Sven Kralisch

A neural network approach for the optimisation of watershed management

Abstract Managing a catchment for drinking water supply with a high proportion of agricultural land use is a difficult task if one has to maintain a reasonable balance between water quality demand and consequent restrictions for the farming industry. In this paper, we present a neural net-based method for finding good approximations to solutions of this problem. This method is capable of ‘inverting’ a hydrological model to identify land use scenarios that match best the leaching criteria defined for establishing a certain water quality level in the stream. The method not only allows simulation land use scenarios like hydrologic models do, but can search systematically for land use scenarios that fulfill specified criteria without worrying about the complexity of combinatorial optimisation.

River Basin Information System: Open Environmental Data Management for Research and Decision Making

An open, standardized data management and related service infrastructure is a crucial requirement for a seamless storage and exchange of data and information within research projects, for the dissemination of project results and for their application in decision making processes. However, typical project databases often refer to only one research project and are limited to specific purposes. Once implemented, those systems are often not further maintained and updated, rendering the stored information useless once the system stops operating. The River Basin Information System (RBIS) presented here is designed to fit not only the requirements of one research project, but focuses on generic functions, extensibility and standards compliance typically found in interdisciplinary environmental research. Developed throughout more than 10 years of research cooperation worldwide, RBIS is designed to manage different types of environmental data with and without spatial context together with a rich set of metadata. Beside data management and storage, RBIS provides functions for the visualization, linking, analysis and processing of different types of data to support research, decision making, result dissemination and information discovery for all kinds of users. The focus of this paper is on the description of the technical implementation and the presentation of functions. This will be complemented by an overview of example applications and experiences during RBIS development and operation.

An Information System for Integrated Land and Water Resources Management in the Kara River Basin ( Togo and Benin )

A prerequisite for integrated land and water resources management (ILWRM) is a holistic river basin assessment. The latter requires information and data from different scientific disciplines but also appropriate data management systems to store and manage historical and real time data, set up protocols that facilitate data and information access and sharing among different stakeholders, and triggering further collaboration among different institutions in support of watershed-based assessment, management and planning. In West Africa in general and especially in the transboundary Volta River basin where different environmental data are collected and managed by different agencies in different countries and also where data access and dissemination are very challenging and difficult tasks, comprehensive river basin information systems are required. This paper presents the Oti River Basin Information System (OtiRBIS), a web-based data storage, management and analysis platform that addresses these needs and facilitates ILWRM implementation in the Kara river basin.

Geospatial Virtual Appliances Using Open Source Software

The hype on the Cloud is based on promising cost savings if, considering the new service platform concepts (IaaS, PaaS, SaaS) the term comes with, IT resources will be used effectively. Therefore, the trend is moving away from physical systems to more instant and short-term environments and virtualization is increasingly taking on a key role in various system architectures. This is already well accepted by a few business units such as customer relationship management or marketing, operated from Salesforce.com for instance [1]. However, earth scientific offers featuring specialized functions and services on demand are still rare but of great benefit in order to overcome the global changes in environmental conditions. Only one task from the field of model preprocessing at the DGHM was picked out for virtualization purposes and the results will be introduced in the following.

RBIS - An Environmental Information System for Integrated Landscape Management

In this paper we present the web-based River Basin Information System (RBIS) for data management, analysis and exchange as an integral standalone part of the Integrated Landscape Management System (ILMS). Its architectural layout will be outlined together with the underlying software platform. Selected RBIS modules will be characterized in more detail to emphasize the benefits of integrated data management as a basis of the holistic environmental planning workflow covered by ILMS.

Hydrological system analysis and modelling of the Kara River basin (West Africa) using a lumped metric conceptual model

ABSTRACT This paper discusses the analysis and modelling of the hydrological system of the basin of the Kara River, a transboundary river in Togo and Benin, as a necessary step towards sustainable water resources management. The methodological approach integrates the use of discharge parameters, flow duration curves and the lumped conceptual model IHACRES. A Sobol sensitivity analysis is performed and the model is calibrated by applying the shuffled complex evolution algorithm. Results show that discharge generation in three nested catchments of the basin is affected by landscape physical characteristics. The IHACRES model adequately simulates the rainfall–runoff dynamics in the basin with a mean modified Nash-Sutcliffe efficiency measure of 0.6. Modelling results indicate that parameters controlling rainfall transformation to effective rainfall are more sensitive than those routing the streamflow. This study provides insights into understanding the catchment’s hydrological system. Nevertheless, further investigations are required to better understand detailed runoff generation processes. EDITOR M.C. Acreman; ASSOCIATE EDITOR N Verhoest

Ecohydrological Modeling and Scenario Impact Assessment in Rural Rio de Janeiro

Understanding hydrological process dynamics is a crucial requirement for river basin management and environmental planning. Possible future climate changes raise questions about their impact on human livelihoods, which strongly depend on water availability and quality, soil fertility, and other ecosystem services. This chapter presents a physically based, spatially distributed ecohydrological model that was applied within three meso- to macroscale watersheds in the hinterland of Rio de Janeiro. While an increasing population and a fast-growing industrial sector create a high demand for water supply, the study region faces serious problems of forest fragmentation, overexploitation, and soil degradation, which create increasing pressures on water resources. This situation is further intensified by the climate conditions with distinct wet and dry periods that can cause floods and landslides in the rainy season and water shortages during dry periods, especially affecting the agricultural and domestic supply sectors. Recent water shortages raise questions how future climate changes will impact the hydrological dynamics and if river basin management needs to take appropriate counteractions. The results show that the developed models allow simulating hydrological processes at a high spatiotemporal resolution. Given the fact that their process representation is physically based, these models can help answer questions about hydrological dynamics under changing environmental conditions.

Analyzing Hydro-Climatic Data to Improve Hydrological Understanding in Rural Rio de Janeiro, Southeast Brazil

The rural area of Rio de Janeiro (RJ) state has experienced increased pressure on water resources, due to an increasing population linked with the growth of the industrial and agricultural sectors. High interannual variability of rainfall causes frequent extreme events leading to droughts, floods, and landslides. Therefore, it is crucial to understand how climate affects the interaction between the timing of extreme rainfall events, hydrological processes, vegetation growth, soil cover, and soil erosion. Ecohydrological modeling can contribute to a better understanding of spatial–temporal process dynamics to develop adaptation strategies. However, prior to modeling, it is crucial to evaluate the reliability of the climate and hydrological data. This study aims to homogenize the climatic data and to analyze the hydro-climatic time series needed for further hydrological studies (e.g., ecohydrological modeling) and to contribute to a better understanding of long-term hydro-climatic patterns in a mesoscale watershed, the Muriae River Basin. The analyses include homogeneity assessment, statistical analyses, and trend detection for a time period of over 50 years. The assessment provides important insights into long-term hydro-climatic patterns, such as an increase of the annual mean temperature, a decrease of the annual relative humidity, and an increase of the frequency of intense rainfall events.