Application of the WEPP model with digital geographic information

The Water Erosion Prediction Project (WEPP) is a process-based continuous simulation erosion model that can be applied to hillslope profiles and small watersheds. One limitation to application of WEPP (or other models) to the field or farm scale is the difficulty in determining the watershed structure, which may be composed of multiple channels and profiles (and potentially other features as well). This presentation describes current efforts to link the WEPP model with Geographic Information Systems (GIS) and utilize Digital Elevation Model (DEM) data to generate the necessary topographic inputs for erosion model simulations. Two automated approaches for applying the WEPP model have been developed and compared to manual application of the model. The first approach (named the Hillslope method) uses information from a DEM to delineate the watershed boundary, channel and hillslope locations, and then configure "representative" hillslope slope profiles from the myriad flowpath data. The second approach (named the Flowpath method) also uses DEM information to delineate the watershed boundary, but then runs WEPP model simulations on every flowpath within a watershed. For a set of research watersheds, the automatic Hillslope method performed as well as a manual application of WEPP by an expert user in predictions of runoff and sediment loss. Tests also showed that the Hillslope and Flowpath methods were not significantly different than each other or different from manual model applications in predictions of hillslope erosion. Additional research work ongoing at the National Soil Erosion Research Laboratory is examining the feasibility of using commonly available digital elevation data (for example from on-vehicle Geographical Positioning Systems (GPS)) to provide input for the automated techniques for driving the erosion model

Community resilience assessment integrating network interdependencies

The concept of Disaster Resilience has received considerable attention in recent years and it is increasingly used as an approach for measuring response of communities to natural disasters. Recently a framework named PEOPLES has been developed by MCEER to measure performance of communities to natural disasters. The method includes seven dimensions that include both technical and socio-economic aspects. All resilience dimensions and their respective indices to measure community performances are obviously interdependent. As first step, the physical dimension has been implemented in software and indices have been proposed to measure performance of buildings and lifelines. This paper tries to focus on developing methodologies to consider interdependencies between buildings (e.g. hospitals, strategic buildings, etc) and lifelines (road networks, etc.). An approach considering network interdependencies have been developed which is based on the time series analysis of the restoration curves of the different infrastructures. The case study of 2011 Tohoku Earthquake has been presented to illustrate the implementations issue

Evaluating spatial and temporal variability in soil erosion risk - rainfall erosivity and soil loss ratios in Andalusia, Spain

Erosion modeling techniques provide a framework for the evaluation of agricultural impacts on soil and water resources. Agricultural policies or economic incentives generally induce land use changes or even agricultural crop rotation changes. This results in a different erosional behavior of cultivated soil. Besides economic benefits, the sustainability of the agricultural practices with regard to soil and water resources has to be evaluated for specific local or regional conditions. This paper analyzes the spatial and temporal variability in soil erosion risks in a changing Mediterranean agro-ecological situation. At first the spatio-temporal variability of rainfall erosivity is analyzed. The depth and erosivity of design storms are determined for different return periods. Then, the temporal variability of soil loss ratios (SLR) due to different agricultural crop rotations are evaluated on watershed scale using the revised universal soil loss equation (RUSLE). The 211 km2 Guadalteba river basin and study area is located in the region of Andalusia, southern Spain, presenting a typical south European agricultural wheat and oil producing area with marked occurrence of soil erosion problems. The spatial soil erosion risk evaluation approach is based on commonly available data and a minimum of additional field observations. The spatial distribution of input and output data is handled with the Integrated Land and Water Information System (ILWIS)

A GIS-based method to determine the volume of lahars: Popocatépetl volcano, Mexico

Lahars are flows composed of water and volcanic sediment which are often dangerous for people living near volcanoes. Therefore, a reliable estimation of lahar volume is needed to effectively assess the risk. This paper proposes a new method to calculate the volume of lahar sediments found in channels of volcanic landscapes. The method requires surveys of several cross-sections along a gorge, a Digital Elevation Model of the study area and measurements of the thickness of the lahar deposits. With these data and a Geographical Information System (GIS), the volume is calculated for the erosive section where deposit volume is divided into oblique parallelepipeds and the sedimentary section where deposit volume is divided into polyhedrons. This new method was applied to the 1997 and 2001 lahars that occurred in the channel of a gorge at Popocatépetl volcano, Mexico. The estimated volumes are 1.85 × 105 and 1.6 × 105m3, respectively, which is about 40% less than those obtained by the traditional method that multiplies lahar flow-path length, sediment width and sediment depth. This observation suggests that the traditional method tends to overestimate volumes

Regionalization methods for watershed management - hydrology and soil erosion from point to regional scales

