Simulated water productivity in Gansu Province,China     

《Physics and Chemistry of the Earth》2015

Economic value of water and economic analysis of water use management in Gansu Province of China have attracted widespread public attention. With the socioeconomic development, research on water resources has become more important than before. In this study, we define “water productivity” as the changes of economic production outputs of sectoral activities in every cubic meter of water input, which is also the technical coefficient of water resource use in each sector. According to Computable General Equilibrium (CGE) framework, based on the Input–Output Table 2007 and water resources bulletin of Gansu Province, we introduced the water into the ORANI-G (A Generic Single-Country Computable General Equilibrium model) model through the nested constant elasticity of substitution (CES) production function to analyze the changes of economic productions caused by water supply changes. We then examined water productivity in different sectors. Empirical results showed that current water productivity is underestimated. Agricultural water productivity is lower than that of the secondary and tertiary industries, even although agricultural water use is the largest part of water use in Gansu Province, and therefore improving agricultural water productivity can greatly mitigate the water shortage. Simulation results indicate that industrial transformation and development of water-saving industries will also mitigate water scarcity. Moreover, sensitivity analysis shows that the empirical results are robust under different scenarios. The results also show that higher constant elasticity of substitution rate (CES) between water and other production factors will contribute to sustainable development.  相似文献   

Impact analysis of government investment on water projects in the arid Gansu Province of China     

《Physics and Chemistry of the Earth》2015

In this paper, we introduced three-nested Constant Elasticity of Substitution (CES) production function into a static Computable General Equilibrium (CGE) Model. Through four levels of factor productivity, we constructed three nested production function of land use productivity in the conceptual modeling frameworks. The first level of factor productivity is generated by the basic value-added land. On the second level, factor productivity in each sector is generated by human activities that presents human intervention to the first level of factor productivity. On the third level of factor productivity, water allocation reshapes the non-linear structure of transaction among first and second levels. From the perspective of resource utilization, we examined the economic efficiency of water allocation. The scenario-based empirical analysis results show that the three-nested CES production function within CGE model is well-behaved to present the economy system of the case study area. Firstly, water scarcity harmed economic production. Government investment on water projects in Gansu thereby had impacts on economic outcomes. Secondly, huge governmental financing on water projects bring depreciation of present value of social welfare. Moreover, water use for environment adaptation pressures on water supply. The theoretical water price can be sharply increased due to the increasing costs of factor inputs. Thirdly, water use efficiency can be improved by water projects, typically can be benefited from the expansion of water-saving irrigation areas even in those expanding dry area in Gansu. Therefore, increasing governmental financing on water projects can depreciate present value of social welfare but benefit economic efficiency for future generation.  相似文献   

Reviews on land use change induced effects on regional hydrological ecosystem services for integrated water resources management     

《Physics and Chemistry of the Earth》2015

This paper proposed to provide valuable information for integrated water resources management through evaluating the research on the interaction mechanism among land use changes, regional hydrological ecosystem services and human well-being. Firstly, the driving mechanism of land use and land cover changes was introduced in this paper. Secondly, the overview of the interaction mechanism among land use and land cover changes, regional hydrological ecosystem services and human well-being was given. Based on the meta-analysis, land use changes have a profound influence on regional hydrological ecosystem services, and the variation of hydrological ecosystem could benefit or impair human well-being. Finally, two suggestions were emphasized for managers or policy makers for the future integrated water resources management: (1) Proper land use makes for the water resource management; (2) Blindly pursuing the provisioning services weakens other services of hydrological ecosystem.  相似文献   

