Hydrologic Unit Research Articles

Environmental exposures and pulmonary function among adult residents of rural Appalachian Kentucky.

Estimated residential exposures of adults to roadway density and several metrics of resource extraction, including coal mining and oil and gas drilling, were hypothesized to contribute to the prevalence of respiratory disease in rural Appalachia. Determine how small-area geographic variation in residential environmental exposures impacts measures of pulmonary function among adults in a community-based study. We examined associations between residential environmental respiratory exposures and pulmonary function among 827 adult participants of the "The Mountain Air Project", a community-based, cross-sectional study in Southeastern Kentucky during 2016-2018. Exposures characterized the density of roadways, oil/gas wells, or current/past surface and underground coal mining at the level of 14-digit hydrologic unit code (HUC), or valley "hollow" where participants resided. Each participant completed an in-person interview to obtain extensive background data on risk factors, health history, and occupational and environmental exposures, as well as a spirometry test administered by experienced study staff at their place of residence. Multivariable linear regression was used to model the adjusted association between each environmental exposure and percent predicted forced expiratory volume in one second (FEV1PP) and forced vital capacity (FVCPP). Adjusted regression models indicate persons living in HUCs with the highest level of roadway density experienced a reduction in both FEV1PP (-4.3: 95% CI: -7.44 -1.15;) and FVCPP (-3.8: 95% CI: -6.38, -1.21) versus persons in HUCs with the lowest roadway density. No associations were detected between the metrics associated with mining and oil and gas operations and individual pulmonary function. Our work demonstrates the potential adverse impact of roadway-related exposures on the respiratory health of rural Appalachia residents. We employed a novel method of small-areaexposure classification based on the hydrologic unit code (HUC), representing potentialexposure levels per hollow occurring in proximity to the residence, and controlled for individual-level risk factors for reducedrespiratory health. We highlightan overlooked yet ubiquitous source of residentialexposure from motor vehiclesthat may contribute to the regionally high prevalence of respiratory disease in rural Appalachia.

A comparison of riparian buffer designs incorporating short‐rotation Salix viminalis to mitigate surface water pollution in the Dunk River watershed on Prince Edward Island

AbstractRiparian buffers protect surface water from diffuse pollutants, mitigating sediment, nutrient, and chemical losses from agricultural landscapes. Prince Edward Island, Canada, has legislated 15‐m riparian buffers, yet stream contamination from agriculture remains widespread. The Soil and Water Assessment Tool and Riparian Ecosystem Management Model were used to simulate 12 years of nutrient and sediment loads from five potato Hydrologic Response Units in the Dunk River watershed on PEI and evaluate water quality impacts of 30 m three‐zone buffers incorporating shrub willow relative to existing 15 m grass and forest buffers and assess optimal buffer width. Willow buffers (30 m) removed 49.9 T ha−1 year−1 sediment, 18.5 kg ha−1 year−1 total N (TN) and 7.8 kg ha−1 year−1 total P (TP). This was 5.6% and 4.1% more sediment and TP than existing 15 m grass buffers and 7.5%, 12.6%, and 16.8% more sediment, TP, and TN than existing 15 m forest buffers. Willow buffers removed significantly more particulate contaminants than forest and significantly more soluble than grass. Optimal willow buffer width downslope of potato fields was 40 m. Overall, incorporating shrub willow and/or riparian widening can have considerable water quality benefits, particularly in regard to sediment retention, and maximize both soluble and particulate pollutant removal on PEI.

Environmental conflicts in municipality areas: land use policy for zoning regulation.

The growing expansion of socioeconomic activities without considering the potentialities and limitations regarding the land use constitutes a potential source of deterioration of the environment. The present work aimed to diagnose the areas of land use conflict in the municipality of Batatais-SP. The methodological procedure consisted of geographic information systems and remote sensing techniques. The municipal area was regionalized into hydrological response units (HRU). The quantitative data of area, length of the drainage network and roughness number were determined, and the processes and their interrelationships were analyzed. The distribution of aptitude classes for land use was confronted with the current land use and allowed the identification and quantification of the land use conflict. Zoning indicated that, from 452.46 km2 of the municipality's area, 28.67% are assigned to conflict class 1 and present risks or severe permanent limitations when used for annual crops and pastures. At higher spatial levels, land use conflict influences sustainable development. States grant authority to pass ordinances and regulations, and municipal governments have autonomy to control land use within their jurisdictions, if it do not conflict with other laws. The land use conflict technique establishes an orderly pattern and can serve as a tool for municipal zoning in regulating land use.

