Small Rural Watersheds Research Articles

Anthropogenic activities significantly interfered distribution and co-occurrence patterns of antibiotic resistance genes in a small rural watershed in Southwest China

The prevalence and spread of antibiotic resistance genes (ARGs) have been a significant concern for global public health in recent years. Small rural watersheds are the smallest units of factor mobility for agricultural production in China, and their ARG profiles are the best scale of the contamination status, but the mapping and the distribution and diffusion of ARGs in the water and soil of small rural watersheds are inadequate. In this study, based on microbial metagenomics, we invested prevalence maps of 209 ARGs corresponding to typical commonly used antibiotics (including multidrug, aminoglycoside, macrolide-lincosamide-streptogramin B (MLSB), and β-Lactamase) in water and soil in different agricultural types, as well as within water-soil interfaces in small rural watersheds in Southwest China. The results revealed that the most abundant ARGs in water and soil were consistent, but different in subtypes, and anthropogenic activities affect the transport of ARGs between water and soils. Livestock wastewater discharges influenced the diversity and abundance of ARGs in water, while in soil it is planting type and fertilizer management, and thus interfered with the co-occurrence patterns between bacteria and ARGs. Co-occurrence analysis revealed that Proteobacteria, Actinobacteria, and Bacteroidetes were the predominant ARG hosts in water and soil, but soil exhibited a more intricate ARG-bacterial association. Overall, this study provides integrated profiles of ARGs in water and soil influenced by anthropogenic activities at the small watershed scale in a typical rural area and provides a baseline for comparisons of ARGs.

Evaluation of Green and Grey Flood Mitigation Measures in Rural Watersheds

Floods cause considerable damages worldwide and mitigation of their adverse effects through effective protection measures is needed. Along with the commonly applied “grey” infrastructure, “green” measures that can offer additional benefits, such as ecosystem services, are increasingly being considered lately. While the recent research tendencies are focused on the effectiveness and the value of green measures in urban areas, this paper presents a comprehensive financial evaluation of green and grey flood mitigation scenarios for a smaller rural watershed. A micro-scale damage model that builds on the hydrodynamic modeling of hazard, detailed asset identification, and damage assessment is presented and applied for evaluation of benefits from various flood mitigation measures in the Tamnava watershed in Serbia. Four scenarios are considered: (1) existing flood protection system; (2) green scenario involving new detention basins; (3) grey infrastructure enhancement by rising of the existing levees and diverting flood discharges; and (4) green-grey scenario that combines scenarios (2) and (3). The benefits (loss reduction) are the greatest with the green scenario and marginally higher with the combined green-grey scenario. The results suggest that for small rural watersheds, a holistic, integrative approach that includes both types of infrastructure can provide the most effective flood risk mitigation.

Water availability, quality, and use in rural communities of the Chilean Coastal Range

Water availability, use, and quality in dispersed rural communities in a rural watershed within the Chilean Coastal Range were investigated through participatory research involving the local community, also called “citizen science.” Research included the quantification of recharge water and water use at the household level; monitoring of water quality of streams, community water intakes, and household faucets; and the determination of land use and water quality interactions. A group of mainly women along with the children of three local rural elementary schools were involved in the principal aspects of the research, from design to implementation and remediation options. The study area receives considerable, but highly variable, rainfall, and the hydrogeological setting does not offer enough interannual natural storage to cope with increasing demand and variable water viability. Our results also showed that chemical quality of the water is relatively good, except for the high concentration of iron (Fe; >0.3 mg L−1), manganese (Mn; >0.1 mg L−1), and turbidity (>5 nephlometric turbidity units [NTU]). From the microbiological point of view, the water is of poor quality. The low water quality could be related to the lack of maintenance of water collection systems, nonmaintenance of septic tanks, animal traffic, and low coverage of associated riparian vegetation. In the present approach the involvement of children in research helped to stimulate the improved management of both land and water resources by the community, and this practice could be applied in small rural watersheds in developed or developing countries.

