GIS Geodatabase Research Articles

The geo-database of caprock quality and deep saline aquifers distribution for geological storage of CO 2 in Italy

One of the most promising options to stabilize and reduce the atmospheric concentration of greenhouse gases is Carbon Capture and Storage (CCS). This technique consists of separating CO 2 from other industrial flue gases and storing it in geological reservoirs, such as deep saline aquifers, depleted oil and/or gas fields, and unminable coal beds. A detailed reworking of all available Italian deep-drilling data was performed to identify potential storage reservoirs in deep saline aquifers. Data were organized into a GIS geo-database containing stratigraphic and fluid chemistry information as well as physiochemical characteristics of the geological formations. Caprock efficiency was evaluated via numerical parameterization of rock permeabilities, defining the “ Caprock Quality Factor” ( Fbp) for each well. The geo-database also includes strategic information such as the distribution of deep aquifers, seismogenic sources and areas, seismic events, Diffuse Degassing Structures, heat flow, thermal anomalies, and anthropogenic CO 2 sources. Results allow the definition of potentially suitable areas for future studies on CO 2 geological storage located in the fore-deep domains of the Alps and Apennines chains, where efficient marly-to-clayish caprocks lie above deep aquifers hosted in sands or limestones. Most of them are far form seismogenic sources and Diffuse Degassing Structures.

Geocollaborative Soil Boundary Mapping in an Experiential GIS Environment

Soil maps are an important and integral component of national geospatial data infrastructures. The creation of these maps involves a geovisualization exercise whereby soil scientists develop cognitive models that correlate observable landscape features to soil occurrence. This is traditionally an analog process, cognitively demanding, time consuming, and invariably non-collaborative. A new geovirtual soil mapping technique is proposed in this paper in the form of an innovative Experiential GIS (EGIS) environment. This immersive environment enables soil maps to be constructed through experiencing and interacting with spatial data through immersion in 3D geovirtual scenes. The system outlined integrates GIS, immersive geovisualization, and robust geodatabase capabilities. Four soil scientists with extensive soil mapping experience ranging from 5 to over 20 years are concurrently immersed in the same 3D geovirtual landscape which more closely mirrors the way in which we view the world around us. The soil scientists are immersed within the 3D scene where they are essentially freed from the laws of physics, and may roam anywhere across the landscape as if in a virtual helicopter. The landscape is draped with any combination of orthoimagery and GIS-derived data allowing soil scientists to interpret, digitally delineate, and attribute soil boundaries. Exploiting the EGIS technology while maintaining the centrality of the soil scientist in soil interpretation and soil map production, promises considerable resource efficiencies than those achieved in traditional soil survey. The paper lays out the nature of this potential paradigm shift in soil mapping. The results of using this technology to construct soil geographic knowledge are also discussed in terms of soil map detail, cost efficiencies, time effectiveness, system usability, geocollaborative soil mapping advantages, and the reduced cognitive workload on practicing soil scientists.

Field mapping and GIS visualisation of Quaternary river terrace landforms: an example from the Río Almanzora, SE Spain

Please click here to download the map associated with this article. This paper presents the mapping results of a Quaternary river terrace staircase associated with the evolution of the Río Almanzora in SE Spain. Prior to map compilation a formal landform stratigraphy was constructed from remote sensing and field reconnaissance using standard allostratigraphic procedures as outlined by the North American Stratigraphic Commission. The stratigraphic framework comprised five allomembers of the Río Almanzora Alloformation corresponding to an inset sequence of river terrace levels that document > 150 m of Quaternary fluvial incision by the Río Almanzora. The terrace stratigraphy was mapped in the field using a hand held GPS to construct control points that tracked breaks and changes in slope associated with terrace stratigraphic boundaries. The field map and survey data were compiled in a GIS geodatabase and overlaid onto a DEM and geological map data for analysis and visualisation purposes. The stratigraphic and mapping procedure outlined here follows a standard methodology for investigations of Quaternary river terrace sequences, which have traditionally been mapped by geological surveys as undifferentiated Quaternary sediments. Ultimately, map compilation was undertaken in order to facilitate reconstruction of the Quaternary fluvial history of the Río Almanzora in order to identify the key environmental controlling mechanisms (tectonics, eustacy, climate change) for driving river terrace aggradation and incision patterns. The identification of five major river terrace landform levels and integration with luminescence age data suggests a climatic control on landform development with river aggradation occurring during glacial and transition periods between glacials and interglacials. River downcutting is attributed to base-level changes linked to a long term uplift trend and climate related sea-level fluctuations.

