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1.
农地利用变化假说与相关的环境效应命题 总被引：15，自引：0，他引：15
将用途转移和集约度升降这两种类型的土地利用变化整合在一个过程中,解释变化机制的理论,有古典经济学的地租理论,还有若干理论性假说。这些假说又常常与一些土地利用的环境效应命题联系在一起,扩充为解释人地关系的假说。综述了解释农地利用变化的四大假说（包括基于马尔萨斯人口论的土地面积持续扩张假说、博斯鲁普的需求诱发型集约化假说、吉尔茨的集约度弹性假说、土地利用粗放化假说）和农地利用环境效应的三大命题（包括农地面积扩张造成土地退化、优质土地的集约化间接促使生态脆弱地区环境改善、农地利用粗放化和弃耕促使环境和生态恢复）,以及围绕这些假说和命题的争论和实证研究,旨在为土地利用变化的情景构建、模型模拟及愿景设计提供学术依据。 相似文献
2.
The agricultural development of mountainous areas in China is undergoing the transformation from the traditional agricultural land use mode dominated by single and inefficient grain production to the new agricultural land use mode such as high-yield and efficient horticultural crops. The research on the impact of farmland fragmentation on the agricultural land intensity degree is the basis of agricultural modernization and land remediation in mountainous areas. Based on the UAV high-resolution remote sensing image data of two typical villages in Guizhou Province and the questionnaire survey data of farmers, using the road accessibility index of farmers' plot, the area index and the shape index to measure the degree of farmland fragmentation, we analyzed the impact of different degrees of farmland fragmentation on the traditional and new types of farmland use intensification. The research showed that the farmland fragmentation had a significant negative impact on the intensive degree of agricultural land, but the impact on the intensive degree of agricultural land in different ways of use was different. With the intensification of the degree of farmland fragmentation, the impact on the input and output of horticultural crops and other new-type agricultural land utilization was less than that of grain crops and other traditional agricultural land utilization. Adjusting agricultural structure and transformation of farmland utilization greatly alleviated the negative impact of farmland fragmentation on farmland intensity in mountainous areas. 相似文献
3.
农业土地利用对岩溶地下水影响研究综述 总被引：4，自引：4，他引：0
地球表层系统最突出的景观标志是土地利用/土地覆被。人类通过土地利用改变天然土地覆被从而对脆弱敏感的岩溶水文系统产生了重大的影响。文章着重从农业土地利用出发综述了当前农业土地利用对岩溶水影响的研究。农业土地利用对岩溶地下水的影响主要围绕着水质和水量两个核心从以下几个方面展开:天然植被的清除,农业灌溉和排水,农业集约化所带来的化肥杀虫剂等的使用以及污染物质在岩溶含水层中的运移和影响。在此基础上作者从研究内容,理论方法和建立模型等方面都提出了自己的想法和建议。 相似文献
4.
Investigation of land use changes on soil erosion process using geographical information system 总被引：1，自引：1，他引：0
K. Solaimani Ph.D. S. Modallaldoust S. Lotfi Ph.D. 《International Journal of Environmental Science and Technology》2009,6(3):415-424
Land use change quantified for the last 50 years within and near a fast growing agricultural land in Neka River Basin, using geographic information systems. Land cover and land use change was projected for the next decade using topography, geology, land use maps and remote sensing data of the study area. The study explored the relationships between agricultural land growth and landscape changes. The land use changes assessed among the different land cover classes. It is important to mention that conducting of the present study a very severe land cover changes taken place as the result of agricultural land development. These changes in land cover led to the forest degradation of the study area. Relationship between land-use changes and agricultural growth offered a more robust prediction of soil erosion in Neka watershed. This study aims to find the relationships between land use pattern, erosion and the sediment yield in the study area. The land use coefficient has applied in the model of erosion potential method to forecast the effect of the land type to reduce the erosion. The results of this study indicated that the total sediment yield of the study area has notably decreased to 89.24 % after an appropriate land use/cover alteration. The estimated special erosion for the southern Neka Basin is about 144465.1 m3/km2 where after management policy is predicted 15542.9 m3/km2/y. Therefore, the total difference for the study area has estimated about 128922.2 m3/km2/y. 相似文献
5.
