Amount Of Runoff Research Articles

Green Pervious Concrete Containing Diatomaceous Earth as Supplementary Cementitous Materials for Pavement Applications.

Portland cement porous concrete (PCPC) has received immense interest recently due to its environmental aids. Its porous structure helps to reduce the water runoff amount while improving the recharge of groundwater. Earlier studies have concentrated on illustrating and knowing the functional as well as structural properties of PCPC. However, very few studies are available on PCPC in combination with natural silica sources as supplementary cementitious materials (SCMs). Most SCMs are by-products of industrial manufacturing processes and cause some environmental concerns, but with their pozzolanic effect, they could be utilized as partial substitute materials for ordinary Portland cement (OPC) to enhance the strength as well as durability performance. The aim of this study is to evaluate the effects of diatomaceous earth (DE) as a supplementary cementitious material for partial substitution of OPC for Portland cement porous concrete application. Compression strength, split tensile strength, and flexural strength tests were performed to determine the effect of partial replacement. To investigate the impact of test variables, basic tests, including void content and water permeability, were also performed. Compared to the control concrete, the results show that a 15% replacement of cement with DE significantly increased the compressive strength (by 53%) while also providing adequate porosity and better water permeability. Statistical analysis (ANOVA) and regression analysis showed that there is a significant (p < 0.05) growth within the physical characteristics of concrete upon the replacement of cement by 15% DE. Collectively, the replacement of cement with DE could not only improve the concrete strength but also reduce the consumption of cement, thereby lessening the cost of construction as well as indirectly reducing the carbon footprint.

Direct comparison of runoff of residual and knockdown herbicides in sugarcane using a rainfall simulator finds large difference in runoff losses and toxicity relative to diuron

Runoff losses of herbicides have rarely been compared simultaneously under the same conditions. Our aim was to directly compare herbicide runoff losses, normalised for the amount present (relative runoff loads) and in absolute terms. Toxicity and runoff concentrations were combined to provide a risk ranking relative to diuron. Four rainfall simulation trials were conducted in sugarcane in the Great Barrier Reef catchment. Herbicides studied were older PSII residuals (atrazine, ametryn, diuron, hexazinone), alternative residuals (isoxaflutole, imazapic, metribuzin, metolachlor, pendimethalin) and knockdown herbicides (glyphosate, 2,4-D, fluroxypyr) and the tracer bromide (Br). Simulations were conducted two days after spraying, before differences due to half-lives were apparent. Two trials had bare soil and two had sugarcane trash. Herbicide runoff losses and concentrations were closely related to the amount applied, runoff amounts and partitioning coefficients. Relative runoff losses and absolute losses were similar for most older and alternative residual herbicides, 2,4-D and Br. Glyphosate and pendimethalin relative runoff losses were low, due to greater sorption. Isoxaflutole, imazapic, and fluroxypyr are applied at much lower rates and runoff losses were low. Herbicides were lost in the dissolved phase, except pendimethalin. There was a large range in toxicity relative to diuron. There is a range of herbicide choices posing less offsite risk than diuron and ametryn, which have high application rates and high toxicity. Herbicide choice should consider application rate, runoff losses, sorption, and toxicity.

Development of a Hydrodynamic Model for Regulating Water Drainage of Reservoir and Water Resources Management, Lamtakong Watershed of Thailand

The goal of this research was to develop a hydrodynamic model (HDD-M) for water resource management in the Lamtakong Watershed (LTKW), as well as to simulate three scenarios: 1) Current land use conditions in 2021, 2) Forecasting predicted land-use changes in 2024, and 3) Water drainage regulation of the Lamtakong Reservoir (LTKR) for water resource management in 2024. The Soil and Water Assessment Tool (SWAT) model and Geographic Information System (GIS) program were used to estimate and simulate the amount of Surface Runoff (S), Sediment Yield (SED), Carbonaceous Biochemical Oxygen Demand concentration (CBOD), and Nitrate concentration (NO3) based on a comparison of simulated and observed data. In scenario 1, the S, SED, CBOD, and NO3 were calculated to be 238.44 million cubic meters (MCM), 840,613.68 tons per year, 2.38 mg/L, and 7.36 mg/L, respectively. In the second scenario, the S decreased to 14.75 MCM, whereas SED, CBOD, and NO3 increased to 56,757.48 tons, 0.56 mg/L, and 0.79 mg/L, respectively, when compared to scenario 1, (Scenario 2). Scenario 3 demonstrated that during the dry season of November to June, the standards of surface water were CBOD and NO3, and that increasing LTKR drainage can help prevent the deterioration of water yields. As a result, the HDD-M, which includes the reservoir's controlling water drainage, may need to be considered to satisfy water resource management goals.

