宜昌山区建立良性循环的农业生态系统的途径

宜昌地区的山区,包括兴山、秭归、五峰、长阳的全部和宜昌、远安、宜都的大部分地区,面积约占宜昌地区的70％以上,是鄂西南山区的主体部分。 目前宜昌山区农业生态系统存在的突出问题是:大多数地方属于生态上薄弱地区,天然植被遭到严重破坏,水土流失日趋加剧;农业空间结构与山区自然环境结构不符,土地资源利用上存在严重问题;     

三峡库区腹地山区农业景观格局动态变化与转型

山区农业景观格局动态分析有利于厘清农业景观发展的动态轨迹与方向,对农地用途的合理规划和管理有重要意义。本文提出了山区农业景观格局转型理论框架,并在三峡库区草堂溪流域进行了实证研究,从整体—微观的角度解析2000—2018年期间,以坡耕地、撂荒地和果园为代表的农业景观格局转型特征。研究发现：① 果园沿河谷的扩张和撂荒地在较高海拔处的扩张明显压缩了坡耕地的空间,这导致区域景观多样性的整体增强,而在局部地形上的差异明显,斑块破碎但聚集度增强;② 研究区农户耕种范围内的农业景观格局转型主要表现为耕—果转换型、综合型、部分撂荒型和撂荒型4种模式,各模式揭示了山区农业景观格局的不同发展阶段;③ 在以社会经济因素为主的驱动下,三峡库区山区的农业景观格局转型具有双向性,表现为以传统均衡分布的纯粮种植景观向河谷生态经济双赢的经果林景观和较高海拔的撂荒地转变。研究结果揭示了近年来中国山区农业景观格局演变的独特性,对库区山区农村土地利用和农业生态系统的深入认识以及库区乡村发展和生态环境的改善均有启示意义。     

山西滹沱河山区湿地生态系统健康评价

根据滹沱河山区湿地生态系统的特征和湿地生态系统健康的内涵,基于PSR理论模型,从生态系统结构、状态、功能和协调度4方面选取了26项指标,构建了滹沱河山区湿地生态系统健康的评价指标体系。应用二级综合模糊评判法、层次分析法等方法,对滹沱河山区湿地生态系统健康进行了评价。结果表明:滹沱河山区湿地生态系统在健康级别的隶属度综合得分是0.095;在亚健康级别的隶属度综合得分是0.368;在一般疾病级别的隶属度综合得分是0.398;在疾病级别的隶属度综合得分是0.139。根据最大隶属度原则,滹沱河湿地生态系统健康属于一般疾病状态。     

农业生态系统模式研究的几个基本问题探讨

对农业生态系统模式的内涵及其基本特征、模式的类型划分方法及其描述方法,以及农业生态系统模式的研究内容与方法进行了系统探讨。认为农业生态系统模式具有地域性与适应怀、整体性、时空特性、阶段性、应变性与弹性、相对优劣性等基本特征。文中提出了农业生态系统模式的综合分类即包括区域自然环境特征地貌形态特征产业链结构、时空结构和经营属性在内的五级分类指标。农业生态系统模式的主要研究内容与方法包括模式调查、模式评     

农业生态系统可持续性评价研究进展

在大量查阅国内外文献资料的基础上,阐述了国内外农业可持续性评价指标体系的选取标准与选取方法,在此基础上,综述了国内外农业可持续评价方法及评价尺度等研究进展情况。发现国内农业可持续性评价指标过多且以农业经济方面的指标为主,指标之间重叠现象严重,对生态环境、政策性和指导性指标重视不够,而且评价方法有待进一步完善。最后,针对农业可持续性评价中存在的问题提出了一些建议,以期对国内农业的可持续评价研究有所借鉴。     

三峡库区农业生态经济系统的预警分析

从系统与环境相统一的角度,研究了农业生态经济系统的模型、特征、预警分析的意义和内容;以三峡库区为例,从系统序化的观点,确定了这个系统的社会、经济、环境功能和状态的主要指标的警戒线;并与这些指标的现状、过去与未来趋势值进行对比;分别对现状预警、趋势预警和突变预警进行了评价;最后作了简易的对策探讨．     

