Riparian Ecology Research Articles

Potential Application Topics of KOMPSAT-3 Image in the Field of Precision Agriculture

Potential application topics of KOMPSAT-3 image in the field of precision agriculture are suggested. The topics can be categorized as fundamental and applied ones that have contents of static and dynamic characteristics respectively. As fundamental topics, precision information of agriculture that is related to farmland and its crop attributes, precision information of rural infrastructure that is related to rural village and its facilities, precision information of stream environment that is related to rural water resources and its facilities, and precision information of eco-environment that is especially related to riparian ecology and environmental status are included. As applied topics, precision rural water resources that has thematic contents of continuous and event-based runoff, spatial and temporal soil moisture and evapotranspiration, precision agricultural watershed environment that has the contents of spatial and temporal soil loss, sediment and pollutants transport, and precision temporal and spatial crop growth that has the contents of temporal crop texture, spectral reflectance, leaf area index, spatial crop protein information.

Downstream hydrologic and geomorphic effects of large dams on American rivers

The hydrology and geomorphology of large rivers in America reflect the pervasive influence of an extensive water control infrastructure including more than 75,000 dams. One hundred thirty-seven of the very large dams, each storing 1.2 km 3 (10 6 acre feet) of water or more, alter the flows of every large river in the country. The hydrologic effects of these very large dams emerge from an analysis of the stream gage records of 72 river reaches organized into 36 pairs. One member of each pair is an unregulated reach above a dam, whereas the other is a regulated reach downstream from the same structure. Comparison of the regulated and unregulated reaches shows that very large dams, on average, reduce annual peak discharges 67% (in some individual cases up to 90%), decrease the ratio of annual maximum/mean flow 60%, decrease the range of daily discharges 64%, increase the number of reversals in discharge by 34%, and reduce the daily rates of ramping as much as 60%. Dams alter the timing of high and low flows and change the timing of the yearly maximum and minimum flows, in some cases by as much as half a year. Regional variation in rivers, dams, and responses are substantial: rivers in the Great Plains and Ozark/Ouachita regions have annual maximum/mean flow ratios that are 7 times greater than ratios for rivers in the Pacific Northwest. At the same time, the ratio of storage capacity/mean annual water yield for dams is greatest for Interior Western, Ozark/Ouachita and Great Plains rivers and least for Pacific Northwest streams. Thus, in many cases those rivers with the highest annual variability have the greatest potential impact from dams because structures can exert substantial control over downstream hydrology. The hydrologic changes by dams have fostered dramatic geomorphic differences between regulated and unregulated reaches. When compared to similar unregulated reaches, regulated reaches have 32% larger low flow channels, 50% smaller high flow channels, 79% less active flood plain area, and 3.6 times more inactive flood plain area. Dams also affect the area of active areas, the functional surfaces that are functionally connected to the present regime of the river. Regulated reaches have active areas that are 72 smaller than the active areas of similar unregulated reaches. The geomorphic complexity (number of separate functional surfaces per unit of channel length) is 37% less in regulated reaches. Reductions in the size of hydrologically active functional surfaces are greatest in rivers in the Great Plains and least in Eastern streams. The largest differences in geomorphic complexity are in interior western rivers. The shrunken, simplified geomorphology of regulated large rivers has had direct effects on riparian ecology, producing spatially smaller, less diverse riparian ecosystems compared to the larger, more complex ecosystems along unregulated reaches of rivers.