A Statistical Approach to Using Remote Sensing Data to Discern Streamflow Variable Influence in the Snow Melt Dominated Upper Rio Grande Basin

Since the middle of the 20th century, the peak snowpack in the Upper Rio Grande (URG) basin of United States has been decreasing. Warming influences snowpack characteristics such as snow cover, snow depth, and Snow Water Equivalent (SWE), which can affect runoff quantity and timing in snowmelt runoff-dominated river systems of the URG basin. The purpose of this research is to investigate which variables are most important in predicting naturalized streamflow and to explore variables’ relative importance for streamflow dynamics. We use long term remote sensing data for hydrologic analysis and deploy R algorithm for data processing and synthesizing. The data is analyzed on a monthly and baseflow/runoff basis for nineteen sub-watersheds in the URG. Variable importance and influence on naturalized streamflow is identified using linear standard regression with multi-model inference based on the second-order Akaike information criterion (AICc) coupled with the intercept only model. Five predictor variables: temperature, precipitation, soil moisture, sublimation, and SWE are identified in order of relative importance for streamflow prediction. The most influential variables for streamflow prediction vary temporally between baseflow and runoff conditions and spatially by watershed and mountain range. Despite the importance of temperature on streamflow, it is not consistently the most important factor in streamflow prediction across time and space. The dominance of precipitation over streamflow is more obvious during baseflow. The impact of precipitation, SWE, sublimation, and minimum temperature on streamflow is evident during the runoff season, but the results vary for different sub-watersheds. The association between sublimation and streamflow is positive in the runoff season, which may relate to temperature and requires further research. This research sheds light on the primary drivers and their spatial and temporal variability on streamflow generation. This work is critical for predicting how warming temperatures will impact water supplies serving society and ecosystems in a changing climate.

Study on Waterlogging Reduction Effect of LID Facilities in Collapsible Loess Area Based on Coupled 1D and 2D Hydrodynamic Model

The accurate evaluation method of LID toward the attenuation of urban flood is still a hot issue. This paper focuses on a coupled 1D and 2D hydrodynamic model, investigating the model parameters set in a collapsible loess area, and the changes in the surface runoff, waterlogged area, and drainage network indicators under different rainfall patterns. The results show that the coupled model can effectively simulate the effect of LID facilities under unaltered and retrofitted conditions. It is found that the infiltration parameters in a collapsible loess area are higher than in other eastern cities by calibration and validation. After implementing the LID facilities, the total runoff, peak flood flow, waterlogged area, runoff coefficient, and drainage pressure under different rainfall patterns have all been reduced. With the increases in the rainfall return period, the waterlogging reduction effect of LID facilities would gradually weaken. The rainfall return period has a great impact on the indicators of surface runoff, waterlogged area, and drainage capacity. The coefficient of rainfall peak has a relatively big impact on indicators of pipelines, such as the proportion of overflow nodes, the proportion of fully loaded pipelines, and the average full-load duration. The rainfall duration has a major impact on the total runoff quantity, runoff coefficient, and average full-load duration.

