Land abandonment,landscape evolution,and soil erosion in a Spanish Mediterranean mountain region: The case of Camero Viejo

The Spanish Mediterranean mountains have played an important social and economic role for many centuries. However, since the 1950s these regions have been considered of little economic interest, and this has led to the abandonment of villages, reduced productive activity, and significant changes in the landscape. In the last 50 years the Camero Viejo region (Iberian System, northeast Spain) has been subject to these changes, and was selected as our study area. Landscape evolution and soil erosion, as a result of agricultural abandonment, were studied using different analysis techniques: photointerpretation, geographic information systems and rainfall simulation. The results showed that a large proportion of previously cultivated land has been subject to plant recolonization processes. From 1956 to 2001, woodlands area increased from 10·1 per cent to 37 per cent, and scrubland increased from 42 per cent to 60 per cent. Changes in landscape structure in the same period suggest that the Camero Viejo is in a transitional stage from a highly humanized landscape to a more natural landscape. Although plant cover expansion is evident on most Camero Viejo hillslopes, in some terraced areas erosion processes are active. The generalized abandonment of agricultural terraces has favored the collapse of the stone walls of the terraces, with sliding of the soil. Surface runoff on abandoned terraces is also important. These erosion processes are related to the hydrological functioning of slopes following abandonment, neglect, and in some areas the intensification of grazing. Terrace destruction has a negative impact on the landscape and represents the loss of fertile soils. Landscape diversity should be preserved as an essential element of the economic potential of the Camero Viejo. Copyright © 2010 John Wiley & Sons, Ltd.     

Agricultural terrace abandonment in the alpujarra,andalucia, spain

The environmental impact of recent changes in land use is assessed in a part of Andalucia, southern Spain, where the deintensification and abandonment of low productivity upland areas is taking place. In the uplands of the Alpujarra, the traditional landscape most at risk is that of the irrigated cultivation terraces. These have often been established centuries ago and rely on water abstracted from streams draining the southern slopes of the Sierra Nevada. The causes of this deintensification include labour shortages, with many Alpujarra municipios reporting population decreases of up to 50 per cent since 1950. Landsat Thematic Mapper digital data from May and August 1992 have been used to identify the various land cover components of the Alpujarra. Ground verification undertaken in September 1992 and April 1993 has confirmed that deintensification of terraced areas around the villages of Trevélez (at 1500m, the highest village in Spain) and Pórtugos (1300 m) can be identified as either grassland or matorral. It is recognized that many classes of land cover are mosaics with several elements at a subpixel scale (e.g. terrace risers with fruit trees). However, the output from image processing has allowed areal estimates of the main land covers representing deintensification within the terraced zone. The pattern of deintensification of terraced land is fairly complex. It can be assumed that all terraces were irrigated and cropped at some stage. Land which is no longer cropped is usually grazed and the invasion of matorral species is common, particularly when irrigation ceases. Unirrigated tree crops and vines are sometimes planted on terraces no longer used for cropping. A model of deintensification of farming on terraced land in the Alpujarra is presented.     

Land use/cover change and landscape fragmentation analysis in the Bindura District,Zimbabwe

Rapid land use/cover change and landscape fragmentation is occurring in many countries in central and southern Africa, as a result of colonial imbalances in land distribution, demographic pressure, agricultural expansion, government policies and environmental factors such as drought. This study analysed the dynamics of land use/cover and land degradation as revealed in landscape fragmentation in the Bindura District of Zimbabwe based on Landsat data for 1973 and 2000. A hybrid supervised/unsupervised classification approach coupled with GIS analyses was employed to generate land use/cover maps from which various class level landscape metrics were calculated using FRAGSTATS®, in order to analyse landscape fragmentation. The results show that agriculture, mixed rangeland, settlements, bareland and water increased, while woodland areas decreased. Consequently, the landscape became more highly fragmented as indicated by an increase in the patch number and a decrease in the mean patch size (MPS) of the woodland and mixed rangeland classes. This suggests that anthropogenic activities driven by agricultural expansion were the main causes of landscape fragmentation, leading to landscape degradation in the study area. Copyright © 2006 John Wiley & Sons, Ltd.     

