Exploring object-oriented GIS for watershed resource management

The adoption of object-oriented programming for spatial technological advancement is an emerging trend in GIS. This research seeks to explore Object-Oriented GIS (OOGIS) and its potential application in watershed resource management. OOGIS provides a more intuitive and realistic abstraction of real world features as intelligent objects. The ability to embed behavior, geometry, and attribution with the objects provides considerable advantages in the processing and analysis of geospatial data. The main objective of this research was to design a prototype OOGIS for watershed resource management using the object relational Arclnfo 8.1 Geodatabase. The study builds on the OOGIS concepts of inheritance, polymorphism, and encapsulation and defines a schema for the project. Behavior is embedded in the watershed features through the use of methods and reflex methods that automatically perform functions such as data validation and text placement. Message propagation is tested using related objects, and a smart object-based topologically integrated geometric network is established for streams and roads. Because of the embedded topological relationships and methods this network is self-adapting. The resulting system indicates that OOGIS has many advantages over the more traditional entity-relationship model. The system provides a more intuitive representation of a watershed through the integration of intelligent behaviors and is particularly effective in addressing GIS maintenance issues at a database level through the use of reflex validation methods

Enhancing Operational Flood Detection Solutions through an Integrated Use of Satellite Earth Observations and Numerical Models

Among natural disasters floods are the most common and widespread hazards worldwide (CRED and UNISDR, 2018). Thus, making communities more resilient to flood is a priority, particularly in large flood-prone areas located in emerging countries, because the effects of extreme events severely setback the development process (Wright, 2013). In this context, operational flood preparedness requires novel modeling approaches for a fast delineation of flooding in riverine environments. Starting from a review of advances in the flood modeling domain and a selection of the more suitable open toolsets available in the literature, a new method for the Rapid Estimation of FLood EXtent (REFLEX) at multiple scales (Arcorace et al., 2019) is proposed. The simplified hydraulic modeling adopted in this method consists of a hydro-geomorphological approach based on the Height Above the Nearest Drainage (HAND) model (Nobre et al., 2015). The hydraulic component of this method employs a simplified version of fluid mechanic equations for natural river channels. The input runoff volume is distributed from channel to hillslope cells of the DEM by using an iterative flood volume optimization based on Manning\u2019s equation. The model also includes a GIS-based method to expand HAND contours across neighbor watersheds in flat areas, particularly useful in flood modeling expansion over coastal zones. REFLEX\u2019s flood modeling has been applied in multiple case studies in both surveyed and ungauged river basins. The development and the implementation of the whole modeling chain have enabled a rapid estimation of flood extent over multiple basins at different scales. When possible, flood modeling results are compared with reference flood hazard maps or with detailed flood simulations. Despite the limitations of the method due to the employed simplified hydraulic modeling approach, obtained results are promising in terms of flood extent and water depth. Given the geomorphological nature of the method, it does not require initial and boundary conditions as it is in traditional 1D/2D hydraulic modeling. Therefore, its usage fits better in data-poor environments or large-scale flood modeling. An extensive employment of this slim method has been adopted by CIMA Research Foundation researchers for flood hazard mapping purposes over multiple African countries. As collateral research, multiple types of Earth observation (EO) data have been employed in the REFLEX modeling chain. Remotely sensed data from the satellites, in fact, are not only a source to obtain input digital terrain models but also to map flooded areas. Thus, in this work, different EO data exploitation methods are used for estimating water extent and surface height. Preliminary results by using Copernicus\u2019s Sentinel-1 SAR and Sentinel-3 radar altimetry data highlighted their potential mainly for model calibration and validation. In conclusion, REFLEX combines the advantages of geomorphological models with the ones of traditional hydraulic modeling to ensure a simplified steady flow computation of flooding in open channels. This work highlights the pros and cons of the method and indicates the way forward for future research in the hydro-geomorphological domain

An enhanced Pfafstetter catchment reference system

The Pfafstetter system delineates and codes hierarchically nested catchments. Its simple coding scheme denotes stream network position, enabling systematic analysis of the impacts of any activity on a river section without need for a GIS. However, widespread application has identified significant limitations. Issues raised include an inability to code complex drainage systems or large numbers of endorheic basins, the variability in both the levels of basin decomposition and sub‐basin sizes and main stem identification criteria not conforming to local understanding. To address these issues, the Pfafstetter system was modified to use an independent regionalization for the initial sub‐division of the continent. New procedures were developed to code distributary drainage networks and endorheic basins and alternate criteria devised to identify the main stem and to produce a more even decomposition of a catchment. These modifications were successfully applied to the task of delineating and coding hierarchically nested catchments for the Australian continent including its complex distributary and anabranching drainage networks and large numbers of endorheic basins. The independent basin grouping produced initially smaller and more evenly sized sub‐basins and modelled estimates of flow identified the main stem correctly slightly more often than the original contributing area criterion. Enabling further sub‐division of catchments with fewer than four tributaries produced the largest change in catchment delineations, doubling the number of sub‐basins and halving their size. Achieving the vision for a comprehensive basin reference system will require further development to include anthropogenic and other hydrological features not controlled by topography

