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1.
陕北地区退耕还林还草工程土壤保护效应的时空特征 总被引：1，自引：1，他引：0
This paper looks at the Green for Grain Project in northern Shaanxi Province.Based on remote sensing monitoring data,this study analyzes the locations of arable land in northern Shaanxi in the years 2000,2010 and 2013 as well as spatio-temporal changes over that period,and then incorporates data on the distribution of terraced fields to improve the input parameters of a RUSLE model and simulate and generate raster data on soil erosion for northern Shaanxi at different stages with a accuracy verification.Finally,combined with the dataset of farmland change,compared and analyzed the characteristics of soil erosion change in the converted farmland to forest(grassland)and the unconverted farmland in northern Shaanxi,so as to determine the project’s impact on soil erosion over time across the region.The results show that between 2000 and 2010,the soil erosion modulus of repurposed farmland in northern Shaanxi decreased 22.7 t/ha,equivalent to 47.08%of the soil erosion modulus of repurposed farmland in 2000.In the same period,the soil erosion modulus of non-repurposed farmland fell 10.99 t/ha,equivalent to 28.6%of the soil erosion modulus of non-repurposed farmland in 2000.The soil erosion modulus for all types of land in northern Shaanxi decreased by an average of 14.51 t/ha between 2000 and 2010,equivalent to 41.87%of the soil erosion modulus for the entire region in 2000.This suggests that the Green for Grain Project effectively reduced the soil erosion modulus,thus helping to protect the soil.In particular,arable land that was turned into forest and grassland reduced erosion most noticeably and contributed most to soil conservation.Nevertheless,in the period 2010 to 2013,which was a period of consolidation of the Green for Grain Project,the soil erosion modulus and change in volume of soil erosion in northern Shaanxi were significantly lower than in the previous decade. 相似文献
2.
Ya Luo Shengtian Yang Changsen Zhao Xiaoyan Liu Changming Liu Linna Wu Haigen Zhao Yichi Zhang 《地理学报(英文版)》2014,24(5):802-814
In areas with topographic heterogeneity, land use change is spatially variable and influenced by climate, soil properties, and topography. To better understand this variability in the high-sediment region of the Loess Plateau in which soil loss is most severe and sediment diameter is larger than in other regions of the plateau, this study builds some indicators to identify the characteristics of land use change and then analyze the spatial variability as it is affected by climate, soil property, and topography. We build two indicators, a land use change intensity index and a vegetation change index, to characterize the intensity of land use change, and the degree of vegetation restoration, respectively. Based on a subsection mean method, the two indicators are then used to assess the spatial variability of land use change affected by climatic, edaphic, and topographic elements. The results indicate that： 1） Land use changed significantly in the period 1998-2010. The total area experiencing land use change was 42,302 km2, accounting for 22.57%of the study area. High-coverage grassland, other woodland, and forest increased significantly, while low-coverage grassland and farmland decreased in 2010 compared with 1998.2） Land use change occurred primarily west of the Yellow River, between 35 and 38 degrees north latitude. The four transformation types, including （a） low-coverage grassland to medium-coverage grassland, （b） medium-coverage grassland to high-coverage grassland, （c） farmland to other woodland, and （d） farmland to medium-coverage grassland, were the primary types of land use change, together constituting 60% of the area experiencing land use change. 3） The spatial variability of land use change was significantly affected by properties of dryness/wetness, soil conditions and slope gradient. In general, land use changed dramatically in semi-arid regions, remained relatively stable in arid regions, changed significantly in clay-rich soil, remained relatively stable in clay-poor soil, changed dramatically in steeper slopes, and remained relatively stable in tablelands and low-lying regions. The increase in vegetation coincided with increasing changes in land use for each physical element. These findings allow for an evaluation of the effect of the Grain to Green Program, and are applicable to the design of soil and water conservation projects on the Loess Plateau of China. 相似文献
3.
