Land use regulations and the dispersion of the IT Industry in the San Francisco Bay area

Urban economists have recently found evidence that land use regulations prevent the efficient migration of workers among regions, generating losses in output. By contrast, there is a lack of work that directly considers the relationship between land use regulations and the geography of firms and industries. Since the 1980s, the IT industry has dispersed from its historical core, Silicon Valley, around the broader San Francisco Bay Area. This study finds that restrictive land use practices have limited IT firm creation in Silicon Valley, pushing the industry to less productive parts of the regional economy.     

Effects of land‐use change and climate variability on streamflow in the Woken River basin in Northeast China

In this study, the soil and water assessment tool, which is a widely used hydrological model, is applied to study the response of streamflow to land‐use changes and climate variability in the Woken River basin in northeastern China. This model is calibrated and verified based on sensitivity analysis to simulate the effects of land‐use change, climate variability, and extreme land‐use scenarios on streamflow. Simulations are performed to construct different scenarios for quantitative analysis. Compared with the base period, the land‐use change reduced the annual average streamflow and had little effect on the monthly streamflow. Climate variability increased the average annual streamflow and had a substantial effect on monthly streamflow. The effect of climate variability on streamflow was much greater than that of land‐use changes. Under the extreme land‐use scenarios, the annual average streamflow under the forestland scenario decreased, and the average annual streamflow under the grassland and agricultural land scenarios increased. Both the forestland and grassland scenarios exhibited lower monthly streamflow from March to August with especially large influences in June–August, which was when floods were more likely to occur. The agricultural land scenario exhibited the opposite trend. These results indicate that climate variability will obviously change streamflow and that natural disasters related to both high and heavy precipitation must be emphasised. Relevant departments can optimize the land‐use structure and spatial layout to mitigate the negative effects of climate variability.     

国内土地利用生态风险研究进展

作为生态风险领域的重要研究主题，土地利用生态风险研究近年来热度持续上升。为考察国内土地利用生态风险的研究进展，选取该研究主题现有国内文献，通过编码、分析和归纳，从研究区域分布、数据采集与处理、土地利用分析方法、生态风险分析理论与方法几个方面进行分析，以期对土地利用生态风险研究现状做出清晰准确的概括，为后续研究提供参考。研究表明，目前的研究区域覆盖面广泛，采样对象特征呈现多样化趋势，其中西部地区占比较大，反映了学术界对西部欠发达地区生态健康的密切关注。“3S”技术作为主要的数据获取手段，为现有研究提供了详实的数据资料。根据数据进行土地利用变化分析是生态风险评估的基础，目前以描述性分析方法为主，较少使用预测模型。生态风险计算方法以国际传统生态风险评价理论和景观生态学理论为主要理论依据，其中基于后者的ERI方法可以进行深入的生态风险时空分析，近年来逐渐成为主流方法。综合来看，由于部分贫困地区数据采集技术普及程度有限，为响应和支持国家乡村振兴、精准扶贫等战略，后续可适当增加对经济欠发达农村地区和山区的研究数据获取。定量研究方式虽然能在一定程度上反映研究区域的土地利用生态风险状态，但其背后复杂的驱动因素仍需更多的研究投入，为减少评价过程中研究者主观经验的干扰，未来可适当引入不确定性分析。     

Making Room for the River

Abstract

Problem, research strategy, and findings: In this study we analyze plan integration for flood resilience in the city of Nijmegen, the site of the largest Room for the River project in The Netherlands. Little is known about the degree to which local and regional plans are coordinated with the national Room for the River program or about the cumulative influence of plans on flood vulnerability. To effectively investigate these issues, we use and build upon the Plan Integration for Resilience Scorecard (PIRS) concept and method, which analyzes the consistency and effects of networks of plans on community vulnerability. We expand the scope to include plans from multiple administrative scales and the focus to include environmental vulnerability. Using a three-phase evaluation process, we demonstrate that Room for the River policies are well integrated in Nijmegen’s network of plans, particularly with respect to flood safety and natural protection. However, we also find that policies at different administrative scales lack consistency in some places, some socially vulnerable neighborhoods receive comparatively little policy attention, and local plans often prioritize development over flood resilience, though higher tier plans sometimes make up for these policy gaps. Flood resilience is still finding its way in the Dutch planning system.