Multi-stakeholder stochastic optimization of urban low impact developments for climate consistency under uncertainty

Sustainable management of urban floods can prevent damage to the city's infrastructure. In particular, low-impact developments (LIDs) collect and reuse urban stormwaters and mitigate their destructive effects. This study aims to optimize the design of urban LIDs in terms of location and surface area, considering the climatic parameters and model uncertainties. Accordingly, the urban runoff quality and quantity, in addition to the climatic parameters and their uncertainties were analyzed in the modeling by repeated execution of a rainfall-runoff model in MATLAB. Then, using the concept of conditional value at risk, the uncertainty risk consideration was incorporated in the optimal design of the LIDs. Using a non-cooperative game model, stakeholders' priorities were also considered in selecting the best design scenario. In comparison with the baseline scenario (no LID, maximum runoff quantity, and worst runoff quality), the selected scenario decreased runoff volume, and two quality indicators (i.e., total suspended solids (TSS) and biochemical oxygen demand (BOD)) by (56.1–64.6%), (22.1–27.1%), and (13.7–19.2%), respectively. This scenario is the best arrangement of LIDs (location and surface area) in different sub-basins that satisfies stakeholders' priorities. The novelty of this study lies in integrating uncertainty with social complexities in a sustainable quantitative and qualitative urban runoff management using a risk-based stochastic optimization and a flexible conflict resolution model. Incorporating conflict resolution concepts in LIDs design prevents wastage of time and money and facilitates achieving socioecological implications such as ecosystem services, neighborhood aesthetics, recreational spaces, and enhancing land values. The suggested methodology was tested in the Velenjak region, northern Tehran.

Runoff Quantity and Quality from Amended Urban Residential Lawns

Runoff Quantity and Quality from Amended Urban Residential Lawns

Identifying Spatiotemporal Patterns of Hillslope Subsurface Flow in an Alpine Critical Zone on the Qinghai‐Tibetan Plateau Based on Three‐Year, High‐Resolution Field Observations

AbstractThe spatial heterogeneity and temporal variability of hillslope subsurface flow (SSF) generation are poorly understood in the alpine critical zone (CZ). Owing to the limitations of observation technology bottlenecks and harsh environments, existing studies lack a holistic and process‐based understanding of SSF generation, particularly for the deep CZ and annual freeze‐thaw (FT) cycle. This study improves the conventional trenching observation scheme and is the first to have successfully monitored SSF processes from the soil to the bedrock layer with high‐resolution from 2017 to 2020 in a headwater catchment of the Qinghai‐Tibetan Plateau. The results show that hillslope runoff generation exhibited similar trends over the years while exhibiting distinct patterns across seasons. Spatially, slope aspects significantly affect the runoff amount and ratio. The south‐facing slope is dominated by overland flow (OF, 84.2%–97.0%), while the north‐facing slope is dominated by SSF (88.9%–97.3%). The runoff depth of the north‐facing slope is 11.0 times that of the south‐facing slope. The SSF in the deep CZ accounts for 20.8%–37.8% of the total runoff along the north‐facing slope. Temporally, runoff generation exhibits distinct patterns across seasons. OF exhibits two different patterns, while SSF exhibits five across seasons. Our results indicate that runoff generation in different FT stages should be studied by the time phase. Therefore, we propose seasonal or FT period‐based classification criteria and divide OF and SSF into two and three consecutive periods throughout the calendar year. We suggest that these inferences and observations should be considered in the framework of hydrological models in cold regions.

Water quality effects of cover crop, grazing and tillage implementation in a long-term no-till wheat system