Temporal Analysis of Water Quality for the Nilo Coelho Reservoir, Terra Nova, Pernambuco, Brazil

The Brazilian northeast has a characteristic relationship with water resources because, in this region, water scarcity is associated with natural factors and accentuated by anthropic actions that interfere with water quality. The present work aimed to perform a temporal analysis of the water quality of the Nilo Coelho reservoir, municipality of Terra Nova, a semi-arid region of Pernambuco. Initially, the parameters of dissolved oxygen, nitrate, and phosphorus, available in the system of hydrological response units for Pernambuco (SUPer), following the resolution of the National Environment Council (CONAMA), for the years 1963–2021, were analyzed. Subsequently, land use and occupation mapping were carried out to identify the activities that developed in the region. The result of the analysis of water quality for the Nilo Coelho reservoir classifies it as little compromised, since the parameters are within acceptable limits, with greater variations for phosphorus. Regarding the use and occupation of the soil, there was an increase in water availability and agricultural areas, with a reduction in the caatinga. Continuous monitoring of water quality in the reservoir is recommended, in addition to the application of SUPer and land use and occupation maps as tools for the management of water resources.

Calibration and validation of hillslope runoff and soil loss outputs from the Water Erosion Prediction Project model in Minnesota agricultural watersheds

AbstractThere is growing interest in studying the impact of alternative agricultural management practices on runoff and soil loss under future climate change scenarios. In order to address this interest, it is important to demonstrate that runoff and soil loss can be accurately simulated under existing climates based on comparisons between modeled and experimental results. This study calibrates and validates the Water Erosion Prediction Project (WEPP) model to quantify the accuracy of predicting growing season runoff and soil erosion in agricultural hillslopes based on comparisons with experimental data from five Minnesota hydrologic unit code 12 watersheds. In order to accurately predict runoff and soil erosion in each watershed, the baseline effective hydraulic conductivity (Kbe), interrill and rill erodibility (EIR and ER), and monthly precipitation standard deviations (Pstdev) were calibrated in WEPP using observed runoff and total suspended solids data from five Minnesota Discovery Farms field sites. Before calibration, Nash–Sutcliffe model efficiency (NSE) and percent bias (PBIAS) values for predicted versus measured monthly average total runoff (Ravg‐T), runoff ratios (RRT), and total soil loss were generally not in acceptable ranges. After calibration, the NSE values showed very good fits between measured and predicted monthly Ravg‐T (0.64–0.98), RRT (0.66–0.93), and soil loss (0.58–0.80). PBIAS values were also within acceptable ranges for Ravg‐T and RRT (±25%) and soil loss (±55%), except for RRT at site BE1. NSE and PBIAS values during validation were within acceptable ranges, except for RRT at site BE1. These findings suggest that the WEPP hillslopes calibrated in this study are sufficiently robust to accurately predict monthly runoff and soil erosion in Minnesota agricultural fields during the growing season.

Post Peat Fire Soil Natural Recovery Based on Physical Properties in South Kalimantan, Indonesia

Indonesia always experiences forest and peatland fires during the extreme dry season. Forest and land fires greatly affect productivity and the environment. The fire was very detrimental to the ecological, economic and social aspects, in addition to the spread of smoke in various countries. This study examines the recovery rate of peat soil after the 2015 fire in the Balangan River - Batangalai River Peat Hydrological Unit (KHG), South Kalimantan. Test results on post-fire land in 2015 after five years (T+5) with a pH value of 2.93; water content is 270.94% and bulk density is 0.225 g cm-3. At (T+7) the test results showed that the pH value was 3.20, the water content was 288.22% and the bulk density was 0.165 g cm-3. Changes in the value of physical properties for five years and seven years after the fire for the pH value increased by 8.60%; the water content value also increased by 5.99% and the bulk density value decreased by 5.99%. Test results on natural (unburn) land in 2015 after five years (T+5) with a pH value of 3.32; water content is 342.60% and bulk density is 0.098 g cm-3. At (T+7) the test results showed that the pH value was 3.43, the water content was 349.94% and the bulk density was 0.082 g cm-3. Changes in the value of physical properties for five years and seven years after the fire for the pH value increased by 3.13%; the value of water content also increased by 2.10% and the value of bulk density decreased by 19.51%. This research is able to indicate that the post fire peat soil naturally become getting close to the unburn condition even though it still in a degraded condition.