基于遥感影像的决策树分类,结合土地利用图,将北京市农业地表覆盖划分为春玉米、冬小麦、果园、林木苗圃、牧草地、设施农业和畜禽饲养地。考虑海拔、坡度和土壤质地三个因子将北京市分成10个景观区,在景观分区和不同农业用地基础上划分出39类农业景观单元。利用基于遥感影像计算的归一化差异植被指数,结合实地调查验证,分类出北京市冬春季裸露农田。结合景观分类,分析了不同景观单元冬春季地表裸露情况。结果表明：2007—2008年冬春季裸露农田共8.05×104 hm2,主要分布在延庆盆地、密云水库北岸和城区边缘的近郊农业区;海拔和土地利用方式对裸露情况影响较大,其中山区春玉米和平原果园裸露情况绝对面积较大,分别占到总裸露农田面积的40%和17%,牧草地、林木苗圃与设施农业地裸露程度较高。基于不同景观单元裸露程度,结合绿肥种植、保护性耕作、生草覆盖等裸露农田治理方法,探讨了北京市农业产业和景观一体化建设策略。 相似文献
6.
Nutrient Loss from Various Land－Use Areas in Shixia Small Watershed of Miyun County,Beijing China 总被引：1，自引：0，他引：1
In the Shixia small watershed,twenty experimental plots and two monitoring channels,the residential area and livestock areas were used to monitor the flow,runoff and erosion,Nitrogen and phosphorous concentrations associated with various land uses were analyzed at the same time.The results are presented as follows:(1)TP ,TN and COD concentrations of runoff samples in the residential area and livestock arease are nearly 10 times those in other land-use areas.High nutrient loads are associated with village land use,which is due to unsuitable livestock rising.These areas should be treated as the critical areas of non-point source pollution.(2)Different land use influences intensity the loss nutrients,especially slope tillings in agricultural land.The amount of nutrient loss from agricultural land per unit is highest,that from forestry is intermediated and that frompastures is lowest,However,in consideration of the variability of land-use areas,agricultural land contributes the greatest to TP and forestry land to TN.(3)The concentrations of TN and TP in sediments from gangues are highest ,those in forestry land are intermediate,and those in agricultural land are lowest.Nutrient loss from hilly areas in much greater than from mountainous areas. 相似文献
7.
Oluwayomi D. Atteh 《Geoforum》1985,16(3):277-286
Since all agricultural systems depend on land, the ownership of, or access to, agricultural land becomes crucial in the consideration of factors which determine agricultural land-use systems. The land tenure system affects agricultural land use and prospects for improvement. This paper examines the structure of the land tenure system in the Okun Area of Kwara State, Nigeria, and its influence on the farming system in that area. It reveals that despite the fact that this is a predominantly agricultural rural community, the operation of the land tenure system is exceptionally liberal and only marginally affects both the size of individual farm holdings and the way the land is cropped. This situation results mainly from two factors. First, the Okun people perceive land as a God-given entity and therefore it is held in trust for Him and second, the population density is very low, with plenty of land to go round. In the present circumstances, large-scale agricultural projects developed in the Okun area over the last decade have been offered land freely by the people rather than finding the land tenure system a hinderance. 相似文献
8.
In this paper, the influence of anthropogenic activity on surface water chemistry is investigated. Base flow samples from dominant land use streams in the Muskegon River Watershed, Michigan, USA, were analyzed for nutrients, major ions, and trace elements. Principal component and hierarchical cluster analysis were used to investigate the processes controlling the effects of land use on the biogeochemistry of streams in this Watershed. Biogeochemical fingerprints of land use were developed based on the results of the cluster analysis. Spider diagrams which referenced the natural environment aided the identification of the individual contributions of urban and agricultural land uses to surface water chemistry. The biogeochemical fingerprints quantified support previous findings (Urb: Na, K, Cl/Ag: Ca, Mg) and produced new insights into the effects of land use on the behavior of nutrients (Ag: N and Urb: N, P) and trace elements (Urb: V, Cr, Co, Cu, Se, Rb, Mo, Sr, Cd, Pb and Ba/Ag: U and As). The higher correlations of urban than agricultural land uses with nutrients, specifically P, were not expected and may reflect the effects of fertilization and wastewater or the season the samples were taken. More study in different geologic and urban settings is needed to help refine these fingerprints, but it is becoming apparent that despite obscuring factors, land use produces consistent, quantifiable associations between biogeochemical analytes. 相似文献
9.