Application of TISCIT Data in Improving Hydraulic Model Reliability

Application of TISCIT Data in Improving Hydraulic Model ReliabilityIn 2005, the City of Dayton initiated a hydraulic modeling program to facilitate the determination of collection system capacity and to ensure that planned future expansions have adequate capacity to handle anticipated wastewater flows. The Dayton hydraulic model was built from a GIS GeoDatabase and additional sewer system survey. Flow and rain monitoring data were used for model calibration. For...Author(s)Qiuli LuEric OnderakGreg StacyScott HolmesSourceProceedings of the Water Environment FederationSubjectSession 12: Flow Monitoring that Pays Real DividendsDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2008ISSN1938-6478SICI1938-6478(20080101)2008:5L.875;1-DOI10.2175/193864708788812820Volume / Issue2008 / 5Content sourceCollection Systems ConferenceFirst / last page(s)875 - 884Copyright2008Word count124

Structure and contents of a new geomorphological GIS database linked to a geomorphological map — With an example from Liden, central Sweden

This paper presents the structure and contents of a standardised geomorphological GIS database that stores comprehensive scientific geomorphological data and constitutes the basis for processing and extracting spatial thematic data. The geodatabase contains spatial information on morphography/morphometry, hydrography, lithology, genesis, processes and age. A unique characteristic of the GIS geodatabase is that it is constructed in parallel with a new comprehensive geomorphological mapping system designed with GIS applications in mind. This close coupling enables easy digitalisation of the information from the geomorphological map into the GIS database for use in both scientific and practical applications. The selected platform, in which the geomorphological vector, raster and tabular data are stored, is the ESRI Personal geodatabase. Additional data such as an image of the original geomorphological map, DEMs or aerial orthographic images are also included in the database. The structure of the geomorphological database presented in this paper is exemplified for a study site around Liden, central Sweden.

Simulating flood events in mesoscale watershed:a case study from River Xitiaoxi Watershed in the upper region of Taihu Basin

以太湖上游西苕溪流域为研究对象，通过分布式水文模型HEC-HMS模拟次降雨洪水过程:采用可视化数据存储系统HEC-DSS建立水义气象数据库，利用Geodatabase地理数据库技术集成流域自然属性数据库，通过距离平方倒数法对雨量数据进行空间插值，SCS曲线数法计算水文损失，运动波法计算直接径流与河道洪水演进，选用基流指数退水法模拟流域基流，并对模型中水库模拟部分进行适当修正．经模型校验，模拟结果表明，计算流量与观测流量拟合较好，效率系数大于0．8．洪峰流量误差低于4%，峰现时间误差低于2 h，该模型在土地利用变化对洪水水文要素的影响研究方面有较好的应用前景．;Flood events in River Xitiaoxi Watershed in the upper region of Taihu Basin were simulated by distributed hydrologic modeling system HEC-HMS. The database of hydrology and meteorology in studied region was set up by visual storage system HEC-DSS. The database of the natural attributes of basin was integrated by the technique of GIS Geo-database. The total storm mean area precipitation was calculated by inverse-distance-squared method. SCS Curve Number Loss Model was selected to compute runoff volumes. Kinematic-wave Model was used to model direct runoff and channel flow. Base flow was modeled by Exponential Recession Model and the reservoir model was improved. After calibration and validation, the simulated flow and observed flow fit so good that the efficiency coefficient was more than 0. 8, with error of peak flow within 4% , and error of peak flow time within 2 hours, which illustrated that HEC-HMS may be applicable area in simulating the impacts of land use change on hydrological regimes such as floods.