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161.
Preliminary Evidence of a Barrier Effect of a Railroad on the Migration of Mongolian Gazelles 总被引:2,自引:0,他引:2
TAKEHIKO Y. ITO†† NAOKO MIURA† BADAMJAV LHAGVASUREN‡ DULAMTSEREN ENKHBILEG‡ SEIKI TAKATSUKI§ ATSUSHI TSUNEKAWA ZHAOWEN JIANG 《Conservation biology》2005,19(3):945-948
Abstract: Much remains to be learned about how anthropogenic structures affect migration in large mammals. We examined the potential influence of the international railroad in Mongolia on migration in Mongolian gazelles (Procapra gutturosa). We examined gazelle movements and the normalized difference vegetation index (NDVI) on both sides of the railroad. The tracked gazelles never crossed the railroad, despite movements that mainly followed the railroad in winter and higher NDVI values on the opposite side. It is likely that the railroad had a barrier effect on gazelle migration because it split the gazelles' habitat. Our results, although based on an extremely small sample, have utility in indicating approaches that might be useful for examining migration in ungulates. 相似文献
162.
Locating and forecasting water needs can assist the location of water in dry regions, and improve the management of reservoirs and the canal network. Satellite, ground data, and agrometeorological data were combined to forecast the volume of irrigation water needed during 1993 and 1994 in an irrigation district of 327 km2 located in the Ebro basin, Spain. The main crops were rice, alfalfa plus forage, winter cereals (barley and wheat), sunflower and maize. Their extent was estimated every year by frame area sampling and a regression estimator with satellite data. Initial crop area statistics were obtained by expansion of the sample areas to the entire study area and then a regression estimator with the multitemporal supervised classification of two Landsat-5 TM images was applied. This procedure improved the precision of the estimates by expansion. Net water requiremets (m3 ha-1) of the above mentioned crops were computed from reference evapotranspiration estimates, crop coefficients and effective precipitation. These computations were performed for an average year, i.e. by using long-term averaged meteorological data. Crop hectarage and net crop water requirements were multiplied to obtain, for the entire study area, the volume (hm3 106 m3) of the net crop water requirements. After subtraction of water taken directly from the rivers and non-productive sunflower, the irrigation water volumes were estimated. The comparison of these forecasts with the volumes of water invoiced by the Ebro Basin Water Authority confirmed the feasibility of forecasting the volume of water applied to an individual irrigation district. This is an objective and practical method for estimating the irrigation water volume applied in an irrigated area. 相似文献
163.
T. K. Vlassova 《Mitigation and Adaptation Strategies for Global Change》2006,11(4):897-909
Three methods of gathering local and traditional knowledge of Indigenous Peoples were used to assess environmental changes
and human impacts in Russian boreal forest communities: structured interviews, followed by an unstructured interview, and
an education/training workshop. The most important environment changes reported by Indigenous Peoples included the disappearance
of animals and plants, climate changes, a decrease in forest and shrub area, and human impacts such as poaching, forests fires,
industrial logging, clearing of forests for firewood, and water pollution by industrial wastes and discharges. We propose
establishment of the Boreal Residents' Network for Socio-environment Assessments and Education for Sustainable Development
to acquire local and traditional knowledge as a supplement to scientific monitoring. The proposed approach would involve permanent
inhabitants living in a broad range of boreal forests to gather local and traditional knowledge and assessments. This could
lead to a meta-database to share with international networks. 相似文献
164.
为深入了解四川盆地PM2.5与PM10污染情况,通过机器学习的方法,基于卫星遥感气溶胶产品(MAIAC)与国家环境空气质量监测网数据以及气象、地理、社会经济变量等,构建2个随机森林机器学习模型(R2均为0.86),反演四川盆地2013~2017年间1km网格逐日PM2.5与PM10浓度时空分布,并分析两者的时空关联性.结果表明:2013~2017年四川盆地地面PM2.5与PM10平均浓度分别为47.8,75.2μg/m3.PM2.5与PM10浓度空间上均整体呈现"倒月牙"状分布,西部与南部区域浓度值较高.5a间,区域颗粒物浓度逐年递减,总降幅均达到27%,季节上则均具有"冬高夏低"的特点;PM2.5与PM10浓度空间相关性显著(相关系数0.96),呈现"内强外弱"的格局,春夏季相关系数(0.91、0.90)低于秋冬季(0.96、0.96).盆地西南部PM2.5与PM10比值较高,比值高低的季节性排序为冬季 > 秋季 > 夏季 > 春季. 相似文献
165.
本文以北京市新规划的11个新城中的门城卫星城(门头沟)为例,从灾害应急模式的系统构建、前期准备、应急互动模型、系统神经网络建设、体制建设等方面探索卫星城市应急救灾系统模式的建设。 相似文献
166.
作者借助于卫星CCT数据进行了人-机对话式信息比值处理,获取了河口区高浓度的悬浮泥沙涡旋水体信息,并与现场考察资料相对证,发现其有规律的出现与输移。为此,结合毛蚶的生活习性,确认黄河入海泥沙扩散对黄河口及其邻近水域毛蚶的资源分布有直接的影响。预测了未来20年内研究区毛蚶场的扩大趋势及其范围。 相似文献
167.
168.
本文介绍了可拓学理论与可拓数据挖掘技术的基本概念与基本方法,并将可拓数据挖掘技术用于“5·12”汶川地震空间电离层电场文本数据文件的处理.利用自行开发的数据挖掘软件进行数据分类,在震前10天数据中,得到了2个关联度异常文件,并计算了挖掘知识的支持度与可信度. 相似文献
169.
170.
介绍了eCognition软件在生态遥感监测工作中的应用。以高分辨率QuickBird,Worldview-1,IKONOS卫星数据为主要信息源,辅以SPOT,TM,ETM和中巴地球资源卫星CBERS等卫星数据,利用不同波段的组合图像,通过目视解译、人机交互解译、计算机自动识别与信息提取等方法,解译本溪典型区域不同时期矿山开采、林地、农田、城镇、道路等生态环境要素变化。 相似文献