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1.
提出了一种基于深度学习技术的遥感分类方法，它能有效解决中分辨率影像在分类过程中出现的像元混分问题。研究选用2016年5月12日武汉市Landsat 7 ETM+遥感影像，基于GoogleNet模型中的Inception V3网络结构，借助迁移学习方法，构建出遥感分类模型，实现了对武汉市主城区4类典型地物（不透水层、植被、水体和其他用地）的自动分类提取，并将分类结果与传统最大似然分类（ML）结果进行了对比分析。研究表明：基于深度学习方法的遥感影像总体分类精度高达88.33%，Kappa系数为0.834 2，明显优于传统ML方法总体分类精度83%和Kappa系数0.755 0，而且有效抑制了地物在分类过程中出现的像元混分现象。 相似文献
2.
基于遥感和GIS武汉城市圈土地资源利用研究 总被引：1，自引：0，他引：1
最近国务院正式批准武汉城市圈为"资源节约型和环境友好型"综合改革试验区.为全面、及时的掌握武汉城市圈土地资源的利用现状,本文利用2004、2005年Landsat TM影像数据,对该区域的土地利用现状进行了遥感制图与分析.研究显示,本区的耕地占绝对的优势地位,占总面积的50.58%,林地覆盖近1/3,水域面积大,占9.89%,建设用地也不少,占6.42%,草地的覆盖率较小,仅占区域面积的2.44%,未利用地所占比重很小.土地利用的区域差异显著,耕地、水域和城镇主要分布在区域内的江汉平原和鄂东沿江平原,林地集中分布在该区的东北部和南部.区域土地利用不合理,人均耕地少,不及全国平均水平,后备耕地资源稀缺,林地质量差.因此,只有实行最严格的耕地保护制度,进一步开展森林恢复与保育工作,持续不断地改善土地利用结构,为建设"环境友好型和资源节约型"的武汉经济圈奠定良好的资源与生态环境基础. 相似文献
3.
洞庭湖区近20年土地利用/覆盖变化的时空特征 总被引：19，自引：2，他引：17
在中国资源与环境时空数据库的支持下,利用20世纪70年代末期、80年代末期和90年代末期获取的陆地资源卫星图像和GIS分析方法,对洞庭湖区近20年的土地利用/覆盖变化的时空特征进行了研究。结果表明,变化比较显著的地类有3种:耕地减少了1 97%,各类建设用地总计增加了14 88%,水域面积增加的幅度为8 77%。耕地与水域相互之间的转变比较频繁。以80年代末为界,前后2个10年间,建设用地、水域和草地的面积在2个时期均持续增加,耕地、林地的面积都持续减少。后期土地利用的动态度大于前期;前期动态度最大的县域有岳阳市、沅江县和汉寿县,后期动态度最大的则为石首市、津市和岳阳市,全部为市级行政区或县改市区。 相似文献
4.
While passing through a lock, a ship usually undergoes a steady forward motion at low speed. Owing to the size restriction of lock chamber, the shallow water and bank effects on the hydrodynamic forces acting on the ship may be remarkable, which may have an adverse effect on navigation safety. However, the complicated hydrodynamics is not yet fully understood. This paper focuses on the hydrodynamic forces acting on a ship passing through a lock. The unsteady viscous flow and hydrodynamic forces are calculated by applying an unsteady RANS code with a RNG k-ε turbulence model. User-defined function(UDF) is compiled to define the ship motion. Meanwhile, the grid regeneration is dealt with by using the dynamic mesh method and sliding interface technique. Numerical study is carried out for a bulk carrier ship passing through the Pierre Vandamme Lock in Zeebrugge at the model scale. The proposed method is validated by comparing the numerical results with the data of captive model tests. By analyzing the numerical results obtained at different speeds, water depths and eccentricities, the influences of speed, water depth and eccentricity on the hydrodynamic forces are illustrated. The numerical method proposed in this paper can qualitatively predict the ship-lock hydrodynamic interaction. It can provide certain guidance on the manoeuvring and control of ships passing through a lock. 相似文献
5.
While passing through a lock, a ship usually undergoes a steady forward motion at low speed. Owing to the size restriction of lock chamber, the shallow water and bank effects on the hydrodynamic forces acting on the ship may be remarkable, which may have an adverse effect on navigation safety. However, the complicated hydrodynamics is not yet fully understood. This paper focuses on the hydrodynamic forces acting on a ship passing through a lock. The unsteady viscous flow and hydrodynamic forces are calculated by applying an unsteady RANS code with a RNG k?ε turbulence model. User-defined function (UDF) is compiled to define the ship motion. Meanwhile, the grid regeneration is dealt with by using the dynamic mesh method and sliding interface technique. Numerical study is carried out for a bulk carrier ship passing through the Pierre Vandamme Lock in Zeebrugge at the model scale. The proposed method is validated by comparing the numerical results with the data of captive model tests. By analyzing the numerical results obtained at different speeds, water depths and eccentricities, the influences of speed, water depth and eccentricity on the hydrodynamic forces are illustrated. The numerical method proposed in this paper can qualitatively predict the ship-lock hydrodynamic interaction. It can provide certain guidance on the manoeuvring and control of ships passing through a lock. 相似文献
6.