Impact of Irrigation Cessation on Wetland Communities within the Elk Ranch, Grand Teton National Park, Moose, Wyoming

Riparian ecology research in Arizona and California has documented the likelihood of a subsurface linkage between irrigation, especially flood-irrigation, and riparian function (Smith et al. 1989; Stromberg et al. 1996). Initial groundwater monitoring results from rural New Mexico indicate water tables rose 1 to 2m after the onset of field irrigation and subsurface flow paths towards the Rio Grande River developed soon after (Fernald et al. 2008). Results from a study of wetlands in southeastern Wyoming suggest that declining flood-irrigation levels would lead to a reduction in the total area of wetlands and related areas of wetland vegetation types in the Laramie Basin (Peck and Lovvorm 2001). Stringham et al. (1998) have reported further evidence for a linkage between irrigation and riparian function. These Oregon researchers noted lower water temperatures in stream reaches receiving subsurface return flows from irrigated hayfields than similar reaches flowing through non-irrigated lands. This information is timely because Grand Teton National Park (GTNP) managers have begun an evaluation of historic irrigation operations within the Park and are endeavoring to learn how cessation of flood irrigation will affect Park wetlands. The historically irrigated hayfields at the Elk Ranch provide an opportunity to address the Park Service's informational needs through identification of vegetation composition, soil physical characteristics and groundwater patterns associated with irrigated and naturally occurring wetlands. Successful description of patterns unique to natural wetlands will provide an avenue for predicting which Park wetlands would remain functional should irrigation efforts be brought to a close. Development of criteria for identifying naturally occurring wetlands could also serve as a basis for identifying areas for wetland mitigation and rehabilitation elsewhere in GTNP and the mountain valleys of the Northern Rocky Mountains.

Approaching the physical-biological interface in rivers: a review of methods for ecological evaluation of flow regimes

New European legislation known as the Water Framework Directive (WFD) challenges catchment hydrologists and freshwater biologists to quantify the risk of damage to the organic communities of rivers that arises from anthropogenic distortion of the natural flow regime. Here, we take the first step towards this goal by collecting together relevant information from the two disciplines. An extensive biological literature is examined for insights into the ways in which the species and communities associated with rivers might change when the flow regime is altered. From the hydrological literature, the indicators of flow regime and flow regime change that are pertinent to ecology are described, and consideration is given to means of deriving flow regime data for ungauged river reaches. Attempts to combine hydrology and ecology in classifying rivers and in setting flow objectives to favour biota are then reviewed, together with integrated approaches to river management that aim to promote ecological quality. A significant scale disparity is noted between the disciplines, hydrology being studied at catchment, subcatchment and reach scales, and biology generally at local level. Nonetheless, both yield methods with potential applications in aspects of WFD implementation. The approach with most appeal for general risk assessment is based on the concept of hydrological alteration. This technique employs flow regime variables selected for their importance to aquatic and riparian ecology, and quantifies deviations from the natural values of these variables at reach scale. For WFD purposes, calibration of the scale of hydrological alteration in terms of risk to ecological status is desirable. In this, priority should be given to identification of the level of hydrological alteration that corresponds to the division between good and moderate ecological status.

A Bayesian decision network approach for assessing the ecological impacts of salinity management

This paper outlines one component of a study being undertaken to provide a new tool for integrated management of dryland salinity, a major environmental problem in Australia. The Little River Catchment in the upper Macquarie River basin of New South Wales (NSW) is used as a case study. A Bayesian decision network (BDN) approach integrates the various system components — biophysical, social, ecological, and economic. The method of integration of the system components is demonstrated through an example application showing the impacts of various management scenarios on terrestrial and riparian ecology. The ecological impacts of management scenarios are assessed using a probabilistic approach to evaluate ecological criteria which are compared with those for the present situation. In considering different ecological indices, the direction and magnitude of change under different management scenarios varies because of the diverse influence of habitat fragmentation.