Optimal selection of cost-effective biological runoff management scenarios at watershed scale using SWAT-GA tool

Study regionStudy region: Hablehrood River (HR) watershed in the northern part of the Iranian Central Plateau. Study focusFinding the most economical management scenarios for implementing biological best management practices (BMPs) in the HR watershed is one way to solve the runoff issue in the study area. As, the best types, quantities, and locations of arid and semi-arid rangeland biological BMPs have not yet been identified or determined using the soil and water assessment tool (SWAT) or genetic algorithm (GA) to maximize runoff reductions at the lowest possible cost in arid and semi-arid rangelands, therefore, to estimate runoff and best identify biological management scenarios at the watershed scale in the current study, the SWAT and a GA model have been used. After determining the hydrological response units (HRUs), eight biological watershed management scenarios were identified through a combination of biological management activities. To determine the best management practice with the highest runoff reduction and the lowest possible cost, optimization was performed by GA based optimization model. New hydrological insights for the regionThe simulation results of this study show that all the developed biological BMPs had a significant effect on the surface runoff rate reduction and reduced the surface runoff from 4.4% to 8.2%. The fifth scenario including seeding using machine (SUM) and seeding without machine (SWM) biological activities as optimal and the best scenario with weighted coefficients of 0.95 and 0.05 for runoff reduction and cost, respectively, was determined to be the optimum practice. The results further indicate that runoff would be decreased by 76.4 million cubic meters compared base scenario runoff volume, at a cost of 469.8 billion IR Rials. The lowest volume of surface runoff, however, was related to scenario number eight, while it had the highest cost (1114.3 billion IR Rials) among all scenarios. Using optimization methods, decision-makers and managers may pinpoint the best biological BMP scenarios in terms of kinds, locations, and amounts that might reduce runoff rates as much as possible at the lowest possible cost.

Characterizing subsidence in used and restored peatland with Sentinel SAR data

Peatland is a fragile ecosystem in the tropical region which is prone to subsidence. Until now, there is still lack of procedure to rapidly assess a tropical peatland subsidence in a large area. Our objective was to compare subsidence in a used and restored zone in a peatland hydrological unit using synthetic aperture radar data from Sentinel-1A products (SAR data) in South Sumatra, Indonesia from the period of 2014–2021. The subsidence rate of used peatland estimated by the D-InSAR procedure were in the range of 28–80 cm year−1 in the early period of its utilization and becoming less for the consecutive year (16–48 cm year−1). Meanwhile, the subsidence rate based on the field surveys was in the range of 4–50 cm year−1 in the early period of peatland utilization. The subsidence rate in the used peatland zone (agriculture and plantations) was higher than that in the restoration zone for all SAR data pairs used in our study. The SAR data is a potential tool for the assessment, monitoring and differentiating subsidence rates among different peatland uses in a large area. This tool will help the Directorate of Peat Ecosystem Degradation Control, Directorate General of Environmental Pollution and Degradation Control, and Ministry of Environment and Forestry to plan for better peatland management and restoration.

A harmonized characterization of drainage units on the African continent

Integrated water resources management framework and other frameworks that approach sustainable resources management from a catchment perspective can benefit from the availability of a characterized and harmonized dataset of hydrological units. Harmonization is particularly relevant for a highly linguistically diverse continent such as Africa where high-resolution topographic relief datasets are not readily available, and most of the continent's waters fall within transboundary drainage units. This article describes and implements a hierarchical coding framework that harmonizes the description, classification, and coding of drainage units on the African continent. The continent is divided and subdivided into successively smaller drainage units, classified into six levels: systems, regions, subregions, basins, subbasins, and catchments, primarily determined by topology, location, type, and size of drainage units. Drainage units are consistently assigned identification codes that show their location and classification level. The classification groups the 1007 catchments (with areas ranging from 10,000 to 50,000 km2) on the mainland continent into 274 subbasins (50,000–250,000 km2), 119 basins (100,000–500,000 km2), and thirty-two subregions, twelve regions and five systems including islands. The characterization provides a high-resolution basin boundary dataset that improves data compatibility and accuracy and is expected to support catchment-based research and application on the continent.

