Industrial land use and heavy metal contaminated wastewater used for irrigation in periurban Zambia

Studies on urban and periurban agriculture in Zambia have not adequately tackled land use practices in relation to problems associated with wastewater irrigated farming. This study investigated land use practices in two wastewater irrigated farming areas in the industrial towns of Mufulira and Kafue respectively in the Copperbelt and Lusaka provinces of Zambia. Drawing on data from field interviews and focus group discussions, as well as laboratory analysis of the heavy metal content in the wastewater used for irrigation in farm plots at both sites, the study outlines the problems associated with wastewater irrigated farming, including the vulnerability context of those whose livelihoods depend on insecure access to vacant land for informal farming. The findings also confirm the heavy metal contamination of the wastewater used for farming, as well as seepage into the surrounding environment, from mining and industrial enterprises located amidst residential areas. The characteristics of mixed land use, high crop diversification, multiple cropping systems and multiple livelihood practices found in these areas of informal farming are similar to those noted in periurban farming in other developing economy contexts. Given that wastewater irrigated crop farming forms part of the livelihood portfolio among the majority of periurban populations, these preliminary results reinforce the need for municipal authorities to improve scrutiny of land use regulation, raise awareness among informal farmers of the hazards associated with using domestic sewage wastewater and untreated industrial effluents, and ensure improve treatment of the wastewater used for human consumption.     

红壤丘岗缓坡地水资源状况与管理

红壤丘岗缓坡地是我国重要的后备耕地资源。就整个区域而言,降雨总量能基本满足坡地农业开发的需求。然而,由于结壤区降雨的时空分配不均,土壤结构性差、保水能力弱,季节性干旱缺水将阻碍坡地农业的开发利用。以蓄水引水工程建设为基础,生态节技术与农艺栽培措施相结合,改善土壤结构,增强土壤持蓄水能力,实施农林草复合经营,提高坡地径流水的积蓄循环利用率,是降低红壤丘岗区季节性干旱危害,促进坡地农业健康稳步发展的必     

农业多功能性与都市区土地利用管理——框架和案例分析

采用理论和案例分析相结合的方法探讨了农业多功能性对都市区土地利用管理的意义和实现途径。论文从农业多功能性的多尺度嵌套层级结构出发,构建了基于农业多功能性评价的都市区土地利用管理框架,然后基于高清卫星遥感影像解译、文献资料整理等分析了北京市海淀区1968—2014年间土地利用、农业多功能性和土地利用管理措施的变化及相互作用。研究指出：都市区土地利用管理者应该在区域尺度和农户/农园尺度农业多功能性评价的基础上,围绕农户/农园与区域、国家等各级社会经济系统的相互作用,从改进土地用途管制分区和发展多功能农业两个方面进行区域的农业用地管理。最后,展望了未来的研究方向,希望优化都市区土地利用管理,推动都市型现代农业建设,并促进区域可持续发展。     

Drought, groundwater management and land use planning: the case of central Oahu, Hawaii

A recent decision to allow higher levels of urban development in central Oahu, Hawaii, has heightened the concern about possible loss of agricultural land and further drops in aquifer levels. This paper examines such potential impacts and offers a procedure for incorporating them into land use planning. First, a water-balance simulation model computes the change in groundwater recharge under changes in land use and irrigation technology. The resulting changes, together with estimated water demands for the agricultural, commercial and residential sectors, are then included in a multiobjective programming model that identifies optimal patterns of land use conversion under different objective trade-offs. Objectives treated are the minimization of agricultural land loss and of water demand, and the maximumization of recharge over withdrawal. The second objective pertains to water management during drought, while the third refers to sustainable groundwater management. Results show that, depending on the relative importance given each of these two objectives, land moving out of sugar cane will differ significantly in amount and by type of irrigation presently used. The relative importance of these objectives thus needs to be determined if water is to play a coherent and guiding role in land use planning.     

城市规划与城市土地经营协调机制研究

城市规划与城市土地经营是城市土地资源配置的两种不同方式,二者之间具有明显的统一性,城市规划是城市土地经营的基础,而城市土地经营对城市规划具有促进作用.但在城市土地经营视角下,城市规划具有刚性与呆滞、体制和机制的约束等缺陷,而城市土地经营也由于经济利益冲动等原因对城市规划产生冲击.因此,作者哌认为,要实现两者的协调互动,应从革新城市土地经营理念、建设土地产权制度、创新城市土地经营模式等方面发展与完善城市土地经营.并且,应不断完善城市规划对城市土地经营的响应,主要响应路径包括强化社会公共政策理念、加强经济思维以及改革城市规划体制等,以此促进城市规划与城市土地经营的协调发展.     

