福州地区土地景观格局动态变化及多样性分析   总被引：1，自引：0，他引：1  

刘清丽  陈友飞  孙然好 《热带地理》2005,25(3):211-214

利用1985年与2000年数据计算了福州地区景观格局变化的若干指标。结果表明,整体上福州地区土地景观多样性指数、破碎度指数有所上升,优势度指数下降,景观格局趋于稳定,系统趋于优化。同时,借助ArcGIS8．3软件平台对福州地区2000年土地利用数据进行处理,计算景观多样性指数,然后进行聚类分析,在区域内部划分出多样性程度不同的3类子区：闽侯县景观多样性程度最高,长乐、福清、福州、罗源、闽清、永泰次之,连江、平潭景观多样性程度最低。  相似文献   

Spatial analysis of groundwater quality for drinking purpose in Sirjan Plain,Iran by fuzzy logic in GIS          下载免费PDF全文

Negar Fathi  Mohammad Bagher Rahnama  Mohammad Zounemat Kermani 《地下水科学与工程》2020,8(1):67-78

At present,due to shortage of water resources,especially in arid and semiarid areas of the world such as Iran,exploitation of groundwater resources with suitable quality for drinking is of high importance.In this regard,contamination of groundwater resources to heavy metals,especially arsenic,is one of the most important hazards that threaten human health.The present study aims to develop an approach for presenting the groundwater quality of Sirjan city in Kerman Province,based on modern tools of spatial zoning in the GIS environment and a fuzzy approach of evaluating drinking water in accordance with the standards of world health organization(WHO).For this purpose,qualitative data related to 22 exploitation wells recorded during 2002 to 2017 were used.In addition,fuzzy aggregate maps were prepared in two scenarios by neglecting and considering arsenic presence in groundwater resources.The results showed a decrease in groundwater quality over time.More specifically,neglecting the presence of arsenic,in 2002,all drinking wells in the area were located in an excellent zone,while in 2017 a number of operation wells were located in the good and medium zone.Also,the final map,considering the presence of arsenic as a limiting factor of drinking water,indicated that parts of the southern regions of the plain would be the best place to dig wells for drinking water.Therefore,the use of new methods can contribute significantly to the usage of groundwater aquifers and provide a good view of the aquifer water quality.  相似文献   

Layered berthing method and experiment of unmanned surface vehicle based on multiple constraints analysis     

《Applied Ocean Research》2019

Considering the dynamic changes of unmanned surface vehicle (USV) in berthing tasks, the planning and control modes are divided into two phases: the remote phase and the terminal phase. According to the main influencing factors of the two phases, an improved artificial potential field method is proposed to complete autonomous berthing trajectory planning based on the analysis of environment constraint, berth point constraint and USV’s dynamics constraint. Combining with the dynamic characteristics and control objectives at different phases of berthing and analyzing the fuzzy rule regulation strategy of USV’s heading and speed control, an improved adaptive fuzzy PID control method is proposed to solve the control problem of USV, which is influenced by weak maneuver, large disturbance, limited water area and strong shore effect. Finally, the comparative test of berthing simulation verifies the superiority of the proposed control method. The autonomous berthing field experiment is completed based on the "Dolphin-I" small USV. It verifies the validity and feasibility of the proposed autonomous berthing method.  相似文献   

3-D reconstruction of coastal bathymetry from AIRSAR/POLSAR data   总被引：1，自引：0，他引：1  

Maged MARGHANY  Mazlan HASHIM  Arthur P.CRACKNELL 《中国海洋湖沼学报》2009,27(1):117-123

This paper introduces a new method for reconstructing three-dimensional (3D) coastal bathymetry changes from Airborne AIRSAR/POLSAR synthetic aperture data. The new method is based on integration between fuzzy B-spline and Volterra algorithm. Volterra algorithm is used to simulate the ocean surface current from AIRSAR/POLSAR data. Then, the ocean surface current information used as input for continuity equation to estimate the water depths from AIRSAR/POLSAR data. This study shows that 3D ocean bathymetry can be reconstructed from AIRSAR/POLSAR data with root mean square error of ±0.03 m.  相似文献   