In areas with topographic heterogeneity, land use change is spatially variable and influenced by climate, soil properties, and topography. To better understand this variability in the high-sediment region of the Loess Plateau in which soil loss is most severe and sediment diameter is larger than in other regions of the plateau, this study builds some indicators to identify the characteristics of land use change and then analyze the spatial variability as it is affected by climate, soil property, and topography. We build two indicators, a land use change intensity index and a vegetation change index, to characterize the intensity of land use change, and the degree of vegetation restoration, respectively. Based on a subsection mean method, the two indicators are then used to assess the spatial variability of land use change affected by climatic, edaphic, and topographic elements. The results indicate that: 1) Land use changed significantly in the period 1998–2010. The total area experiencing land use change was 42,302 km2, accounting for 22.57%of the study area. High-coverage grassland, other woodland, and forest increased significantly, while low-coverage grassland and farmland decreased in 2010 compared with 1998. 2) Land use change occurred primarily west of the Yellow River, between 35 and 38 degrees north latitude. The four transformation types, including(a) low-coverage grassland to medium-coverage grassland,(b) medium-coverage grassland to high-coverage grassland,(c) farmland to other woodland, and(d) farmland to medium-coverage grassland, were the primary types of land use change, together constituting 60% of the area experiencing land use change. 3) The spatial variability of land use change was significantly affected by properties of dryness/wetness, soil conditions and slope gradient. In general, land use changed dramatically in semi-arid regions, remained relativelystable in arid regions, changed significantly in clay-rich soil, remained relatively stable in clay-poor soil, changed dramatically in steeper slopes, and remained relatively stable in tablelands and low-lying regions. The increase in vegetation coincided with increasing changes in land use for each physical element. These findings allow for an evaluation of the effect of the Grain to Green Program, and are applicable to the design of soil and water conservation projects on the Loess Plateau of China. 相似文献
4.
华北平原禹城市耕地变化与驱动力分析(英文) 总被引：2，自引：0，他引：2
Taking Yucheng, a typical agricultural county in Shandong Province as a case, this study applied Logistic regression models to spatially identify factors affecting farmland changes. Using two phases of high resolution imageries in 2001 and 2009, the study obtained the land use and farmland change data in 2001-2009. It was found that the farmland was reduced by 5.14% in the period, mainly due to the farmland conversion to forest land and built-up land, although part of forest land and unused land was converted to farmland. The results of Logistic regressions indicated that location, population growth and farmer income were main factors affecting the farmland conversion, while soil types and pro-curvature were main natural factors controlling the distribution of farmland changes. Regional differences and temporal-spatial variables of farmland changes affected fitting capability of the Logistic re-gression models. The ROC fitting test indicated that the Logistic regression models gave a good explanation of the regional land-use changes. Logistic regression analysis is a good tool to identify major factors affecting land use change by quantifying the contribution of each factor. 相似文献
5.
《地理学报(英文版)》2019,(2)
The formation mechanism and influencing factors identification of soil erosion are the core and frontier issues of current research. However, studies on the multi-factor synthesis are still relatively lacked. In this study, the simulation of soil erosion and its quantitative attribution analysis have been conducted in different geomorphological types in a typical karst basin based on the RUSLE model and the geodetector method. The influencing factors, such as land use type, slope, rainfall, elevation, lithology and vegetation cover, have been taken into consideration. Results show that the strength of association between the six influencing factors and soil erosion was notably different in diverse geomorphological types. Land use type and slope were the dominant factors of soil erosion in the Sancha River Basin, especially for land use type whose power of determinant(q value) for soil erosion was much higher than other factors. The q value of slope declined with the increase of relief in mountainous areas, namely it was ranked as follows: middle elevation hill small relief mountain middle relief mountain. Multi-factors interactions were proven to significantly strengthen soil erosion, particularly for the combination of land use type with slope, which can explain 70% of soil erosion distribution. It can be found that soil erosion in the same land use type with different slopes(such as dry land with slopes of 5° and above 25°) or in the diverse land use types with the same slope(such as dry land and forest with a slope of 5°), varied much. These indicate that prohibiting steep slope cultivation and Grain for Green Project are reasonable measures to control soil erosion in karst areas. Based on statistics of soil erosion difference between diverse stratifications of each influencing factor, results of risk detector suggest that the amount of stratification combinations with significant difference accounted for 55% at least in small relief mountain and middle relief mountainous areas. Therefore, the spatial heterogeneity of soil erosion and its influencing factors in different geomorphological types should be investigated to control karst soil loss more effectively. 相似文献
6.