Fluid Institutions: Commons in Transition in the Periurban Interface

Amidst growing concern about the decline of the commons, this case underscores the importance of understanding how the commons are refashioned and remade to address emerging challenges in periurban spaces. This article describes how institutions surrounding the use of common property resources get transformed and evolve in periurban contexts. What were once johads – common property village ponds – undergo a change in their usage from storing rainwater to storing waste water of the city for irrigation. This emerges as a collective response to the uncertainty attached to the availability of waste water. New institutions evolve with regard to contributions to waste water infrastructure, as well as the appropriation of waste water. Further research should document the changing use of village commons and the emergence of new institutions governing them.     

Patterns of Irrigated Agricultural Land Conversion in a Western U.S. Watershed: Implications for Landscape-Level Water Management and Land-Use Planning

In irrigated agricultural landscapes, land-use conversion may have landscape-level social, hydrological, and ecological effects. We used geographic information systems (GIS) and interviews to analyze development effects on irrigation in the Henry's Fork Watershed, Idaho. Farmers developed irrigation there in the 19th century, and incidental recharge from canal seepage and flood irrigation raised groundwater levels and expanded wetlands. Cohesive culture in agricultural communities sustained irrigation systems until amenity-driven demographic shifts beginning in the 1970s led to development approved by local governments with land-use planning but no water-management authority. Although only 5% of irrigated land has been converted, development has fragmented irrigated landscapes and made canal-system operation more difficult, potentially reducing groundwater levels, wetland extent, and return flows critical to downstream irrigators and fish and wildlife. We discuss future scenarios, highlighting the need for increased communication among local and state governments regarding land use and water management in irrigated landscapes across the West.     

Land use legacies of the Ohio River Basin: Using a spatially explicit land use change model to assess past and future impacts on aquatic resources

Land uses and their legacies are a major driver of human impacts on the environment. Decision makers have recognized that the legacies of land-use activities continue to influence ecosystems, particularly aquatic ones, for decades or centuries. The main objectives of this paper are to develop land use legacy maps to (1) assess historical and future (predicted) shifts in dominant land use classes (urban, agriculture, forest) in the Ohio River Basin (ORB), and (2) determine the past and future location of catchments in the ORB exceeding critical land use thresholds (10% and 38% urban and agricultural use of catchment respectively) for water quality and other aquatic resources. Our land use legacy simulations show that approximately 80% of the ORB has remained as agriculture (∼37%), forest (∼34%), urban (∼7%) and other classes (∼2%) from 1930 to 1990. Within the remainder of landscape, agriculture to forest (∼16%) and agriculture to urban (∼1.5%) transitions were the most common land use changes between 1930 and 1990. Our forecast model shows that approximately 94% of the ORB will remain as forest (∼47.46%), agriculture (∼35.77%), urban (∼8.84%) and other classes (∼2.07%) between 2000 and 2050. 1.44% and 1.37% of the ORB is predicted to transition from forest to urban and agriculture to urban between 2000 and 2050, respectively. Our results also demonstrate that 13% and 74% of the catchments in the ORB already exceeded critical urban and agricultural land use thresholds in 1930, respectively. We predict that 37% of catchments in the ORB will have exceeded critical urban land use thresholds by 2050, whereas the proportion of catchments to exceed critical agricultural use will decrease to 45%.     

Efficient use of resources: urban waste ash and soil fertility on the Jos Plateau, Nigeria

Waste disposal constitutes an acute problem in numerous African cities. One solution could lie in the recycling of the nutrient-rich waste into agriculture taking place in and around cities. Farmers involved in vegetable production around Jos, Nigeria, have developed a sophisticated soil fertility management strategy combining inorganic fertilizers, manure and urban waste ash. This paper: (1) investigates the socio-economic constraints linked to obtaining scarce organic inputs, particularly urban waste ash and the health hazards (particularly heavy metal contamination of soil and crops) caused by using this ash and (2) suggests ways to improve use of this important resource.     