把影响农用土地环境质量的所有环境要素综合起来,分解量化指标,重建评价体系,提出宏观指标分等、微观指标定级的新观点,并就县市级农用土地环境质量进行全要素整合评价和等级评定进行了探讨。结果表明,保证评价精度和把握等级评定的关键步骤是正确选择和划分评价单元;土地农业综合生产能力和清洁度指标是农用土地环境质量的综合反映和集中体现,是所有被整合调查要素和评价因素中最重要的两个刚性指标,在评价中必须加大权重;全要素整合评价可以弥补农业或土地部门多指标评价的不足,能够比较全面和客观地反映农用土地环境质量状况。农用土地环境质量的全要素整合评价为新一轮土地利用规划修编、基本农田保护区准确划定、农用土地分等定级和建设用地的区划调整以及土地基准定价能提供有力技术支持。 相似文献
10.
This study demonstrated the use of fuzzy logic approach in mapping land limitations for agricultural land use planning using publicly available data for the province of Marinduque, Philippines. The paper focused only on the two major crops in the province, coconut, and banana. Based on the results, slope is the major factor limiting the production of these two crops. Slope is identified as a limitation in approximately 80% and 18% of the agricultural land of the province for coconut and banana production, respectively. Other land limitations for coconut production in the province include rainfall, soil, and combination of these factors with slope. In the case of banana, soil and combination of this factor with slope were identified as land limitations.
相似文献11.
Nitrate pollution of ground waters from shallow basaltic aquifers,Deccan Trap Hydrologic Province,India 总被引：2，自引：0，他引：2
Analyses of groundwater samples collected from several locations in a small watershed of the Deccan Trap Hydrologic Province, indicated anomalously higher values of nitrate than the background. However, the NO3 concentrations in water from dug wells under pastureland where the subsurface material consisted of stony waste were minimum. The maximum values were reported for water from dug wells where the principal land use was agricultural. Lowering of NO3 values under shallow water-table conditions suggests denitrification. Higher concentrations of nitrate determined for samples collected from the wells with a deeper water-table indicate that denitrification process is inactive. The high values of nitrate coinciding with agricultural land use indicate fertilizers as the main source of nitrate pollution of ground-water. Decrease in Cl/NO3 ratio for agricultural land use confirms this inference. 相似文献
12.
蒙阴县充分利用城乡建设用地增减挂钩政策,加大农村居民点的整合搬迁复垦力度,积极推进新农村建设,改变了村容村貌,缓解了发展与用地的矛盾,加快了城乡统筹的步伐。 相似文献
13.
随着我国经济的快速发展,大气污染问题日益严重,旅游城市的空气质量问题也备受关注。本文基于2018年30座热门旅游城市的气温和空气质量数据,从气象条件的角度出发,研究了气温与空气质量之间的关系。采用函数型数据描述性分析的方法对空气质量和气温变化特征进行分析,用函数型回归分析研究气温对空气质量的影响。结果显示：函数型线性模型拟合优度R2=0.898 1,F=11.8212大于临界值2.385 9,函数型检验统计量F=8.723 3大于α=0.05水平下的临界值1.7058,说明气温与空气质量的函数型线性关系显著;气温对空气质量呈谐波正负影响交替出现,这与空气质量平均变化相似,在实际生活中是合理的。 相似文献
14.
The aim of this study was to determine land use changes in Datong basin using multitemporal Landsat data for the period of
1977–2006. Four dates of Landsat images from 1977, 1990, 2000, and 2006 were selected to classify the study area. Based on
the supervised classification method of maximum likelihood algorithm, images were classified into six classes: water, urban,
forest, agriculture, wetland, and barren land. A multidate postclassification comparison change detection algorithm was used
to determine changes in land use in four intervals. It is found that (1) urban land area increased 213% due to urbanization
that resulted from rapid increase of urban population and high-speed economic development, (2) agriculture area increased
34.0% due to land reclamation that resulted from rapid increase of rural population and improvement of irrigation capacity,
(3) forest area decreased 20.9% due to deforestation for urban area and agricultural use, (4) barren land area decreased 78.2%
due to cultivation for agricultural use, and (5) water and wetland decreased 39.1 and 67.1%, respectively, due to exploitation
of surface water and decrease of recharge from groundwater to surface water that resulted from over exploitation of groundwater. 相似文献
15.