Modelling water discharge and nitrogen loads from drained agricultural land at field and watershed scale

This thesis examines water discharge and NO₃-N loads from drained agricultural land in southern Sweden by modelling at field and watershed scale. In the first stage of the work, the ability of DRAINMOD to simulate outflow in subsurface drains and that of DRAINMOD-N II to simulate NO₃-N loads in these drains was evaluated in field experiments. In addition, the ROSETTA pedotransfer model was used to estimate soil hydraulic properties required by DRAINMOD. In the second stage, DRAINMOD was integrated with Arc Hydro in a GIS framework (Arc Hydro-DRAINMOD) to simulate the hydrological response of an artificially drained watershed. DRAINMOD-N II and a temperature-dependent NO₃-N removal equation were also included in Arc Hydro-DRAINMOD to predict NO₃-N loading. Arc Hydro-DRAINMOD used a distributed modelling approach to aggregate the results of field-scale simulations, where the Arc Hydro data model described the drainage patterns in the watershed and connected the model simulations from fields through the stream network to the watershed outlet. GLUE methodology was applied to estimate uncertainties in the framework inputs. At field scale, monthly values of drain outflows simulated by DRAINMOD and NO₃-N loads simulated by DRAINMOD-N II showed good agreement with observed values. Good agreement was also found between observed and DRAINMOD-simulated drainage rates when ROSETTA-estimated Ks values were used as inputs in DRAINMOD. At watershed scale, temporal trend and magnitude of monthly measured discharge and NO₃-N loads were well predicted by Arc Hydro-DRAINMOD, which included uncertainty estimation using GLUE methodology. Sensitivity analysis showed that NO₃-N loads from the stream baseflow and N removal in the stream network processes had the most sensitive parameters. These results demonstrate the potential of DRAINMOD/DRAINMOD-N II and Arc Hydro-DRAINMOD for simulating hydrological and N processes in drained agricultural land at field and watershed scale. These models can contribute to improve water use efficiency in watersheds and to evaluate best management practices for preventing surface water and groundwater pollution

Development of a GIS-Based Information System for Watershed Monitoring in Mato Grosso, Central Brazil

This paper describes the conceptual framework and implementation of a prototype for a GIS-based Information System for Watershed Monitoring and Planning in the state of Mato Grosso, Central Brazil. The system was developed to support the implementation of water resources management policies passed by Brazilian federal and state legislatures in 1997.The first phase of the information system development was focused on database design, to create modules for the storage and pre-processing of diverse environmental data sets and for georeferenced registration and control of water users. The GIS environment includes tools for data mining and integrating the NGFlow and QUAL2E models for river runoff and water quality simulation; these tools were successfully validated in the Cuiabá River basin. To guarantee acceptance and continuity of system maintenance in regions under development, GIS applications for watershed management should be component-based. They should also integrate models with robustness for input data that are poor in consistency and quality. Finally, they should be implemented with development tools already used by local technical staff and have a high degree of user friendliness.This paper describes the conceptual framework and implementation of a prototype for a GIS-based Information System for Watershed Monitoring and Planning in the state of Mato Grosso, Central Brazil. The system was developed to support the implementation of water resources management policies passed by Brazilian federal and state legislatures in 1997.The first phase of the information system development was focused on database design, to create modules for the storage and pre-processing of diverse environmental data sets and for georeferenced registration and control of water users. The GIS environment includes tools for data mining and integrating the NGFlow and QUAL2E models for river runoff and water quality simulation; these tools were successfully validated in the Cuiabá River basin. To guarantee acceptance and continuity of system maintenance in regions under development, GIS applications for watershed management should be component-based. They should also integrate models with robustness for input data that are poor in consistency and quality. Finally, they should be implemented with development tools already used by local technical staff and have a high degree of user friendliness

An explicit GIS-based river basin framework for aquatic ecosystem conservation in the Amazon