COCKPIT-PLUS: A proposed method for rapid groundwater vulnerability-driven land use zoning in tropical cockpit karst areas

Karst groundwater is highly vulnerable to contamination, which urges better land use zoning. This paper proposes a new approach, called COCKPIT-PLUS, to minimize groundwater contamination within cockpit karst regions. The method employed four parameters: P (the existence of ponor/swallow hole), L (lineament density), U (sinking stream to an underground river), and S (distance to spring/pumping site). These parameters are essential for identifying contaminant pathways and transport from the surface to the karst groundwater/springs. COCKPIT-PLUS has been developed and validated in the Gunungsewu karst in Java, Indonesia. This research considers a cockpit as a single hydrological unit that uniquely recharges karst groundwater. We analyzed 2,811 cockpits and 81 other closed depressions to develop a land use planning map. The research used the time to first arrival (Ta), time to peak (Tp), and Qmax/min ratio parameters of two karst springs and two underground pumping sites for validation. Cockpits with ponors/swallow holes, sinking streams, high lineament density, and short distances to springs are vulnerable to groundwater and thus must be restricted areas for any land uses. The findings show that though the COCKPIT-PLUS uses a limited karst dataset, the proposed method seems reliable enough for a rapid land-use zoning approach in cockpit karst areas.

Longer simulation time step of the tracer-aided hydrological model estimates lower contribution of slow runoff components

Uncertainty and parameter equifinality are important issues for hydrological models, especially in cold mountainous regions where multiple runoff components enhance the hydrological complexity. Tracer-aided hydrological models integrating water isotope modules are helpful for improving the physical representation of the model structure and parameter identification. Under the common complete-mixing assumption in the distributed tracer-aided model, the simulation time step reflects the water movement velocity at the hydrological unit scale and influences the model performance, which has yet to be addressed in previous studies. Consequently, the question of how the simulation time step influences the performance of tracer-aided hydrological models is poorly understood. In this study, we utilized a tracer-aided model THREW-T for a mountainous basin on the Tibetan Plateau to explore the above questions. The results showed that (1) the simulated variations in streamflow, snow cover area and stream water isotopes were similar among different time scales, but the isotope simulation performance worsened when adopting longer time steps. Simulation time steps ranging from 1 to 24 h led to a 10% difference in the estimated contribution of subsurface runoff, which decreased with increasing time scale. (2) A longer simulation time step yielded a lower simulated variability of stream water isotopes because of the lower water velocity within hydrological units. To offset this effect, the model characterized quicker water movement at the catchment scale by estimating a lower contribution of the slow runoff component. (3) Despite the additional uncertainty resulting from the simulation time step, the involvement of isotopes in the calibration objective still improved the model confidence by increasing the parameter sensitivity to the partitioning among the different runoff components, resulting in more reasonable water apportionment estimates. This study addresses the influence of the time scale on the performance of tracer-aided hydrological models and highlights the importance of adopting a suitable time step when applying these models, rather than the daily scale commonly adopted in most existing modeling practices.

An integrated distributed robust optimization framework for agricultural water-food-energy management integrating ecological impact and dynamic water cycle processes

Sustainable Development Goals (SDGs) appeal to decision-makers to consider the impact of agriculture on different aspects, including the economic, social, ecological and environmental influences. This study establishes an integrated distributed water-food-energy management model that simultaneously considers resource-saving, economic development, ecological restoration, social security guarantee and environmental improvement to realize sustainability according to optimal resource allocation. The developed model considers the full dynamic of the water cycle, including water exchanges between river, canal, soil and aquifer. The irrigation units are regarded as decision units and hydrological response units, which are determined based on the canal distribution. A net-primary-productivity-based method is proposed for ecological and environmental benefits of agricultural production. Additionally, a comprehensive multi-objective robust programming is proposed to deal with uncertainties in both objectives and constraints, with optimality and feasibility robustness guaranteed. Taking an arid area in northwestern China as a working example, the modeling outputs offer strategies for water and energy uses under 27 risk scenarios. The feasibility robustness analysis uncovers the degree and source of risks faced by different vegetation and decision units. The optimality robustness analysis shows the influence of different uncertainties on the objectives and helps recognize sensitive objectives. These outputs can satisfy decision-makers with different risk preferences, reveal the independent and mutual effects of different uncertainties, and help recognize the key indicators of sustainable development.

