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题名	县级尺度土地利用格局与优化模式研究─以固原市原州区为例
学位类别	博士
答辩日期	2009
授予单位	中国科学院研究生院
授予地点	陕西
导师	李壁成
学位专业	土壤学
中文摘要	原州区位于黄土高原西部的宁南山区，为固原市的一个县级行政单位，长期以来被国家确定为生态环境重点建设地区。早在20世纪80年代初，中科院等相关单位就在该地区开展以小流域为基本地域空间单元的水土保持综合治理科研实践。2000年以后，该区又正式实施了国家退耕政策，土地利用变化明显。同时基于两点考虑：首先，县级尺度作为基层行政单位，是我国土地持续利用、管理和规划的最佳尺度。其次，在黄土高原地区，小流域综合治理的关键和核心就在于土地利用格局优化调整。因此，本文以原州区为例，基于3S技术，结合野外工作以及社会经济统计数据，从系统角度，在县级和小流域两个关键尺度层次上，以县为主，以小流域为补充，优势互补，动、静结合，层层深入，开展县级尺度土地利用格局与优化模式研究。主要研究结论如下:1土地利用条件从系统角度，综合分析原州区土地利用的地理区位、自然和社会经济条件的优、劣势。2土地利用现状格局从动态与静态联系来看，土地利用现状格局既是土地利用格局历史演变的结果，又是土地利用格局功能分区的现实基础。研究表明，2006年原州区土地利用现状格局基本特征可以概括为：以草地和耕地为土地景观基质，以耕地、草地、林地为主要景观类型，并表现出一定的地域分异性规律，这就为合理利用土地资源奠定了空间格局基础。3 土地利用格局变化过程对原州区1990-2000年退耕前期和2000-2006年退耕期间土地利用格局变化进行对比分析。研究表明，1990-2000年耕地增加较多，增加面积比例为2.45%，草地减少明显，减少面积比例为3.26%，林地有少量增加，景观多样性增加，优势度减少、破碎度增加，土地利用格局变化极具不合理性；2000-2006年耕地减少较多，减少面积比例为4.67%，林地增加较多，增加面积比例为4.35%，草地数量变化较小，草地质量存在一定的退化现象，在退耕影响下，土地利用格局总体趋于稳定和合理。并从地学图谱角度，进一步探讨土地利用格局变化分析方法，以弥补定量分析方法的不足。4土地利用格局变化生态环境效应从耕、林、草地适宜性、NDVI、土壤侵蚀三方面对比分析土地利用格局变化生态环境效应。研究表明，在1990-2000年，原州区草地转为耕地的主要过程中，草地和耕地适宜性等级降低，植被覆盖状况变差。轻度土壤侵蚀减少面积比例9.82%,而强度侵蚀和极强度侵蚀分别增加面积比例10.63%和 5.18%，土壤侵蚀强度总体趋于增大。在2000-2006年，受退耕影响，耕地转为林地的主要过程中，耕地、林地、草地适宜性等级上升，但各地类最适宜性等级面积比例增加并不明显。植被覆盖状况有所好转，但处于不良植被状况的第4等级面积比例在70%以上。强度土壤侵蚀减少和中度土壤侵蚀增加均较明显，面积比例变化分别为 11.06%和13.49%，土壤侵蚀总体状况好转。5耕地变化驱动机制利用1990-2006年社会经济统计数据初步探讨了原州区耕地变化驱动机制。研究表明，在假定社会经济政策没有大的改变前提条件下，耕地变化驱动机制可归纳为经济发展、人口增长以及农业现代化与粮食生产水平。就社会经济政策而言，其驱动耕地变化阶段性特征明显，而且更具主导性。6县域土地景观功能分区以原州区土地利用现状格局为基础，以景观生态学原理为指导，进行土地景观功能分区，并结合前面各章分析，进而为原州区土地合理利用和总体景观格局优化调整指明方向。7小流域土地景观功能分区与优化模式最后，以原州区河川乡上黄村小流域为例，基于2006年土地利用现状格局，通过小流域土地景观功能分区和土地综合评价，提出相应土地景观优化模式。
英文摘要	Yuanzhou District, located in the south of Ningxian Hui Autonomous Region of the western Loess Plateau, is a county administrative unit of Guyuan City.It has been identified as the national key construction areas of the ecological environment with a long time. In the early of 1980s,Chinese Academy of Sciences and other related units studied on the comprehensive management of water and soil conservation taking the small watershed as a basic territorial unit. After 2000 year, subsidy policy of returning land for cropland to forest and grass land was practised, which made land use change greatly.Besides,the two following reasons are considered:one hand, the county, as a basic administrative unit in China, is considered as the best scale of the management and planning of land use;on the other hand,the key factor of comprehensive management on small watershed scale is the optimal adjustment of land use pattern on the Loess Plateau.Therefore,taking Yuanzhou District as an example,this work aims to explore land use pattern and its optimization at county scale to build integrated ecological model as reference to future policy designs and practises based upon 3S technique and field works as well as socio-economic data. The main content:1 The analysis of land use conditionsFrom the point of view of system, we took a comprehensive analysis on the geographical position,natural and socio-economic advantages and disadvantages of land use in Yunazhou District.2 Current land use patternIn 2006,grassland and cropland are predominant.The main land use types include cropland, grassland and forest land. Also we can find the areal differentiation rule in the land distribution, which lays the foundation for appropriate land use in spatial pattern. 