Application of Export Coefficient Model and QUAL2K for Water Environmental Management in a Rural Watershed

Water quality deterioration caused by excessive nutrient discharge from various point and non-point sources are a global challenge. Understanding the pollution sources and their respective contribution is the prerequisite for environmental planning, management and restoration. In this study, the influence of complex pollution sources on the water quality of the Dengsha River watershed in Dalian, China, was investigated. The export coefficient method was coupled with the QUAL2K water quality model to estimate the loads of ammonia nitrogen (NH4-N) and total phosphorus (TP) from different sources, and to explore their respective contributions. Results indicated that animal feedlot and crop production were major sources for NH4-N load, and crop production, soil erosion and animal feedlot are the largest three sources of TP load with an annual total contribution of 98.4%. The pollutant load exhibited an intra-annual variation mainly due to the seasonality of rainfall and anthropogenic agricultural activities. The overall waste assimilation capacity (WAC) is overloaded and suggestions for water pollution control and treatment regarding each pollution source were proposed. This study addressed a new application of QUAL2K model coupled with the export coefficient model for watershed managers towards a sustainable water environmental management, and can therefore be a reference example for other small and medium-sized rural watersheds.

Remote sensing in water balance modelling for evapotranspiration at a rural watershed in Central Greece

There is an increasing trend in water balance modelling for remote sensing tools, which provide distributed information of watershed features. The paper's objective consists of exploring the remote sensing potential for evapotranspiration estimation in water balance modelling of a small rural watershed with limited data, namely Portaikos rural mountainous watershed of 132 km2 in Central Greece. Three water balance models with small number of parameters are used, namely Abulohom's, GR2M and Xiong-Guo model, respectively. Two approaches are considered. At first, monthly potential evapotranspiration derived from conventional meteorological data is used as input to the models. Second, air temperature is derived from land surface temperature (LST) of NOAA/AVHRR satellite images for monthly evapotranspiration estimation. Time series of the above parameters for 13 years (1981-1993) are used. The remote sensing potential for evapotranspiration estimation is assessed by comparing the observed and simulated monthly runoff at the output of Portaikos watershed. Four error statistics are used for validation. The results are considered quite satisfactory for the four error statistics. The GR2M shows relatively better performance than the other models for all the error statistics, as well as for the satellite-based approach, which shows slightly better performance than the conventional approach.

Relaciones intensidad-duración-frecuencia de la lluvia registrada en Chapingo, México

Intensity-duration-frequency (IDF) equations of rainfall have applications in the design of urban drainage works and are also used in the estimation of flows in small rural watersheds. In the present work rainfall IDF equations were created and compared based on pluviometer and pluviograph information recorded on the weather station of Chapingo during the period of 1975-2005. The methodology of creating IDF equation based on pluviograph consisted of: a) obtaining heights of rainfalls in millimeters of the studied area, for the durations of 5, 10, 15, 20, 30, 40, 60 min and for 2, 3, 4, 5, 10, 15 and 24 h, b) transforming heights to intensities, c) obtaining return periods for each intensity, and d) obtaining multiple linear regression equations. The methodology of creating IDF equation based on pluviometer was similar to the pluviograph, however the difference were the empirical relations, using as a main data the duration 24 h rainfall, the intensities for the durations of 5, 10, 15, 20, 30, 40, 60 min and for 2, 3, 4, 5, 10, 15 and 24 h were obtained, each one for different return periods. In this last step, the methodology of pluviometer carried out important errors related to the data obtained with pluviograph; however in many parts of Mexico only pluviometric information is available. A statistical comparison between both methods was performed and it was observed that IDF rainfall equation obtained with pluviometric underestimate the real IDF equation obtained with pluviograph; this error increases with the return period of the rainfall intensity

Sediment loss in semiarid small watershed due to the land use

The aim of this study was to evaluate and compare the sedimentological behavior in two small rural watersheds in the semiarid Northeast of Brazil, examining the influence of human activity on the sediment yields. The studied area is sited in the Alto Jaguaribe basin, more precisely in the Iguatu County, Ceara State. The experimental area was composed of two small watersheds denominated B1 and B2. In watershed B1 a treatment (thinning) was applied, eliminating the plant species with diameters lower than 10 cm. The results showed that the Caatinga clearing practice did have an influence in changing the sediment yield during the first events. It was also found that the magnitude of previous events contributed to an increase in the sediment yields by the subsequent events as a consequence of the sediment deposit in the drainage network. The accumulated sediment yields reached at the end of the 2009 rainfall season values of 1.45 and 1.39 tons ha -1 year -1 for B1 and B2, respectively, with no significant difference at 5%. It was concluded that, even when the effect of treatment on the sediment yields at the beginning of the rainy season is measured, the total sediment yields was not changed by the adoption of clearing. Therefore, it is a management system that can be employed in the land use at semiarid regions.