Takeaway for practice: The PIRS offers planning practitioners a method to assess how networks of plans influence community vulnerability and, as demonstrated in this analysis, to determine the degree to which plans at multiple administrative scales target the most physically, socially, and environmentally vulnerable geographic areas. It can be used to support the ambitious goals of a program like Room for the River and align them with local development priorities.     

黄河故道—豫北平原土地整治片区水生态环境现状分析与评价

山水林田湖草作为生命共同体，其生态保护与修复必须以生态系统服务功能提升为导向，而且需要考虑生态系统本身脆弱性，协调好保护与发展关系，从山、水、林、田、湖、草六大生态要素总体归纳生态保护修复指导。按照生命共同体理念，系统分析黄河故道—豫北平原土地整治片区水生态环境问题，对片区水生态环境现状进行整理，采用多因素综合评价方法对片区水生态环境进行综合评价，为片区山水林田湖草综合分析耦合评价提供技术支撑。     

矿业用地股份合作制：法律机理与实现路径

矿业用地股份合作社是我国土地股份合作社的一种特殊类型。与矿业用地征收以及临时用地等相比较，其具有减少交易成本、促进负外部性内部化，以及有利于农民分享土地增值收益等优势。矿业用地股份合作制具有复合型的企业产权结构，是以产权联合为基础的成员联合，在企业内部治理结构中，须采用双重决策机制，从而兼顾企业的决策效率和维护企业的人合性特征。在企业盈余分配中，一方面要发挥资本在企业中的主导作用，另一方面也要兼顾现阶段农地所承担的社会保障功能的发挥。由于矿业用地的负外部性，国家在矿业企业设立过程中，应该对矿业用地行为进行公法规制，从而为矿业用地股份合作社提供长效发展机制。     

北京市2005～2015年植被覆盖变化对蒸散发量的影响

为更准确了解蒸散发量(ET)时空分布及其随土地利用变化的规律,以MOD16数据为基础,探讨不同土地利用类型及其相互间转化对北京市蒸散耗水的影响。结果表明,2005~2015年间,北京市约有2587.69km^2的面积发生了土地利用类型的转变,其中变化最多者为林地转变为耕地,达213.57km^2;北京市植被覆盖区域多年ET平均值为406.63mm,北京市ET空间分布呈西北山区高、东南平原低的特点,且不同植被类型的ET大小不同,其中林地最大,草地次之,耕地最小;在2005~2015年,北京市ET呈上升趋势,速率为8.64mm/a,总耗水量的增加速率为4881.09×104 m3。植被覆盖减少和气象因素变化的综合作用导致北京市的蒸散耗水呈逐年上升趋势。     

Inverse Planning in the Cracks of Formal Land Use Regulation: The Bottom-Up Regularisation of Informal Settlements in Maputo,Mozambique

This paper focuses on a case of ‘non-public planning’ in an informal neighbourhood of Maputo, Mozambique. Here, several residents undertook some planning duties (e.g. drawing up a detailed plan) in order to regularise their informal dwellings in lieu of the Municipality, due to its inertia. This was an attempt to deal with the shortcomings of urban planning in Maputo, not by flouting the system, but by remoulding it and creating a sort of alternative formality. The detailed analysis of this case is an opportunity for critical reflection on the risks, potentialities and inherent limits of such a form of non-public planning in Mozambique, which we label ‘inverse planning’.     

宗地划分界址点坐标的计算

在土地划分和地籍变更测量中，通过地籍变更的新界址线应满足面积条件、图形条件和方向条件，列出了相应的条件方程式后，解出新增界址点的坐标及实地标定要素，从而达到比较精确地划分土地并准确标定新界址点的目地．     

石屑水泥管在农田地下排水工程中的推广应用

通过技术引进和试验，利用当地采石场废弃的石屑研制经济有效的暗管管材，应用治理渍害稻田地下暗管排水工程技术，并合理确定暗管埋深及间距，有效地排除了田间渍水，改善了土壤生态环境，提高了作物产量，同时进一步研究了石屑水泥管管材配比及管子结构，提高了管材性能，减少了工程投资，并对石屑水泥管地下排水工程的施工和运行管理等进行了探讨和部结。