Designing Iowa Agricultural Landscapes to Improve Environmental Co-Benefits of Bioenergy Production

Cellulosic bioenergy feedstocks are needed to improve carbon (C) management while provisioning biomass for bioproducts and biofuel. The transition to increased cellulosic biomass production can be guided by land management plans designed to improve economic, environmental, and ecological performance. We constructed a sustainability model to compare landscape designs for biofuel production from corn (Zea mays L.) stover and switchgrass (Panicum virgatum L.) in central Iowa, USA. We used the model to compare environmental and socioeconomic outcomes associated with four landscape management strategies, with and without cellulosic biomass markets. We evaluated (1) a fuelshed area containing over 1.2 million ha (3 million acres) of corn and soybean (Glycine max (L.) Merr.) within 80 km (50 miles) of a commercial-scale cellulosic biorefinery in Nevada, Iowa, and (2) the South Fork watershed containing over 72,000 ha (178,000 acres) of these row crops within eight north central Iowa HUC-12 (hydrologic unit code) watersheds. At both landscape scales, we found that it is possible to achieve multiple environmental and socioeconomic benefits concomitantly with cellulosic biomass production by strategically collecting corn stover and converting the 10% of the lowest-profitability row crop land to perennial switchgrass. Potential benefits from landscape design include increased biodiversity, soil and water quality improvements, increased soil carbon sequestration for climate change mitigation, and reduced fertilizer use and cost. Our model results showed that increasing benefits can accrue when complementary conservation practices (e.g., reduced tillage, use of a rye cover crop) are combined and integrated throughout a fuelshed or watershed area. We conclude that ecologically based landscape designs offer valuable insights about costs and benefits of land management alternatives, with relevance for achieving stakeholder goals.

A network-based approach to identifying correlations between phylogeny, morphological traits and occurrence of fish species in US river basins.

The complex network framework has been successfully used to model interactions between entities in Complex Systems in the Biological Sciences such as Proteomics, Genomics, Neuroscience, and Ecology. Networks of organisms at different spatial scales and in different ecosystems have provided insights into community assembly patterns and emergent properties of ecological systems. In the present work, we investigate two questions pertaining to fish species assembly rules in US river basins, a) if morphologically similar fish species also tend to be phylogenetically closer, and b) to what extent are co-occurring species that are phylogenetically close also morphologically similar? For the first question, we construct a network of Hydrologic Unit Code 8 (HUC8) regions as nodes with interaction strengths (edges) governed by the number of common species. For each of the modules of this network, which are found to be geographically separated, there is differential yet significant evidence that phylogenetic distance predicts morphological distance. For the second question, we construct and analyze nearest neighbor directed networks of species based on their morphological distances and phylogenetic distances. Through module detection on these networks and comparing the module-level mean phylogenetic distance and mean morphological distance with the number of basins of common occurrence of species in modules, we find that both phylogeny and morphology of species have significant roles in governing species co-occurrence, i.e. phylogenetically and morphologically distant species tend to co-exist more. In addition, between the two quantities (morphological distance and phylogentic distance), we find that morphological distance is a stronger determinant of species co-occurrences.

Leveraging a century of fisheries surveys to prioritize conservation efforts for species in Great Plains streams of Oklahoma (USA)

Abstract Although non‐game fishes typically dominate lists of threatened and imperilled species, funding mechanisms for non‐game species are usually less robust than those for game species. This imbalance emphasizes the need for methodologies to identify imperilled species effectively and ensure efficient allocation of limited conservation resources. A database comprising >3,900 fisheries surveys conducted between 1905 and 2020 in Great Plains streams of Oklahoma (USA) was used to develop methodology for identifying species in need of conservation by assessing differences in species occurrences and trends in species ranges through time. Changes in occurrence for 92 species at both river catchment and ecoregion scales were assessed. Generalized linear models indicated significant differences between historical and contemporary fish communities at both scales. Univariate testing showed 84 instances of species occurrences changing in at least one catchment. Declines in occurrence were observed for eight species currently listed as species of greatest conservation need in Oklahoma and were used to identify five candidate species for listing. Family‐level trends in species occurrences suggested declines of native true minnow species and increases in generalist sunfishes and catfishes through time. Trends in detections within each hydrologic unit code sampled were used as a proxy for tracking changes in species range within each catchment. Various species were used as case studies to highlight this method. The results demonstrate how managers can apply an empirical methodology that extracts information from long‐term datasets to optimize conservation efforts for stream fishes and associated taxa.