山区气温空间分布模拟的DEM尺度影响

以浙江省仙居县为实验区,通过气温空间分布的地形调节统计模型,并使用了10个气象站(哨)的气温资料和不同空间分辨率的DEM(均来源于1:1万的数字化地形图),模拟了不同空间尺度的年平均气温空间分布,比较了它们的误差大小以及随宏观地形(海拔)和微观地形(坡度和坡向)的分布差异.结果表明:基于不同空间分辨率DEM模拟的平均气温呈现较大的空间分布差异性;随着DEM空间分辨率的减小,误差逐渐增加(最大绝对误差为2.04℃,相对误差为15.10％),且空间差异性降低.而且微观地形因子(坡度和坡向)随着空间分辨率的变化产生显著变化,进而明显影响气温的空间分布,不同坡度之间的年平均气温差最大为9.5℃,最小为1.8℃.不同坡向之间的年平均气温差最大为12.2℃,最小为2.4℃.     

山区的山地经济协同开发研究——以重庆市三峡库区为例

山区是生态环境和经济社会发展问题集中的区域。以国家有关资源型城市发展、重庆市近年来区域经济城乡统筹发展、三峡库区治理贯彻实施的大政方针为宏观背景,以三峡库区山地资源系统开发为个案,并将该区域资源状况进行统计学意义上的分析综合,从具体到抽象,再从抽象到具体,为我国山地资源系统开发与山地区域经济发展的科学整合做了探索性研究。最后,有针对性地提出了相应对策措施。     

川西山区的家庭农业系统

调查了川西山区家庭农业系统的类型和分布,比较分析了它们的结构特征、运行机制和运行过程。     

传统农业地区能值生态足迹分析——以贵州省从江县为例

传统农业生态系统正面临着来自现代化发展及其带来的技术经济变革的严重威胁,在一些传统农业地区现代农业替代传统农业已经引发了严重的生态环境问题。生态足迹,作为可持续发展评价的方法之一,由于无法全面衡量人类活动对生态系统造成的各种影响,因此无法揭示传统农业地区真实的生态环境状况,也无法给出科学合理的可持续发展评价。能值生态足迹是对传统生态足迹的一种改进,试图利用能值分析理论的优点囊括人类利用生态系统产品和服务的各种活动。然而,目前能值生态足迹研究往往受到传统生态足迹理论的局限,无法真正将人类消费的各种资源、产品和服务纳入进来。为此,本文将生态系统服务概念引入能值生态足迹理论框架中,进一步改进和完善了能值生态足迹模型,使之能够全面衡量人类活动的生态环境影响。本文利用改进的能值生态足迹模型,以我国传统农业地区贵州省从江县为例,开展生态环境状况评估和可持续发展评价。结果表明,从江县2007年人均能值生态承载力为9.3311 ha,人均能值生态足迹为14.5638 ha,人均能值生态赤字为5.2327 ha。可见,从江县的生态承载力仅能满足当地居民消费总需求的64%,当地处于不可持续发展状态,生态环境状况不容乐观。这与传统生态足迹的评价结果差异十分显著。传统生态足迹评价结果显示,从江县的生态承载力不仅能够满足当地居民的消费需求而且有少量生态盈余。进一步分析显示,从江县居民对生态系统的污染物吸纳服务和侵蚀控制服务的消费,在从江县总生态足迹中占有相当大的比例。这说明,从江县传统农业生产方式受现代农业影响而发生的部分改变,所产生的生态环境影响已经逐步显现。过量施用化肥农药所引起的面源污染以及频繁翻耕和砍伐森林所引起的水土流失,已经严重威胁当地的生态环境健康和可持续发展。     

三峡库区山区农业生态系统转型

The Three Gorges Reservoir Area(TGRA)is typical of an ecologically vulnerable area,comprised of rural and mountainous areas,and with high immigration.Because of its economic and ecologic importance,studying the traditional agroecosystem changes in the TGRA is key to rural development and revitalization.In this study,we apply a framework of theoretical analysis,empirical study,and trend prediction to the Caotangxi River watershed within the TGRA.Using QuickBird high-resolution remote sensing images from 2012 to 2017 to evaluate natural resources and farmers’behavior,we analyze the transition and trends in the traditional agroecosystem in mountainous areas of the TGRA at spatial scale of the man-land relationship.We find that the agroecosystem in the TGRA can be divided into four modes using 100 m interval buffer rings:high-low-low,high-low-high,low-high-low and low-low-high mode where the different modes represent the agricultural development stages in the TGRA.Furthermore,the traditional agroecosystem in TGRA,represented by system elements such as farmers and sloping farmland,is transforming to accommodate the diversification of farmer livelihoods.For example,sloping farmland,which was dominated by a production function,now has equal emphasis on ecological and economic functions.Spatially,the range of the agroecosystem transition has migrated beyond high mountain areas to flat valley areas.Generally,this study provides an overview of land use in rural areas,controls on soil and water loss in mountainous areas,and better rural living environments in the TGRA.     

