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991.
城乡土地市场一体化对土地利用/覆被变化的影响研究综述 总被引:6,自引:1,他引:5
为了破除城、乡土地市场分割现状,最终实现“山水林田湖”共同发展的目标,需要推进城乡土地市场一体化发展。分别从城市土地市场、农村集体性建设用地非正式市场和农村农用地流转市场3个方面对土地利用/覆被变化的影响机理研究进行梳理。结果认为:第一,城乡土地市场割裂的状况仍然存在,并且对土地利用/覆被变化产生较大影响;第二,城市国有建设用地市场的发育程度不同,直接影响土地供求关系和土地利用结构,甚至对土地利用配置效率产生影响;第三,农村集体性建设用地市场已现雏形,但由于产权的模糊性而缺乏法律上的监管和保障,加快了土地利用类型的过度非农化转化。另外,农用地流转市场的出现也改变了土地利用的功能和类型;最后,城乡土地市场分割现象会对土地利用系统的可持续性和生态环境产生一定影响。在以上研究结果基础上认为未来研究需要进一步加强对城乡土地市场一体化的分析,且揭示城乡土地市场一体化对区域土地利用/覆被变化影响机理(格局、过程、效应)。 相似文献
992.
基于GIS建模的海水环境质量可变模糊识别评价 总被引:1,自引:1,他引:0
基于对立统一与质量互变定理的可变模糊评价方法引入海水水质综合评价,构建基于对立统一与质量互变定理的海洋环境质量可变模糊评价模型,首先分析可变模糊评价方法的原理和方法,然后结合GIS栅格数据在表达空间信息方面具有的独特优势,以栅格数据为基础,利用地理信息系统空间叠置分析、地理信息系统空间建模等计算,建立基于多源栅格数据的海水环境可变模糊综合评价模型,得到莱州湾2004~2010年海水环境空间分布图。实践证明,该模型应用于海水水质综合评价是完全可行的,为海洋环境领域的多目标综合评价与决策提供了新的思路与方法。 相似文献
993.
针对利用全球导航卫星反射信号(GNSS-R)进行空中目标探测时,信号微弱无法可靠接收的问题,该文提出了一种计算信号处理增益的方法。通过合理设置信号处理算法参数,保证了对微弱信号的后续处理。首先对GNSS-R信号接收链路进行了分析,计算得到了当目标的雷达散射截面(RCS)变化时对应的目标回波功率范围;然后对空中目标上升、平飞和下降三种飞行状态双基地雷达系统几何模型进行了研究,给出了3种飞行状态下对应的有效探测时间,为接收机后续相干/非相干累加算法的处理时间提供阈值限制;最后在阈值范围内,选定合适相关时间,分析了经过相干/非相干累加处理后的反射信号输出信噪比范围。结果表明:在有效探测时间的限制下,相关处理时间取0.6s时,处理后的信噪比在10dB左右,满足一般码跟踪环所需的门限要求,可以保证接收机后续数据处理的顺利进行。 相似文献
994.
Kuntal Ganguly Rajiv Kumar K. Mruthyunjaya Reddy P. Jagadeeswara Rao Manoj Raj Saxena G. Ravi Shankar 《国际地球制图》2017,32(7):777-796
This study investigated land use/land cover change (LULCC) dynamics using temporal satellite images and spatial statistical cluster analysis approaches in order to identify potential LULCC hot spots in the Pune region. LULCC hot spot classes defined as new, progressive and non-progressive were derived from Gi* scores. Results indicate that progressive hot spots have experienced high growth in terms of urban built-up areas (20.67% in 1972–1992 and 19.44% in 1992–2012), industrial areas (0.73% in 1972–1992 and 3.46% in 1992–2012) and fallow lands (4.35% in 1972–1992 and ?6.38% in 1992–2012). It was also noticed that about 28.26% of areas near the city were identified as new hot spots after 1992. Hence, non-significant change areas were identified as non-progressive after 1992. The study demonstrated that LULCC hot spot mapping through the integrated spatial statistical approach was an effective approach for analysing the direction, rate, spatial pattern and spatial relationship of LULCC. 相似文献
995.
The understanding influence of multiple factors variations on land surface temperature (LST) remains elusive. LST was retrieved by the atmospheric correction algorithms. Based on the correlation coefficients, stepwise regression analysis was developed to examine how multiple factors variability led to LST variations. The differences in LST between impact factors vary depending on time in a day. The elevation and land use types significantly affect the LST in sunny slope or shadow areas has a significantly quadratic curve correlation or a negative linear correlation with it, the influence of slope and aspect is not very significant. LST for forestland, grassland and bare land in the sunny slope and shadow area was the cubic polynomial related to its elevation. Normalized difference vegetation index (NDVI) and normalized difference moisture index (NDMI) effectively express LST in mountainous. LST and NDMI or NDVI have a significantly negative correlation, NDMI is more effective and more applicable for the expression of LST. 相似文献
996.