Field scale SWAT+ modeling of corn and soybean yields for the contiguous United States: National Agroecosystem Model Development

CONTEXTDespite a steady increase in staple crop yields over the past ten years, current agricultural production must escalate even more to keep pace with the expected world population growth, which in turn will require improved agricultural methods that are adapted to many environmental pressures. Comprehensive models that can simulate crop production systems and the impact of management and conservation practices on natural resources and the environment, including water quality at large scale present important contributions to this challenge. OBJECTIVETo this end we developed the National Agroecosystem Model (NAM): a comprehensive model that uses the updated Soil and Water Assessment Tool (SWAT+) to accurately simulate staple crop yields across the contiguous United States (CONUS), with an initial focus on Corn (Zea mays L.) and Soybean (Glycine max L. Merr.) yields. METHODSAvailable open-access data was used to setup this high-resolution modeling system, where every 8-digit hydrologic unit (HUC8) is represented as an individual SWAT+ simulation. A total of 2201 HUC8 simulations across the CONUS were interconnected from upstream to downstream to make the NAM. Field boundary data was used to setup the NAM in such a way that every identified cultivated field is modeled as a unique Hydrologic Response Unit (HRU). Simulated corn and soybean yield from over 2.5 million field-type HRUs were compared to reported average annual corn and soybean yields for the respective area for the 2015–2020 period. RESULTS AND CONCLUSIONSResults show a good agreement between simulated and reported yields (R2 = 0.90 for corn and R2 = 0.70 for soybeans), with a very good model performance in the high corn and soybean production region of the US Corn Belt (Relative Error < ±5%). SIGNIFICANCEApart from assessing the capability of the updated SWAT+ model, we also demonstrate the new crop yield calibration module embedded in SWAT+, highlight changes to the plant growth module, and model parameterization. Results of an analysis of possible crop production differences for corn and soybeans in irrigated, tiled, and non-irrigated-non-tiled fields are also discussed. The versatility of the NAM provides the possibility to analyze information on impacts of changing conservation practices and enables identification of conservation gains and remaining conservation needs at the national scale.

Analisis Usahatani Perkebunan Kelapa Sawit Rakyat Berdasarkan Jasa Ekosistem Pengaturan Tata Aliran Air dan Banjir di Provinsi Riau

Riau Province has the largest oil palm plantation in Indonesia consisting of large national private plantations and community plantations located in various land typologies and landscapes. Each landscape has characteristics of forest areas and peat hydrological units that can affect the level of land productivity. This study aims to determine the carrying capacity of environmental capacity based on ecosystem services of water flow and flood management services in smallholder oil palm plantations in Riau Province. The analysis method consists of spatial analysis and farming analysis, spatial analysis to determine the carrying capacity of environmental capacity based on ecosystem services for water flow and flood management services. Farming analysis to determine land productivity, fresh fruit bunch (FFB) prices, production costs and farmer income based on environmental capacity criteria based on ecosystem services for water flow and flood management services. The results showed that based on the capacity of environmental capacity based on ecosystem services for water flow and flood management services on smallholder oil palm plantations in Riau Province consisted of very low, low, medium, high and very high criteria. Furthermore, the level of productivity, FFB prices, production costs and farmers' income are influenced by the typology of the capacity of water flow and flood management services. The higher the capacity of water flow and flood management services, the higher the land productivity and farmers' income.