Evaluating urbanization,fragmentation and land use/land cover change pattern in Istanbul city,Turkey from 1971 TO 2002

Spatiotemporal analysis of landscape dynamics is crucial in formulating an appropriate set of actions in landscape management. This paper presents a large scale analysis of the spatiotemporal structure of Istanbul, a highly urbanized city in Turkey, from 1971 to 2002 using forest cover type maps analysed with geographical information systems (GIS) and a spatial statistics programme. The quantitative evidence indicated that increasing population and expanding urbanization caused drastic changes to the temporal and spatial dynamics of land use/land cover pattern in Istanbul. There was a net increase of 5387·3 ha in total forested areas (1·0 per cent) due to mainly reforestation activities even though the population increased three times over a 31‐year period. Increase in number of patches and decrease in mean patch size together demonstrated that the landscape developed into a more fragmented structure that would negatively affect biodiversity and the resilience of the ecosystems. In conclusion, plain increase in forest areas may not always be a favourable situation. The quality, composition and the configuration of forest landscape should also be analysed to present the dynamics of ecosystem in terms of ecological and economical sustainability over a longer time and larger area. Copyright © 2008 John Wiley & Sons, Ltd.     

Vineyards in Terraced Landscapes: New Opportunities from Lidar Data

Vineyard landscapes are a relevant part of the European culture, and several authors concluded that they are the agricultural practice that causes the highest soil loss. Grape quality depends on the availability of water, and soil erosion is an important parameter dictating the vineyard sustainability; therefore, soil and water conservation measures are often implemented. Among them, the construction of terraces is the most widely used system. However, while favouring agricultural activities, terraces if not properly maintained can lead to local instabilities creating hazards for settlements and cultivations, and for the related economy. Terraced fields are also served by agricultural roads that can have deep effects on water flows triggering surface erosion. The goal of this research is to use lidar elevation data for a hydro‐geomorphological analysis of terraced vineyards. The work is divided in two parts. At first, the Relative Path Impact Index is tested in two vineyards to identify terrace‐induced and road‐induced erosions. Statistical thresholds of the Relative Path Impact Index are then defined to label the most critical areas. On the second step, using the index and the defined thresholds, we simulate different scenarios of soil conservation measures, establishing the optimal solution to reduce erosion. The results highlight the effectiveness of high‐resolution topography in the analysis of surface erosion in terraced vineyards, when the surface water flow is the main factor triggering the instabilities. The proposed analysis can help in scheduling a suitable planning to mitigate the consequences of the anthropogenic alterations induced by the terraces and agricultural roads. Copyright © 2014 John Wiley & Sons, Ltd.     

基于农户视角的陕南坡地利用与治理措施调查研究

[目的]开展基于农户尺度经济视角的坡地利用现状和治理措施调查研究,了解陕南地区坡地弃耕原因,提高土地利用效率,完善坡耕地治理对策。[方法]根据农户尺度经济行为特点设计调查问卷,通过典型村庄农户调查,对陕西省商州区梯田和经济作物坡地的利用现状、经济收益和农民的治理需求进行研究;采用二项Logistic回归模型和比例分析法,研究陕南地区土地利用存在的问题;通过对比坡改梯治理措施效果的优缺点,提出坡地治理建议。[结果]调查共涉及6个村庄,93家农户。2018年农户家庭年均收入约为39 419元;农业生产收入主要来自经济作物,户年均约3 661元,仅占总收入的11.26%;坡耕地经济收入低,导致坡耕地和梯田弃耕现象严重,弃耕率高达15%;弃耕的原因主要有经济收入低,交通不便,农村劳动力不足,土地质量差产出低等因素。坡改梯是提高土地利用效率的重要措施,但仍存在易积水、土层薄等问题,对于梯田田坎类型,干砌石田坎在透水性和耐久性两方面综合性最好。[结论]陕南梯田和坡耕地弃耕现象严重,弃耕原因比较明确;在新的历史时期,需要综合考虑人口、经济效益和环境效益等因素,制定兼具生态与经济效益的水土保持治理与土地利用方案。     