武汉市城市边缘区村镇发展模式与土地利用政策研究

在城乡统筹发展战略的指引下,探讨武汉市城市边缘区实现生态框架构建、区域经济发展诉求、城市整体空间优化与农用地资源保护协调共赢的土地利用机制。分析武汉市城市边缘区的土地利用特点、产业发展规划及其导向作用对村镇建设模式与土地利用政策的要求,将该区涉及的12个区、37个乡(镇、街、场)分为生态控制型乡镇、引导发展型乡镇和城镇发展型乡镇3类。以区域产业布局为支撑,构建"镇区+社区+园区"的区域村镇发展体系;将区域内650个原有村庄分为搬迁型、控制性和发展型进行社区化建设,以期为促进城市边缘区村镇发展提供模式借鉴;并从城乡建设用地增减挂钩、集体建设用地流转、农用地制度改革及区域土地综合整治等方面,探索相关土地利用政策的应对机制。     

基于农业多功能视觉的都市农业用地效益时空变化研究——以西安都市圈为例（英文）

The excessive expansion of urbanized areas has resulted in haphazard land utilization, immoderate consumption of superior agricultural land and water resources, significant fragmentation of agricultural landscape, and gradual deterioration of the agro-ecological environment. Combined, these factors cause poor land use efficiency. Under these circumstances, comprehensively assessing land use efficiency for urban agriculture is a key issue in land use research. Currently, evaluation methods for agricultural land use efficiency narrowly concentrate on aspects of economic input and output. However, urban agro-ecosystems can provide diverse economic, social, and ecological services and functions. In particular, the social and ecological services and functions originating from agricultural land, which have a higher value than economic services, play a significant role in ensuring regional social, ecological, and environmental security. However, recent research has rarely taken these benefits into consideration. Therefore, land use value has been greatly underestimated, which has resulted in mishandled and poor land use policies. In this study, we apply Landsat imagery and social and economic statistical data for the Xi'an metropolitan zone(XMZ) to investigate agricultural multi-functionality. We develop an evaluation framework for urban agricultural land use efficiency and identify agro-ecosystem services and functions as important outputs from agricultural land. The land use efficiency of urban agriculture is then evaluated using ecosystem services models, providing a mechanism for assessing spatial-temporal changes in land use efficiency in the XMZ from 1999 to 2015. Four important conclusions are reached from this analysis. First, the rapid urbanization and agricultural transformation from traditional cereal cultivation to modern urban agriculture has resulted in steadily increasing costs, outputs, and land use efficiency of urban agriculture. The total output value increased 41% and land use efficiency per hectare increased by 33.13% on average. Second, the spatial patterns of comprehensive output and land use efficiency were dominated by economic outputs from agricultural land. Areas near cities, which are dominated by orchard and arable land, providemore economic functions. These areas support and regulate services due to the transformation from extensive cereal production to intensive modern urban agriculture; therefore, they have higher output value and land use efficiency. In contrast, areas distant from cities, towns, and high traffic roads, namely, remote rural areas, provide more support and regulating services, but have relatively lower economic function due to inaccessibility to urban markets and slow agricultural transformation. Therefore, these areas have lower output value and land use efficiency. The spatial change in agricultural output and land use efficiency in urban areas is strongly dependent on the degree of urbanization and agricultural transformation. Third, the total output value and land use efficiency of urban agriculture measured with our approach are much higher than evaluations using traditional methods. However, the spatial patterns measured using the two approaches are in agreement. The evaluation framework integrates ecological services and economic and social functions into a comprehensive output from agricultural land. This approach is more methodical and accurate for evaluating the comprehensive efficiency of land use based on quantities and spatial scale because they are at the pixel scale. Finally, the evaluation results have important implications for enhancing current agricultural subsidies and even implementing ecological payment policies in China. Most importantly, they can be directly applied to agricultural transformation regulations, decision-making, and guidance for rational land utilization.     

Spatial-temporal change in urban agricultural land use efficiency from the perspective of agricultural multi-functionality: A case study of the Xi’an metropolitan zone