北京城市空间发展和土地利用—伦敦经验启示 总被引：3，自引：0，他引：3
Beijing is facing a huge challenge to manage the growth of its built-up area whilst also retaining both productive arable land and land for conservation purposes in order to simultaneously realize the three aims of economic development,protecting arable land and generating environmental improvements. Meanwhile,London,as a world city with more than 200 years of industrialization and urbanization,has accumulated rich theoretical and practical experiences for land use planning in a major urban area,such as the creation of Garden Cities,a designated Green Belt and New Towns. This paper firstly analyzes the main characteristics of the spatial distribution of the built-up area,arable land and conservation land in Beijing. Then,some of the key aspects of urban fringe planning in the London region are examined. Lastly,several implications from the experience of London are provided with respect to land-use planning for Beijing,concentrating on a re-appraisal of land-use functions around Beijing,measures to improve the green belt,the development of small towns to house rural-urban migrants and urban overspill,and effective implementation of land-use planning. 相似文献
7.
三工河流域绿洲土地利用对土壤特性的影响 总被引：2，自引：1，他引：1
Understanding the effect of human activities on the soil environment is fundamental to understanding global change and sustainable development. In the process of transformation of tropical rain forests and semiarid grasslands to farmlands, land degradation usually occurs. But the transformation of arid desert landscape to oasis is found to have quite different consequences. Taking an alluvial plain oasis in the north piedmont of the Tianshan Mountains as a case study, we investigate oasis soil properties related to different land-use systems during the transformation of arid desert to oases. Selected land-use systems con- sisted of an annual crop field less than 3 years old, annual crop field 3-6 years old, annual crop field more than 6 years old, perennial crop field less than 4 years old, perennial crop field of 4-6 years old, perennial crop field more than 6 years old, abandoned farmland more than 3 years old, woodland field more than 6 years old, ecological forestation field, natural shrubbery field, desert grass land, and saline or alkaline field. Different land-use systems affect significantly the distribution of sand, silt and clay. Sand content in oasis soil tends to decrease with cultivation years but silt and clay contents tend to be increased in the oasis soils. Soil fertility is higher in the land-use systems under strong human disturbance than under weak human disturbance. Oasis soil nutrients also tend to increase with cultivation years. Soils have a significantly lower salinity in the land-use systems under strong human disturbance than under weak human disturbance. Soil organic matter and nutrients of the annual and perennial crop systems in the oasis tend to increase with cultivation time with the oasis soil acting as a carbon sink. These results show that soils are not degraded and the soil quality is gradually improved under rational land use and scientific management patterns, including uniform exploitation of land resources, effective irrigation systems, sound drainage systems, balanced ferti 相似文献
8.
Central Ningxia is a desert-steppe area with a sparse population and fragile ecosystem. Having an annual average rainfall of 180-350mm, the area is dominated by animal husbandry and dry land farming. As the population grows, livestock increased and farmland expanded, which leads to damages of primitive grasslands vegetation and serious degeneration of steppe ecosystem due to over-grazing. Southern Ningxia is a populous loessic hilly area subject to serious soil erosion. Since 1975, the local … 相似文献
9.
Soil erosion is a major threat to sustainable agriculture. Evaluating regional erosion risk is increasingly needed by national and in-ternational environmental agencies. This study elaborates a model (using spatial principal component analysis [SPCA]) method for the evaluation of soil erosion risk in a representative area of dry-hot valley (Yuanmou County) at a scale of 1:100,000 using a spatial database and GIS. The model contains seven factors: elevation, slope, annual precipitation, land use, vegetation, soil, and population density. The evaluation results show that five grades of soil erosion risk: very low, low, medium, high, and very high. These are divided in the study area, and a soil erosion risk evaluation map is created. The model may be applicable to other areas of China because it utilizes spatial data that are generally available. 相似文献
10.