工程设计视角下山区梯田撂荒影响因素分析

为分析山区梯田撂荒的影响因素,科学指导山区梯田的建设,该研究以位于山区的林州市、沂水县、寻甸县、华池县为研究区,在每个县选取若干采样区,以遥感解译结合实地调研的方式识别出山区撂荒梯田,并从山区梯田工程设计的角度对其撂荒的影响因素进行分析。研究结果表明:1)4个研究区内梯田均呈现出不同程度的撂荒现象,其中华池县、寻甸县、林州市和沂水县的采样区平均撂荒率分别为4.11%、7.68%、24.03%、9.46%;2)梯田的田面宽度是影响山区梯田撂荒的主要因素;3)在以沂水县和林州市为代表的石质山区,地面坡度与土层厚度是制约梯田宽度的主要因素,梯田的宽度随着地面坡度增加而变窄,随着土层厚度的变薄而变窄;在以华池县和寻甸县为代表的土质山区,地面坡度是梯田宽度的主要限制因素。该研究可为山区梯田的优化提出科学理论指导,并为国家相关部门制定政策提供理论依据。     

喀斯特峰丛坡地灌木林地与梯田旱地土壤水分入渗特征

为明确喀斯特峰丛坡地土壤的入渗特性,该文测定了灌木林地和梯田旱地不同土层的入渗过程,同时分析了影响入渗的因素,并用不同入渗模型对其过程进行拟合。结果表明:(1)梯田旱地的入渗性能低于灌木林地,其平均入渗系数约是灌木林地的78.6%,尤其在土层30~60 cm的平均初渗率、稳渗率仅为灌木林地的4.3%和4.4%,存在明显的入渗隔层,其原因是梯田旱地本身的土壤黏粒含量充足,加上人为翻耕促使较细颗粒向下移动后堆积。(2)灌木林地土壤中的砂粒含量和有机质含量较高,孔隙度较大,不同土层间的性质差异较小,而梯田旱地0~30 cm与30~60 cm土层的土壤性质差异明显,表现为下层土壤容重大、土壤孔隙度小。两者入渗性能均与土壤容重、孔隙度的相关性极显著(P0.01)。(3)Horton模型对灌木林地和梯田旱地的拟合效果较好(R20.9),且对梯田旱地表层和深层的拟合度比对灌木林地的拟合度更好。Kostiakov模型和Philip模型的拟合效果较差。该文为喀斯特土壤水分管理及土壤入渗模拟提供了理论依据。     

Traditional Agrarian Landscape in the Mediterranean Mountains. A Regional and Local Factor Analysis in the Central Spanish Pyrenees

Development of rural areas needs information about sustainable use of the land. The main objective of this research is to study the spatial distribution pattern of different field types in the traditional agricultural landscape in the Central Spanish Pyrenees (flat fields, four different terrace fields, sloping field and shifting agriculture) related to different geoecological variables: slope, exposition, altitude, distance to the villages, rainfall (intensity and volume), lithology and demographic pressure. Agricultural land patterns were mapped in five valleys in the Central Pyrenees from aerial photographs (1957). These maps were digitised and implemented in a Geographic Information System on a scale 1:50,000. We determined the influence of different geoecological variables in the spatial distribution of land agricultural patterns at local and regional valley using statistical analysis. The results showed that the agricultural area occupied a large extension, despite physical environment limitations, extending even in marginal slopes, with little agricultural skills, creating a complex landscape with different field patterns. At the local scale (valley), slope and distance are the more influence variables to explain the spatial distribution of the different field types. At the regional scale, in the Western valleys, sloping fields and shifting agriculture predominate, while terraces dominate in the Eastern valleys. Distance to the village and rainfall intensity is the more determinant factors in the spatial distribution. Copyright © 2017 John Wiley & Sons, Ltd.     