The excessive expansion of urbanized areas has resulted in haphazard land utilization, immoderate consumption of superior agricultural land and water resources, significant fragmentation of agricultural landscape, and gradual deterioration of the agro-ecological environment. Combined, these factors cause poor land use efficiency. Under these circumstances, comprehensively assessing land use efficiency for urban agriculture is a key issue in land use research. Currently, evaluation methods for agricultural land use efficiency narrowly concentrate on aspects of economic input and output. However, urban agro-ecosystems can provide diverse economic, social, and ecological services and functions. In particular, the social and ecological services and functions originating from agricultural land, which have a higher value than economic services, play a significant role in ensuring regional social, ecological, and environmental security. However, recent research has rarely taken these benefits into consideration. Therefore, land use value has been greatly underestimated, which has resulted in mishandled and poor land use policies. In this study, we apply Landsat imagery and social and economic statistical data for the Xi’an metropolitan zone (XMZ) to investigate agricultural multi-functionality. We develop an evaluation framework for urban agricultural land use efficiency and identify agro-ecosystem services and functions as important outputs from agricultural land. The land use efficiency of urban agriculture is then evaluated using ecosystem services models, providing a mechanism for assessing spatial-temporal changes in land use efficiency in the XMZ from 1999 to 2015. Four important conclusions are reached from this analysis. First, the rapid urbanization and agricultural transformation from traditional cereal cultivation to modern urban agriculture has resulted in steadily increasing costs, outputs, and land use efficiency of urban agriculture. The total output value increased 41% and land use efficiency per hectare increased by 33.13% on average. Second, the spatial patterns of comprehensive output and land use efficiency were dominated by economic outputs from agricultural land. Areas near cities, which are dominated by orchard and arable land, provide more economic functions. These areas support and regulate services due to the transformation from extensive cereal production to intensive modern urban agriculture; therefore, they have higher output value and land use efficiency. In contrast, areas distant from cities, towns, and high traffic roads, namely, remote rural areas, provide more support and regulating services, but have relatively lower economic function due to inaccessibility to urban markets and slow agricultural transformation. Therefore, these areas have lower output value and land use efficiency. The spatial change in agricultural output and land use efficiency in urban areas is strongly dependent on the degree of urbanization and agricultural transformation. Third, the total output value and land use efficiency of urban agriculture measured with our approach are much higher than evaluations using traditional methods. However, the spatial patterns measured using the two approaches are in agreement. The evaluation framework integrates ecological services and economic and social functions into a comprehensive output from agricultural land. This approach is more methodical and accurate for evaluating the comprehensive efficiency of land use based on quantities and spatial scale because they are at the pixel scale. Finally, the evaluation results have important implications for enhancing current agricultural subsidies and even implementing ecological payment policies in China. Most importantly, they can be directly applied to agricultural transformation regulations, decision- making, and guidance for rational land utilization.     

流域尺度土地利用调蓄视角的雨洪管理探析

发达国家雨洪管理焦点历经管网设计、不透水面阈值控制、低影响开发及土地利用管理等过程,呈现"多尺度多视角衔接"趋势。本文聚焦太湖流域土地利用调蓄功能变化机制及管理应用,揭示了1985-2015年来建设占用耕地是调蓄功能降低的主要原因;发现基于小流域的调蓄功能变化与建设用地强度整体低关联,但局部高相关,高相关的地区位于大城市或某些乡镇周边的建设增长热区,而这些热区的建设用地与调蓄空间规模较大且接触机会更多,是开发之前调蓄空间保护、开发控制以及开发之后综合管理等3个土地利用调蓄目标因子协调不当的结果;最后提出流域尺度土地利用调蓄视角的雨洪管理"345"模式,即以3个目标因子和5类控制要素为基础,实施土地利用调蓄创建、防御、拓展与保护等4类差别化战略模式,从更大尺度认识老城区和新区的雨洪关联,拓展海绵城市建设的本土认知和视野。     

城市旅游综合体土地利用空间格局演变及驱动机制——以西安曲江为例

判识城市旅游综合体用地格局的演变规律及驱动机制,对于优化城市功能结构和构建城市现代服务体系具有重要意义。本文以西安曲江城市旅游综合体为例,采用土地利用变化指数模型和GIS分析技术,探究其用地分异过程及机制。结果显示,曲江由农业生产和村居功能为主导的乡镇聚落,转变为以旅游功能为核心、多元用地形态圈层布局的城市旅游综合体过程中,其用地形态共经历了均质无序、极化–扩散和均衡集约三个阶段。而这一演化过程,实则是在土地差异化增值形成级差地租的条件下,多元用地主体理性选择的结果。文章认为,保证城市旅游综合体合理的发展用地、有序实现土地增值及发挥地价杠杆的调节作用,是实现城市旅游综合体土地集约利用和功能协同发展的根本前提。     

城市土地利用扩展的空间模式与动力机制

本文通过系统地评析国外不同学术派系对城市土地利用扩展的空间模式、动力机制及管理政策的研究进展 ,指出其研究重点已从归纳空间演替模式深化到探究城市土地开发过程中的决策过程与动力机制 ,从崇尚土地市场的自由运作转向对其进行精明管理。     

Human impacts on fluvial systems in the Mediterranean region

The long history of substantial human impacts on the landscape of the Mediterranean region, and their effects on fluvial systems, is documented. These effects have included impacts of deforestation and other land use changes, agricultural terracing on a wide scale, water transfers, and irrigation schemes. During the 20th century, major changes were made directly to channels through channelisation, construction of dams of various sizes, and extraction of gravel, and indirectly by reforestation. These changes have caused a major phase of incision on some rivers. Runoff and soil erosion have been affected by types of crops and agricultural practices as well as by the varying extent of cultivation and grazing. Some recent agricultural practices involve wholescale relandscaping of the topography and alteration of surface properties of material. The importance of analysing the connectivity within different land units and of the spatial position of human activity within a catchment is illustrated. The analysis of connectivity is the key to understanding the variability of impact and the extent of propagation of effects.     

