Cross-site analysis of perceived ecosystem service benefits in multifunctional landscapes     

《Global Environmental Change》2019

Rural development policies in many Organization for Economic Co-operation and Development (OECD) member countries promote sustainable landscape management with the intention of providing multiple ecosystem services (ES). Yet, it remains unclear which ES benefits are perceived in different landscapes and by different people. We present an assessment of ES benefits perceived and mapped by residents (n = 2,301) across 13 multifunctional (deep rural to peri-urban) landscapes in Europe. We identify the most intensively perceived ES benefits, their spatial patterns, and the respondent and landscape characteristics that determine ES benefit perception. We find outdoor recreation, aesthetic values and social interactions are the key ES benefits at local scales. Settlement areas are ES benefit hotspots but many benefits are also related to forests, waters and mosaic landscapes. We find some ES benefits (e.g. culture and heritage values) are spatially clustered, while many others (e.g. aesthetic values) are dispersed. ES benefit perception is linked to people’s relationship with and accessibility to a landscape. Our study discusses how a local perspective can contribute to the development of contextualized and socially acceptable policies for sustainable ES management. We also address conceptual confusion in ES framework and present argumentation regarding the links from services to benefits, and from benefits to different types of values.  相似文献   

铁路工程地质选线咨询系统   总被引：3，自引：0，他引：3  

乔平  王云鹏 《工程地质学报》1994,2(4):77-83

本文考虑了铁路线位选择的特点，从地质的角度出发，将铁路地质选线中涉及的主要问题（滑坡、泥石流、风沙、岩溶）归纳、总结建立知识库，通过推理为铁路总体选线提供地质依据，以减少工程失误，节约工程造价，保证工期。本文重点介绍该系统的组成部分及各个部分的具本设计思想和设计技巧。  相似文献   

Phosphorus and nitrogen limitation of algal biomass across trophic gradients   总被引：1，自引：0，他引：1  

Knut L. Seip 《Aquatic Sciences - Research Across Boundaries》1994,56(1):16-28

Regression results based on data from 46 northern temperate lakes show that total phosphorus (TP) is the best predictor for phytoplankton (as chl-a) at lower trophic levels, TP < 200 mg · m^–3. A regression including both TP and TN as regressors is the best predictor for lakes with TP > 200 mg · m^–3. However, the good correlation is probably due to a high correlation between lake average chl-a (all years observed) and lake average TP and TN. Within single hypereutrophic lakes, TN alone is the best predictor. It was not possible to identify a medium trophic domain where TN and TP in combination was the best predictor for chl-a. The ratio TN:TP in the water decreases from about 40 to about 5 with increasing trophic level. Optimum TN:TP ratio for algal species with high abundance during late summer and autumn reflects this decreasing ratio, but within a lesser range, i.e., 20 to 5. In contrast, TN:TP ratios for species abundant during the early vernal period showed no, or an inverse, relation to the TN:TP ratio of the water.  相似文献   

安徽铜陵地区含金硫化物矿床成矿作用     

戴瑞榕 《大地构造与成矿学》1991,15(1):23-30

铜陵地区位于华中地洼区,苏鄂地洼系。具工业价值的金矿床多赋存于地洼期次一级构造以及它们的交汇处,这是本区构造控矿的特点。近矿围岩以地台型碳酸盐岩为主,矿体明显受地层层位控制。与矿化有关的侵入岩,主要形成于地洼期(燕山早、中期)。岩体形成后叠加了成矿热液的多次活动。金的成矿作用及金矿床的形成,通常与含金丰度相对较高的地台构造层有密切的成因联系,它们提供了重要的物质来源,可认为是矿源层(Source beds)。本区各主要矿床是以地洼型岩浆期后热液作用为主的多因复成层控含金硫化物矿床。  相似文献   

运用人工神经网络作汛期降水预报   总被引：2，自引：0，他引：2  

蔡煜东  宫家文 《气象科学》1994,14(4):386-389

本文提出汛期降水预报的人工神经网络方法，并选择一组标样进行了具体分析，预报成功率达100％，结果表明，该方法性能良好，可望成为汛期降水预报的有效手段。  相似文献   

新疆天格尔金矿成矿带矿物包裹体研究   总被引：1，自引：0，他引：1  

刘养杰  王润三  王居里  炎金才 《新疆地质》1994,(2)