APPLICATION OF A MULTIPURPOSE UNEQUAL PROBABILITY STREAM SURVEY IN THE MID‐ATLANTIC COASTAL PLAIN1

ABSTRACT: A stratified, spatially balanced sample with unequal probability selection was used to design a multipurpose survey of headwater streams in the Mid‐Atlantic Coastal Plain. Objectives for the survey include unbiased estimates of regional stream conditions, and adequate coverage of unusual but significant environmental settings to support empirical modeling of the factors affecting those conditions. The design and field application of the survey are discussed in light of these multiple objectives. A probability (random) sample of 175 first‐order nontidal streams was selected for synoptic sampling of water chemistry and benthic and riparian ecology during late winter and spring 2000. Twenty‐five streams were selected within each of seven hydrogeologic subre‐gions (strata) that were delineated on the basis of physiography and surficial geology. In each subregion, unequal inclusion probabilities were used to provide an approximately even distribution of streams along a gradient of forested to developed (agricultural or urban) land in the contributing watershed. Alternate streams were also selected. Alternates were included in groups of five in each subregion when field reconnaissance demonstrated that primary streams were inaccessible or otherwise unusable. Despite the rejection and replacement of a considerable number of primary streams during reconnaissance (up to 40 percent in one subregion), the desired land use distribution was maintained within each hydrogeologic subregion without sacrificing the probabilistic design.

Down by the riverside: urban riparian ecology

Riparian areas are hotspots of interactions between plants, soil, water, microbes, and people. While urban land use change has been shown to have dramatic effects on watershed hydrology, there has been surprisingly little analysis of its effects on riparian areas. Here we examine the ecology of urban riparian zones, focusing on work done in the Baltimore Ecosystem Study, a component of the US National Science Foundation’s Long Term Ecological Research network. Research in the Baltimore study has addressed how changes in hydrology associated with urbanization create riparian “hydrologic drought” by lowering water tables, which in turn alters soil, vegetation, and microbial processes. We analyze the nature of past and current human interactions with riparian ecosystems, and review other urban ecosystem studies to show how our observations mirror those in other cities.

Down by the Riverside: Urban Riparian Ecology

Down by the Riverside: Urban Riparian Ecology

Down by the riverside: urban riparian ecology

Down by the riverside: urban riparian ecology

A tool for community-based assessment of the implications of development on water security in hillside watersheds

Development and population growth in Latin American countries with steep slope farming are likely to further increase pressures on water and land resources. A methodology was developed for assessing water availability and use under different development pathways at a watershed scale to determine whether water security is a potential problem, and if so, under what conditions it is likely to occur. This methodology makes use of a GIS-based spatial water budget model for simulating stream water availability, water use and stream flow control on a daily basis at a watershed scale. Here, we analysed water availability under three plausible development scenarios for the 3246 ha Cabuyal River watershed in southwest Colombia in the year 2025: Corporate Farming (CF), Ecological Watershed (EW), and Business as Usual (BU). Simulated average river flows at the watershed outlet were, respectively, 874, 796 and 925 l s −1 for the CF, EW and BU scenarios. The contribution of base flow to river flow (base flow index) was on average, 80.8, 85.6 and 77.9%, respectively, for the three scenarios. The watershed had the potential to meet the anticipated increase in water use under each explorative scenario. However, dams were necessary to store irrigation water in the CF scenario, otherwise over 60% of the available water would have been used during the dry season. Such a high figure raises concerns about effects on aquatic and riparian ecology, concentrations of potential contaminants, water reserves for especially low rainfall years, and the watershed resilience to meet temporarily higher water needs during the day. Analyses indicated that current water-use conflicts in the watershed can be resolved if irrigation water supply is separated from drinking water supply. This study helped reduce some of the complexity associated with the interdependencies between land and water resources, the impact of using them, and spatial linkages within the watershed. Results of this study can be used for teaching local stakeholders about basic landscape responses and helping multi-institutional alliances to become proactive and to guide development to the benefit of local communities.