Geological risk assessment for the rapid development area of the Erhai Basin     

《Physics and Chemistry of the Earth》2015

For low-slope hilly land development to have more new land space in a watershed, it is particularly important that to coordinate the sharply increasing conflicts between mountainous and urban land utilization in the city. However, development of low-slope hilly land easily induce potential risks of geologic hazards such as landslide and landslip. It may lead to further environmental losses in a watershed. Hence, it is necessary to study potential risks of geo-hazards in low-slope hilly land development in urban area. Based on GIS spatial analysis technique, we select a study area, Dali City in the Erhai Basin located in watershed belt of Jinsha River, Lancang River and Red River in Yunnan Province of China. Through studying some relevant key indexes and parameters for monitoring potential risks of geo-hazards, we establish a composite index model for zoning the area with potential risks of geo-hazards in development of low-slope hilly land in the study area. Our research findings indicate that the potential risks of geo-hazards in eastern Dali City is relatively low while of that on slow hills with gentle slopes in the western area are relatively high. By using a zoning research method, generated maps show geological information of potential risks of geo-hazards on low-slope hilly land which provide important messages for guarding against natural geo-hazards and potential environmental losses in a watershed.  相似文献   

近21 a来京津冀城市发展空间特征及其与宏观地貌的关系分析     

赵敏  程维明  黄坤 《地球信息科学学报》2015,17(8):917-926

基于全国1:100万数字地貌数据库和1992-2012年的DMSP/OLS夜间灯光数据,从城市重心迁移变化、城市内部变异度和城市相对发展速率3方面,对近21 a来京津冀城市发展的空间特征,以及不同宏观地貌下城市发展的差异性进行了对比分析。结果表明：1992-2012年京津冀重心迁移方向大致经历西南-东北-西南3个阶段,不同城市重心迁移的轨迹和方向不同;京津冀整体发展水平不断提高,各城市间的差距呈减小趋势;不同地貌类型城市,其城市内部各辖区间的差异随时间变化的规律不同,平原型城市基本稳定不变,山地-平原型或平原-山地型城市有所下降,山地型城市各辖区间的差异随时间大幅减小;山地型城市相比其他地貌类型城市,城市重心偏移明显,城市整体发展水平较低。最后讨论了长时间序列下,城市发展与地貌间存在关联性。  相似文献   

基于RTP的矢量数据流式传输研究     

苗茹  宋佳 《地球信息科学学报》2015,17(9):1029-1038

针对WebGIS中大规模矢量数据的网络传输问题,提出采用流式传输方式分批次向客户端传输所需数据,从而达到矢量数据在线实时应用的目的。通过研究流式传输机制,建立了适应于矢量数据流式传输的服务框架;按照流式传输的要求,对矢量数据进行分块组织,保证每个批次的要素作为独立的单元传输并在客户端处理;在传输过程中,实时传输协议实现了矢量数据流式传输机制,并参照流媒体文件“边传边播”的模式,设计了矢量数据的封包和解包算法。该方法实现了矢量数据的发送和接收,达到了多次往复传输的目标,且能通过差错控制和压缩加密等手段提高数据传输效率、保证数据传输质量和安全。实验证明,矢量数据的流式传输能降低约一半的数据传输量,有效地提高了传输效率,降低了系统响应时间。  相似文献   

1999-2013年中国耕地复种指数的时空演变格局   总被引：7，自引：0，他引：7  

丁明军  陈倩  辛良杰  李兰晖  李秀彬 《地理学报》2015,70(7):1080-1090

耕地复种是中国普遍的农业种植制度,对保障国家粮食安全和促进农村经济发展十分必要。本文基于1999-2013年1 km×1 km旬SPOT-NDVI数据和3期耕地数据,利用S-G （Savitzky-Golay）滤波方法,重建了农作物生长NDVI曲线;基于二次差分算法及相关阈值限定,提取了各时相复种指数;分析了1999-2013年中国耕地复种指数的时空变化过程。结果表明：① 中国耕地复种指数从北到南逐渐增加,其中种植制度上43.48%的耕地实行一年一熟,56.39%的耕地实行一年两熟,仅有0.13%的耕地实行一年三熟。② 1999-2013年间,中国耕地复种指数整体上呈现显著上升趋势,年均增加约为1.29%（P < 0.001）;但空间差异明显,复种指数显著降低（P < 0.1）的耕地仅占全国耕地的2.12%,主要分布在河北、北京、天津交界地区,安徽中部,四川的成都平原,江西的鄱阳湖平原,湖南的北部和南部以及广西的中部;16.40%的耕地复种指数显著上升（P < 0.1）,主要分布在甘肃的东部,陕西的渭河平原,山西的西部,河北、山东和天津交界处,山东的山东半岛和湖北的江汉平原。③ 耕地复种指数年际变化率与地形起伏和经济发展水平具有较好的相关关系：起伏度增强,复种指数上升;经济发展水平提高,复种指数降低。  相似文献   

