Ecological Risk Assessment of Heavy Metals Pollution in Soil and Lotus Seeds in Xiangtan Lotus Planting Area

In order to study the pollution characteristics and potential ecological risks of heavy metals in soil of Xiangtan lotus planting area,the contents of Mn,Cu,As,Cd,Pb and Cr in soil and lotus seeds were analyzed in six main lotus planting areas.The comprehensive potential ecological risks of heavy metals in soil were evaluated by the potential ecological hazard index.The results showed that Cd concentration(mean value)was higher than the risk screening value and lower than the risk control value,and other heavy metals were lower or close to the risk screening value.The ecological risks of each element from large to small were Cd,Pb,As,Cu,Cr and Mn.The average value of the comprehensive ecological hazard index of the six sites was 224.7,which was a medium level of pollution risk.The lotus seeds corresponding to each site were also polluted by heavy metals to a certain extent,and Cd and Pb in the seeds exceeded the standard.Through the above analysis,the heavy metals in the soil of the lotus planting area presented a medium ecological risk.In order to ensure the safety of lotus production,it is necessary to strengthen the soil testing and management in the lotus planting area.

Assessment and Countermeasures of Ecological Civilization Construction in Changsha,Zhuzhou and Xiangtan

[Objective] The aim was to assess the ecological civilization construction in urban agglomeration composed of Changsha,Zhuzhou and Xiangtan synthetically.[Method] By means of analytic hierarchy process,the assessment system of ecological civilization in Changsha,Zhuzhou and Xiangtan was established firstly,and then the ecological civilization construction in Changsha,Zhuzhou and Xiangtan was evaluated comprehensively,and the existing problems and causes of ecological civilization construction were analyzed,finally the corresponding suggestions and countermeasures were put forward.[Result] For natural subsystem and social subsystem,the comprehensive scores of Changsha,Zhuzhou and Xiangtan were 0.143 and 0.214,and Changsha had the highest scores (0.150 and 0.221),and next came Xiangtan (0.142 and 0.219),while the scores were the lowest in Zhuzhou (0.136 and 0.213).From economic subsystem,the comprehensive score of urban agglomeration composed of Changsha,Zhuzhou and Xiangtan was 0.216,and the maximum score appeared in Changsha (0.247),Zhuzhou the second (0.201),while Xiangtan owned the lowest score (0.197).In cultural subsystem,the comprehensive score of urban agglomeration was only 0.078 which was the lowest score among four subsystems,and it was related to its low weight.In addition,the scores of Changsha and Xiangtan took the first place (0.079),while it was lower in Zhuzhou (0.077).[Conclusion] The ecological civilization construction in Changsha,Zhuzhou and Xiangtan persisted at a higher level and developed well on the whole.

Spatial Pattern Evolution and Casual Analysis of County Level Economy in Changsha-Zhuzhou-Xiangtan Urban Agglomeration, China

In order to evaluate whether or not the county units′ economy in the Changsha-Zhuzhou-Xiangtan(Chang-Zhu-Tan) Urban Agglomeration was growing as expected, this study analyzed the spatial economy pattern at county-level by using the Exploratory Spatial Data Analysis(ESDA) method. In this process, the global Moran′s I and local Getis-Ord G*i indexes were employed to analyze indicators including per capita GDP and three industrials(i.e. primary, secondary and tertiary industry) from 2000 to 2010. The results show that: 1) the county units′ economy in the Chang-Zhu-Tan Urban Agglomeration has exhibited a strong spatial autocorrelation and an accelerated integration trend since 2008(Moran′ s I increased from 0.26 to 0.56); 2) there is a significant difference in economy development between the northern and southern county units in the Chang-Zhu-Tan Urban Agglomeration: the hotspot zone with high economic level was formed among the northern county units whereas the coldspot zone with low economic level was located in the southern areas. This difference was caused primarily by the increasingly prominent economic radiation effect of Changsha ′upheaval′; 3) town density, secondary industry, and the integration policy are the major contributors driving the evolution of the spatial economy pattern in the Chang-Zhu-Tan Urban Agglomeration.

Evaluation of Overall Coordination of Urban and Rural Land Use in Xiangtan City

Based on regional characteristics of Xiangtan City and in line with relevant principle of overall coordination of urban and rural land use,this paper builds an evaluation system for overall urban and rural land use in Xiangtan City. With weight of each index determined by Analytic Hierarchy Process,it makes quantitative analysis of overall urban and rural land use of Xiangtan City in recent 8 years. Finally,it proposes feasible recommendations for overall coordinated development of urban and rural land use in Xiangtan City according to current land use situations.