Utilization of Multitemporal Land Cover Data and GIS for SWAT-Based Sedimentation and Runoff Modeling in the Lasolo Watershed, Indonesia

Sedimentation and surface runoff are two vital processes occurring in a watershed, and calculating the constituent transports of sediments and surface water is the initial step in planning. This research was intended to model surface runoff and sedimentation temporally (2008, 2013, 2018, and 2021) on hydrological response unit (HRU) and subwatershed levels for the Lasolo Watershed in Southeast Sulawesi, Indonesia. Soil and Water Assessment Tool (SWAT), a physically based hydrological modeling instrument, was selected for the simulation using these input data: SRTM DEM, land cover, soil type, and several climatological data sourced from ERA5, NASA GLDAS, and the NASA POWER Project. Results showed fluctuating surface runoff and sediment yield throughout the simulation time frame. The mean surface runoff peaked at a capacity of 216.6 mm/year in 2013, and the mean sediment yield was also the highest this year, 10.8 tonnes/ha/year. In 2021, there was a significant reduction to 18.2 mm/year for surface runoff and 0.91 tonnes/ha/year for sediment yield. Simulations suggested that the watershed’s surface runoff capacity is directly proportional to the sediment yield produced. &#x0D;

Determination of the macrophyte index MIR as an indicator of water quality in the Pripet river

Introduction. The river basin and the catchments of small rivers within it is a complete ecological, hydrological and economic unit with clear boundaries and a set of natural conditions. Increasing the stability of the geosystem of the river basin is impossible without monitoring the dynamics of the state of natural resources and factors of negative impact. A significant part of the water management complex of the Volyn region is the Pripet River basin which has a significant degree of development. The watercourse forms part of the state border between Ukraine and the Republic of Belarus, the tributary basins are located on the territory of both states. The source, lower course and mouth of the Pripet River are on the territory of Ukraine. Therefore, it is necessary to observe the strategic principles of rational nature management to restore and preserve the optimal ecological state of the Pripet River basin. The objective of the work is to assess the ecological state of the Pripet River using bioindication methods and the Macrophyte Index for Rivers (MIR). Methods. Research methods are expeditionary, mathematical statistics, bioindication, and determination of the Macrophyte Index for Rivers (MIR). Results. Four test sites of at least 100 m length each were used to determine the ecological state of the waters of the Pripet River. Research found 48 species of higher aquatic and coastal aquatic plants in the test sites of the Pripet River. All species belong to the division Magnoliophyta, of which 21 species of the class Magnoliopsida (43.75%), and the larger share (27 species, 56.25%) to the class Liliopsida. 35 indicative species of macrophytes were selected in the test sites of the river to determine the Macrophyte Index for Rivers (MIR). According to the MIR classification, the river belongs to lowland watercourses, the macrophyte type M-VIII (organic rivers). MIR calculations established that the river water quality in the test site No. 1 (village of Polozhevo, upper reaches) has a satisfactory ecological state, MIR is 33.84; in the site No. 2 (v. Luchytsi) satisfactory ecological state, MIR is 34.04; in the site No. 3 (v. Liubyaz, border between Volyn and Rivne regions) good ecological state, MIR is 40.6; water quality in the site No. 4 (v. Senchytsi, border with Belarus) has satisfactory ecological state, MIR is 33.57. Conclusions. According to the Macrophyte Index for Rivers, it was established that the Pripet River waters have a satisfactory or good ecological state. This gives reason to state that the research in the test sites and the MIR calculations fully reflect the ecological state of the watercourse, which allows the use of this research algorithm for other rivers of the basin.

Economic case for sustainable peatland management: A case study in Kahayan-Sebangau Peat Hydrological Unit, Central Kalimantan, Indonesia

As Indonesia continues to promote peatland restoration to serve its climate target, current policies and economic practices on peatlands remain to be fully consolidated with conservation principles. Meanwhile, studies comparing costs and benefits of different peatland management models are limited. This study applies economic cost-benefit analysis on two peatland management scenarios, with a case study in Kahayan-Sebangau Peat Hydrological Unit (PHU), Central Kalimantan province. The first scenario consists of current peatland management and restoration practices, in line with existing policy target. Second scenario proposes implementation of strengthened peatland rewetting, paludiculture, and cessation of drainage-based operations, among others. Information on the costs and benefits was collected through a survey of 690 respondents, combined with literature review. Monte Carlo simulation technique is applied to account for parametric uncertainty within the cost-benefit analysis. The result shows that second scenario results in higher average Net Present Value in 50 years compared to the first scenario, with approximately 21% difference. This implies that peatlands may generate higher long-term societal welfare when conservation principles are fully endorsed, and the restoration ambition is enhanced. Also, improving the spatial alignment of Central Kalimantan land use plan (Rencana Tata Ruang Wilayah / RTRW) with the proposed land utilization model in second scenario may further prevent negative impact of emissions in the PHU, compared to the case where the existing RTRW is wholly implemented.