公路岩质边坡地质灾害防治及SNS柔性防护系统的应用 总被引：3，自引：0，他引：3
本文在简单评述公路岩质路堑边坡地质灾害防治措施,尤其是预应力锚固的基础上,着重介绍了SNS柔性钢绳网防护系统的基本原理和功能,并结合山东省博山一莱芜高速公路路堑边坡防护实例,显示了SNS柔性防护系统于特定条件下,与其它防护形式相结合,在技术、经济和环保等方面的综合优势。 相似文献
7.
Numerical Prediction of Hydrodynamic Forces on A Berthed Ship
Induced by A Passing Ship in Different Waterway Geometries 
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下载免费PDF全文 An investigation has been conducted to quantify the effect of waterway geometry on the form and magnitude of forces and moment experienced by a berthed ship due to a passing ship. By using the dynamic mesh technique and solving the unsteady RANS equations in conjunction with a RNG k?ε turbulence model, numerical simulation of the three-dimensional unsteady viscous flow around a passing ship and a berthed ship in different waterway geometries is conducted, and the hydrodynamic forces and moment acting on the berthed ship are calculated. The proposed method is verified by comparing the numerical results with existing empirical curves and a selection of results from model scale experiments. The calculated interaction forces and moment are presented for six different waterway geometries. The magnitude of the peak values and the form of the forces and moment on the berthed ship for different cases are investigated to assess the effect of the waterway geometry. The results of present study can provide certain guidance on safe maneuvering of a ship passing by a berthed ship. 相似文献
8.
An investigation has been conducted to quantify the effect of waterway geometry on the form and magnitude of forces and moment experienced by a berthed ship due to a passing ship.By using the dynamic mesh technique and solving the unsteady RANS equations in conjunction with a RNG k?ε turbulence model,numerical simulation of the three-dimensional unsteady viscous flow around a passing ship and a berthed ship in different waterway geometries is conducted,and the hydrodynamic forces and moment acting on the berthed ship are calculated.The proposed method is verified by comparing the numerical results with existing empirical curves and a selection of results from model scale experiments.The calculated interaction forces and moment are presented for six different waterway geometries.The magnitude of the peak values and the form of the forces and moment on the berthed ship for different cases are investigated to assess the effect of the waterway geometry.The results of present study can provide certain guidance on safe maneuvering of a ship passing by a berthed ship. 相似文献
9.
近50年来气候变化背景下中国大豆生产潜力时空演变特征 总被引：6，自引：0，他引：6
大豆是中国最重要的粮食兼油料作物之一,随着人口的增长和人们生活水平的提高,中国对大豆产品的消费需求不断增加.全球气候变化给大豆生产带来了一定影响,其中有负面的,也有正面的.本文以2010年中国耕地空间分布遥感监测数据为基础,在1961-2010年的长时间序列气象数据、土壤数据等数据基础上,采用GAEZ模型,综合考虑光、温、水、CO2浓度、病虫害、农业气候限制、土壤、地形等因素,估算了中国大豆生产潜力,进而分析了近50年来气候变化导致的中国大豆生产潜力的时空格局特征.研究表明:①中国大豆生产潜力呈现由南向北、由西向东增加的趋势.东北平原区、长江中下游地区和黄淮海平原区是大豆高产区.②近50年来,中国大豆适宜种植面积持续增加,而大豆平均生产潜力却持续下降,大豆生产潜力总量先降后增.③中国大豆生产潜力的变化区域差异明显.东北平原区大豆生产潜力总量居全国第一,长江中下游地区和黄淮海平原区分别居第二、三位.本文揭示了近50年来气候变化背景下中国大豆生产潜力的时空格局演变特征,对合理安排大豆种植布局,高效利用气候和土地资源,实现大豆稳产高产具有指导意义. 相似文献
10.
区域间劳动力转移规模逐步扩大,其对土地利用效率的影响研究亟待加强。在对2010年我国31个省市劳动力转移的特征(包括数量、素质特征)及农用地和建筑用地的利用效率进行分析的基础上,探讨了劳动力转移与土地利用效率的耦合关系。研究显示:发生转移的劳动力的总体素质不高,平均受教育水平为9.85a,相当于高中教育初期阶段;京津沪地区和西北地区劳动力转移度较高;全国农用地和建筑用地综合利用效率水平较低,大多数省市农用地和建筑用地的规模效率较高,经济发达地区农用地和建筑用地纯技术效率较高;大部分省市建筑用地利用效率处于规模报酬递增趋势;农用地和建筑用地利用效率均与劳动力转移度呈显著正相关,而与转移的劳动力素质无关;对有效拟合方程求解得到劳动力转移度最优值为0.84。目前土地利用效率的提高应该侧重于提高纯技术效率,合理配置其投入产出关系;从提高土地利用效率出发,未来的政策应该鼓励劳动力省际转移。 相似文献