Effects of Roads on Hydrology, Geomorphology, and Disturbance Patches in Stream Networks

Abstract: We outline a view of how road networks interact with stream networks at the landscape scale and, based on examples from recent and current research, illustrate how these interactions might affect biological and ecological processes in stream and riparian systems. At the landscape scale, certain definable geometric interactions involving peak flows ( floods) and debris flows (rapid movements of soil, sediment, and large wood down steep stream channels) are influenced by the arrangement of the road network relative to the stream network. Although disturbance patches are created by peak‐flow and debris‐flow disturbances in mountain landscapes without roads, roads can alter the landscape distributions of the starting and stopping points of debris flows, and they can alter the balance between the intensity of flood peaks and the stream network's resistance to change. We examined this conceptual model of interactions between road networks and stream networks based on observations from a number of studies in the H. J. Andrews Experimental Forest, Oregon (U.S.A.). Road networks appear to affect floods and debris flows and thus modify disturbance patch dynamics in stream and riparian networks in mountain landscapes. We speculate that these changes may influence the rates and patterns of survival and recovery of disturbed patches in stream networks, affecting ecosystem resilience, and we outline an approach for detecting such effects based on a patch dynamics perspective. A field sampling scheme for detecting the magnitude of various road effects on stream and riparian ecology could involve (1) landscape stratification of inherent stream network susceptibility to floods or debris flows, (2) overlay of road and stream networks and creation of areas with various densities of road‐stream crossings, emphasizing midslope road‐stream crossings, and (3) designations of expected high‐ and low‐impact stream segments based on numbers of upstream road‐stream crossings where sampling of selected biological variables would be conducted.

Riparian Ecology and Management in the Pacific Coastal Rain Forest

Riparian Ecology and Management in the Pacific Coastal Rain Forest

Abiotic aspects of channels and floodplains in riparian ecology

Summary1. The ecology of riparian zones is enormously influenced by the heterogeneous sedimentary structures and associated complex hydrologic flow paths that mediate surface‐ and groundwater exchanges. Sedimentary structures form a three‐dimensional, dynamic framework that controls subsurface flow and the vertical and horizontal exchange of water between channels and floodplains in gravel bed rivers. The modern structure of the bed sediments reflects the legacy of cut and fill alluviation for a particular river basin.2. Highly permeable sedimentary textures, particularly open framework gravels, allow rapid exchange between surface and groundwaters.3. Ground penetrating radar provides high resolution information on the nature and three‐dimensional distribution of the sediments within the shallow subsurface (4–25 m) of gravel bed rivers. Bed sediments can be mapped at the decimeter scale.4. Exchange and mixing of ground and channel water occurs along losing, gaining and flow‐through reaches as determined by the hydraulic gradient and transmissivity of the bed sediments.5. Spatial and temporal patterns of surface‐ and groundwater interactions can be quantified by mass flux measurements and by assessing geochemical contrasts. Natural tracers, such as temperature or radon, are well suited for mapping exchange sites and quantifying interactions. Artificial signals produced by injecting anions, like chloride, bromide and organic dyes are also useful.6. The study of riparian ecosystems requires an understanding of the geomorphic structures and processes that build and maintain bed sediments and flow pathways through them.

Learning about Riparian Rehabilitation: Assessing Natural Resource and Landscape Architecture Student Teams

This case study began as a 6-wk class project between two disciplines that had fundamental differences in terminology, knowledge base, skills, and perceptions. Natural resource students (NR) and landscape architecture students (LA) were teamed up to learn about riparian restoration. The instructors attempted to teach students skills for being effective members of a team. They also taught them rudimentary survey skills. Students completed weekly surveys to assess perceptions of the project, skills acquired through the experience, and the knowledge gained. At the beginning of the project both LAs and NRs felt they had similar individual abilities for working on team projects and had similar experiences with riparian restoration; however, the NRs felt significantly more knowledgeable about riparian ecology. By the end of the project, compared to the NRs, the LAs were significantly more positive about their ability to work as a member of a group. The LAs had caught up to the NRs in their knowledge of riparian ecology. The level of riparian restoration skills, similar for both groups at the beginning, had improved equally for both groups. Instructors felt that all of their course objectives had been met. Student team reports were well written and complete and their posters showed that they had integrated the information presented. Evaluations indicated that the students felt they had learned about the other's discipline. The student projects were awarded the 1994 Washington State Natural Resource Conservation Service award for volunteerism and provided impetus for a bioengineering grant award from the Washington State Department of Ecology.