Mohamed Mostafa Mohamed 《国际地球制图》2017,32(10):1120-1138
This study has modified an approach based on fuzzy logic in a GIS and multi-criteria decision making (MCDM) for groundwater potentiality mapping in Al Fo’ah area, the United Arab Emirates. The proposed approach uses nine groundwater conditioning factors recognized by local hydrology experts. Each factor and class of each factor was given a weight and score based on its level of contributions to groundwater accumulation using analytical hierarchy process and MCDM. Our results revealed that the areas of very high harbouring groundwater are located at the foot of the Oman mountains and occupies an area of about 8.46 km2 (4%) of the study area. We validated our results using the Relative Operating Characteristics. The area under the curve showed a ratio of 0.8957 (of 89.57%). The modified approach is timely and economically effective and can be applied in semi-arid regions to help hydrologists. 相似文献
997.
Remotely sensed data show details of the geomorphic features and landscape evolution west of the Nile. The detected features include remnants of paleochannels, flutes and rock-mass movements. Fused radar/optical data, altitudinal profiles and 3D perspective view provided evidences of massive landslides that fully blocked the earlier Nile channel near to the Western Desert plateau. This channel was ~30 km west of the present Nile at ~100 m above the present level of the Nile. Subsequently, the fluvial activities shifted about ~10 km eastward, leaving behind several remnants of paleochannels, fluvial deposits, ancient landscape and Nilotic fauna. The automatic extraction of stream networks clearly depicts the developments of paleochannels. Our results revealed that fluvial activity switched from the Gallaba plain to the present Nile course through a series of tectonic and climatic changes. Furthermore, integration of radar and optical images provided an explanation for causes of the undulated forms ‘flutes’. 相似文献
998.
This study aims to illustrate how remotely sensed oceanic variables and fishing operations data can be used to predict suitable habitat of fishery resources in Geographic Information System. We used sea surface height anomaly (SSHa), sea surface temperature (SST), chlorophyll concentration (CC), photosynthetically active radiation (PAR) and fishing depth as predictor variables. Fishery data of Indian squid (Loligo spp.) and catfish (Tachysurus spp.) for study period (1998–2004) were segregated randomly to create training and validation. Catch was normalized into Catch per unit Effort (kg h?1). Generalized additive modelling was performed on training data and then tested on validation data. Suitable ranges of SST, CC, SSHa and PAR for different species distributions were derived and integrated to predict their spatial distributions. Results indicated good match between predicted and actual catch. Monthly probability maps of predicted habitat areas coincide with high catch of the particular month for the study period. 相似文献
999.
Delineation of groundwater potential zones using remote sensing and GIS-based data-driven models 总被引:5,自引:0,他引:5
The rapid increase in human population has increased the groundwater resources demand for drinking, agricultural and industrial purposes. The main purpose of this study is to produce groundwater potential map (GPM) using weights-of-evidence (WOE) and evidential belief function (EBF) models based on geographic information system in the Azna Plain, Lorestan Province, Iran. A total number of 370 groundwater wells with discharge more than 10 m3s?1were considered and out of them, 256 (70%) were randomly selected for training purpose, while the remaining114 (30%) were used for validating the model. In next step, the effective factors on the groundwater potential such as altitude, slope aspect, slope angle, curvature, distance from rivers, drainage density, topographic wetness index, fault distance, fault density, lithology and land use were derived from the spatial geodatabases. Subsequently, the GPM was produced using WOE and EBF models. Finally, the validation of the GPMs was carried out using areas under the ROC curve (AUC). Results showed that the GPM prepared using WOE model has the success rate of 73.62%. Similarly, the AUC plot showed 76.21% prediction accuracy for the EBF model which means both the models performed fairly good predication accuracy. The GPMs are useful sources for planners and engineers in water resource management, land use planning and hazard mitigation purpose. 相似文献
1000.
针对非公网环境下的应急GIS平台指挥决策信息传递受限问题,提出了一种不依赖于互联网的消息传递方法。采用ADB+Web Service技术实现内网环境下指挥决策者与一线救援人员间的消息传递,有效地解决了非公网环境下的指挥决策信息传递问题。相较于传统方式,保证了应急平台的灵活性与独立性,降低了平台维护成本,同时由于减少了第三方运营商代理接口的运作环节,从整体上提高了决策指挥者与救援单位间的通信效率,保障了救援工作的及时性与高效性。研究结果对解决应急管理工作中存在的实际问题具有重要的现实意义。 相似文献