3 Change of land use patternComparative analysis on Change of land use pattern was conducted between the time period of 1990 to 2000 and the time period of 2000 to 2006 in the Yuanzhou District. Results indicate that cropland has increased by 2.45% while the grassland has appreciably decreased by 3.26% in the study period of 1990 to 2000. Forestland increased a little. Landscape heterogeneity index and degree of separation increased while dominance of landscape decreased, which reflects the inappropriate land use changes.Cropland has decreased by 4.67% while the forest land area has appreciably increased by 4.35% in the study period of 2000 to 2006. The land use pattern tends to be reasonable and stable. To make up the shortcomings of the quantitive method, we further applied Geo-informatic Tupu in studying the land use pattern change based on three time period TM image. 4 Eco-environmental effect of land use pattern changeEco-environmental effect of land use pattern change was quantified and analyzed in the three aspects such as area and percentage of the suitable cropland, forest land and grassland, Normalized Difference Vegetation Index (NDVI ) and soil erosion. Results indicate that the suitable grade of the grassland and cropland decreased in the conversion of grassland to cropland from 1990 to 2000. And vegetation cover condition became poor in this period. The lightly eroded area decreased by 9.82%, while the severe eroded area increased by 10.63% followed by very severe erosion by 5.18%.Overall soil erosion intensity increased from 1990 to 2000.Under the policy of returning cropland to grassland and forest land, the suitable grade of cropland,forest land and grassland increased in the conversion of cropland to forest land from 2000 to 2006. But the area and percentage of the most suitable in each land type only increased a little.Although the NDVI partially tended to ascend during the period of 2000 to 2006, the percentage of poor and bad vegetation condition still accounted for more than 70%. The severe eroded area decreased by 11.06% while moderate eroded area increased with 13.49%, which indicate that the whole soil erosion became better. 5 Driving force of cropland changeSurposing the socio-economic policy has not changed greatly, by using the socio-economic statistical data from 1990-2006, the results showed that cropland change was mainly driven by economy development, population growth,and agriculture and grain production level. However, the socio-economic policy is in the lead position in the study area. 6 Landscape functional zoning at county scaleGuided by the landscape ecology theory,landscape function zoning at county scale was conducted on the basis of current land use pattern to provide directions for region rational land use7 Landscape functional zoning and its optimization model at small watershed scaleTaking the Shanghuang small watershed as an example,on the basis of land use pattern in 2006, we put forward corresponding landscape optimization model through landscape functional zoning and assessment of land resource.
公开日期	2011-07-01
内容类型	学位论文
源URL	[http://ir.iswc.ac.cn/handle/361005/4108]
专题	水土保持研究所_水保所知识产出(1956-2013)
推荐引用方式 GB/T 7714	. 县级尺度土地利用格局与优化模式研究─以固原市原州区为例[D]. 陕西. 中国科学院研究生院. 2009.

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