Cellular automata approach for modelling climate change impact on water resources

ABSTRACT

In this work, we consider the cellular automata (CA) approach for modelling the climate change impact on water resources. This consists in: constructing a CA model that describes the water cycle dynamics taking into account physical terrain attributes and climatic constraints; coupling the CA model with climate projection scenarios for a considered region as input data; determining and analysing in output the variations of the underground, surface and evaporated water. We present these variations per time interval and per zone of influence. As an application, we consider simulation for a basin in northern Morocco using a simulation software we have designed in Java Object Oriented Programming.

We consider cellular automata (CA) approach for modelling climate change impact on water resources. This consists in, first constructing a CA model that describes the water cycle dynamics taking into account physical terrain attributes and climatic constraints, then coupling the CA model with climate projection scenarios for a considered region as input data, and we determine and analyze in output the variations of the water resources (groundwater and surface water). We present these variations per time interval and per zone of influence. The approach application is for a basin in northern Morocco for which we use simulation software that we have designed in Java Object Oriented Programming. Digital terrain model, geological map and satellites image are used for input data.     

Linking GIS and water resources management models: an object-oriented method

Many challenges are associated with the integration of geographic information systems (GISs) with models in specific applications. One of them is adapting models to the environment of GISs. Unique aspects of water resource management problems require a special approach to development of GIS data structures. Expanded development of GIS applications for handling water resources management analysis can be assisted by use of an object oriented approach. In this paper, we model a river basin water allocation problem as a collection of spatial and thematic objects. A conceptual GIS data model is formulated to integrate the physical and logical components of the modeling problem into an operational framework, based on which, extended GIS functions are developed to implement a tight linkage between the GIS and the water resources management model. Through the object-oriented approach, data, models and users interfaces are integrated in the GIS environment, creating great flexibility for modeling and analysis. The concept and methodology described in this paper is also applicable to connecting GIS with models in other fields that have a spatial dimension and hence to which GIS can provide a powerful additional component of the modeler’s tool kit.     

Sequential optimization of integrated climate change models

A sequential optimization approach is applied to optimize the behavior of a complex dynamical system. It sequentially solves a large set of mathematical equations and next optimizes the behavior of a reduced-system, fixing certain variables of the larger original problem. These two steps are repeated till convergence occurs. The approach is applied to the problem of identifying response strategies for climate change caused by antropogenic emissions of different trace gases. The convergence properties are analyzed for this example.     

Assessing the propagation of uncertainties in multi-objective optimization for agro-ecosystem adaptation to climate change

It is widely acknowledged that uncertainty needs to be accounted for in climate impact studies, be it in scenario analyses or optimization applications. In this study we investigate how climate and crop model uncertainties affect multi-objective optimization outputs aiming to identify optimum agricultural management adaptations for Western Switzerland. Results are visualized by ternary plots that map optimum management measures, crop yield, erosion and leaching with associated uncertainties for navigating through the optimum adaptation space. We find that the relevance of climate model vs. parameter uncertainty can differ substantially depending on the prioritization of objectives and local conditions. The optimum choice of irrigation level was found to be the decision variable subject to greatest uncertainty particularly on coarser soil. This finding suggests that for the long-term planning of irrigation infrastructure and management, a robust adaptation approach is required for approaching unavoidable uncertainty from a risk management perspective.     

Towards best practice implementation and application of models for analysis of water resources management scenarios

Water resources management models are widely used to evaluate planning or operational scenarios to support water resource management decision-making. However, the approaches to modelling used in the past have led to problems, such as modellers having difficulty establishing the credibility of their model with stakeholders, and stakeholders having difficulty understanding and trusting model results. A best practice approach to the implementation and application of water resources management models based on a quality assurance procedure is an appropriate means of overcoming these difficulties, and there are a number of guidelines and papers available promoting this approach. However, guidance in these on the use of models to analyse water resource planning scenarios is limited or not provided. This paper therefore provides guidance on the implementation and application of water resources management models with an emphasis on scenario analysis. This guidance is principally intended for practising modellers, and also for peer reviewers and stakeholders such as managers, decision makers, and community-based groups. Adoption strategies and recommendations for future directions are also discussed.     