The Effects of Road Salt on Stream Water Chemistry in Two Small Forested Watersheds, Catoctin Mountain, Maryland, USA

The Hauver Branch and Hunting Creek watersheds in Catoctin Mountain, Maryland, USA, are small rural watersheds that receive road salt during the winter. Base cation evidence of road salt application in stream water disappears by approximately September for Hauver Branch, but never disappears for Hunting Creek. The fraction of the precipitation-corrected watershed fluxes of both Mg2+ and Ca2+ attributable to cation exchange associated with road salt Na+ inputs are 14 and 19 % for Hauver Branch and Hunting Creek, respectively. The percentage of divalent cations in stream waters resulting from road salt application is calculated using the watershed chemical weathering Na+/SiO2 molar ratio. Calculation of a representative chemical weathering Na+/SiO2 molar ratio may be problematic with spatially variable bedrock, and/or inputs from water softeners, septic systems, and wastewater treatment plants. Therefore, investigations of small forested rural watersheds offer insights into road salt dynamics that may be lost at larger scales and/or with increased urbanization. The quantities of road salt application to the Hauver Branch and Hunting Creek watersheds are 3.3 and 11 t km−2 year−1, respectively. The per-lane-length-normalized road salt application rates for the Hauver Branch and Hunting Creek watersheds are 10 and 22 t lane−1 km−1 year−1, respectively. These per-lane-length-normalized road salt application rates are relatively large compared to more urbanized watersheds located north of the study site where the application rates are reported by municipalities. These findings may indicate that road and highway administrations may underestimate their rates of road salt application.

Multiple sources of boron in urban surface waters and groundwaters

Previous studies attribute abnormal boron (B) levels in streams and groundwaters to wastewater and fertilizer inputs. This study shows that municipal drinking water used for lawn irrigation contributes substantial non-point loads of B and other chemicals (S-species, Li, and Cu) to surface waters and shallow groundwaters in the St. Louis, Missouri, area. Background levels and potential B sources were characterized by analysis of lawn and street runoff, streams, rivers, springs, local rainfall, wastewater influent and effluent, and fertilizers. Urban surface waters and groundwaters are highly enriched in B (to 250μg/L) compared to background levels found in rain and pristine, carbonate-hosted streams and springs (<25μg/L), but have similar concentrations (150 to 259μg/L) compared to municipal drinking waters derived from the Missouri River. Other data including B/SO42-−S and B/Li ratios confirm major contributions from this source. Moreover, sequential samples of runoff collected during storms show that B concentrations decrease with increased discharge, proving that elevated B levels are not primarily derived from combined sewer overflows (CSOs) during flooding. Instead, non-point source B exhibits complex behavior depending on land use. In urban settings B is rapidly mobilized from lawns during “first flush” events, likely representing surficial salt residues from drinking water used to irrigate lawns, and is also associated with the baseflow fraction, likely derived from the shallow groundwater reservoir that over time accumulates B from drinking water that percolates into the subsurface. The opposite occurs in small rural watersheds, where B is leached from soils by recent rainfall and covaries with the event water fraction.

Use of the swat model for hydro-sedimentologic simulation in a small rural watershed

Mathematical models have great potential to support land use planning, with the goal of improving water and land quality. Before using a model, however, the model must demonstrate that it can correctly simulate the hydrological and erosive processes of a given site. The SWAT model (Soil and Water Assessment Tool) was developed in the United States to evaluate the effects of conservation agriculture on hydrological processes and water quality at the watershed scale. This model was initially proposed for use without calibration, which would eliminate the need for measured hydro-sedimentologic data. In this study, the SWAT model was evaluated in a small rural watershed (1.19 km²) located on the basalt slopes of the state of Rio Grande do Sul in southern Brazil, where farmers have been using cover crops associated with minimum tillage to control soil erosion. Values simulated by the model were compared with measured hydro-sedimentological data. Results for surface and total runoff on a daily basis were considered unsatisfactory (Nash-Sutcliffe efficiency coefficient - NSE &lt; 0.5). However simulation results on monthly and annual scales were significantly better. With regard to the erosion process, the simulated sediment yields for all years of the study were unsatisfactory in comparison with the observed values on a daily and monthly basis (NSE values &lt; -6), and overestimated the annual sediment yield by more than 100 %.