Policies,plans, practice,and prospects: irrigation in northeastern Syria

Over the past half‐century the agricultural landscape of northeastern Syria has been transformed, due in large part to the introduction of significant irrigation to the steppe. At the beginning of this period, irrigation was confined almost entirely to river floodplains and natural depressions. The steppe was dominated by wintertime rain‐fed agriculture and year‐round grazing. The introduction of diesel‐powered wells and, subsequently, state‐operated dam and canal systems, has led to the expansion of both wintertime and summertime irrigation on the steppe away from the floodplain. The sustainability of these irrigation projects has always been suspect. Even as technologies for water extraction have allowed for previously impossible patterns of cultivation, the combination of declining water quality, a deepening water‐table, and degradation‐prone soils have limited crop yields and led to the rapid abandonment of many steppe farms. The actual trajectory of land‐use in the region is determined by social and political forces as well as by hydrology and surficial geology. In this paper we examine recent land‐use history in the watersheds of two tributaries of the Euphrates River, the Balikh and Khabur. A review of historical drivers of development in the region is combined with satellite analyses to provide an overview of the structure and dynamics of land‐use in this water‐limited region. Copyright © 2006 John Wiley & Sons, Ltd.     

三江平原现代农业区景观生态安全时空分异分析

作为与自然关系紧密的生态产业,现代农业不仅是经济社会发展和粮食安全保障的基础,其生态安全也是生态文明建设的重要内容。该研究以位于中国三江平原现代农业区的国营友谊农场为研究区域,以1984年、1995年、2004年和2014年4期Landsat TM/OLI影像为主要数据来源,以景观格局安全指数和生态质量指数为变量构建现代农业区景观生态安全评价模型,对近30 a来研究区的景观生态安全时空分异进行分析。结果表明:研究区景观生态安全格局变化明显,4个时期研究区的景观生态安全指数依次为0.65、0.57、0.55和0.60,整体呈现出先下降后回升的趋势;景观生态安全值的空间集聚性呈先增加后降低的趋势,生态安全分布的热点和冷点面积比例持续降低,不显著区域的面积比例持续增加。研究结果一方面说明农业开发对景观生态系统具有一定的负面影响,另一方面也说明积极的土地整治对景观生态安全具有促进作用,为此,后续的土地整治工作应在促进现代农业发展的同时,保障土地资源的可持续利用。     

基于遥感影像数据的建设项目区域土地覆被变化分析

利用遥感影像数据分析区域土地覆被变化,目前在开发建设项目环境影响调查中已得到广泛应用。选取水电站工程（天生桥一级水电站工程）和天然气开发工程（孝新合气田开发工程）两类建设项目作为分析对象,利用TM遥感影像进行项目区域土地覆被变化分析。通过FRAGSTATS方法,对6个有代表性的景观空间结构与异质性的定量指标进行计算,研究建设项目周边区域景观结构与景观格局变化。研究结果表明,两类项目周边区域土地覆盖类型均发生较大变化,景观格局呈破碎化,多样化发展。水电站项目建设通过水库蓄水和工程占地直接影响库周土地覆被变化,天然气开发项目通过带动经济发展,对区域土地覆被变化主要是间接影响。     

滇东南石漠化土地整理区土地利用变化及其生态经济效应

运用典型样地调查法、参与式农村评估法和GIS技术,分析了西畴石漠化土地整理模式实施中典型样地16年来(1990—2006年)土地利用在数量、速度和空间方面的变化及其所产生的生态经济效应,结果表明:16年来,研究区内的土地利用结构变化明显,主要表现为梯地、坡旱地及裸岩石砾地之间的相互转化。随着石漠化土地整理区土地利用的变化,在16年里裸岩石砾地和坡旱地比例下降,梯地比例提高,农业植被覆盖率和生物多样性增加,水土流失减轻;同时,粮食产量大幅度增长,农民人均纯收入和生活水平逐步提高,生态经济效应良好。     