The increasing demand for watershed management tools at local and regional scales makes it necessary to develop regionalization techniques for applications of continuous process-based models. To be useful for decision-makers, models must be applicable to all parts of the world with minimum calibration and must consider spatial variability in modeling hydrological and soil erosion processes. We develop regionalization methods for the point model SIMULAT and the hillslope model of the Water Erosion Prediction Project (WEPP). These methods provide model simulations that include spatial variability in detail and are able to reduce time consuming simulation runs by using hydro-pedotopes or hillslope units to represent the hydrological or erosional behavior of a watershed or larger region. Each method is designed to use geo-referenced commonly available data in a Geographical Information System (GIS) by aggregation and disaggregation procedures with a minimum of quality lost in the spatial and temporal distribution of the original input data. The results show that these regionalization methods produce detailed spatially distributed results on a daily basis either for relative water balances components of hydro-pedotopes or soil detachment rates for cells along flow paths on hillslopes within a small watershed that match well with runoff and sediment measurements in both study areas. The evaluation of different quality of topographical model input on regionalization results demonstrates the importance of different data quality and scales on model assessment results and decision-making

Updating channel morphology in digital elevation models: lahar assessment for Tenenepanco-Huiloac Gorge, Popocatépetl volcano, Mexico

In contrast to dramatic flow regime changes by less frequent large-scale volcanic eruptions, those caused by more frequent small-scale processes in volcanic landscapes may also drastically change the direction and dynamics of flow in a drainage system formed solely by fluvial processes. During such periods of channel morphology change, it is necessary to frequently update channel flow parameters to assess preventive measures for civil protection purposes. Often aerial photography is impracticable, since parts of the channels are covered by dense vegetation, while total station and laser topographic surveys are often too slow and costly, particularly during a high frequency of events. This article introduces and validates a new methodology for updating the representation of channel morphology in Digital Elevation Models (DEM) used specifically for assessing the dangers of frequently occurring lahars along gorges in volcanic landscapes during eruptive and non-eruptive periods. The updating of channel cross-sections was achieved by inserting more detailed representative profiles of homogeneous channel sectors in DEMs derived from existing less detailed topographic maps. The channel profiles were surveyed along the thalweg in equidistant points according to Universal Transverse Mercator (UTM) (x,y) coordinates and elevation derived from the existing DEM. The proposed technique was applied at Tenenepanco-Huiloac Gorge on Popocatépetl volcano, Mexico, in an area affected by major lahars during the volcano’s most recent eruptive period from 1994 to 2005. The proposed method can reduce the cost and person-hours of a regular channel topographic survey dramatically and the enhanced DEM can determine volume parameters and flood zones associated with the 1 July 1997 and 21 January 2001 lahars, respectively. In addition, the updated DEM with better channel representation allowed a more realistic fluid flow and lahar simulation with the process-based TITAN2D model

Rapid building damage assessment system using mobile phone technology

One common scenario during disasters such as earthquakes is that the activity of damage field reconnaissance on site is not well-coordinated. For example in Italy the damage assessment of structures after an earthquake is managed from the Italian Emergency Authority, using printed forms (AeDES) which are filled by experts on site generating a lot of confusion in filling and transferring the forms to the Disaster Management Operative Center. Because of this, the paper explores the viability of using mobile communication technologies (smart phones) and the Web to develop response systems that would aid communities after a major disaster, providing channels for allowing residents and responders of uploading and distributing information, related to structural damages coordinating the damage field reconnaissance. A mobile application that can be run by residents on smart phones has been developed, to give an initial damage evaluation of the area, which is going to be very useful when resources (e.g. the number of experts is limited). The mobile application has been tested for the first time during 2012 Emilia earthquake to enhance the emergency response, showing the efficiency of the proposed method in statistical terms comparing the proposed procedure with the standard procedur

ASCE first generation testbed for evaluating resilience of structures

The ASCE Sub-Committee on Disaster Resilience of Structures and Infrastructures initiated a testbed study on Resilience-Based design (RBD) considering two critical strategic structures (Town Hall and Hospital), a University Campus and the water distribution network of a small town. These structures were chosen because of the widespread interest in critical structures and infrastructures. In particular, the first two structures are considered critical, because they must not only survive the shaking, but must remain in operation. They require the largest investment of resources to insure that they can provide services following an earthquake. The test bed study will be developed using discrete event simulation models which are going to be calibrated using real data collected in the field. The development of these test beds will facilitate the comparison among different resilience frameworks which are available in literature. The paper presents an overview and problem definition of a hospital testbed which intends to help move the earthquake engineering community another step toward the realization and implementation of resilience-based design strategie