On the land use in Three Gorges Reservoir area

In this study the arable land changes in two counties (Zigui and Xingshan) in the Three Gorges Reservoir area in China are investigated. The statistical data from the officially published statistical books are used to study these changes in the two counties during the past 50 years since 1949. The changes of arable land, changes of arable land per capita, and changes of multiple crop index in Zigui and Xingshan counties are examined. Using an index method, we conclude that the two counties are critical in the sustainable utilization of arable land.     

三峡库区秭归县和兴山县的土地利用

In this study the arable land changes in two counties (Zigui and Xingshan) in the Three Gorges Reservoir area in China are investigated. The statistical data fTom the officially published statistical books are used to study these changes in the two counties during the past 50 years since 1949. The changes of arable land, changes of arable land per capita, and changes of multiple crop index in Zigui and Xingshan counties are examined. Using an index method, we conclude that the two counties are critical in the sustainable utilization of arable land.     

Dynamic changes and transitions of agricultural landscape patterns in mountainous areas: A case study from the hinterland of the Three Gorges Reservoir Area

Analyzing the agricultural landscape patterns in mountainous areas is critical to clarify the dynamic changes and development direction of agricultural landscapes. This also plays a significant role in the rational planning and management of agricultural land. A theoretical framework for agricultural landscape pattern transitions in mountainous areas is proposed to fill the gap of current research with an empirical study in the Caotangxi Watershed, Three Gorges Reservoir Area (TGRA), China. The transition characteristics of agricultural landscape patterns from 2000 to 2018 as represented by sloping farmland, abandoned land, and orchards are analyzed from a holistic-local perspective. The results indicate that the orchards expanded along river valleys, and abandoned land expanded at high elevations, which led to reduced sloping farmland. This phenomenon gives regional landscape differences at the holistic and local levels. Namely, it enhances the region’s holistic landscape diversity but causes fragmentation and aggregation of landscape patches in local areas. The agricultural landscape pattern transitions within the farming range in the study area are manifested primarily in four modes: sloping farmland-orchard conversion type (FOCT), comprehensive conversion type (CCT), partially abandoned type (PAT), and wholly abandoned type (WAT). Each transition mode reveals different development stages of the mountainous agricultural landscape patterns. In general, the agricultural landscape pattern transition is driven by socioeconomic factors in mountainous areas of the TGRA and is bidirectional. This attribute is expressed as the transition from the traditional grain-planting landscape with an even distribution to the eco-economic win-win orchard in valleys and transitions from sloping farmland to abandoned land in high-elevation areas. Overall, the results of this study reveal the uniqueness of agricultural landscape pattern evolutions in China’s mountainous areas in recent decades, which has enlightened the in-depth understandings of rural land use and agricultural ecosystems in mountainous areas of the TGRA, as well as improvements in rural developments and ecological environments.     

GIS支持下三峡库区秭归县滑坡灾害空间预测

基于GIS空间分析和统计模型相结合进行区域评价与空间预测是滑坡灾害研究的重要方向之一。以三峡库区秭归县为研究区,选择坡度、坡向、边坡结构、工程岩组、排水系统、土地利用和公路开挖作为评价因子。为提高模型的预测精度、可信度和推广能力,利用窗口采样规则降低训练样本之间的空间相关性。建立Logistic回归模型,对滑坡灾害与评价因子进行定量相关性分析。计算研究区滑坡灾害易发性指数,对其进行聚类分析,绘制滑坡易发性分区图,其中高、中易发区占整个研究区面积的38.9%,主要分布在人类工程活动频繁和靠近排水系统的区域。经过验证,该模型的预测精度达到77.57%。     