小城镇土地利用问题与对策研究--以深圳市坪地镇为例

主要探讨了以下几个问题：一是城市建设用地规模巨大,乡镇企业占地比例过高;二是城镇发展过程中侵占耕地数量大,且发展速度快;三是在土地高速的开发利用过程中,非农建设用地的利用率低,存在严重的土地资源浪费现象;四是在非农建设用地发展过程中,违法使用土地的现象十分普遍。并提出了科学编制土地利用总体规划、开展土地分等定级估价工作、加强土地管理及完善土地立法等建议。     

Land reform and the new elite: Exclusion of the poor from communal land in Namaqualand, South Africa

The reserves and homelands across South Africa share a common history of policy interventions resulting in sedentarization, villagization and formalization of communal land use. In Namaqualand, such interventions culminated in the 1980s with attempts by the state and local vested interests to privatize the commons in the three largest Namaqualand reserves, including Leliefontein. This proposed privatization, although ostensibly aimed at averting land degradation and modernizing agricultural production, was as much about the apartheid state's broader strategy of co-option, and served to further long standing processes of class formation in the coloured communal areas of Namaqualand. In the post-apartheid period land reform has expanded the communal land-base in Namaqualand by over 25%. In spite of this, the management of the new commons in Leliefontein has many of the characteristics of land management policies imposed during apartheid. As a result, the new commons have effectively been arrogated by the same category of people who would have benefited under past privatization initiatives.This paper examines how the interests of a local elite have gained exclusive access to the new commonage farms. This has come about despite the government's commonage policy which privileges access by poorer, disadvantaged communal farmers. This case study uncovers the dynamic complexity of community driven land reform especially in relation to the roles of rural elites and their relationship to government institutions.     

城乡土地市场一体化对土地利用/覆被变化的影响研究综述

为了破除城、乡土地市场分割现状,最终实现“山水林田湖”共同发展的目标,需要推进城乡土地市场一体化发展。分别从城市土地市场、农村集体性建设用地非正式市场和农村农用地流转市场3个方面对土地利用/覆被变化的影响机理研究进行梳理。结果认为：第一,城乡土地市场割裂的状况仍然存在,并且对土地利用/覆被变化产生较大影响;第二,城市国有建设用地市场的发育程度不同,直接影响土地供求关系和土地利用结构,甚至对土地利用配置效率产生影响;第三,农村集体性建设用地市场已现雏形,但由于产权的模糊性而缺乏法律上的监管和保障,加快了土地利用类型的过度非农化转化。另外,农用地流转市场的出现也改变了土地利用的功能和类型;最后,城乡土地市场分割现象会对土地利用系统的可持续性和生态环境产生一定影响。在以上研究结果基础上认为未来研究需要进一步加强对城乡土地市场一体化的分析,且揭示城乡土地市场一体化对区域土地利用/覆被变化影响机理（格局、过程、效应）。     

转型期省际城镇土地利用绩效格局演变与机理

以中国省域单元为例,在界定城镇土地利用绩效内涵基础之上,从结构、效益、效率及管理四维度构建城镇土地利用绩效评价体系,利用改进熵值法测度省际城镇土地利用绩效;并运用空间统计模型、R/S分析法及PCA模型,对2000-2012年中国省际城镇土地利用绩效格局时空演变及机理进行了初步的探讨。研究表明：① 2000年以来省际城镇土地利用绩效水平不断提升,区域差异较显著;绩效演变呈现出东西方向递增,南北方向倒“U”型分布格局。② 省际城镇土地利用绩效全局空间上表现出显著的正自相关,呈现绩效高(低)—高(低)集聚模式;局部Ⅰ绩效热点区主要集聚在东部沿海的京津及江浙沪,且不断向珠三角演化,Ⅱ绩效次热区主要集中在中原城市群、华北、华中及华南地区,Ⅲ绩效次冷区主要分布在西南地区及东北地区,而Ⅳ绩效冷点区主要集中在西部的藏疆蒙甘青地区,形成稳定“L”型塌陷形态;省际城镇土地利用绩效具有明显的分形特征,未来绩效值将呈现出继续增长的演化态势,且增长显著区分布在京津及长三角地区。③ 城镇化、产业升级、科技发展及市场化综合驱动转型期省际城镇土地利用绩效格局演变。