中国近期农村人口迁移态势研究

采用第四次、第五次人口普查所获得的人口迁移数据,分析了中国农村人口迁移在全国总迁移人口中的地位变化的省际总体特征和个体特征,探讨了各省级单元农村人口迁移在总人口迁移中的地位在20世纪80年代和90年代随时间变化的原因。进一步重点研究了中国农村人口迁移的时空分布格局,分别从省际、省内两个空间尺度,分迁入、迁出两个角度对中国农村人口迁移的规模和流向态势进行了深入分析。     

A late Holocene record of land-use history,soil erosion,lake trophy and lake-level fluctuations at Bjäresjösjön (south Sweden)

Land-use history, soil erosion, lake trophy and lake-level fluctuations during the last 3000 years were reconstructed through a multidisciplinary palaeolimnological study (pollen, plant macrofossils, diatoms, physical and chemical analysis, magnetic measurements and radiometric methods) of a small eutrophic lake in southern Sweden (Bjäresjösjön, Scania). There are striking responses in diatom, chemical, sediment yield and magnetic records to land-use changes documented by pollen analysis or historical sources, and to lake-level changes identified from sedimentary changes. Our multidisciplinary approach assists interpretation of the processes controlling long-term changes and separation of the effects of different factors (land-use changes, lake-level fluctuations) on individual biostratigraphical records. Climate has controlled processes in the lake indirectly, through lake-level fluctuations, from the Late Bronze Age to the Viking Age (700 BC-AD 800). Since the Viking Age, land-use controlled most of the changes observed in the lake's development and soil erosion processes. Major changes in lake development occurred during the last 200 years, due to a drastic increase in soil erosion and water eutrophication during a period of agricultural modernization.     

Distinct export dynamics for dissolved and particulate phosphorus reveal independent transport mechanisms in an arable headwater catchment

This paper investigates particulate phosphorus (PP) and soluble reactive phosphorus (SRP) concentrations at the outlet of a small (5 km²) intensively farmed catchment to identify seasonal variability of sources and transport pathways for these two phosphorus forms. The shape and direction of discharge‐concentration hystereses during floods were related to the hydrological conditions in the catchment during four hydrological periods. Both during flood events and on an annual basis, contrasting export dynamics highlighted a strong decoupling between SRP and PP export. During most flood events, discharge‐concentration hystereses for PP were clockwise, indicating mobilization of a source located within or near the stream channel. Seasonal variability of PP export was linked to the availability of stream sediments and the export capacity of the stream. In contrast, hysteresis shapes for SRP were anticlockwise, which suggests that SRP was transferred to the stream via subsurface flow. Groundwater rise in wetland soils was likely the cause of this transfer, through the hydrological connectivity it created between the stream and P‐rich soil horizons. SRP concentrations were the highest when the relative contribution of deep groundwater from the upland domain was low compared with wetland groundwater. Hence, soils from non‐fertilized riparian wetlands seemed to be the main source of SRP in the catchment. This conceptual model of P transfer with distinct hydrological controls for PP and SRP was valid throughout the year, except during spring storm events, during which PP and SRP exports were synchronized as a consequence of overland flow and erosion on hillslopes. Copyright © 2015 John Wiley & Sons, Ltd.     

国外生态工业园区的建设及其对我国的启示

本文在引进生态工业园区基本概念与理念的基础上,介绍了生态工业园区的产生及其在世界各国的发展历程,然后以美国与荷兰生态工业园区的建设为例,介绍了生态工业园区成功运行所需要的因素,尤其是论证了生态工业园区建设中各利益方参与和信息收集的重要性,从而为我国生态工业园区的建设和发展提供了有益借鉴.     

江苏省乡村经济类型的初步分析

本文采用模比系数法,按乡村经济发展水平、产业结构和农业结构三类指标,将江苏省65个县(县级市)划分为8个乡村经济类型(含12个亚类型),以便为乡村发展的宏观决策和分类指导提供参考,为开展江苏乡村地理的选点调查打下基础,对乡村经济类型的研究方法作初步尝试。     

明确目标强化措施推进地震安全农居工程建设

我国是一个农业大国,又是一个多地震国家.近年来随着经济社会的快速发展,农村面貌也发生了根本变化,但是农村民居的抗震设防工作仍十分薄弱.为了贯彻全国农村民居防震保安工作会议精神,枣庄市研究制定了推进农居地震安全工程的意见.本文简述了枣庄市政府推进农居安全工程工作的目标、任务、 实施步骤和措施.     

欠发达地区农村工业化与小城镇发展关系再分析

为深入重新认识现阶段中国农村工业化与小城镇发展的相互关系及其政策意义，深化对中西部地区农村工业发展现状和前景及其对发展重点小城镇战略的支持和贡献能力的认识，文章结合洞庭地区移民建镇工程实施的具体经验，基于对当地乡镇企业和移民的问卷调查结果，分析案例地区农村工业发展和农业剩余劳动力转移的现状和前景，从企业联系和劳动力就业空间行为和区位选择角度，论述了广大农村地区人口和经济活动空间分布的动态特征，进而探讨不同类型小城镇的社会经济空间集聚潜力，并为地方政府制定科学合理的农村工业化和城市化战略提出政策建议。     

Modelling the impact of agroforestry on hydrology of Mara River Basin in East Africa

Land‐use change is one of the main drivers of watershed hydrology change. The effect of forestry related land‐use changes (e.g. afforestation, deforestation, agroforestry) on water fluxes depends on climate, watershed characteristics and spatial scale. The Soil and Water Assessment Tool (SWAT) model was calibrated, validated and used to simulate the impact of agroforestry on the water balance in the Mara River Basin (MRB) in East Africa. Model performance was assessed by Nash–Sutcliffe Efficiency (NSE) and Kling–Gupta Efficiency (KGE). The NSE (and KGE) values for calibration and validation were: 0.77 (0.88) and 0.74 (0.85) for the Nyangores sub‐watershed, and 0.78 (0.89) and 0.79 (0.63) for the entire MRB. It was found that agroforestry in the watershed would generally reduce surface runoff, mainly because of enhanced infiltration. However, it would also increase evapotranspiration and consequently reduce baseflow and overall water yield, which was attributed to increased water use by trees. Spatial scale was found to have a significant effect on water balance; the impact of agroforestry was higher at the smaller headwater catchment (Nyangores) than for the larger watershed (entire MRB). However, the rate of change in water yield with an increase in area under agroforestry was different for the two and could be attributed to the spatial variability of climate within the MRB. Our results suggest that direct extrapolation of the findings from a small sub‐catchment to a larger watershed may not always be accurate. These findings could guide watershed managers on the level of trade‐offs that might occur between reduced water yields and other benefits (e.g. soil erosion control, improved soil productivity) offered by agroforestry. Copyright © 2016 John Wiley & Sons, Ltd.     

低空摄影测量在农村地籍调查中的应用

通过改进低空摄影测量传统的像控点布设方法、内业测图方式、外业调绘方法,实现了低空摄影测量在农村地籍调查中的应用。并对实验区加密成果及图形精度进行检查、统计、分析,总结出影响图形精度的主要原因,并提出有益于提高图形精度的方法,确保农村地籍图形精度。