This fluvial geomorphic landscape computer-design software (GeoFluv™) uses an algorithm based on fluvial geomorphic principles. The essence of this approach is to identify the type of drainage network, i.e., stream channels and valleys, which would tend to form over a long time given the site’s earth materials, relief, and climate to achieve a stable landform, and to design and build that landform. The resulting slopes and stream channels are stable because they are in balance with these conditions (Rosgen, 1996). They are a reclamation alternative to uniform slopes with terraces and down-drains. Rather than fight the natural forces that shape the land, the algorithm helps the user create a landscape that harmonizes with these forces.
The channel and swales in the foreground, and the steep slope ridges, valleys, and channels in the center of Figure 2., are examples of portions of a 115-acre coal mine reclamation project completed using this innovation fluvial geomorphic approach.
Figure 2. Steep slope reclamation using the fluvial geomorphic
approach shown during the second growing season |
Natural Stability
Over the last thirty-some years hydrologists have observed and measured
stable natural streams and determined mathematical relationships that
describe these stable stream types. Essential among these
determinations is that channel morphology is directly related to a
relatively small, but frequently recurring annual flood event. The
natural channel is shaped to keep its sediment load and stream flow
in balance during these low-flow events, as well as during extreme
events. The GeoFluv™
fluvial geomorphic approach to land
reclamation
relates the upland landforms to the stream channel form. Both can
be formed similarly by flowing water. Reclamation landscapes created
using fluvial geomorphic principles provide stability against erosion
with runoff waters capable of meeting water quality criteria, and
support a
diverse vegetative community. These landscapes offer the benefits
of lower initial cost, no long-term maintenance costs, and they promote
bond release (Bugosh, 2002, 2003).
Promotes Bond Release
The GeoFluv™ fluvial geomorphic approach
provides a high degree of confidence that reclamation projects will
demonstrate long-term stability against erosion similar to adjacent
undisturbed lands because the reclamation channels are designed to
maintain the hydrologic balance, as the natural channel does. This means that the reclaimed land does not have to be regularly
disturbed to repair erosion problems. Additionally, the varied
landform provides niches for different plants, wildlife, and
livestock. These benefits demonstrate to regulatory authorities
that the site will remain stable and productive; that demonstrated
stability can promote bond release.
Benefits of Computerizing the Fluvial
Geomorphic Approach
Previous application of alternative land-shaping practices may have
been limited for several reasons, including the limited extent of
training in fluvial geomorphic principles of the designers, the
complexity of the design calculations to create a thoroughly integrated
landform, and the difficulty of guiding the heavy equipment operators
to build more sophisticated designs. The Natural Regrade module
addresses all these potential limitations. GeoFluv™
creates a draft landform based on empirically determined fluvial
geomorphic mathematical relationships. The draft landform is an
idealized solution that uses the input parameters to create a stable
landform. The designer can then modify this idealized draft
landform to conform to special site conditions, such as an
archaeological site, landmark, or other feature, or to create a more
natural appearance.
User Friendly
Existing computer software for earth-moving designs does not
incorporate this innovative approach, is often not “user friendly”, and
does not have the broad applications for landscape designs that are
stable against erosion offered by Natural
Regrade. GeoFluv™ makes “user
friendly” computer design software available to a large body of users
that do not have advanced training in fluvial geomorphology, as well as
to those who do have this background. Natural Regrade has been designed
to be as “user friendly” as possible; the program commands are
organized following a left-to-right and top-to-bottom format that
follows the project design work sequence, with minimal input needed and
with guidance provided in the “Help” resource and documentation.
Minimizes Training
The Natural Regrade module
minimizes the training necessary to immediately use the fluvial
geomorphic approach for reclamation at disturbed sites, or when
evaluating proposed reclamation designs. Users can compress
design time and build reclamation landscapes from disturbed earth to
seeded reclamation. GeoFluv™’s
developer has successfully introduced this reclamation approach to the
largest mining company in the world at truck-and-shovel and dragline
operations. The Natural Regrade
module is designed to quickly make the GeoFluv™ design approach available to the widest range of users including
professional hydrologists, environmental scientists, and engineers
responsible for reclamation design at disturbed sites, and for
regulatory personnel responsible for evaluating reclamation
designs.
Simplifies numerous complex
calculations
An important advantage of the Natural
Regrade module’s GeoFluv™
computerized approach is the ease by which the user can create
landscapes that are functional, stable against erosion,
low-maintenance, aesthetically pleasing, and cost-effective. The
GeoFluv™ computer design software offers
several options for developing input parameters from climatic and
hydrologic data, and several options for creating landscape features,
e.g., ephemeral, intermittent and perennial stream channels, complex
slopes, ridges and valleys, and calculating material balances and
centroids, and optimum material movement routes, for the
resulting design. The user can design channels with appropriate
characteristics, including channel patterns, sinuosity, longitudinal
profiles, cross sectional areas, width to depth ratios, etc. and their
contiguous uplands as functional components of a stable
topography for tens of acres of land in minutes. GeoFluv™
allows the
user to view topographic maps and three-dimensional images of the
resulting landscape design. The GeoFluv™
approach replaces lengthy and tedious manual calculations and allows
rapid evaluation of many landscape design alternatives. This
allows the user to select the optimum landscape design for his needs.
Promotes Bonding Alternatives
The ability to quickly create and evaluate alternative reclamation
designs provides great utility for both industry and regulatory
personnel working on reclamation bonds. Because designing a
reclamation surface has been such a lengthy and expensive process,
often only a ‘worst case scenario’ design has been created for setting
a reclamation bond. For example, this ‘worst case scenario’ may
have been based on the disturbance in year four of a five-year mine
permit. The ability to quickly create design surfaces and conduct
mass balance comparisons makes it practical for the Natural Regrade module user to
propose bonds for several stages of mine development, i.e., incremental
bonding, that can reduce bond costs and promote release of more acres
from bond.
Interface with GPS and Machine-control
Software
This software also is ideal for integrating with Global Positioning
System and laser machine control to simplify and speed construction and
reduce costs. Construction of the complex landforms that are
characteristic of stable natural landscapes, and which GeoFluv™
helps the user design, is facilitated by GPS and machine guidance
technologies. The need to survey and stake the designs in the
field is eliminated using these technologies, as is the need for the
construction team to constantly provide guidance to the equipment
operators.