Runoff estimation in small rural watersheds using DEMS in North West of Argentina

Basic information from analytical-descriptive methodologies on the relief of watersheds provides the necessary physical parameters for studying natural resources for, e.g., integrated management of watersheds, environmental impact, soil degradation, deforestation, conservation of water resources, and so forth. Geographic information systems can be used for all of these processes, which are linked to a strong spatial component. Digital elevation models (DEM) and their derivatives are a relevant component of these data sources. The parameters found from these models, such as the slope, are used directly or indirectly (as a component of these factors) in many surface runoff estimation equations. In Latin America, the Rational Method has been and continues to be one of the most widely used for the study of microdrainage in small watersheds. The experiment was conducted in the Yatasto district of the Province of Salta, North West Argentina and has an approximate surface of 270 hectares. This zone is located on the piedmont plain of the Metán sierra, where crops are grown, with relatively high slopes and high potential of soil erosion. In this area were studied five small rural watersheds all of them within the total DEM study area and none of them over 81 hectares. This work studied whether potential surface runoff found from the Rational Method (RAMSER) in small rural watersheds shows significant differences depending on whether the mean slopes are found from the DEM derived model or by the usual field methodology. We found that the small-sized grids increase the average slope (between 045% and 0.79%) found over those found from field data. The differences observed in volume of the peak runoff (between 0.003 m 3 s −1 and 0.062 m 3 s −1) were not significant. The results assure that there are no differences in the parameter evaluated (average slope) under the studied methodology and conditions.

Influence of hydrological conditions on the Escherichia coli population structure in the water of a creek on a rural watershed

BackgroundEscherichia coli is a commensal bacterium of the gastro-intestinal tract of human and vertebrate animals, although the aquatic environment could be a secondary habitat. The aim of this study was to investigate the effect of hydrological conditions on the structure of the E. coli population in the water of a creek on a small rural watershed in France composed of pasture and with human occupation.ResultsIt became apparent, after studying the distribution in the four main E. coli phylo-groups (A, B1, B2, D), the presence of the hly (hemolysin) gene and the antibiotic resistance pattern, that the E. coli population structure was modified not only by the hydrological conditions (dry versus wet periods, rainfall events), but also by how the watershed was used (presence or absence of cattle). Isolates of the B1 phylo-group devoid of hly and sensitive to antibiotics were particularly abundant during the dry period. During the wet period and the rainfall events, contamination from human sources was predominantly characterized by strains of the A phylo-group, whereas contamination by cattle mainly involved B1 phylo-group strains resistant to antibiotics and exhibiting hly. As E. coli B1 was the main phylo-group isolated in water, the diversity of 112 E. coli B1 isolates was further investigated by studying uidA alleles (beta-D-glucuronidase), the presence of hly, the O-type, and antibiotic resistance. Among the forty epidemiolgical types (ETs) identified, five E. coli B1 ETs were more abundant in slightly contaminated water.ConclusionsThe structure of an E. coli population in water is not stable, but depends on the hydrological conditions and on current use of the land on the watershed. In our study it was the ratio of A to B1 phylo-groups that changed. However, a set of B1 phylo-group isolates seems to be persistent in water, strengthening the hypothesis that they may correspond to specifically adapted strains.

Assessing water use and quality through youth participatory research in a rural Andean watershed

Water availability, use and quality in a rural watershed of the Colombian Andes were investigated through participatory research involving local youth. Research included the quantification of disaggregated water use at the household level; comparison of water use with availability; monitoring water quality of streams, community water intakes and household faucets; and the determination of land use – water quality interactions. Youth were involved in all aspects of the research from design to implementation, dissemination of results and remediation options. Quantification of domestic and on-farm water use, and water availability indicated that water availability was sufficient during the study period, but that only an 8% decrease in dry season supply would result in shortages. Elevated conductivity levels in the headwaters were related to “natural” bank erosion, while downstream high conductivity and coliform levels were associated with discharges from livestock stalls and poorly maintained septic tanks in the stream buffer zone. Through the involvement of youth as co-investigators, the knowledge generated by the research was appropriated at the local level. Community workshops led by local youth promoted water conservation and water quality protection practices based on research, and resulted in broader community participation in water management. The approach involving youth in research stimulated improved management of both land and water resources, and could be applied in small rural watersheds in developed or developing countries.