亚热带第四纪沉积型红土与风化壳型红土的磁学特征对比     

杨立辉  叶玮  郑祥民  周立旻  苏优 《地理科学》2015,35(11):1475-1481

对浙江新昌玄武岩、花岗岩风化壳红土和江西南昌第四纪沉积型红土剖面的磁学特征进行了分析,结果表明,同一气候区内风化壳红土的磁学特征受母质特征影响较大。随着风化强度的增加,强磁性的玄武岩风化壳磁化率先减小后增加,磁性矿物颗粒先变粗后变细,弱磁性的花岗岩风化壳磁化率逐渐增加,磁性矿物颗粒逐渐变细。第四纪沉积型红土剖面中,均质红土磁化率远大于网纹红土,磁性矿物颗粒亦较网纹红土层细。这些差别说明了第四纪沉积型红土剖面中均质红土与网纹红土不完全相同的物质来源。  相似文献   

社区恢复力研究进展及其地理学研究议题   总被引：10，自引：2，他引：8  

郭永锐  张捷 《地理科学进展》2015,34(1):100-109

随着人口、资源与环境的矛盾日益加深,灾害已成为可持续发展的重要障碍。在这一背景下,恢复力成为推动社会经济系统可持续发展的新理念和新范式。恢复力研究的范式也由早期的生态恢复力逐渐转向社区恢复力的研究。现有的社区恢复力研究成果主要集中在概念内涵探索、影响因素识别、基于客观指标和基于行动者感知的社区恢复力测度等方面。迄今尚未形成公认的可接受的社区恢复力理论框架;对普通乡村社区研究较多,对特定资源依赖型社区恢复力研究较少;对突发性自然灾害对社区恢复力的影响研究较多,对其他灾害和危机对社区恢复力的影响研究较少;社区恢复力测度方法的适用性和科学性仍待加强;社区恢复力关键影响因素的作用机制仍需进一步探索。在此基础上,提出从地理学视角研究社区恢复力的主要议题,包括社区恢复力的形成机制及其区域差异、动态演变过程、影响因素的作用机理、基于人地关系的社区恢复力感知量表以及具有尺度效应的社区恢复力测度指数等。  相似文献   

A preliminary quantitative reconstruction of precipitation in southern Mu Us sandy land at margin of Asian monsoon-dominated region during late Quaternary     

Yingyong CHEN  Huayu LU  Shuangwen YI  Enlou ZHANG  Zhiwei XU  Kaifeng YU  A. MASON Joseph 《地理学报(英文版)》2015,25(3):301-310

We present the first quantitative estimation of monsoon precipitation during the late glacial-Holocene in the sandy land of northern China, based on organic carbon isotopic composition data from a loess-sand sequence at margin of the Mu Us sandy land. We use the relationship between monsoon precipitation and the carbon isotopic composition of modern soils as an analogue, with a minor modification, to reconstruct precipitation back to c. 47 ka ago. The preliminary results indicate that annual monsoon precipitation was high after 8 ka, with an average of 435 mm; and it decreased during 18 and 8 ka with a mean value of 194 mm. The precipitation value of 47-18 ka varied between the two. We compare the reconstructed precipitation with other records and paleoclimatic modeling results, showing that our record agrees with reconstructions of the monsoon precipitation from other sources, even capturing short climatic events such as the Younger Dryas. We suggest that solar irradiance, high-latitude temperature/ice volume and local evaporation have together modified moistures in the sandy land.  相似文献