Land-use and soil management affects soil organic carbon （SOC） pools, nitrogen, salinity and the depth distribution. The objective of this study was to estimate land-use effects on the distribution of SOC, labile fractions C, nitrogen （N） and salinity in saline-alkaline wetlands in the middle reaches of the Heihe River Basin. Three land-use types were selected： intact saline-alkaline meadow wetland, artificial shrubbery （planting Tamarix） and farmland （cultivated for 18 years） of soils previously under meadow wetland. SOC, easily oxidized carbon, microbial biomass carbon, total N, NO3--N and salinity concentrations were measured. The results show that SOC and labile fraction carbon contents decreased significantly with increasing soil depth in the three land-use wetlands. The labile fraction carbon contents in the topsoil （0-20cm） in cultivated soils were significantly higher than that in intact meadow wetland and artificial shrubbery soil. The aboveground biomass and soil permeability were the primary influencing factors on the contents of SOC and the labile carbon in the intact meadow wetland and artificial shrubbery soil, however, the farming practice was a factor in cultivated soil. Agricultural measures can effectively reduce the salinity contents; however, it caused a significant increase of NO 3--N concentrations which posed a threat to groundwater quality in the study area. 相似文献
11.
基于遥感技术和GIS的小流域土地利用/覆被变化分析 总被引：36，自引：3，他引：33
根据贵州省平坝县克酬流域1973年MSS影像数据,1989、1995、2000年Landsat TM影像数据,利用RS和GIS信息获取技术、空间分析技术和数理统计方法,分析了该流域土地利用的数量变化和空间变化特征,明确了土地利用变化的主要类型和方向,并探讨了土地利用变化和地形因子的关系。结果显示,该流域土地利用以农田和灌草用地为主,1973~2000年林地和灌草地减少,农田、水域、村镇、交通用地增加,林地转化为灌草、灌草转化为农田及农田转化为村镇居民点和公路用地是研究区主要土地利用变化类型。研究区土地利用空间分布与海拔高程、坡度等地形因子有密切关系。1973~2000年农田、林地和灌草分布的海拔高程和坡度均呈增加趋势,这和上述土地利用类型间的转化规律相一致。 相似文献
12.
13.
1960-2010 年贵州省喀斯特山区陡坡土地利用变化 总被引：6，自引：0，他引：6
基于GIS 与RS技术, 以贵州省喀斯特山区坡度大于25°的区域为研究对象, 利用1960 年1:50000 地形图、1990 年Landsat TM遥感影像以及2010 年的环境减灾卫星(HJ-1A/1B)影像, 解译获取1960、1990、2010 年3 个时间点的土地利用数据, 并结合贵州省水文地质图、坡度图进行陡坡土地利用变化分析。结果表明:①1960-1990 年的30 年间, 有林地、灌木林、水体呈减少趋势, 其中灌木林减少的最多, 其次是有林地;而草地、建设用地、裸岩和耕地呈持续增长趋势, 其中草地增加的最多, 其次是耕地。②1990-2010 年的20 年间, 灌木林、裸岩、耕地呈减少趋势, 其中耕地减少的最多;而有林地、疏林地、草地、水体呈增长趋势, 其中疏林地增加的最多。③随坡度增加覆盖比例呈降低趋势的土地利用类型为有林地、疏林地、水体、建设用地和耕地;随坡度增加覆盖比例呈增加趋势的土地利用为灌木林、草地和裸岩。 相似文献
14.
Understanding the effect of human activities on the soil environment is fundamental to understanding global change and sustainable development. In the process of transformation of tropical rain forests and semiarid grasslands to farmlands, land degradation usually occurs. But the transformation of arid desert landscape to oasis is found to have quite different consequences. Taking an alluvial plain oasis in the north piedmont of the Tianshan Mountains as a case study, we investigate oasis soil properties related to different land-use systems during the transformation of arid desert to oases. Selected land-use systems consisted of an annual crop field less than 3 years old, annual crop field 3?6 years old, annual crop field more than 6 years old, perennial crop field less than 4 years old, perennial crop field of 4-6 years old, perennial crop field more than 6 years old, abandoned farmland more than 3 years old, woodland field more than 6 years old, ecological forestation field, natural shrubbery field, desert grass land, and saline or alkaline field. Different land-use systems affect significantly the distribution of sand, silt and clay. Sand content in oasis soil tends to decrease with cultivation years but silt and clay contents tend to be increased in the oasis soils. Soil fertility is higher in the land-use systems under strong human disturbance than under weak human disturbance. Oasis soil nutrients also tend to increase with cultivation years. Soils have a significantly lower salinity in the land-use systems under strong human disturbance than under weak human disturbance. Soil organic matter and nutrients of the annual and perennial crop systems in the oasis tend to increase with cultivation time with the oasis soil acting as a carbon sink. These results show that soils are not degraded and the soil quality is gradually improved under rational land use and scientific management patterns, including uniform exploitation of land resources, effective irrigation systems, sound drainage systems, balanced fertilizer application, crushed straw return to soil and transformation of annual crop fields to perennial ones. 相似文献
15.