A Study on Spatial Distribution of Commercial Housing Prices in Xiangtan City

ArcGIS technology is used to study the spatial pattern of housing prices in Xiangtan City,and it is found that the spatial pattern of housing prices shows primary and secondary two-center rings. In Hedong Jianshe Road and near Hexi Jijianying,there are primary and secondary polar nuclei,respectively; the secondary housing price area is located near the east-west and south-north trunk road in the urban area; there are significant regional differences in housing price changes( fastest reduction of prices in the Hedong main center-southwest direction; slow reduction of prices in the main center-northwest,southeast direction; slowest reduction of prices in the main center-northeast direction). In Hexi sub-center,except slow reduction of prices in the Xiangjiang River direction,the prices decline rapidly in other directions. The housing prices exhibit an obvious overall decreasing trend from primary and secondary centers to the suburbs,but there are also exceptions. On this basis,this paper analyzes the driving factors for spatial pattern of housing prices in Xiangtan City,and finds that the spatial pattern of housing prices is mainly influenced by commercial centers,residential environmental conditions,traffic conditions,and urban land layout differences.

Study on the Collaborative Governance Mechanism of Ecological Environment in Changsha-Zhuzhou-Xiangtan Region under the Green Development Perspective

Natural resources and the environment,environmental capacity of China has been approaching the red alert,and long-term accumulation of ecological debt needs to be solved. The transformation of economic development mode and green economic development path are inevitable choices. The complexity and the pressureof the ecological environment governance force Changsha-Zhuzhou-Xiangtan region to change the ecological governance method. The " government-market-society" is taken as the overall framework,to build a diversified body of eco-environment collaborative governance platform. Through collaborative governance among governments,government-market collaborative governance and government-society collaborative governance,ecological capital stock is improvedin the quantity and quality,thus contributing to benigndevelopment of regional economy and society.

基于PLUS模型的长株潭都市圈景观生态风险动态分析

基于土地利用数据和景观生态风险评价模型,分析2000—2020年长株潭都市圈景观生态风险时空演变特征,结合PLUS模型科学预测自然发展情景和生态保护情景下2030年长株潭都市圈的景观生态风险空间分布格局。结果表明:①2000—2020年长株潭都市圈景观生态风险呈现北高南低、西高东低的空间分布特征,较低和中等生态风险区域总面积占比大于60%,生态风险加剧区域面积不到生态风险降低区域面积的1%,整体表现出高等级生态风险区向低等级生态风险区转移的特征;②研究区景观生态风险表现出较强的空间集聚特征,高—高集聚区主要分布在宁乡市、望城区、渌口区、雨花区和长沙县,低—低集聚区主要分布在研究区边界;③相比自然发展情景,生态保护情景下生态用地减少速率变缓,有助于缓解研究区生态风险,有利于构建和谐有序的生态安全格局。

Change of Low-level Jet in a Heavy Rainstorm Process of Xiangtan in July 2016

Based on the previous research on the model of rainstorm weather with low-level jet in Xiangtan,using the classification result of radar echo characteristics,the wind profile data provided by new generation of weather radar in Changsha and hourly rainfall data,a thorough study of the heavy rainfall from 2 to 5 July 2016 in Xiangtan was conducted. It was concluded that heavy precipitation had the characteristics of the WPSH pattern of rainstorm with low-level jet at early stage,and then it converted to cold shear jet pattern in latter stage. When low-level southwest jet began to have momentum download,that is to say,there was more than 12 m/s of southwest jet below 1 km,and it rapidly strengthened and expanded downward,it was conducive to the occurrence of short-term rainstorm. The low-level jet would not immediately cause a strong precipitation when it reached the station,with a certain lag. A positive correlation existed between the increase of low-level jet index and precipitation intensity,and low-level jet index could predict the occurrence of heavy rainfall and rain intensity.