Agricultural trajectories in a Mediterranean mountain region (Priorat,NE Spain) as a consequence of vineyard conversion plans

In mountain regions of Mediterranean European countries, recent economic and technologic changes have involved the intensification of crops, based on heavy land levelling and/or terracing, and the abandonment or marginalization of traditional land use management. These trends have been reinforced by the subsidy policies of the European Union. The objectives of the present research were: (a) to contribute to the understanding of agricultural trajectories and farming systems that are entirely transforming the social and environmental characteristics of Mediterranean mountain areas, focusing on the analysis of the main agricultural trajectories in a sample area of this environment (the Priorat region, NE Spain) over the last 20 years (1986–2005); and (b) to analyse the farming systems that coexist in the region with regard to the landscape impacts they involve and the influence of CAP subsidies in each one. A methodological approach based on the combination of multivariate statistical techniques was used to obtain a better knowledge of the heterogeneity of farming systems on a local scale. The results show that, although most farms cultivate a mosaic of traditional crops and have small mechanized areas, a minority group follows a high intensification and specialization strategy based on new mechanized‐terraced vineyards. This group only comprises 12 per cent of the farmers in the region, but owns 61 per cent of the new vineyard plantations and 42 per cent of the total agricultural land, receiving most of the subsidies from the EU vineyard conversion and restructuring policy (68 per cent of total Common Agricultural Policy (CAP) subsidies assigned to the region). Copyright © 2008 John Wiley & Sons, Ltd.     

基于景观农业理论的综合土地整理项目规划实证

从景观农业基本理论出发,运用农业景观生态规划与设计方法,探讨由单一农田土地整理规划扩展到涵盖农田、ⅱ水系、林地和村庄的区域性综合土地整理规划与设计的新模式.实证表明,综合了农田系统、水网系统和人居系统的土地整理项目规划融合了区域内的景观基质、斑块和廊道等要素,保证农业景观单元的整体性和统一性,为土地整理项目构建一个空间结构和谐、生态稳定、社会经济效益理想的区域农业景观系统奠定规划基础.     

红河哈尼稻作梯田旅游资源价值空间差异评价

红河哈尼稻作梯田拥有丰富的自然与文化景观资源,是全球/中国重要农业文化遗产、世界文化遗产。目前该地区旅游发展水平空间极不平衡,在对其资源进行科学评价的基础上,提出差异化发展的策略是现实需要,也具有示范意义。本研究以哈尼稻作梯田十大片区所在8个乡镇的旅游资源为评价对象,根据自然景观与人文景观特征的差异,从资源特征和影响力两个方面,分别构建评价指标体系(自然景观6个指标,人文景观7个指标),采用层次分析-模糊数学分析方法对其资源价值进行评价。研究结果表明,自然景观价值方面,马鞍底乡、阿得博乡和三猛乡依托国家级保护区资源具有较明显的优势,其中马鞍底乡因景观奇特、规模宏大而优势突出,甲寅镇则因其水域和植物等组合景观而具有自然景观优势;人文景观价值方面,攀枝花乡、新街镇、甲寅镇和宝华镇因梯田而知名度高,民族文化典型而优势明显,其他乡镇也因具有优美的梯田景观、古村落、传统文化等人文景观资源而得到较高评价。哈尼稻作梯田系统的人文景观价值高于自然景观价值,但自然景观资源尚未得到开发,旅游发展水平空间差异巨大。最后,本研究根据各乡镇的资源优势,提出了各有侧重的旅游发展策略。     

Spatio‐Temporal Patterns of Land Use/Cover Changes Over the Past 20 Years in the Middle Reaches of the Tarim River,Xinjiang, China