多流域降雨和土地利用格局对土壤侵蚀影响的比较分析——以陕北黄土丘陵沟壑区为例 总被引：2，自引：0，他引：2
土壤侵蚀是制约黄土高原可持续发展的瓶颈因素,为分析不同面积流域降雨和土地利用格局对土壤侵蚀影响的变化趋势,本文基于土壤侵蚀评价指数,发展了降雨和土地利用格局对土壤侵蚀影响的表征方法,探讨了多流域降雨和土地利用格局对土壤侵蚀的影响。结果表明：① 2006-2012年,研究区降雨侵蚀力因子R总体上呈现上升的趋势,植被覆盖与管理因子C呈现下降趋势;② 随流域面积的增加,研究区内降雨格局对土壤侵蚀的影响逐渐降低,而土地利用格局对土壤侵蚀的影响变大;③ 在流域面积较小时,降雨格局对土壤侵蚀的影响要大于土地利用格局对土壤侵蚀的影响,而在流域面积较大时,土地利用格局对土壤侵蚀的影响大于降雨格局对土壤侵蚀的影响;④ 随着流域面积的增加,研究区的林地比例有所下降,陡坡植被覆盖类型趋于单一,这是在流域面积增大时土地利用格局对土壤侵蚀影响增加的主要原因。同时,流域面积较小时,降雨对土壤侵蚀的影响较大,但随着流域面积的增加,松软的土壤性质和沟壑纵横的地形增大了发生重力侵蚀的可能性,土壤和地形对土壤侵蚀的影响增大。 相似文献
16.
多尺度土地利用与土壤侵蚀 总被引：20，自引：5，他引：15
土地利用能够通过改变一系列的自然现象和生态过程影响土壤侵蚀,尺度不同,土地利用与土壤侵蚀的作用机制也会发生变化。本文针对坡面尺度、小流域／流域尺度和区域尺度,综述了不同尺度上土地利用对土壤侵蚀的影响研究。其中,在坡面尺度上,土地利用与土壤侵蚀的研究主要包括土地利用方式和土地管理措施对土壤侵蚀的影响,相应尺度上的模型有USLE／RUSLE、WEPP等;在小流域／流域尺度上,土地利用与土壤侵蚀的研究主要涉及土地利用结构和土地利用格局对土壤侵蚀的影响,相关的模型有LISEM、AGNPS、EUROSEM和SEDEM等;在区域尺度上土壤侵蚀评价研究主要是通过尺度上推和宏观因子评价的方法进行。多尺度土地利用与土壤侵蚀研究作为自然地理学研究中的热点问题,在进一步的研究中需要关注多尺度综合与尺度转换、土地利用政策效应、土地利用格局与土壤流失过程等方面的研究内容。 相似文献
17.
