Revealing ecosystem services relationships and their driving factors for five basins of Beijing

A clear understanding of the relationships among multiple ecosystem services(ESs) is the foundation for sustainable urban ecosystem management. Quantitatively identifying the factors that influence ES trade-offs and synergies can contribute to deepening ES research, from knowledge building to decision making. This study simulated soil conservation, water yield and carbon sequestration in Beijing, China, from 2015–2018. The spatial trade-offs and synergies of these three ESs within the five major river basins in Beijing were explored using geographically weighted regression. Furthermore, geographical detector was applied to quantitatively identify the driving mechanism of the environmental factors for the ES trade-offs and synergies. The results show the following:(1) the spatial relationships between soil conservation and water yield, as well as between water yield and carbon sequestration, were mainly trade-offs. There was a spatial synergy between soil conservation and carbon sequestration.(2) Regarding the spatial trade-off/synergy between soil conservation and water yield in Beijing, the dominant influencing factor was temperature/elevation, and the dominant interactions of the spatial trade-off and synergy between these two ESs in Beijing and the Chaobai River Basin are all manifested in the superposition of precipitation and potential evapotranspiration, temperature, and elevation.(3) Topographic factors were the dominant factors influencing the spatial relationship between soil conservation and carbon sequestration in Beijing and its five major river basins. As a result of the distribution of water systems and hydrological characteristics of the basins, differences were observed in the effects of different combinations of interaction factors on the spatial relationship between these two ESs in different basins.(4) Temperature had the strongest explanatory power in terms of the spatial trade-offs and synergies between water yield and carbon sequestration. The interactions between precipitation and temperature and between precipitation and elevation were the dominant interactions affecting the spatial relationship between water yield and carbon sequestration in Beijing. Overall, the explanatory power of influencing factors on the trade-offs and synergies and the degree of interaction between factors coexist in different basins with consistency and differences. Therefore, understanding the quantitative characteristics of basin-scale spatial trade-offs and synergies between ESs is important for ecosystem management and the promotion of synergy in different basins.     

Simulation of leaf area index and biomass at landscape scale

The method for simulating the temporal and spatial distribution patterns of leaf area index (LAI) and biomass at landscape scale using remote sensing images and surface data was discussed in this paper. The procedure was: (1) annual maximum normalized difference vegetation index (NDVI) over the landscape was calculated from TM images; (2) the relationship model between NDVI and LAI was built and annual maximum LAI over the landscape was simulated; (3) the relationship models between LAI and biomass were built and annual branch, stem, root and maximum leaf biomass over the landscape were simulated; (4) spatial distribution patterns of leaf biomass and LAI in different periods all the year round were obtained. The simulation was based on spatial analysis module GRID in ArcInfo software. The method is also a kind of scaling method from patch scale to landscape scale. A case study of Changbai Mountain Nature Reserve was dissertated. Analysis and primary validation were carried out to the simulated LAI and biomass for the major vegetation types in the Changbai Mountain in 1995.     

Large‐scale climatic influences on precipitation and discharge for a British river basin

This article aims to identify the large‐scale climate variables that yield significant statistical relationships with precipitation and discharge for a British river basin (Dyfi). Ranked correlation analysis was performed between gridded ERA‐40 atmospheric data and Dyfi precipitation and discharge for individual months. Precipitation and discharge demonstrate significant negative correlation with mean sea level pressure (MSLP). Strongest MSLP correlation areas move from north of Britain in winter to central Britain in summer; this shift is associated with a displacement of geopotential (Z) and zonal wind (U). Movement of significant correlation regions (not captured by the North Atlantic Oscillation Index) highlights the dynamic nature of precipitation and river flow generating weather systems throughout the year. Existence of strong significant correlation shows potential for exploiting large‐scale climate variables in forecasting precipitation and river flow in Britain. Copyright © 2010 John Wiley & Sons, Ltd.     

Insights into Convective-scale Predictability in East China: Error Growth Dynamics and Associated Impact on Precipitation of Warm-Season Convective Events

This study investigated the regime-dependent predictability using convective-scale ensemble forecasts initialized with different initial condition perturbations in the Yangtze and Huai River basin(YHRB) of East China. The scale-dependent error growth(ensemble variability) and associated impact on precipitation forecasts(precipitation uncertainties) were quantitatively explored for 13 warm-season convective events that were categorized in terms of strong forcing and weak forcing. The forecast err...     

干旱区绿洲扩展过程中的景观变化分析

绿洲化过程中的景观变化和尺度效应是景观生态学研究的热点之一。针对这一目标以黑河中游张掖绿洲为研究区域,应用“3S”技术的缓冲分析方法,以绿洲标志景观类型农田、林地和湿地为核心,确定了不同时期绿洲范围并划分了老绿洲区和新增绿洲区。在此基础上,从景观组成动态和斑块连通度的尺度依赖特征两个方面分析了绿洲化过程中的景观变化机制和尺度效应。研究结果表明,绿洲化过程是以农田和建设用地斑块动态为主要特点。主要表现为：在不同的分区中,农田斑块以总面积和最大斑块指数增加为特点,说明农田斑块趋向集中连片分布;建设用地斑块总面积、斑块密度和最大斑块指数等3个指标都为增加,在景观上呈星点状扩张分布。老绿洲与新增绿洲的比较分析显示,新增绿洲的建设用地面积增加速率小于老绿洲,而农田面积的增加速率大于老绿洲。从景观斑块连通度的尺度依赖特点来看,在老绿洲中景观斑块类型的空间尺度依赖规律明显,但在时间尺度上的变化不显著;在新增绿洲内,林地、水域和建设用地的尺度依赖性比老绿洲高,其中林地、建设用地的空间变化规律明显,在时间尺度上无明显的差异;而水域斑块的尺度依赖性1985年高于2006年。     

区域生态服务价值时空异质性研究——以铜川市城郊区为例

以国内外众多关于生态服务价值研究成果为基础,利用研究区近10年地形、气候、土壤、植被和土地利用变化数据,运用生态服务价值测算模型,在GIS的支持下尝试性地研究了区域不同时段生态服务价值的时空异质性、各自然要素和人类活动对生态服务价值的影响,结果表明:(1)由于各自然要素和土地利用的共同影响,近10年铜川市城郊区生态服务价值年际间变化很大,最大年份达到了15．91亿元,最小年份为5．10亿元。(2)在假定其他要素不变的情况下,LUCC对生态服务价值的变化的影响是积极的,近10年土地利用变化有利于该区生态环境质量的提高。(3)研究区生态服务价值存在空间上的差异性:不同生态系统单位面积生态服务价值不同,同一生态系统又存在内部差异。     

论DEM地形分析中的尺度问题

DEM及其地形分析具有强烈的尺度依赖特征。本文以黄高原地区的研究为例,结合地学建模和地学模拟的需求,重点讨论DEM地形分析中的尺度问题。文中从DEM建立与应用出发,首先建立了DEM地形分析中的尺度概念体系,剖析了各类尺度之间的关系,其次讨论了尺度所引起的各种地形分析效应问题,最后探讨了DEM地形分析中的尺度转换类型和方法。     

论地理信息的尺度特性

尺度是地理信息一种固有的本质属性,尺度问题是当前地理信息科学研究的核心内容之一。该文根据地理信息在获取、处理、传输、表达和分析中尺度显现的基本规律,将地理信息的尺度特性概括为尺度依赖性、空间形态可分性与可聚合性、语义层次性与语义连通性、尺度不变性、尺度一致性,并探讨其具体内涵。