青海湖流域草地产草量与MODIS植被指数的相关性分析          下载免费PDF全文

周薇薇  殷青军 《盐湖研究》2012,20(4):8-12

借鉴国内外基于遥感手段监测植被的方法,利用MODIS-NDVI遥感影像数据,探讨如何对草地变化进行监测。提取青海湖流域典型草原遥感影像植被指数,并与野外调查获得的79个样方生物量数据进行对比分析,建立了多个回归模型用于研究植被指数与草地产草量的相关关系。结果表明,植被指数与草地产草量之间存在较好的相关性,但是不同的回归模型与草地产草量相关性程度存在一定的差别,非线性回归模型优于一元线性回归模型,该方法的提出有助于监测青海湖流域草地变化情况。  相似文献   

中国中、东部典型样区不同发展水平下土壤与土地利用多样性的对比分析(英文)   总被引：1，自引：0，他引：1  

段金龙  张学雷 《地理学报(英文版)》2012,22(6):1101-1116

Two typical provincial capitals (Nanjing and Zhengzhou) and two counties (Rugao and Yuanyang) in east (Jiangsu Province) and central (Henan Province) China were chosen respectively as the developed and less developed comparative cases for pedodiversity and land use diversity correlative analysis by borrowing the recently better developed pedodiversity methodology. Land use classification was worked out using remote sensing images in three different periods (1986-1988, 2000-2001 and 2004-2006) for these studied case areas before the calculation of the constituent diversity index and spatial distribution diversity index modified after Shannon entropy in 2 km×2 km grid scale of the soil and land use pattern were conducted and then a connection index was proposed to evaluate the relationship between soil and land use diversity. Results show that during the years from 1986 to 2006, the composition and spatial distribution of regional land use pattern had changed greatly. The agricultural land area of all the studied case areas decreased obviously in which Nanjing has the highest decrement of 895.98 km 2 mainly into urban use while the other land use type area changes show the same trend. The connection index of four typical soil family types and typical urban land use types, i.e., urban construction land, transportation land and industrial and mining area all increased in this period. In the studied case areas, there is the highest soil constituent diversity in Zhengzhou at 0.779 while the simplest soil constituent diversity in Rugao at 0.582. Meanwhile we have higher land use diversity in the more urbanized Jiangsu Province than Henan Province, Nanjing is ranking the first that has been getting higher and higher in the three periods at 0.366 in 1986-1988, 0.483 in 2000-2001 and 0.545 in 2004-2006. Finally, the connection index figures to evaluate the relationship between soil and land use diversity of the studied areas were compared to show the similar phenomenon that this figure grows fastest in Nanjing followed by Zhengzhou and other places.  相似文献   

基于SINMAP模型的区域滑坡危险性定量评估及模型验证   总被引：1，自引：0，他引：1  

武利 《地理与地理信息科学》2012,28(2):35-39,113

利用稳定态水文学理论与无限斜坡稳定性模型,构建分布式斜坡稳定性定量评估模型SINMAP,以坡体滑塌十分发育的陕西省略阳县为试验区,利用Grid DEM提取坡度、流向、地形湿度指数和有效汇水面积等流域地形水文数据,将GIS专题图、遥感数据等作为模型输入数据,获得地表斜坡稳定性分级专题图,实现滑坡危险性定量评估;将模型模拟结果与目前国内最具有权威性的中国县(市)地质灾害调查结果进行对比分析,发现两者在稳定性分级标准划分、滑坡点定性评价、滑坡危险性分区等方面都具有很好的相似性和可比性,说明模型的模拟结果能够客观反映研究区地表滑坡危险性,对可能出现的滑坡具有一定的预测精度。因此,该模型的研究有望为定量分析区域滑坡与环境因子的关系、区域滑坡预测等工作奠定基础。  相似文献   

A Comparative Study of Pollutant Removal Stability in Hybrid Wetland Columns     

Tanveer Ferdous Saeed 《湿地科学》2012,10(2):142-148

This study investigated the effects of two alternative substrates(wood mulch and zeolite) on the performance of three laboratory-scale hybrid wetland systems that had identical system components and configurations.Each system consisted of a vertical flow(VF) wetland column,followed by a horizontal flow(HF) column and a vertical flow column.The substrates employed were wood mulch,gravel and zeolite,and Phragmites australis were planted in each column.The systems received synthetic wastewater,with pollutant loadings in the range of 8.5-38.0 g/(m2·d) total nitrogen(TN) and 4.0-46.4 g/(m2·d) biological oxygen demand(BOD5).Wood mulch and zeolite substrates showed higher efficiencies in terms of removing nitrogenous compounds and biodegradable organics.The supply of organic carbon from the organic mulch substrates enhanced denitrification,while adsorption of influent ammoniacal nitrogen(NH4-N) in zeolite played a major role in the removal of nitrogenous species in the wetland columns.Overall,the average percentage removals of TN and BOD5 reached >66% and >96% respectively,indicating stable performances by the hybrid wetland systems under the experimental loading ranges.Mathematical models were developed,based on the combination of Monod kinetics and continuously-stirred tank reactor(CSTR) flow patterns to describe the degradation of nitrogenous compounds.Predictions by the models closely matched the experimental data,indicating the validity and potential application of Monod kinetics in the modelling and design of treatment wetlands.  相似文献   