基于Markov-PLUS模型的长株潭城市群建设用地扩张模拟及碳排放响应分析

在双碳目标和新型城镇化背景下,保证经济平稳增长的同时减少碳排放是实现城市高质量发展的重要任务之一,更是长沙、株洲、湘潭等国家低碳试点城市重点建设目标之一。因此以长株潭城市群中用地变化和碳排放最为剧烈的中心城区作为研究区域,在现状分析的基础上运用Markov-PLUS耦合模型和碳排放响应模型,模拟了自然状态发展情景、耕地保护发展情景、生态保护发展情景和绿色低碳发展情景下建设用地扩张及碳排放响应情况。结果表明:①2000—2020长株潭城市群建设用地面积呈现阶段性的波动增长趋势,耕地和林地是其主要来源,扩张强度在2010—2015年最大,主要集中在城市群中心区域;碳排放量呈现倒“V”型曲线,可以划分为碳排放量快速上升阶段(2000—2005年)和碳排放量下降阶段(2005—2020年),以2010年为节点,下降幅度先增加后减缓;二者之间存在较为密切的正相关关系,整体表现为建设用地面积增加(减少)碳排放随之增加(减少)的较强扩张与较高排放模式。②Markov-PLUS模拟结果显示,长株潭城市群建设用地在自然状态发展情景下扩张面积最大(235.9503km^(2)),在生态保护发展情景下扩张面积最小(200.6354km^(2));绿色低碳发展情景下建设用地扩张所占用的生态碳汇面积相对较少(169.78km^(2)),占未利用地相比其他情景较多(1.20km^(2)),扩张分布较为合理,带来的生态环境压力和碳排放压力较小,既有利于生态环境保护也有利于社会经济发展。③碳排放响应结果显示,在不同情景下长株潭城市群各区县的碳排放对建设用地扩张均表现出一定的敏感性,综合建设用地扩张与碳排放响应结果,绿色低碳发展情景是长株潭城市群未来的较优发展模式。

Spatiotemporal Measurement of Regional Expansion in Changsha-Zhuzhou-Xiangtan Metropolitan Area Based on Nighttime Light Data

The research purpose is to accurately reveal the temporal and spatial law of the urban expansion of Changsha-Zhuzhou-Xiangtan, one of the seven major urban agglomeration areas in China, and provide decision-making basis for the future urban construction land layout and regional development policy-making. Based on the night lighting data (DMSP/OLS), this paper extracts the boundary of the urban construction land of Changsha-Zhuzhou-Xiangtan urban agglomeration from 1993 to 2017, and quantitatively studies the spatial and temporal characteristics of the expansion of the metropolitan area in the past 25 years according to the methods of spatial expansion analysis, center of gravity migration measurement, landscape pattern index, spatial autocorrelation, etc. The results show that: 1) it is scientific and feasible to extract urban agglomeration construction land by the method of auxiliary data comparison for the study of urban expansion;2) the expansion of regional space in Changsha-Zhuzhou-Xiangtan metropolitan area shows a trend of “weakening first and strengthening later”. The construction land keeps increasing, and the expansion form gradually changes from extensive type to intensive type;3) the center of gravity of the metropolitan area fluctuated and repeated in part during the past 25 years, but it was always located in the municipal district of Changsha city. The eastern region, mainly Changsha city, was still the core area of urban agglomeration expansion;4) strengthening the territorial space protection and control of ecological green core in the metropolitan area is a key measure for the high-quality development of urban agglomeration.

The Land Management Pattern in " Green Heart" Area——A Case Study of Changsha-Zhuzhou-Xiangtan Urban Agglomeration

By analyzing the status quo of land resources in " green heart" area of Changsha-Zhuzhou-Xiangtan urban agglomeration,and problems existing in land management,this article puts forward some countermeasures and proposals as follows:establish new land management mechanism in " green heart" area;based on land planning," green heart" overall planning and policies and regulations,manage land and promote the protection of urban ecological environment.

Dynamic Evaluation of Rationality of Land Use Structure in the Changsha-Zhuzhou-Xiangtan Area

The rationality of land use structure was evaluated with dynamic TOPSIS method based on changing data of land use from 2008 to 2011 in the Changsha-Zhuzhou-Xiangtan area. The results showed that during 2008- 2011,the rationality of land use structure was totally high,the dynamic value hi of Changsha,Zhuzhou,Xiangtan and the Changsha-Zhuzhou-Xiangtan area was 0. 7954,0. 7821,0. 8245 and0. 8186,respectively; the value Ci( tk) reflecting the rationality of land use structure at different time points was rapidly increased,and the gap between regions was not big and shrinking. According to the grey relational analysis,the change of different land use types had different effects on the rationality of land use structure: transportation land,the land for cities,towns and villages and the land for mining and industry are most highly correlated with the rationality of land use structure,while arable land,woodland,water area and water conservancy facility land have also an important impact on the rationality of land use structure; controlling the excessive growth of transportation land,the land for cities,towns and villages and the land for mining and industry,protecting arable land,forest land,water area and water conservancy facility land,and moderately increasing the garden plot,plays a decisive role in optimizing the land use structure in the Changsha-Zhuzhou-Xiangtan area.