Despite large-scale infrastructure development, deforestation, mining and petroleum exploration in the Amazon Basin, relatively little attention has been paid to the management scale required for the protection of wetlands, fisheries and other aspects of aquatic ecosystems. This is due, in part, to the enormous size, multinational composition and interconnected nature of the Amazon River system, as well as to the absence of an adequate spatial model for integrating data across the entire Amazon Basin. In this data article we present a spatially uniform multi-scale GIS framework that was developed especially for the analysis, management and monitoring of various aspects of aquatic systems in the Amazon Basin. The Amazon GIS-Based River Basin Framework is accessible as an ESRI geodatabase at doi:10.5063/F1BG2KX8. © Author(s) 2016

The JGrass-NewAge system for forecasting and managing the hydrological budgets at the basin scale: models of flow generation and propagation/routing

Abstract. This paper presents a discussion of the predictive capacity of the implementation of the semi-distributed hydrological modeling system JGrass-NewAge. This model focuses on the hydrological budgets of medium scale to large scale basins as the product of the processes at the hillslope scale with the interplay of the river network. The part of the modeling system presented here deals with the: (i) estimation of the space-time structure of precipitation, (ii) estimation of runoff production; (iii) aggregation and propagation of flows in channel; (v) estimation of evapotranspiration; (vi) automatic calibration of the discharge with the method of particle swarming. The system is based on a hillslope-link geometrical partition of the landscape, combining raster and vectorial treatment of hillslope data with vector based tracking of flow in channels. Measured precipitation are spatially interpolated with the use of kriging. Runoff production at each channel link is estimated through a peculiar application of the Hymod model. Routing in channels uses an integrated flow equation and produces discharges at any link end, for any link in the river network. Evapotranspiration is estimated with an implementation of the Priestley-Taylor equation. The model system assembly is calibrated using the particle swarming algorithm. A two year simulation of hourly discharge of the Little Washita (OK, USA) basin is presented and discussed with the support of some classical indices of goodness of fit, and analysis of the residuals. A novelty with respect to traditional hydrological modeling is that each of the elements above, including the preprocessing and the analysis tools, is implemented as a software component, built upon Object Modelling System v3 and jgrasstools prescriptions, that can be cleanly switched in and out at run-time, rather than at compiling time. The possibility of creating different modeling products by the connection of modules with or without the calibration tool, as for instance the case of the present modeling chain, reduces redundancy in programming, promotes collaborative work, enhances the productivity of researchers, and facilitates the search for the optimal modeling solution

Flood hazard hydrology: interdisciplinary geospatial preparedness and policy

Thesis (Ph.D.) University of Alaska Fairbanks, 2017Floods rank as the deadliest and most frequently occurring natural hazard worldwide, and in 2013 floods in the United States ranked second only to wind storms in accounting for loss of life and damage to property. While flood disasters remain difficult to accurately predict, more precise forecasts and better understanding of the frequency, magnitude and timing of floods can help reduce the loss of life and costs associated with the impact of flood events. There is a common perception that 1) local-to-national-level decision makers do not have accurate, reliable and actionable data and knowledge they need in order to make informed flood-related decisions, and 2) because of science--policy disconnects, critical flood and scientific analyses and insights are failing to influence policymakers in national water resource and flood-related decisions that have significant local impact. This dissertation explores these perceived information gaps and disconnects, and seeks to answer the question of whether flood data can be accurately generated, transformed into useful actionable knowledge for local flood event decision makers, and then effectively communicated to influence policy. Utilizing an interdisciplinary mixed-methods research design approach, this thesis develops a methodological framework and interpretative lens for each of three distinct stages of flood-related information interaction: 1) data generation—using machine learning to estimate streamflow flood data for forecasting and response; 2) knowledge development and sharing—creating a geoanalytic visualization decision support system for flood events; and 3) knowledge actualization—using heuristic toolsets for translating scientific knowledge into policy action. Each stage is elaborated on in three distinct research papers, incorporated as chapters in this dissertation, that focus on developing practical data and methodologies that are useful to scientists, local flood event decision makers, and policymakers. Data and analytical results of this research indicate that, if certain conditions are met, it is possible to provide local decision makers and policy makers with the useful actionable knowledge they need to make timely and informed decisions

Driver-pressure-impact and response-recovery chains in European rivers: observed and predicted effects on BQEs

The report presented in the following is part of the outcome of WISER’s river Workpackage WP5.1 and as such part of the module on aquatic ecosystem management and restoration. The ultimate goal of WP5.1 is to provide guidance on best practice restoration and management to the practitioners in River Basin Management. Therefore, a series of analyses was undertaken, each of which used a part of the WP5.1 database in order to track two major pathways of biological response: 1) the response of riverine biota to environmental pressures (degradation) and 2) the response of biota to the reduction of these impacts (restoration). This report attempts to provide empirical evidence on the environment-biota relationships for both pathways

Integrating Knowledge for River Basin Management: Progress in Thailand

Resource /Energy Economics and Policy,