多时域航空影象与GIS应用——武昌县土地资源变迁分析

通过对武昌县多时域航空影象的判读和 GIS 的快速处理,结合其它辅助数据,对不同时期武昌县土地资源变化情况作了定性、定量和定位的分析研究.研究结果表明,多时域航空影象能较快地获取有关土地资源演变的静态和动态信息。GIS 是进行土地变迁复合研究及县域规划管理的一种有效技术手段。     

多目标排队决策法——在大连地区土地利用结构调整中的应用

本文采用多目标排队决策法对专家的咨询意见进行了定量处理,从各用地部门的经济、生态和社会效益出发,确定了他们的优先级,并结合土地利用现状对今后的土地利用结构作出了合理的调整规划设想。     

HYDROLOGIC EFFECTS OF TWO METHODS OF HARVESTING MATURE SOUTHERN PINE1

ABSTRACT: Hydrologic responses to logging with skidders and responses to logging with a cable yarder are compared. After a 23-year calibration with an undisturbed control catchment, mixed stands of shortleaf pine (Pinus echinata Mill.) and hardwoods were clearfelled on two small catchments in the hilly Coastal Plain of north Mississippi and observed for five years. Runoff increased 370 mm (skidded) and 116 mm (yarded) during the first year with 1876 mm of rainfall, and 234 mm (skidded) and 228 mm (yarded) during the second year when 1388 mm of precipitation equaled the calibration mean. Sediment concentrations for the yarded catchment during the first two years averaged 641 and 1,629 mg L^?1, respectively, and yields were 6,502 and 12,086 kg ha^?1. Compared to calibration means of 74 mg L^?1 and 142 kg ha^?1, these extreme values can be attributed largely to transport of sediment stored in the channel and to erosion of subsurface flow paths, which was exacerbated by high flow volumes. During the first year, the concentration (231 mg L^?1) and yield (2,827 kg ha^?1) for the control catchment also exceeded the calibration means. However, concentrations (134 mg L^?1) and yields (1,806 kg ha^?1) for the skidded catchment were about 40 percent lower than for the control catchment during the first year, and were higher than those for the control only during the second year. Because deep percolation was limited and because rainfall was unusually high, increases in flows and sediment concentrations and yields probably approximate maximum responses to clearcut harvesting in the uplands of the southern Coastal Plain.     

The containment of toxic wastes: I. Long term metal movement in soils over a covered metalliferous waste heap at Parc lead-zinc mine, North Wales

In order to stabilise and contain a toxic metalliferous waste heap at Parc Mine, North Wales, it was covered with 30-40 cm layer of quarry waste in 1977-1978, and sown with a grass/clover seed mixture. This study has examined subsequent metal movement in the cover material and its effect on vegetation. The results, especially when compared with previous observations, give no evidence of upward migration of metals by capillarity in the cover material. Sideways movement of leachate, however, appears to be carrying the metals into the cover material on the sloping sides, giving rise to increasing concentrations of heavy metals in the vegetation and dieback in some places. Root growth on the flat top of the heap is greater than on the slope, but the roots have not penetrated the waste and the contents of Pb, Zn and Cd in surface vegetation remain low. Surface covering of toxic waste with coarse materials restricting capillary rise is therefore a valid reclamation technique so long as lateral movement of toxic leachate can be controlled.     

应用马尔可夫链分析预测福建以林为主的土地利用趋势

土地利用状况的研究是国土整治及林业发展规划的重要研究内容,本文根据森林资源连续清查的资料,应用马尔可夫链理论,建立预测模型,分析、预测土壤利用的动态状况,提出宏观控制的对策,为土地利用规划,林业生产决策提供科学的方法与依据。     

黄河三角洲土地资源开发对策的探讨

黄河三角洲是我国三大三角洲之一,面积约5930km²,它拥有丰富的土地资源,但从大农业角度来看,其土地质量较差,生态环境脆弱。当前,其土地资源的合理开发利用具有十分重要的现实意义。 首先,本文将区内土地类型划为 5类和19个亚类。其次,应用二级模糊综合评判,将其土地质量分为8等13级。其中宜农地占28.83％,宜牧地占34.44％,渔业用地占27.98％。最后,应用层次分析法（AHP）对土地资源合理开发利用的对策作了分析探讨。认为:对于黄河三角洲土地资源的开发,必须强调遵循经济效益服从社会效益和生态效益的总原则。在此前提下,提出了以保证工矿业用地为首的6项开发策略,以及以引黄放淤改良盐碱地为首的20项开发措施。     

浙江省嘉兴市土地资源生产能力及人口承载量的初步研究

本文在分析嘉兴市农业自然资源特点和合理用地结构的基础上,预测不同时期一定生产条件下,单位面积土地上粮食、油料、肉类的生产潜力和在不同生活水平下所能承载的人口数量。     

循环经济催生绿色GDP

发展循环经济是实施可持续发展的必由之路。循环经济的发展将催生新型国民核算体系———绿色GDP。文中给出绿色GDP定义和计算方法,以宁波为例,估算了绿色GDP,指出宁波发展循环经济和建立绿色GDP必要性。     

土地适宜性评价中“主宜性”划分问题之探讨

在土地适宜性评价中,划分双宜或多宜性土地的主宜性是很有必要的。本文探讨了土地主宜性划分的原则、指标和方法,提出了分析土地主宜性的综合定量指标——“土地经济-社会适宜性指数”的概念,并以点苍山花甸坝为例,分析了这块土地的主宜性——适宜于耕作利用,利用方式是种植一年一熟喜凉作物。     

海岛土地与土地系统生态设计刍议

本文依据生态学理论对海岛土地及土地系统生态功能进行了重新的认识,并探讨了海岛土地系统生态设计的依据、原则和模式.设计中强调以土地系统生态保护性功能为主体,以海岛土地系统高层次调合发展作为海岛建设的最终目标.