Ontology models of the impacts of agriculture and climate changes on water resources: Scenarios on interoperability and information recovery

Agriculture is both highly dependent on water resources, and impacting on these resources. Regardless of advances in the area, the impacts of water scarcity and climatic changes on agriculture, as well as the impacts of agriculture on water resources, remain uncertain. Potentially, collaborative systems can support the management and information sharing of multifaceted and large scale data sources, providing valuable and indispensable information for research. However, these solutions rely on semantic interoperability, the construction of complex knowledge representation models, as well as information recovery. This work describes interoperability issues in the engineering process of the OntoAgroHidro, an ontology that represents knowledge about impacts of agricultural activities and climatic changes on water resources. The paper presents representative scenarios and questions, and discusses the reuse and integration of concepts using knowledge visualization techniques. Experiments on the information recovery scenario point out the potential and limitations of the OntoAgroHidro.     

青海水资源监控管理系统建设的探讨

水资源监控管理系统为实行最严格的水资源管理制度提供数据支撑,通过对青海水资源管理特点、水资源监控体系的现状分析,结合水资源监控能力建设项目的实施,提出从监测体系、网络环境、资源整合、运维体系等方面建设完善监控管理系统,保障监控目标的实现。     

Incentive- and compulsion-based cooperative approach in water resources quality management

Simulating control systems for water resources quality is considered. A hierarchical approach to organization of these systems and hierarchical control methods are taken as the basis. Moving from non-cooperative to cooperative relations is proved to be reasonable. A new way to distribute the payoff in the cooperative game is proposed for the problem of water resources quality control. Typical examples are given to illustrate various optimality principles in the cooperative game.     

Combining watershed models and knowledge-based models to predict local-scale impacts of climate change on endangered wildlife

Climate change is expected to have significant impacts on native, threatened and endangered wildlife. Understanding and modeling these impacts useful for wildlife managers, however, remain difficult due to complex climate change, and costly and high data requirements. Consequently, we proposed an easily-interpretable and data-efficient decision support approach to understand climate change impacts on the abundance of three endangered wetland birds (Hawaiian Stilt, Hawaiian Coot and Hawaiian Moorhen). We coupled a watershed model, AnnAGNPS, and ecological models using fuzzy-cognitive mapping software, Mental Modeler, in Hanalei watershed, Kauaʻi. Results suggested that increased precipitation would increase Stilt abundance, but decrease Coot and Moorhen abundance. Decreasing precipitation might have negative effects for all three species. Moreover, decision-makers should pay equal attention to controlling components (water depth, food availability and disease) with system-wide influence. Finally, besides being adaptable to similar environmental contexts, our approach captured both direct and indirect climate change impacts through ecological connectivity.     

A continuous coupled hydrological and water resources management model

Human exploitation of water resources is widespread and its impact on hydrological fluxes is expected to increase in the future. Water use interacts in a complex manner with the hydrological system causing severe alterations of the hydrological fluxes with multifaceted feedbacks. Implementing this coupling within hydrological models is essential when dealing with the impact of human activities on water resources at all relevant scales. We contribute to the effort in developing models coupling natural and human systems with a distributed continuous model, named GEOTRANSF. The model allows to quantify, within the same framework, alterations in the natural regime and constraints and limitations to water resources availability. After presenting GEOTRANSF, an example of application to a medium-size Alpine catchment with streamflow modified by hydropower and distributed uses is discussed, followed by the analysis of the effect of suitable water uses scenarios in the same catchment.     

Regional integrated modelling of climate change impacts on natural resources and resource usage in semi-arid Northeast Brazil

Semi-arid regions are characterised by a high vulnerability of natural resources to climate change, pronounced climatic variability and often by water scarcity and related social stress. The analysis of the dynamics of natural conditions and the assessment of possible strategies to cope with drought-related problems require an integration of diverse knowledge including climatology, hydrology, and socio-economics. The integrated model introduced here dynamically describes the relationships between climate forcing, water availability, agriculture and selected societal processes. The model has been designed to simulate the complex human-environment system in semi-arid Northeast Brazil quantitatively and is applied to study the sensitivity of regional natural resources and socio-economy to climate change. The validity of the model is considered.Climate change is concluded to have an enormous potential impact on the region. River flow, water storage and irrigated production are specifically affected, assuming a continuous regional development and unfavourable but plausible changes in climate. Under plausible favourable changes in climate, these variables remain stressed. The impact of the integrated model and its applications on present policy making and possible future roles are briefly discussed.     