Infrared spectroscopy tracing of sediment sources in a small rural watershed (French Alps)

The present article describes a first attempt to use infrared spectroscopy to trace the origin of suspended river sediments. Fifty samples of the main potential sediment sources within a small catchment area (990 ha) in the French Alps were collected and compared with samples of suspended sediment from the river, collected on various dates during 2006 and 2007 using sediment traps. Two major categories of sediment source were identified: topsoils and river channel sediments. For the qualitative part of the study, each of these two main categories was divided into two sub-categories, that is to say, cultivated and pastureland topsoils, and riverbed and riverbank sediments. Discriminant analysis on the source samples showed that Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy can be used to differentiate between the four potential source materials. To determine whether or not immersion in the river altered the infrared spectra of these source materials, we measured the infrared spectra of samples that had been immersed in the river, in litter bags, for periods of up to 24 days. Immersion did not cause any major changes in the infrared spectra. The contribution of each type of source material to the suspended sediment in the river was quantified using partial least squares (PLS) analyses of DRIFT spectra to compare actual river sediment samples with an experimental model. This model was produced from the DRIFT spectra of a range of calibration samples produced by mixing source material samples in different ratios. The predictions of the model were valid and fell within the confidence interval calculated for the calibration set. Comparisons between suspended sediment samples and the model indicate that the predominant source of the sediment is riverbank erosion, which, in this case, is probably due to trampling by cattle.

Simulação da dinâmica do carbono do solo numa microbacia rural pelo modelo Century

O objetivo deste trabalho foi combinar o modelo Century com técnicas de geoprocessamento e sensoriamento remoto, para avaliar a dinâmica espaço-temporal do carbono orgânico total do solo (COT). O estudo foi implementado numa microbacia rural, na encosta superior do Nordeste do Rio Grande do Sul, RS, que apresentava inicialmente uma cobertura florestal que foi convertida para agricultura, ao longo de 80 anos. A calibração adequada do modelo, principalmente dos parâmetros relacionados à decomposição do COT, nos anos iniciais de exploração agrícola, foi fundamental para possibilitar a simulação coerente dos valores de COT. Em relação à distribuição espacial do COT, foi verificado que o maior impacto da agricultura, sobre o estoque original de COT, ocorreu nas áreas sob cultivo desde 1925, nas quais se constatou decréscimo de 58,2% do COT. Verificou-se que a integração do Century com um sistema de informações geográficas torna possível o estudo da dinâmica espaço-temporal do COT e a realização de inventários relativos à distribuição do COT.

Origins of Sediment-Associated Contaminants to the Marais Vernier, the Seine Estuary, France

The Marais Vernier is the largest freshwater wetland in the Seine Estuary in northern France. It is in a heavily urbanized and industrialized region and could be affected by atmospheric deposition and by fluvial input of contaminants in water diverted from the Seine River. To evaluate contaminant histories in the wetland and the region, sediment cores were collected from two open-water ponds in the Marais Vernier: the Grand-Mare, which was connected to the Seine by a canal from 1950 to 1996, and the Petite Mare, which has a small rural watershed. Diversions from the Seine to the Grand-Mare increased sedimentation rates but mostly resulted in low contaminant concentrations and loading rates, indicating that the sediment from the Seine was predominantly brought upstream by tidal currents from the estuary and was not from the watershed. Atmospheric sources of metals dominate inputs to the Petite Mare; however, runoff of metals from vehicle-related sources in the watershed might contribute to the upward trends in concentrations of Cr, Cu, and Zn. Estimates of atmospheric deposition using the Petite Mare core are consistent with measured deposition in the region and are mixed (similar for Hg and Pb; larger for Cd, Cu, and Zn) compared with deposition estimated from sediment cores in the northeastern United States. A local source of PAHs in the watershed of the Petite Mare is indicated by higher concentrations, higher accumulation rates, and a different, more petrogenic, PAH assemblage than in the Grand-Mare. The study illustrates how diverse sources and transport pathways can affect wetlands in industrial regions and can be evaluated using sediment cores from the wetland ponds.