The interaction between land use/cover change and landscape pattern is pivotal in research concerning global environmental change. This study uses three different Landsat images of 1989, 1998 and 2009 to study the land use/cover and landscape pattern changes in the middle reaches of the Tarim River basin. envi ®, erdas ®, ArcGIS ® and fragstats ® software were used to analyse the land use/cover changes. The objectives of study were to map and study the changes in land use/cover and landscape pattern, and propose some possible factors in making the land use/cover changes from 1989 to 2009. Seven different types of land use/cover are analysed, and the results are listed in tables. From 1989 to 1998, the percentage of farmland, slight–moderate saline land, heavy saline land and water areas have increased; woodland, desert and the undeveloped land have decreased. From 1998 to 2009, farmland, heavy saline land and the undeveloped land have increased; the other types of land use/cover have decreased. The gravity centre of each land use/cover types has shifted. The farthest shifting of the gravity centre was heavy saline land, which occurred between 1989 and 1998. The transformation and changes of land use/covers and landscape occurred more frequently from 1989 to 2009. Other types of land use and land cover changes to saline land have increased, which implied that a serious salinization took place in the Tarim Basin. The results from this study would show the adverse environmental changes (e.g. salinization and desertification) and they can be used for future sustainable management of land resources. Copyright © 2013 John Wiley & Sons, Ltd.     

Changes in Agricultural Land Use Affecting Future Soil Redistribution Patterns: A Case Study in Southern Tuscany (Italy)

Land‐use changes (LUCs) can be defined as the result of the direct action of the stakeholders in a particular area and natural or human driving forces. LUCs can influence various processes within the landscape and can have an impact on landscape functions. An analysis of the impact of LUCs on landscape processes can help to focus future rural policies. LUCs in Mediterranean areas particularly affect landscape functions because of their agro‐pedoclimatical characteristics. The aims of this work are as follows: (i) to characterise LUCs in the last 11 years in a typical Mediterranean area, the Trasubbie river basin (southern Tuscany, Italy); (ii) to extrapolate these changes and create spatially explicit LUC scenarios for the near future; and (iii) to simulate how and where the predicted LUCs may affect soil redistribution. We carried out an analysis of LUCs within the study area and used the trends to propose alternative scenarios for 2013. For these years, we spatially allocated land use (using the Conversions of Land Use and its Effects model) and used a landscape process model (landscape process modelling at multi‐dimensions and scales) to assess soil redistribution patterns. Land use in the study area changed almost linearly between 1996 and 2007, with cereals and annual fodder crops decreasing, and vineyards, perennial pastures and land abandonment increasing. Our LUC scenario extrapolates these dynamics to make predictions for 2013. A comparison of LAPSUS results between LUC and baseline scenarios for 2013 showed an increase in terms of net soil loss and total erosion, and a decrease in terms of sediment delivery ratio. Copyright © 2013 John Wiley & Sons, Ltd.     

1986-2013年南京市土地利用/覆被景观格局时空变化及驱动力因素分析

以南京市为研究对象,采用南京市1986年、1996年、2002年、2013年的四期土地利用/覆被数据,运用景观生态学原理,借助ArcGIS软件和Fragstats软件,从土地利用类型结构、变化速度、转化关系和景观格局等方面分析南京市近30年土地利用/覆被和景观格局的时空变化状况及其驱动因素。结果表明:（1）南京市近30 a中土地利用/覆被发生了剧烈变化,耕地在整个研究区起到主导作用,其面积比例均在48%以上,但是其优势度逐渐降低,大量自然景观向人为景观转变是研究区土地利用变化最显著的特征;（2）整体景观类型变化速度都在增大,而草地和其他用地变化最为活跃,林地相对最稳定,土地利用结构处于快速调整阶段;（3）耕地的转出最大,主要转向为居民点及建设用地;（4）景观格局变化明显,破碎化程度越来越高,景观格局趋向复杂化,景观结构不稳定性增加;（5）人口增长、经济发展、区域政策和城市规划等共同推动了研究区景观格局的变化。该研究结果对于南京市的科学规划及可持续发展提供重要参考。