基于水资源监控平台建设的取水计划研发及实践应用

基于水资源监控平台研发取水计划模块,包括建议、反馈、核定、调整和查询等五大功能,并首次应用于浙江省部分市县取水计划管理工作。实践表明通过水资源监控平台取水计划模块能够帮助取水户和水行政主管部门增进沟通交流,实现取水计划网上办理,提升工作效率。     

Taguchi-factorial type-2 fuzzy random optimization model for planning conjunctive water management with compound uncertainties

In this study, a type-2 fuzzy random optimization (TFRO) method is developed for planning conjunctive water management system associated with compound uncertainties. TFRO can effectively address compound uncertainties expressed as type-2 fuzzy sets, probability distributions, and type-2 fuzzy random variables. Solution algorithm based on the degree of probability and the information of plausibility is proposed to transform nonlinear objective function and constraints into their linear equivalents. A real case of water-resources allocation problem in Zhangweinan River Basin (China) is employed to demonstrate the applicability of the proposed method. A Taguchi-factorial type-2 fuzzy random model is also formulated through introducing Taguchi design and ANOVA technique into the TFRO framework. Results obtained can help reveal the relationship among multiple impact factors of economic, environmental and resource (water conveyance efficiency, water delivery cost, and system violation risk), as well as quantify their contributions to the variability of system benefit and water allocation schemes.     

Geological uncertainties associated with 3-D subsurface models

Subsurface models are generally built from both subjective interpretation and mathematical interpolation/extrapolation techniques. These models are therefore uncertain, but their uncertainty is rarely expressed in a geological forecast. In this paper, an evaluation method of geological uncertainties related to 3-D subsurface models is proposed and tested on a real case. This method is based on the subsurface model, which is considered the most probable prediction (best guess). The various geological interfaces are handled as Gaussian random fields to which a model of spatial variability describing possible fluctuations around the best guess is applied. Several structural constraints, such as the shape of folds and thickness of layers are accounted for in the model. At this point, the local variance can be estimated throughout the study area by application of the simple kriging technique. Finally, the variability is converted into probabilities of occurrence of the various rock masses present in the study area. The probabilities are calculated according to intersection rules governing the stratigraphic sequence of the subsurface model. They enable one to probabilistically model subsurface structures in the form of a three-dimensional (3-D) probability field.     

Detection and resolution of conflicting change operations in version management of process models

Version management of process models requires that different versions of process models are integrated by applying change operations. Conflict detection between individually applied change operations and conflict resolution support are integral parts of version management. For conflict detection it is utterly important to compute a precise set of conflicts, since the minimization of the number of detected conflicts also reduces the overhead for merging different process model versions. As not every syntactic conflict leads to a conflict when taking into account model semantics, a computation of conflicts solely on the syntax leads to an unnecessary high number of conflicts. Moreover, even the set of precisely computed conflicts can be extensive and their resolution means a significant workload for a user. As a consequence, adequate support is required that guides a user through the resolution process and suggests possible resolution strategies for individual conflicts. In this paper, we introduce the notion of syntactic and semantic conflicts for change operations of process models. We provide a method how to efficiently compute conflicts precisely, using a term formalization of process models and consider the subsequent resolution of the detected conflicts based on different strategies. Using this approach, we can significantly reduce the number of overall conflicts and reduce the amount of work for the user when resolving conflicts.     

管道流量计现场校准技术在新疆水资源取用水管理中的应用

基于对管道流量计现场校准方法的研究,开展新疆5个地区取水户21个管道流量的现场校准工作,以便携式超声波管道流量计所测得的管道流量数据与现有计量设施的管道流量数据进行比对,分别对2组数据的相对示值误差、重复性和不确定度进行分析,从中得出各取水管道合理的优化整改办法.对个别示值误差异常的取水管道计量设施给出具体解决方案,同...