Agricultural anthropogenic nitrogen (N) and phosphorus (P) continue to be major surface and subsurface water pollutants in developed countries. Integrated crop-livestock systems in the semi-arid Texas Rolling Plains are characterized by continuously cultivated monoculture combined with grazing. Improperly managed grazing can increase soil compaction, and subsequently, decrease infiltration, which leaves the soil exposed to erosion. Grazing is therefore of paramount importance to water quality. Cover crop (CC) use improves soil ecosystem services and functions. The objective of the current study was to characterize soil water quality following CC under continuous wheat (Triticum aestivum), grazing, tillage, and no-till practices under a typic Haplustepts, Rotan clay loam soil type. Treatments evaluated include 1) conventional tillage without a CC (CT); 2) no-till without a CC (NT); 3) no-till with a CC (NTC); and 4) no-till with a grazed CC (NTCG). Portable rainfall simulators were used to assess surface runoff water quantity and quality after CC implementation in a long-term no-till continuous wheat system. Cover crop treatments, both grazed and un-grazed, reduced the amount of runoff by 4–6 times compared to no CC treatments (NT and CT). Converting 12-year-old NT to CT reduced infiltration by at least 43 % and increased runoff by 58 % compared to long-term NT. Consequently, total solids load and concentration for CT were 4–14 times greater than all NT treatments (NT, NTC, NTCG). Conventional tillage (CT) also increased total P loads and concentrations by 2–11-fold compared to all NT treatments (p < 0.05). Rainfall events occurring within three weeks after CC termination resulted in about 6 times greater soluble reactive P (SRP) (except NTCG) and about 2–3 times greater dissolved organic C (DOC) concentrations from CC treatments than non-CC treatments, although this was not observed for subsequent runoff events. Tilling the soil had more deleterious effects compared to flash grazing CC. Adopting NT, either alone, or long-term in combination with CC (either flash grazed or un-grazed) are potentially sustainable viable practices in semiarid regions that can reduce environmental contamination.

A Comparison of Some Methods for Determination of Potential Evapotranspiration for Rogerm Basin, Mangesh, Kurdistan Region of Iraq

Potential evapotranspiration is an important component of the hydrological cycle at various spatial scales that impacts the runoff quantity and the irrigation water requirements. Potential evapotranspiration is a projectile worker in the ecosystem of the operation of evapotranspiration. The aims of this is to find the most suitable method for calculating monthly potential evapotranspiration in Rogerm basin area by comparing several methods. The climatic data for the period 2012-2021 were used in the models to estimate the potential evapotranspiration. The performance index was applied by using statistical criteria including R2, RMSE, MBE, and MAPE were used to compare the FAO-56-PM into four temperature-based methods and four radiation-based methods of PET at Mangesh Agrometeorological station. The study found that the Hargraves method is the most accurate one compared with other

A Comparison of Some Methods for Determination of Potential Evapotranspiration for Rogerm Basin, Mangesh, Kurdistan Region of Iraq

Potential evapotranspiration is an important component of the hydrological cycle at various spatial scales that impacts the runoff quantity and the irrigation water requirements. Potential evapotranspiration is a projectile worker in the ecosystem of the operation of evapotranspiration. The aims of this is to find the most suitable method for calculating monthly potential evapotranspiration in Rogerm basin area by comparing several methods. The climatic data for the period 2012-2021 were used in the models to estimate the potential evapotranspiration. The performance index was applied by using statistical criteria including R2, RMSE, MBE, and MAPE were used to compare the FAO-56-PM into four temperature-based methods and four radiation-based methods of PET at Mangesh Agrometeorological station. The study found that the Hargraves method is the most accurate one compared with other

Plant growth-promoting microbes improve stormwater retention of a newly-built vertical greenery system

On-site decentralized urban stormwater management has gained significant momentum in urban planning. Recently, vegetated roofs have been recommended as a viable decentralized stormwater management system and nature-based solution to meet the challenge of urban floods. However, as another type of unconventional green infrastructure, vertical greenery systems (VGS), also known as vegetated facades, have received much less research attention. Even though some researchers suggest that stormwater management by VGS is comparable to that of vegetated roofs, empirical evidence to substantiate this claim is limited. In this study, we conducted rain simulations on newly-built vegetation containers with water storage compartments. These vegetation containers were designed to be incorporated into a VGS specifically for stormwater management. We tested variables that could influence water retention efficiency and evapotranspiration of the containers under field conditions, i.e., inoculation of plant growth-promoting microbes (PGPMs) (Rhizophagus irregularis and Bacillus amyloliquefaciens), different substrate types (sandy loam and reed-based substrate), simulated rain quantity, natural precipitation, substrate moisture, and air temperature. The inoculation of PGPMs significantly reduced runoff quantity from the vegetation containers. Meanwhile, the well-ventilated sandy-loam substrate significantly reduced the remaining water in the water storage compartments over 1-week periods between rain simulation events, achieving high water-use efficiency. The selected microbes were established successfully in the containers and promoted the growth of 2 out of 5 plant species. R. irregularis colonization responded to substrate type and host plant species, while B. amyloliquefaciens population density in the substrate did not respond to these factors. Environmental conditions, such as antecedent substrate moisture, air temperature, and natural precipitation also influenced the efficiency of stormwater retention and/or evapotranspiration. In conclusion, this study provides instructive and practical insights to reduce urban flood risk by using VGS.