随着我国农业现代化发展,传统农业逐步向现代农业转变,尤其是近年来农村土地承包经营权流转进程加快,农业生产经营规模不断扩大,农业设施快速增加,势必要占用大量的农用地。因此,为适应现代农业发展需求,必须加强和完善设施农用地管理,防止以发展设施农业为名,滥占乱用土地,促进耕地保护和设施农业的健康有序发展。 相似文献
16.
In Egypt, major sustainability variables could be identified as scarce of soil and water resources, environmental degradation, rapid population growth, institutional arrangement that includes land tenure and farm fragmentation, agricultural administration, lack of infrastructure, and credit utilization. The main objective of the current work is to evaluate the sustainable land use management (SLM) model through biophysics and socioeconomic elements for the purpose of combating sustainability constraints that preclude the agricultural development geospatially. In this research, from the geomorphologic point of view, the obtained results showed three main landscapes. They were identified in the study area as: fluviolacustrine plain, Aeolian deposits, and flood plain. The study area was dominated by some physical and chemical degradation processes with different scales breaking down the equilibrium of soil stability. The SLM model was implemented and assessed from multivariate perspective points of productivity, security, protection, economic viability, and social acceptability. Four SLM classes were outlined as follows: class I, land management practices that did meet sustainability requirements with a score ≥0.65, which represented 31.0 % of the considered agricultural study area; class II, land management practices that were marginally above the sustainability threshold and represented 12.6 %; class III, land management practices that were slightly below the threshold of sustainability and represented 8.60 %; class IV, land management practices that did not meet sustainability requirements with index values >0.1 that represented 47.86 %. As a general conclusion, it is found that land management practices tend to be unsustainable in the area under investigation for certain constraints that play motivated roles in lowering the targeted land sustainability. 相似文献
17.
Although some scholars describe migrant farmers as ‘exceptional resource degraders’ others do not. This paper uses evidence from the transitional agro-ecological zone of Ghana, to examine whether there are substantial differences between households of migrants and the host population regarding agricultural land use. The aim is to determine whether migrants are more destructive of the land (and hence the environment) than the host population. This will be examined using a standard model of the determinants of agricultural land use, to which we add variables representing demographic impacts, including in-migration. The data used are from a household survey undertaken in 2002 among 110 migrant and 142 host population farming households in central Ghana. Results are mixed. We find no support for the hypothesis that households with migrants are less likely to consider the long-term effects of land use by increasing the land area in cultivation, but at the same time there is evidence of use of more land-intensive agricultural practices which tend to degrade farm land over time. 相似文献
18.
采用土地利用动态度分析方法和GIS技术,通过建立土地利用空间数据库,构建土地利用时空变化模型,分析上一轮规划以来邹平县土地利用时空变化特征及驱动力。研究结果表明,从1996到2005年近10年间,邹平县土地利用／覆被变化明显。其中耕地和未利用地面积减少量最大,耕地面积逐年减少的主导原因为城镇工矿及交通水利等建设用地的逐年增加,这与邹平县城镇化水平不断提高及经济快速发展密不可分,而城镇工矿用地与GDP、非农业人口存在很强的线性相关关系;未利用转出地类主要为农用地,这一定程度上缓减了因建设占用农用地所引发的农用地规模不断下降的压力。 相似文献
19.
R. M. Mundie 《GeoJournal》1982,6(6):513-517
The effectiveness of farmland preservation programs in fast-growth areas cannot be determined solely on the basis of stability in the agricultural land supply within the subject jurisdiction, but must take into consideration extrajuridictional agricultural land loss which can result from stringent local development controls. A better measure of program effectiveness is the coefficient of conversion, which expresses the area of agricultural land converted to urban use per unit of urban growth. The rationale for such a measure and its application in Modesto, California are discussed. 相似文献
20.
推动土地合理流转、实施土地规模经营,是提高农民积极性、发展合作社的有效途径。在土地流转中切实做到坚持保证农民土地承包经营权和流转后的土地农业用途;坚持做到不限定流转时间、不限定流转模式、不强迫农民意愿、不侵害农民利益。在规范管理中,引入现代企业管理制度,执行统一的土地流转操作程序,确保土地流转双方在平等互利的基础上签订书面土地经营权流转合同,明确土地流转形式、面积、年限以及双方的权利和义务。通过土地的合理流转,提升了广大农民的思想观念,把土地自觉地推向农村市场,实施农业产业化发展,最大限度地发挥土地增值效益。 相似文献