天格尔金矿成矿带矿物包裹体的均一温度、爆裂温度、成矿压力、气相成分及物理化学条件的研究表明，金矿化可分为两个成矿阶段，矿化深度１～１．５ｋｍ，成矿热液具有酸性还原特性，金是以金硫络合物形式迁移沉淀的。  相似文献   

Development of Artificial Intelligence Technology in Weather Forecast     

Leiming Ma 《地球科学进展》1986,35(6):551-560

Numerical weather prediction, which is the major basis of current weather forecast, has some shortcomings, such as the understanding of the law of atmospheric motion, the assimilation and application of observation data, the expression of model physics, etc., leading to the forecast error of weather. The rapid development of artificial intelligence technology in recent years provides a new possibility for the advancement and innovation of weather forecast. In this paper, the background of the development of artificial intelligence, the current situation of the application of artificial intelligence technology to weather forecast and the future development trend are mainly described to account for this possibility. After that, the idea for development of weather forecast technology based on the integration of artificial intelligence and numerical forecast is put forward. Particularly, this study stresses that, in order to advance the AI algorithm of weather forecast in the future, it is requested to focus on the nonlinear and chaotic characteristics of atmospheric motion leading to the uncertainty of forecast. Starting from the essence of mathematics and physics, we need to realize the hybrid modeling of mathematics and physics, not only to establish the framework of input-output mapping, but also to provide solutions to the bottleneck problems of weather forecast.  相似文献   

Fate of copper and cadmium in a sediment-water system,and effect on chitin degrading bacteria     

H. Neumann-Hensel  W. Ahlf 《洁净——土壤、空气、水》1995,23(2):72-75

Fate and effect of copper and cadmium on the degradation of chitin were studied in sediment microcosms. Artificial sediment was spiked with metals, and metal partitioning between sediment components, overlying water and bacteria was described. Most of the added metals were bound to sediment particles. Remarkable metal enrichments were found on Fe-oxide, Mn-oxide, and chitin. In sediments containing the nominal concentration of 100 mg/kg Cu, the chitin-degrading bacteria Cytophaga johnsonae showed a significant decrease in N-acetylglucoseaminidase activity. Toxicity of copper was attributed to free ions in the overlying water. The bacteria were more sensitive to copper than to cadmium. Inhibitory effects of cadmium were primarily caused by sediment-associated cadmium.  相似文献   

Environmental impact assessment of risk associated with groundwater overdraft remediation in cone of depression,Jining, China     

B. T. I. Ong′or  Long-cang Shu  Pei-gui Liu 《Environmental Geology》2007,53(4):751-762

In this paper, a simple scenario and probabilistic approach is used to assess the potential groundwater risk due to proposed overdraft remedial actions in cone of depression, Jining City, China. Focusing on the concentrations of Chloride ions (Cl⁻) and total hardness (TH), the impact of artificial recharge and reduced pumping on groundwater quality and quantity is analysed by using the three-dimensional finite difference groundwater flow and transport model, Visual MODFLOW, to simulate groundwater flow and transport within the study area based on scenarios, and utilizes SURFER software to map risk levels. Although 5, 10 or 15% reduced pumping with artificial recharge leads to more decrease in Cl⁻ and TH concentrations than the 25%, less volume increase is achieved for the remediation of land subsidence and other environmental problems in the cone of depression. The Cl⁻ concentrations in recovered groundwater are within the desired concentration of 200 mg/l; however, TH in some cases are above the maximum permissible limit of 500 mg/l, with an exceedence probability of about 0.67 for recharge and recharge with reduced pumping at 25%. The presence of fractures and hydrogeological complexity greatly determines impacts of remediation, and the 22% reduced pumping with artificial recharge offers an optimum strategy for overdraft remediation in the Jining cone of depression.  相似文献   

基于MatLab的神经网络在江苏矿山地质环境评估中的应用     

刘洪  张宏斌 《江苏地质》2007,31(4):348-353

神经网络作为一种新的方法体系,具有分布并行处理、非线性映射、自适应学习和鲁棒容错等特性,在模式识别、控制优化和智能信息处理等方面有着广泛的应用。利用MatLab的神经网络工具箱,建立了江苏矿山地质环境质量的评估模型,评估结果经过实际验证,具有较高的可信度和实用性。  相似文献