北京市城乡交错带土地利用调控对策

城乡交错带是城市扩展和农村发展的前沿,也是统筹城乡关系的重点地区.选择北京市城乡交错带为研究区域,以调查统计、变更调查和实地调查资料为基础,采用统计分析和综合的方法,认为北京市城乡交错带20世纪80年代以来土地利用变化具有以城市发展为主、国家建设占用和点轴面的外延扩展方式的特点,从而导致交错带的生态屏障功能日益受到蚕食,合理的用地功能布局和用地效益受到影响.建议采取加强城乡一体化编制土地利用总体规划、调整结构和优化布局等调控措施.     

贫困地区旅游开发的土地利用--以安徽舒城县百丈岩旅游区为例

通过对贫困地区旅游开发过程中土地利用变化的分析,提出了土地利用变化的驱动力和评价原则,并根据旅游地生命周期理论,对未来土地利用的趋势和方向进行了分析,同时指出在开发旅游时应注意的问题.以安徽省舒城县百丈岩旅游区为例,在分析旅游开发可行性的基础上提出了本区的旅游发展战略,最后分析了旅游开发对土地利用结构变化的影响.     

淮北市采煤塌陷区的土地复垦

安徽省淮北市的淮北矿区是我国重要的十大煤炭生产基地之一,现有大小煤矿30余座.长期以来,因采煤而造成的塌陷土地累计达14667hm2,由此引起的地貌变形、房屋倒塌、生态环境恶化等灾害,严重影响了当地工农业生产和人们的生活.因此,加强对采煤塌陷区土地复垦的研究极为重要.在实地考察和有关数据分析的基础上,将淮北矿区因采煤塌陷而被破坏的土地分为四个区,总结出两大土地复垦模式,并对复垦后的土地利用进行适宜性评价.     

贵州省黔南州耕地保有量研究

根据2001～2010年土地开发复垦规划、建设项目用地、生态退耕等预测,分析了1997～2010年土地利用总体规划存在问题,提出了黔南州下一轮修编土地利用总体规划应达到的耕地保有量.     

我国城市周边规划建设用地利用探讨

随着我国城市面积的不断扩大，大量的郊区耕地成为或即将成为城市的建设用地，同时与城市建设相伴相随的建筑渣土的堆放已成为城市的一大问题，本文按照循环经济原则，提出利用规划期内即将建设的城市周边耕地资源建立供应城市建筑的制砖企业，同时利用取土坑填埋建筑渣土，建立城市物质的有效循环，实现城市建筑的循环经济。并对此物质循环方式做了生态经济的分析，也对此物质循环中存在的障碍提出了解决的方法。     

AGRICULTURE LAND‐USE EFFECTS ON NUTRIENT LOSSES IN WEST TIAOXI WATERSHED,CHINA1

ABSTRACT: Five types of land use/land covers in the West Tiaoxi watershed of China were studied for nutrient losses in artificial rainstorm runoff. A self‐designed rainfall simulator was used. In situ rainfall simulations were used to: (1) compare the concentrations of nitrogen and phosphorous in different land use/land covers and (2) evaluate the flux of nitrogen and phosphorous export from runoff and sediment in various types of land use/land covers. Three duplicated experiments were carried out under rain intensity of 2 mm/min, each lasting 32 minutes on a 3 m² plot. Characteristics of various species of nitrogen and phosphorous in runoff and sediment were investigated. The results showed that the concentrations of total nitrogen (TN) and total phosphorous (TP) were greatest in runoff from mulberry trees and smallest from pine forest. The TN and TP export was mainly from suspended particulate in runoff. TN and TP exports from the top 10 cm layer of five types of land use/land covers were estimated as high as 4.66 to 9.40 g/m² and 2.57 to 4.89 g/m², respectively, of which exports through sediment of runoff accounted for more than 90 percent and 97 percent. The rate of TN and TP exports ranged from 2.68 to approximately 14.48 and 0.45 to approximately 4.11 mg/m²/min in runoff; these rates were much lower than those of 100.01 to approximately 172.67 and 72.82 to approximately 135.96 mg/m²/min in the runoff sediment.     

西气东输工程靖边至宁陕界沙地生态环境保护对策

靖边至宁陕界的西气东输工程段属于毛乌素沙地南缘与陕北黄土高原北缘的过渡地带,项目区生态环境状况不稳定。一旦沙地植被遭到破坏,风吹蚀与沙搬运的荒漠化过程就会迅速发生,从而形成流沙使生态系统退化或破坏。在详细介绍了沙地特征和生态环境特点的基础上,提出了相应的荒漠化防治和治理措施,以将项目区的生态尽可能恢复成原状或将其不良影响降到最低。     

论土地资源的永续利用

土地资源是最重要的自然资源,而土地资源的永续利用是实现社会、经济和生态可持续发展的基础。本文分析了土地资源永续利用的重要性,讨论了土地永续利用的概念、内涵、判据、利用方向和模式等内容,并在此基础上提出了实现我国土地资源永续利用的生态经济措施。     

LARGE AREA HYDROLOGIC MODELING AND ASSESSMENT PART I: MODEL DEVELOPMENT1

ABSTRACT: A conceptual, continuous time model called SWAT (Soil and Water Assessment Tool) was developed to assist water resource managers in assessing the impact of management on water supplies and nonpoint source pollution in watersheds and large river basins. The model is currently being utilized in several large area projects by EPA, NOAA, NRCS and others to estimate the off-site impacts of climate and management on water use, non-point source loadings, and pesticide contamination. Model development, operation, limitations, and assumptions are discussed and components of the model are described. In Part II, a GIS input/output interface is presented along with model validation on three basins within the Upper Trinity basin in Texas.     

都市扩张与土地资源利用集约化：关于上海市城市发展模式的研究

随着我国经济的持续高速增长,人口向城市,尤其是大城市集中的趋势越来越明显,城市规模正在迅速膨胀。具体说来,主要体现在以下三个方面－城市占地面积的扩张;城市人口的膨胀;城市经济实力的增长。