用最优方案可以有效地提高MODES对贵州月气温和降水预测能力。  相似文献   

The Shared Socioeconomic Pathways and their energy,land use,and greenhouse gas emissions implications: An overview     

《Global Environmental Change》2017

This paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 400–1200 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO₂ emissions of the baseline scenarios range from about 25 GtCO₂ to more than 120 GtCO₂ per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: (1) the policy assumptions, (2) the socio-economic narrative, and (3) the stringency of the target. The carbon price for reaching the target of 2.6 W/m² that is consistent with a temperature change limit of 2 °C, differs in our analysis thus by about a factor of three across the SSP marker scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quantifications span a wide range of different futures broadly representative of the current literature. This allows their subsequent use and development in new assessments and research projects. Critical next steps for the community scenario process will, among others, involve regional and sectoral extensions, further elaboration of the adaptation and impacts dimension, as well as employing the SSP scenarios with the new generation of earth system models as part of the 6th climate model intercomparison project (CMIP6).  相似文献   

SSP3: AIM implementation of Shared Socioeconomic Pathways     

《Global Environmental Change》2017

This study quantifies the Shared Socioeconomic Pathways (SSPs) using AIM/CGE (Asia-Pacific Integrated Assessment/Computable General Equilibrium). SSP3 (regional rivalry) forms the main focus of the study, which is supposed to face high challenges both in mitigation and adaptation. The AIM model has been selected as the model to quantify the SSP3 marker scenario, a representative case illustrating a particular narrative. Multiple parameter assumptions in AIM/CGE were differentiated across the SSPs for quantification. We confirm that SSP3 quantitative scenarios outcomes are consistent with its narrative. Moreover, four key features of SSP3 are observed. First, as SSP3 was originally designed to contain a high level of challenges to mitigation, mitigation costs in SSP3 were relatively high. This results from the combination of high greenhouse gas emissions in the baseline (no climate mitigation policy) scenario and low mitigative capacity. Second, the climate forcing level in 2100 for the baseline scenarios of SSP3 was similar to that of SSP2, whereas CO₂ emissions in SSP3 are higher than those in SSP2. This is mainly due to high aerosol emissions in SSP3. A third feature was the high air pollutant emissions associated with weak implementation of air quality legislation and a high level of coal dependency. Fourth, forest area steadily decreases with a large expansion of cropland and pasture land. These characteristics indicate at least four potential uses for SSP3. First, SSP3 is useful for both IAM and impact, adaptation, vulnerability (IAV) analyses to present the worst-case scenario. Second, by comparing SSP2 and SSP3, IAV analyses can clarify the influences of socioeconomic elements under similar climatic conditions. Third, the high air pollutant emissions would be of interest to atmospheric chemistry climate modelers. Finally, in addition to climate change studies, many other environmental studies could benefit from the meaningful insights available from the large-scale land use change resulting in SSP3.  相似文献   

基于核密度估计的点群密度制图应用研究   总被引：1，自引：0，他引：1  

卢敏  杨柳  王金茵  黄煌  王结臣 《测绘工程》2017,26(4)

随着信息技术的发展,点状专题数据激增,需要突破传统制图方法的表达局限,利用海量点群数据对专题信息进行快速、直观、综合的制图表达。文中以南京市银行的ATM网点数据以及全国KTV营业点分布为制图数据源,探讨了点群数据核密度估计图以及三维核密度曲面图的制作方法,并对其中的关键技术作了深入的研究。研究表明,基于核密度估计的网点密度制图方法,消除了边界分隔对密度计算精度的影响,能更好反映点群数据的空间分布密度、区域差异、动态变化等特征,具备更丰富的表现力。  相似文献   

中国“胡焕庸线”东西两侧能源消耗空间格局的系统动力学模拟     

赵莎  胡最  郑文武 《地理科学进展》2021,40(8):1269-1283

“胡焕庸线”是中国人口、经济和社会发展格局特征的真实写照,科学地刻画了中国能源生产与消费的基本特征。定量模拟该线东西两侧能源消耗的空间格局可以为国家实现能源与区域协调发展提供参考。论文根据中国能源统计年鉴(2005—2014年),结合系统动力学模型(System Dynamic, SD)与灰色模型构建了胡焕庸线能源消耗空间格局预测模型(HLECSM-SD);再以省域为基本研究单元,构建50 km×50 km空间格网,模拟2020年并预测2021—2025年“胡焕庸线”东西两侧能源消耗的空间格局,设置3种情景方案分析中国能源消耗情况。结果表明：① HLECSM-SD模型具有较好的拟合效果。② 全国能源消耗总量呈现“东多西少”的空间格局。③ 该线两侧的能源消耗量增长率曲线变化趋势一致,且东侧的增长率低于西侧。④ 在胡焕庸线东侧,煤炭消耗量具有“北部多、南部少”的空间特征,这与中国煤炭资源蕴涵量的空间格局一致;石油、天然气和电力消耗量具有“东部多、中部少”的空间特征,这是由各省区资源禀赋、经济水平、人口规模及产业结构等因素共同决定的。⑤ 在情景设置中,不同影响因子对能源消耗量影响程度不同。  相似文献   

新型多级隔震装置试验及最优参数分析          下载免费PDF全文

赵帅兵  刘文光  何文福  张强  李雪 《世界地震工程》2021,(1):057-65

基于橡胶支座和滑板支座的水平力学性能,开发了一种新型多级隔震装置并介绍了该装置的组成、运动状态及力学模型。为了验证多级隔震装置在多水准地震作用下具有多级刚度的特性,设计了一幢相似比为1/10的四层混凝土框架结构,并根据结构模型设计了四套多级隔震装置进行了新型多级隔震结构振动台试验。试验与模拟结果表明:新型多级隔震装置隔震性能良好且在不同水准地震作用下能表现出多级抗震性能,相较于普通隔震装置,在大震下能较好的控制隔震层位移。针对不同多级隔震结构给出了多级隔震装置的最优参数的筛选流程,并基于某实际工程通过筛选流程选取了装置的最优参数。  相似文献   

集合百分位融合法在广东台风降水预报中的改进     

张华龙  程正泉  肖柳斯  吴乃庚  罗聪 《气象》2022,48(1):84-95

基于欧洲中期天气预报中心(ECMWF)集合预报的客观检验结果,构建了针对广东台风降水的最优百分位融合产品,检验表明强降水风险评分(TS)较集合平均产品提升显著,预报时效越长,提升幅度越大,但预报偏差(Bias)与虚警率(FAR)也相应增大.最优百分位融合产品的强降水预报范围偏大与台风路径预报的发散度有较大关联,因融合产...  相似文献   

OLR资料在ENSO监测中的应用   总被引：4，自引：0，他引：4       下载免费PDF全文

郭艳君  翟盘茂  贺敬安 《热带气象学报》2003,19(1):101-106

通过对1988—1997年十年中冷空气造成的广东沿海强东北季风过程的统计研究，挑选出多个与强东北季风相关程度较高的因子作最优因子组合，分月份、分时次共设计了24条概率预报方程，从而建立起冬春季强东北季风概率预报方法。因子结构合理，处理技术科学，所有计算过程完全客观定量：预报检验和业务试验表明，该方法的预报结果效果良好，有较高的应用参考价值。  相似文献