基于RUSLE的卧虎山水库流域土壤侵蚀特征分析 总被引：3，自引：0，他引：3
通过RUSLE模型对卧虎山水库流域土壤侵蚀进行全面评价验证和总结。结果表明：① 水库流域平均侵蚀模数为462 t/(km2·a),该数值与通过水库淤积等资料推算评估结果基本一致,表明本研究结果具有较高的可信度;水库流域年均侵蚀量达到2.6×106t,其中高于容许土壤流失量的面积为176 km2,占到流域总面积的31.51%。从不同侵蚀级别来看,占流域面积27.77%的轻度侵蚀,对流域侵蚀总量的贡献率为54.64%; 面积占比3.74%的中度及以上侵蚀,侵蚀量贡献率达到30.94%。② 流域内土壤侵蚀空间差异较大,回归分析发现地形因子是导致各子流域土壤侵蚀模数差异的主要因素;就土地利用类型而言,旱地和农村居民点是流域内的主要侵蚀土地利用类型;流域内土壤侵蚀模数随着坡度增加呈现相应增大趋势,8°~25°坡度段面积比例不仅最大,而且侵蚀量占比最高,是水库流域的主要侵蚀坡度段。 相似文献
18.
LIU Jiyuan LIU Mingliang DENG Xiangzheng Zhuang Dafang ZHANG Zengxiang LUO Di 《地理学报》2002,12(3):275-282
In the mid-1990s, we established the national operative dynamic information serving systems on natural resources and environment. During building the land-use/land-cover change (LUCC) database for the mid-1990s, 520 scenes of remotely sensed images of Landsat Thematic Mapper (TM) were interpreted into land-use/land-cover categories at scale of 1:100,000 under overall digital software environment after being geo-referenced and ortho-rectified. The vector map of land-use/land-cover in China at the scale of 1:100,000 was recently converted into a 1-km raster database that captures all of the high-resolution land-use information by calculating area percentage for each kind of land use category within every cell. Being designed as an operative dynamic information serving system, monitoring the change in land-use/land-cover at national level was executed. We have completed the updating of LUCC database by comparing the TM data in the mid-1990s with new data sources received during 1999-2000 and 1989-1990. The LUCC database has supported greatly the national LUCC research program in China and some relative studies are incompletely reviewed in this paper. 相似文献
19.
山地生态系统的土壤侵蚀和水源供给变化对评估区域生态环境质量有重要意义。基于2000-2015年四期土地利用数据,借助InVEST模型对淇河流域近16年间山地生态系统的土壤侵蚀和水源供给变化进行评估。结果表明：① 研究区主要土地利用类型为耕地、草地和林地,共占流域总面积的90%以上。近16年间淇河流域的耕地面积显著减少,草地和水域面积大幅增加,建设用地扩张明显。② 平均土壤侵蚀模数显著降低,2000年土壤侵蚀模数为154.27 t/（hm2·a）,2015年减少到32.09 t/（hm2·a）;强度侵蚀、极强侵蚀和剧烈侵蚀由9.03%、12.19%和25.96%分别减少到7.17%、6.36%和4.21%,微度侵蚀、轻度侵蚀和中度侵蚀由24.31%、16.96%和11.57%增加到41.89%、27.71%和12.68%;退耕还林、还草措施优化了土地利用格局,促进植被恢复,对治理土壤侵蚀起到了显著效果。③ 水源供给量整体呈现先增加后减少的趋势,2005年达到峰值（1.79亿m3）。相邻两期水源供给量增减变化不一,2000-2005年水源供给量增加的面积大于减少的面积,其水源供给的量值也呈增加趋势,水源供给能力整体增强;而2005-2010年、2010-2015年的水源供给能力随之减弱,其中,2010-2015年水源供给减少的较小;林地和草地面积的增加造成水源供给量降低,土壤水源涵养能力增强。土壤侵蚀和水源供给是山地生态脆弱性响应的重要指标,制定合理的水土保持措施对增强山区生态系统的服务能力具有重要意义。 相似文献
20.
云南金沙江流域水土保持型可持续土地利用规划研究 总被引：2，自引：2，他引：2
水土流失是当今我国乃至世界性的头号土地生态环境问题,它已成为广大山区可持续土地利用的最大障碍和主导性制约因素。未来土地利用的主要方向是可持续土地利用,水土流失山区可持续土地利用有着特殊的内涵。本文以水土流失极其严重的全国生态建设重点区域——云南金沙江流域为研究区域,对水土保持型可持续土地利用规划的基本内涵、原则和重点内容进行了初步探讨,并制定了该流域水土保持型可持续土地利用规划的战略指导思想、基本方针、主要目标、规划方案和实施措施。 相似文献