Spatial Variation in Stream Water Quality in Relation to Riparian Buffer Dimensions in a Rural Watershed of Eastern New York State

Studies of forested rural watersheds provide estimates of background contamination for comparison with streams and rivers in other settings. We performed a landscape analysis and measured major dissolved ions and benthic macroinvertebrates for a small rural watershed in Albany County, NY, to determine spatial variation in water quality. An estimated 73% of the surface cover is post-agricultural forest, with only 2.3% of the watershed covered by roads and other impervious surfaces. Although water quality was consistently high in most of the creek, we detected three relatively distinct zones separated by impoundments; zonation was most apparent in relative concentrations of major ions, less so with benthic macroinvertebrate community similarity. At ten sample stations, buffer size, measured as upstream land cover and distance to nearest road, did not correlate well with chemical water quality indicators. In particular, we found the highest levels of chloride, indicative of road-salt contamination, in areas of maximum forest buffer. Small feeder creeks that drain nearby roads may function as “leaks” in otherwise well-buffered watersheds with low road densities.

Compositions of first flush and composite storm water runoff in small urban and rural watersheds, north-central Texas

The objective of this study was to evaluate chemical compositions of first flush and composite storm water runoff in four small, mixed land use watersheds in north-central Texas. The watersheds range from urban to rural, all discharging to a local lake providing aquatic habitat, recreation, flood control and drinking water. Automated devices near watershed outlets collected samples from seven storm events, from April 2001 to September 2003. Samples were analyzed for suspended solids, pesticides (diazinon, triazine and chlorpyrifos), nutrients (nitrogen and phosphorus), fecal coliforms and metals. Observed concentrations of most parameters were low relative to drinking water maximum contaminant levels (MCLs) and aquatic life criteria. Fecal coliforms and lead were detected in most samples, with highest lead concentrations in the most developed watershed, likely influenced by building material and automobile traffic. Pesticide concentrations were higher in an initial spring storm event following applications to control weeds and insects. Typical of urban runoff, most ammonia and phosphorus observations exceeded freshwater criteria for streams draining to lakes. Treated wastewater effluent accounted for the highest nitrogen and phosphorus observations. For most constituents, composite concentrations exceeded first flush concentrations, though differences were significant only for fecal coliforms.

Changes in Nutrient Loading in an Agricultural Watershed and Its Effects on Water Quality and Stream Biota

Non-point-sources of nitrogen (N) and phosphorus (P) are recognized as major causes of eutrophication of surface waters. Adoption of policies to reduce pollution in the former German Democratic Republic following re-unification of Germany in 1990 provided an opportunity to examine how taking agricultural land out of production affected nutrient loads and aquatic biota in a small rural watershed. Between 1994 and 1996, soluble reactive phosphorus (SRP) and dissolved inorganic nitrogen (DIN) loads in a first-order agricultural stream decreased by >90% while instream concentrations decreased by 89% for DIN and 40% for SRP. This reduction in nutrients coincided with a decrease in precipitation (from 760 to 440 mm between 1994 and 1996) and an increase in the area of land set aside from agricultural production (from 0.3% in 1990 to a maximum of 8% in 1994). The biomass of primary producers (episammic algae) showed no clear response to this decrease in nutrient concentrations. However, benthic invertebrate composition shifted from a chironomid–amphipod to an oligochaete–gastropod dominated community in response to the decrease in DIN and changes in episammic algal abundance and sediment organic carbon concentrations. Results from our 4-year study showed reductions in soil nutrient losses combined with less precipitation resulted in less P and N in a rural stream and a change in benthic invertebrate community composition and abundance.

Can Watershed Management Unite Town and Country?

ABSTRACT Resource agencies in the United States have taken up collaborative watershed management planning as a general policy tool. In doing so, they have adapted methods originally developed by voluntary partnerships in small rural watersheds and applied them across larger drainage areas with more diverse patterns of land use. Using Henri Lefebvre's concepts of social space, this article reviews research to identify the varied political, social, and physical characteristics that watershed organizers confront in urbanized and rural areas. Planners working in watersheds with diverse settlement patterns may find it difficult to meet the guiding principles suggested by the U.S. Environmental Protection Agency (U.S. EPA) and National Research Council: organizing watershed partnerships to involve those most affected by management decisions, making decisions within a specific geographic area, and using science and data to guide decisions over time.