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1.
以1990年、2000年和2009年榆阳区TM卫星影像为信息源,采用分区域的先监督分类后对解译结果进行目视修改的方法获得研究区的土地利用数据.在对研究区土地利用情况进行分析的基础上,运用生态价值估算方法对研究区各年度生态系统服务价值进行估算和分析.研究表明:研究区近20年来土地利用变化较快,所产生的生态效应总体来说是积极的,生态系统服务总价值年度总量增幅明显.林地面积变化所产生的生态服务价值变化在各时段变化中均占有主导地位,植树造林、退耕还林政策的实施和飞播造林、封禁管护措施的推行是研究区生态服务价值提高的主要原因.  相似文献   

2.
生态系统服务功能是指生态系统形成和所维持的人类赖以生存和发展的环境条件与效用,是人类赖以生存和发展的基础。本文研究阿城区土地利用生态系统服务价值,可以为哈尔滨市城市建设规划提供科学依据。本文基于生态系统服务功能价值理论,根据阿城区土地利用变化的情况,定量估算了其土地生态系统为人类提供服务的经济价值.  相似文献   

3.
土地利用变化对区域生态系统维持其服务功能起决定性作用,对由土地利用变化引起的生态系统服务价值变化进行研究,可以为区域生态环境的保护和经济的发展提供科学依据,以使环境保护和经济的发展能够达到和谐的统一。现利用罗甸县1996~2006的土地利用变更数据,采用谢高地等(2007)计算生态系统服务价值的方法对贵州省罗甸县1996~2006年的生态系统服务价值进行了估算,并对因为土地利用变化引起的生态系统服务总价值和结构的变化进行了分析,得出罗甸县生态系统服务价值呈下降趋势,与经济的发展呈负相关关系,因此建议罗甸县在发展经济的同时,也要采取积极的生态保护措施,使环境改善和经济发展同时进行。  相似文献   

4.
生态系统服务价值的研究是目前生态学研究的热点之一.该文以贵港市1996-2005年的土地利用变更调查数据为依据,在分析研究区的土地利用变化的基础上,运用生态系统服务价值测算方法,对贵港市研究时段内各年度生态系统服务的经济价值进行核算.通过分析该市9年来生态系统服务价值的变化过程,探求其变化的特点及存在的问题,并提出了改善区域生态系统服务的功能和质量的建议.  相似文献   

5.
近年来,西藏昌都地区土地利用变化很大,研究其对生态系统服务价值的影响,可为生态环境可持续发展和土地利用结构调整提供依据。本文参考谢高地等制定的中国陆地生态系统单位面积服务价值当量,利用昌都地区三期土地利用数据,估算了1988~2004年土地利用变化引起的生态系统服务价值的变化。结果表明生态系统服务价值总量一直呈增长趋势,生态环境总体质量在提高。针对变化,为该区农业可持续发展,提出了土地结构调整目标:农业用地内部结构调整、加大未利用地开发、培肥土壤。  相似文献   

6.
土地利用效益一直是土地变化的研究热点.由土地利用变化引起的经济效益和生态效益消长关系尤其受到关注.生态效益可以由生态系统服务功能估算转换为可比较的市场价格,与传统GDP衡量的经济效益进行比较.文章以海峡西岸经济区为例,比较2003~2010年期间土地利用变化的生态效益与经济效益消长动向.结果表明:该区与土地利用变化相对应的经济效益增长量为生态效益损失量的1倍多,经济效益是土地用变化和生态服务价值下降的直接驱动力,优化土地利用规划是区域经济建设和生态文明建设两不误的重要保障.  相似文献   

7.
根据2001-2007年晋江市土地利用变更数据,采用Costanza生态系统服务价值计算方法,参照谢高地等人制定的中国陆地生态系统单位面积生态服务价值当量表,计算出晋江市各土地利用类型单位面积生态服务价值,并且评估土地利用变化所引起的生态系统服务价值变化。研究表明,土地利用变化对一个区域的生态系统服务价值有重大影响,所以有必要加强晋江市土地利用管理,合理利用和保护土地资源。  相似文献   

8.
根据民乐县土地利用变更和二调数据,运用灰色预测法和平均增长率法对民乐县地类规模的规划面积进行预测。利用农田生态系统生物量因子和生态服务价值当量因子,进行民乐县土地利用结构和生态服务价值分析。研究表明:民乐县土地利用结构多样性指数和均匀度指数增加而优势度指数降低,土地利用趋于多样化和均匀化;各地类中林地生态服务价值贡献最大,土地利用生态服务价值总体呈增加趋势;土地利用结构与土地利用生态服务价值呈线性相关,通过增加林地、园地等生态用地面积,提高土地利用集约度;土地利用结构的调整有利于促进土地利用的多样化和均匀化,进而增加生态系统稳定性和提高生态系统服务价值的经济价值,指导土地结构调整和合理利用土地。  相似文献   

9.
总结16年来翔安区土地利用类型的变化,并探讨其产生的生态服务价值损益。利用从1989年和2005年的遥感影像中获取的土地利用类型数据,估算了不同时期各类土地利用类型的生态服务价值,并分析了土地利用类型间的转化所引起的生态服务价值的变化。结果表明:翔安区生态服务价值总量变化不大,2005年比1989年下降了1557.65万元,但各类土地利用类型间的生态服务价值变动较大,特别是城市建设占用其它土地利用类型所带来的生态服务价值损失达到3603万元。这些研究可以为区域可持续发展政策的制定提供依据,并对于区域生态环境的保护,促进区域经济持续、健康的发展具有重要意义。  相似文献   

10.
沽源县生态系统服务价值变化研究   总被引:1,自引:0,他引:1  
在分析1990~2006年土地利用的数量、结构和程度变化特点的基础上,参考Costanza、谢高地等人的研究成果,结合研究区的实际情况,估算出研究区各年度生态系统服务价值并分析其变化特点及其原因.然后通过敏感性分析,结果表明研究区ESV对生态服务功能价值指数是缺乏弹性的,研究结果是可信的.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

15.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

16.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

19.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

20.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

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