近10年重庆市归一化植被指数变化分析

运用1 km分辨率经过Savitzky-Golay滤波技术平滑处理的SPOT/VGT数据,通过对1998~2007年的归一化植被指数(NDVI)时间序列数据、NDVI与气象因子的关系、10 a来NDVI变化率的空间分布以及NDVI与海拔高度的关系等进行分析,研究重庆市植被变化及空间分布情况。结果表明,重庆市NDVI年变化相对稳定,在空间上变化较大,东北及东南部分地区植被退化,而西部地区NDVI变化率增加,表明植被覆盖有所增多。另外引起NDVI时空变化的原因中,温度远大于降水量,海拔高度也与NDVI有较好的相关性。     

三峡库区重庆段水土流失的时空格局特征

Soil and water loss has been the most serious eco-environmental problem in the Three Gorges Reservoir Area of Chongqing. In this paper the authors studied the spatiotemporal features of soil and water loss from 1999 to 2004 based on RS and GIS techniques. The results showed that: (1) The soil and water loss area decreased from 1999 to 2004. (2) Soil and water loss mainly exists in purple soil, yellow soil, limestone soil, paddy soil and yellow brown soil distributed areas. (3) The dry slope land and sparse woodland that are intensively influenced by human activities experienced most serious soil and water loss. (4) Soil and water loss in the study area indicated an obvious vertical differentiation characteristic. (5) There is a significant correlation between soil and water loss and slope. (6) There is no obvious correlation between soil and water loss and aspect. (7) Soil and water loss mainly exists in the values of R between 300 and 340 distribution area. The very-high soil and water loss has obvious correlation with R. Foundation: National Natural Science Foundation of China, No.40801077; Science & Technology Research Project Supported by Chongqing Municipal Education Commission, No.KJ070811; Doctoral Fund of Chongqing Normal University, No.06XLB004; Project by Chongqing Water Conservancy Bureau Author: Li Yuechen (1974–), Ph.D and Associate Professor, specialized in the study of remote sensing application and land use/land cover change.     

Spatiotemporal features of soil and water loss in Three Gorges Reservoir Area of Chongqing

Soil and water loss has been the most serious eco-environmental problem in the Three Gorges Reservoir Area of Chongqing. In this paper the authors studied the spatiotemporal features of soil and water loss from 1999 to 2004 based on RS and GIS techniques. The results showed that: (1) The soil and water loss area decreased from 1999 to 2004. (2) Soil and water loss mainly exists in purple soil, yellow soil, limestone soil, paddy soil and yellow brown soil distributed areas. (3) The dry slope land and sparse woodland that are intensively influenced by human activities experienced most serious soil and water loss. (4) Soil and water loss in the study area indicated an obvious vertical differentiation characteristic. (5) There is a significant correlation between soil and water loss and slope. (6) There is no obvious correlation between soil and water loss and aspect. (7) Soil and water loss mainly exists in the values of R between 300 and 340 distribution area. The very-high soil and water loss has obvious correlation with R.     

长江三峡库区草丛群落多样性的研究

通过对三峡库区草丛群落的初步调查,发现该地区灌丛现有20个群落类型,常见的班茅茅叶草丛群落、拟金草草丛群落、芒草丛群落、光叶里白草丛群落、香附子草丛群落,其丰富度指数、多样性指数相对较高,而小颖羊茅草丛群落、油芒草丛群落、金发草草丛群落、鸢尾草丛群落、牛鞭草草丛群落、马唐草丛群落、黄茅草丛群落、类芦草丛群落、斑茅草丛群落、瘦脊野谷草草丛群落丰富度适中;双花草草丛群落、狗牙根草丛群落、矛叶荩草草丛群落、白茅草丛群落、尼泊尔芒草丛群落的丰富度相对较低;草丛群落多样性在海拔梯度上未表现出明显的规律性,这可能与库区内强烈的人为干扰活动有关.     

三峡库区土地持续利用潜力与途径模式

建立了量化评价模型,对三峡库区土地资源持续利用的潜力及其差异性进行了评价与分析。指出库区土地利用总体上处于弱持续发展的阶段,而且地区差异悬殊、面临的障碍因素多。因此,未来库区土地利用优化决策的关键在于遵照因地制宜和分类指导的原则,正确处理生态建设、移民安置和经济协调发展的关系。主要的途径模式包括植树造林、坡地改梯田、优化结构和产业突破等四个方面。