基于MODIS数据的长株潭地区城市热岛时空分析

基于MODIS影像,采用分裂窗算法反演的地表温度对长株潭地区城市热岛空间分布与季相变化特征、影响因子进行定量研究。结果表明,长株潭地区春季和夏季存在明显的城市热岛效应,而冬季和秋季城市热岛并不明显;地表覆盖类型对城市热岛的影响十分明显,长株潭地区春、夏、秋季植被绿地状况与城市热岛呈现明显负相关分布,其中以夏季最为明显,夏季地表温度与NDVI相关系数的平方R2达到0.8193,即植被覆盖对城市地表温度的影响显著。因此,城市植被的分布与季节变化影响着城市热岛的强度与时空分布,揭示出植被绿地对降低城市热岛效应具有重要的作用,大范围的绿地建设能有效降低城市热岛效应。

基于GIS和BP神经网络的城镇土地集约利用时空差异分析——以湖南省湘潭市为例

在建立土地集约利用评价体系的基础上,运用BP神经网络构建定量评价模型,并结合GIS技术对湘潭市城镇土地集约利用水平进行了时空评价。研究结果表明:1998-2007年湘潭市城镇土地集约利用水平呈波动上升趋势,但集约程度还不够高,仍需继续挖掘城市内部潜力;湘潭市各地区土地利用水平存在着较大差异,发展不平衡,韶山市城镇土地集约度最低,湘乡市和湘潭县次之,湘潭市区最高;产生时空差异的主要原因在于经济发展水平和产业结构的不同。

基于InVEST模型的长株潭城市群生境质量时空演变分析研究

生境质量的评估,对于维护区域生态系统,重塑区域生态安全格局有着重要作用。选取长株潭城市群作为研究对象,运用InVEST模型及ArcGis软件,分析2000年、2010年、2020年区域土地利用和生境质量的空间格局及时空演变特征,并进一步分析其演变机制与影响因素。结果表明:1)土地利用同生境质量水平的分布具有明显的相关性;2)长株潭城市群整体生境质量经历了一个努力维持到加速恶化的演变趋势;3)生境质量水平的动态演变与区域规划政策的发布落实有明显的相关性。

基于ArcGIS与GAP分析的长株潭城市群水安全格局构建

为解决长株潭城市群较为突出的水生态安全问题,基于ArcGIS和GAP分析,构建综合水安全格局并分析其GAP的位置与类型。结果表明:长株潭城市群核心区水安全格局由总面积256km^2的3个水生态保护区斑块、总长度654 km的水生态蓝线廊道和总长度516km的水生态绿线廊道构成;洪灾风险和地下水资源被破坏风险是研究区域最突出的水安全问题,其次是湿地生物多样性保护问题;水生态保护区有3个保护空缺GAP和2个修复空缺GAP,水生态蓝线廊道有7个修复空缺GAP,水生态绿线廊道有2个保护空缺GAP和10个修复空缺GAP,它们是水安全格局中决定整体安全水平的“短板”,需要在下一步生态建设中被优先考虑。

嫒尚I&S 突破传统“大圣”系列完美逆袭!

N年前,一只桀骜不驯的猴子,出现在世人的眼前。四百年后,嫒尚（I＆S）珠宝＂大圣＂黄金系列强势袭来!飒爽的英姿,灼烫了一代人回忆的泪点。每个人心中都住着一位＂大圣＂,它无所不能,身如玄铁,火眼金睛;它长生不老,有着七十二变的魔法。一个跟头,翻到十万八千里外。它是庇佑我们一路平安的超级英雄,更是猴年的护身符。＂大圣＂聪明、机智、勇敢、活泼,

I&S总部迎乔迁大喜开启新征程

11月7日,在这个风和日丽的日子里,I＆S珠宝迎来了盛大的乔迁喜事。I＆S公司总部正式乔迁到深圳罗湖区水田二街宝琳国金珠宝交易中心7楼,为I＆S珠宝品牌的发展开启了崭新的篇章。当天,I＆S举行了隆重的揭牌仪式。I＆S新的办公楼,装修风格融入了＂耀·不一样＂的品牌理念,把潮流时尚与高端品位展现的淋漓尽致。同时,展厅轮播着＂风尚盛典＂I＆S品牌发布会的精彩内容以及绝美的女神宣传片,让来宾更加了解I＆S。