模糊聚类分析在粤西芒果炭疽病流行区域划分上的应用     

冯荣扬 《广东海洋大学学报》2000,20(1)

根据粤西 6个市 (县 )种植的 3个主要芒果品种芒果炭疽病 (Gloeosporium mangiferae P.Henn.et al)病情指数 ,应用模糊聚类分析方法 ,划选出粤西种植芒果的适宜区域。并指出干旱地区不利于该病发生  相似文献   

Fuzzy synthetic evaluation of water quality of Naoli River using parameter correlation analysis     

Jianhua Wang  Xianguo Lu  Jinghan Tian  Ming Jiang 《中国地理科学(英文版)》2008,18(4):361-368

In order to improve the effectiveness of Fuzzy Synthetic Evaluation （FSE） models, a Parameter Correlation Analysis （PCA） was introduced into the FSE and a case study was carried out in the Naoli River in the Sanjiang Plain, Northeast China. The basic principle of the PCA is that the pairs of parameters which are highly correlated and linear with each other would contribute the same information to an assessment and one of them should be eliminated. The method of the PCA is that a correlation relationship among candidate parameters is examined before the FSE. If there is an apparent nonlinear or curvilinear relationship between two parameters, then both will be retained; if the correlation is significant （p〈0.01）, and the scatter plot suggests a linear relationship, then one of them will be deleted. However, which one will be deleted？ For solving this problem, a sensitivity test was conducted and the higher sensitivity parameters remained. The results indicate that the original data should be preprocessed through the PCA for redundancy and variability. The study shows that introducing the PCA into the FSE can simplify the FSE calculation process greatly, while the results have not been changed much.  相似文献   

Significant wave height forecasting using wavelet fuzzy logic approach   总被引：2，自引：0，他引：2  

Mehmet Özger 《Ocean Engineering》2010,37(16):1443-1451

Wave heights and periods are the significant inputs for coastal and ocean engineering applications. These applications may require to obtain information about the sea conditions in advance. This study aims to propose a forecasting scheme that enables to make forecasts up to 48 h lead time. The combination of wavelet and fuzzy logic approaches was employed as a forecasting methodology. Wavelet technique was used to separate time series into its spectral bands. Subsequently, these spectral bands were estimated individually by fuzzy logic approach. This combination of techniques is called wavelet fuzzy logic (WFL) approach. In addition to WFL method, fuzzy logic (FL), artificial neural networks (ANN), and autoregressive moving average (ARMA) methods were employed to the same data set for comparison purposes. It is seen that WFL outperforms those methods in all cases. The superiority of the WFL in model performances becomes very clear especially in higher lead times such as 48 h. Significant wave height and average wave period series obtained from buoys located off west coast of US were used to train and test the proposed models.  相似文献   

基于层次分析法和模糊评判法的西藏国家气象公园评价研究     

四郎措姆  熊亚军  洛桑卓嘎  洛松桑邓  边巴江村  旦增克珠 《气象与环境学报》2022,38(3):162-168

本研究依据中国气象局发布的国家气象公园评价指标体系充分考虑高原文化特色, 采用层次分析法(AHP)构建了适用于高原的气象公园评价体系。结果表明: 在准则层中, 天气景观＞人文气象景观＞环境保护＞科学性, 权重值分别为45.94%、32.48%、14.91%、6.67%, 在因子层中, 稀有度＞人文价值＞气候特征＞科学性, 权重值依次为25.80%、17.20%、9.70%、5.00%。在此基础上, 对纳木措、羊卓雍措、玛旁雍措进行模糊综合评价分析表明, 纳木措各因素综合评价为优, 羊卓雍措各因素综合评价为良, 玛旁雍措各因素综合评价为良。因此, 在经济条件有限的基础上, 认为纳木措建设成为国家气象公园是最优选择。本研究结果可为环境规划等相关部门和行业提供决策参考。  相似文献