The contribution of physical geography to environmental public policy development in Mexico

In recent years, physical geography in Mexico has contributed to the enterprise of geographical science by integrating with fields of study closely related to topics of sustainable development. This paper outlines the contribution of the discipline to environmental public policy development, particularly ecological land use planning and integrated watershed management. In terms of applications, physical geography appears to have reached a stage of maturity in Mexico. However, it must offer a stronger leadership in areas such as ecoregional analysis (in an integrated fashion, and not only from the biological‐ecological perspective) and regional vulnerability to global change processes. An excellent opportunity exists for scientists and decision makers to develop a common agenda.     

Back to the Future? Planning for environmental outcomes and the new Caring for our Country program

The Australian government Caring for our Country (CfoC) program, first announced in 2008, has sought to build on and enhance previous experience with Australian natural resource management policy. This paper critically examines the initial design, planned delivery, and first round of competitive funding outcomes of the new program. This analysis shows that the initial design and delivery of the CfoC model was ad hoc, politicised, and lacking in transparency. The paper concludes that a more systematic and transparent approach for achieving sustainable environmental outcomes is required in order for this new program to achieve its intended objectives. These implications are of interest to Australian and international geographers, natural resource planners, scientists and policy makers concerned with the design, delivery and outcomes of large natural resource and environmental management programs.     

Agricultural effluent control under uncertainty: An inexact double-sided fuzzy chance-constrained model

An inexact double-sided fuzzy chance-constrained programming (IDFCCP) method was developed in this study and applied to an agricultural effluent control management problem. IDFCCP was formulated through incorporating interval linear programming (ILP) into a double-sided fuzzy chance-constrained programming (DFCCP) framework, and could be used to deal with uncertainties expressed as not only possibility distributions associated with both left- and right-hand-side components of constraints but also discrete intervals in the objective function. The study results indicated that IDFCCP allowed violation of system constraints at specified confidence levels, where each confidence level consisted of two reliability scenarios. This could lead to model solutions with high system benefits under acceptable risk magnitudes. Furthermore, the introduction of ILP allowed uncertain information presented as discrete intervals to be communicated into the optimization process, such that a variety of decision alternatives can be generated by adjusting the decision-variable values within their intervals. The proposed model could help decision makers establish various production patterns with cost-effective water quality management schemes under complex uncertainties, and gain in-depth insights into the trade-offs between system economy and reliability.     

基于知识对象的土地管理空间数据库模型设计与实现

空间数据模型建立的目的是反映现实世界。当今的GIS系统的空间数据模型,主要反映地图制图领域的点、线、面对象管理与操作的几何知识。本文通过对比研究,发现土地管理空间概念的领域知识,包含几何知识。几何知识是依据几何特征属性识别的土地管理领域知识之一。将土地管理领域空间概念的领域知识对象化,建立与几何知识对象等价的对象组件,扩展对象关系型的空间数据模型,建立了"[领域空间知识对象]+[GIS的点、线、面的几何对象]+[扩展属性]"的空间数据模型。这种模型简化了空间数据库的管理操作,降低了对工作人员制图专业知识的要求,降低了空间对象实例与其属性的耦合度,减少了政策变化对数据的影响程度,提高了数据的稳定性和共享度。鉴于这种空间数据库模型,本文开发了空间知识对象的江苏省"515"城乡一体化地籍系统的数据检查子系统,在镇江市、江都市等多个市县的"515"城乡一体化地籍调查的数据检查入库工作中得以应用,证明了模型设计的可行性,收到了良好的效果,为专题GIS空间数据管理,提供了一种的新的空间数据模型。     

改进的模拟退火遗传算法在地下水管理中的应用

对于高度非线性、非凸的地下水管理模型,传统优化方法难以找到全局最优解。本文采用模拟退火遗传算法求解地下水管理模型,并从三个方面对算法进行改进:引入小生境技术,采用自适应交叉和变异概率,在选择过程中采用最优保存策略,从而提高算法的全局寻优能力和收敛速度。采用惩罚函数法处理约束条件。用Fortran 90语言编制了计算程序,并通过Schaffer测试函数验证了该算法不仅具有强大的全局寻优能力和局部搜索能力,而且具有较快的收敛速度和较高的优化精度。将该算法应用到某研究区地下水管理中,取得了较好的效果。     

Modelling infiltration enhancement in a tropical urban catchment for improved stormwater management

To mitigate the impacts of impervious surfaces in urban areas, structures such as bioretention systems and permeable pavements have been installed to enhance infiltration in many countries. However, relatively little knowledge is available regarding the performance of such infiltration‐based structures in humid tropical and highly urbanized areas. This study investigates the feasibility of enhancing the infiltration of stormwater in tropical urbanized areas using Singapore as a case study. It first shows that the rainfall depth and intensity are both high, but the time interval between consecutive rainfall event is long in Singapore. It then numerically simulates single‐event local infiltration and finds that the fraction of infiltrated rainfall is actually high. It finally performs catchment‐scale simulations and finds that bioretention systems can enhance infiltration and groundwater recharge particularly during wet periods. However, local mounding of groundwater can be significant and can hinder the performance of those structures. Furthermore, with 5% of catchment area being converted to such structures, the infiltration of the entire catchment is enhanced but still not yet up to the natural level. To increase the overall effectiveness, future studies can look into bioretention systems with underdrain systems. Copyright © 2016 John Wiley & Sons, Ltd.     

Root properties of vegetation communities and their impact on the erosion resistance of river dikes

Predicted climate change and the associated sea level rise poses an increased threat of flooding due to wave overtopping events at sea and river dikes. To safeguard the land from flooding it is important to keep the soil erosion resistance at the dikes high. As plant roots can be very effective in reducing soil erosion rates by concentrated flow, the main goal of this study is to explore the variability in root system characteristics of five dike vegetation communities along the Scheldt River (Belgium) and to assess their effectiveness in controlling soil erosion rates during concentrated flow. This study is the first one to investigate systematically the erosion‐reducing potential of the root properties of representative dike vegetation communities in a temperate humid climate. Results show that the presence of Urtica dioica resulted in large differences in root length density (RLD) among dike vegetation communities. Observed RLD values in the topsoil ranged from 129 to 235 km m^‐3 for dike vegetation communities without U. dioica, while smaller values ranging from 22 to 58 km m^?3 were found for vegetation communities with U. dioica. The erosion‐reducing effect of the dike vegetation communities was estimated based on a global Hill curve model, linking the RLD to the soil detachment ratio (SDR; i.e. the ratio of the soil detachment rate for root‐permeated topsoils to the soil detachment rate for root‐free topsoils). Concentrated flow erosion rates are likely to be reduced to 13–16% of the erosion rates for root‐free topsoils if U. dioica is absent compared to 22–30% for vegetation communities with U. dioica. Hence, to maintain a high resistance of the soil against concentrated flow erosion it is important to avoid the overgrowth of grassland by U. dioica through an effective vegetation management. Copyright © 2016 John Wiley & Sons, Ltd.     

大数据架构的遥感资源存储管理方法

随着遥感数据获取能力的日益增强,一方面导致遥感数据的多元化和海量化,使“存不起”的问题日益突出,另一方面由于缺少有效和高效的存储管理方法,难以及时发现终端应用所需的数据,使结果“存而无用”。本文围绕巨量、高吞吐、空间结构化的遥感影像数据及其基础土地信息产品的存储与管理问题,提出采用大数据架构的遥感资源存储管理方法,并基于MongoDB数据库实现了原型系统;通过使用PB量级数据进行试验,证明了该方法满足大数据时代对遥感矢栅数据的存储管理需求。