An evaluation of the Wellington Regional Genuine Progress Index     

Ralph Chapman 《New Zealand geographer》2012,68(1):1-13

There is widespread discontent with the gross domestic product (GDP) as a measure of progress for society. Alternative measures have been proposed, including the genuine progress indicator (GPI). This paper examines the changing institutional arrangements and attitudinal context in the recently developed Wellington region (New Zealand) GPI. We found an alignment between the GPI framework and the Local Government Act. Despite this fit, we identified challenges, including the need to revitalise public participation through deliberative techniques. It remains too early to judge whether the GPI initiative will launch a viable alternative to the GDP for the Wellington region.  相似文献   

中国草原牧区和半牧区草畜平衡状况监测与评价   总被引：7，自引：0，他引：7  

徐斌  杨秀春  金云翔  王道龙  杨智  李金亚  刘海启  于海达  马海龙 《地理研究》2012,31(11):1998-2006

草原超载过牧是造成我国草原大面积退化、沙化的主要原因之一,草畜平衡监测、评价和管理是实现我国草原植被恢复和重建的关键,也是研究的热点和难点。本文采用遥感和地面调查相结合的方法从宏观上监测和评价了农业部认定的264个牧区和半牧区县的草畜平衡状况,主要结论如下:(1)2008年监测区平均草畜平衡指数为33.58%,总体处于超载状态;(2)120个牧区县草畜平衡指数为27.37%,144个半牧业县为42.07%,半牧区县是我国实行草畜平衡管理的重点和难点;(3)六大牧区中牧区县2008年超载程度排序为:甘肃>四川>新疆>青海>西藏>内蒙古,半牧区县超载程度排序为青海>西藏>内蒙古>新疆>四川>甘肃。本文所得结论可为我国草原资源管理和保护提供参考价值和借鉴意义。  相似文献   

遥感分景数据的剖分索引模型     

谭亚平  程承旗  耿晓晖 《地理研究》2012,31(6):1132-1142

随着空间技术和对地观测技术的飞速发展,海量遥感影像索引成为目前国内外学术界和应用部门面临的一大难题,地球剖分系统的产生为这一难题的解决开辟了新的途径。本文首先研究了遥感分景数据的特征和EMD全球剖分的特征,然后针对现有遥感影像数据索引方法的不足,提出了基于EMD剖分系统的三种索引模型:基于影像—面片映射关系的索引模型、基于EMD数据模型的索引和剖分数据标识索引模型,从三个不同的方面探讨了解决索引问题的方法和思路。并给出了利用遥感分景数据的剖分索引模型对线状对象和面状对象进行索引应用的实例。遥感分景数据的剖分索引模型的建立为遥感影像数据的高效存储和索引提供了一种有益的新思路。  相似文献   

沿海港口自然灾害风险评价   总被引：4，自引：1，他引：3  

王静静  刘敏  权瑞松  陆敏  牛海燕  许世远 《地理科学》2012,(4):516-520

以多灾种复合为背景,选取沿海城市中重要的基础设施——港口为研究区域,包括大连港、天津港、青岛港、上海港、宁波—舟山港、厦门港、深圳港、广州港,从危险性、暴露性和脆弱性等方面选取指标,探讨构建了沿海港口自然灾害风险评价指标体系与评估模型:评价结果为:沿海港口的灾害风险指数相差较大,风险值在空间上表现出长江三角洲沿岸>珠江三角洲沿岸>环渤海沿岸:评价结果可以为沿海港口防灾减灾提供理论依据。  相似文献   

The Norwegian Nature Index: Expert evaluations in precautionary approaches to biodiversity policy     

《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(5):257-271

The Norwegian Nature Index is a comprehensive effort to ‘make nature visible’ in communications between policymakers and the general public. To ensure that appropriate ‘early warnings’ for biodiversity loss are made available as a basis for precautionary approaches to sustainability and biodiversity policy, different knowledge sources need to be applied, such as the Red List for threatened species and the Nature Index, which gives a comprehensive overview of biodiversity. The article shows how the Nature Index can be supplemented with ‘early warnings’ of biodiversity from involved scientific experts, who were asked to assess the situation in 2020 for the indicators, in view of all available knowledge. They also assessed the uncertainty in their forecasts and their considerations of the need for and difficulty of implementing management measures to maintain biodiversity at the current level. Particularly for the major ecosystems considered to have a poor state, namely forests and open lowlands, experts indicated that urgent action was needed to improve the state of many indicators and that such management action would be possible. The findings indicate potential for eliciting experts' formal and informal knowledge in assessing the need and potential approaches to biodiversity policy.  相似文献   

河流健康评价的主评指标筛选   总被引：5，自引：0，他引：5  

冯彦  何大明  杨丽萍 《地理研究》2012,31(3):389-398

河流健康是近年来探讨水资源问题的一个热点,其评价指标体系正成为河流管理的目标。为了筛选出一些基本的、易于量化的主要评价指标来揭示河流健康基本状况和变化趋势,通过对1972～2010年约150篇相关文献、45个河流健康评价指标体系902项指标的整理和归纳,应用统计、层次和相关性分析法,确定各指标的被采用率,并同时综合考虑指标的重要性、普遍性、可量化性和易获得性,筛选出揭示河流生境物理、水环境、生物和水资源利用4类特征的主要指标。结果表明,有以下8个指标可作为河流健康的主评指标:河岸植被覆盖率、河流连通性、湿地保留率、径流量变化率、水质达标率、鱼类生物完整性指数、水资源利用率和流域天然植被覆盖率。  相似文献