Evolution of the Relationship between Runoff and Sediment Transport during Flood Event in the Chabagou Watershed of the Loess Plateau

Research on flood events is one of the most important parts to study runoff and sediment transport in the typical watershed on the Loess Plateau. Based on 101 floods in Period I (PD-I, 1970 to 1990) and Period II (PD-II, 2006 to 2018), and combined with rainfall data, the study indicated the evolution of runoff and sediment transport characteristics during flood events in the Chabagou watershed, and reveal its influencing factors in both periods. Results showed: (1) Sediment yield (SY) increased linearly with runoff amount (RA), and the increasing rate of SY in PD-II was around 20% of PD-I, the relationship between peak flow (PF) and sediment concentration (SC) was the power function, and the SC in PD-II was lower than that in PD-I under the same PF. (2) SY was more sensitive to P (precipitation) of the flood event than rainfall intensity (RI), and the sensitivity of RA and SY to P in PD-II was greater than that in PD-I. The sediment delivery modulus (SDM) with rainfall erosivity (RE) was also linear, and the increasing rate of SDM in PD-II was 27% of PD-I. (3) The better improvement of the underlying surface not only raised the threshold of RA and corresponded with peak SC, but also shortened the duration of high sediment concentration and lowered the sediment transportation capacity by contrasting the flood processes.

Urban runoff quality and quantity control: a functional comparison of various types of detention basins

ABSTRACT Hydraulic behavior and pollutant removal efficiency of three stormwater end-of-pipe control structures were evaluated and compared. Three detention basins (wet, dry, and semi-dry, i.e. dry with a wet central channel) were monitored within three sites of Southern Quebec, Canada. Water samples were collected upstream and downstream of the basins and analyzed for total suspended solids (TSS), nitrogen, total phosphorous, and ions related to de-icing salts. Generalized linear models and hydrological/hydraulic (SWMM) models were developed to compute the long-term TSS and total phosphorous load removal efficiency for two of the studied basins. Results indicate that even when considering uncertainties, removal rates are the highest for the wet basin and the lowest for the dry one. The addition of a wet channel in the semi-dry basin leads to higher removal efficiency than in the dry basin (e.g. median TSS concentration removal of 69% and 14%, respectively, for the semi-dry and dry basins).

Impacts of Rainstorm Characteristics on Runoff Quantity and Quality Control Performance Considering Integrated Green Infrastructures

Green infrastructure (GI) has been implemented globally to mitigate the negative effects of urbanization. GI also regulates the urban runoff process and reduces non-point source pollution by intercepting initial runoff pollution and stormwater storage. In this paper, the impacts on GI were quantified and analyzed, considering eight designed storms with a 24 h duration and eight others with a 2 h duration with the combination of two characteristics (return period and peak time). The runoff process and reduction effect of pollutants were simulated for GI combinations (green roofs, vegetative swale, bio-retention units, and permeable pavement) using the Storm Water Management Model, taking the Dongshan campus of Shanxi University as an example case study. The results show that the GI combination can reduce runoff, suspended solids (SS), and chemical oxygen demand (COD). For short- and long-duration rainstorms, the average reduction rates of runoff, SS, and COD were 39.7%, 38.8%, and 39.6%, and 36.5%, 31.7%, and 32%, respectively, indicating its better effectiveness for short-duration storms. The GI’s effect was more sensitive during the short-duration storms owing to the greater absolute value of the 2 h elastic coefficients versus that of the 24 h, and the best reduction effect was observed with a rainfall peak coefficient of 0.1. These results provide a scientific reference for GI planning and implementation under a changing climate in the future.

Giant Aufeis—Unknown Glaciation in North-Eastern Eurasia According to Landsat Images 2013–2019

Based on the analysis of Landsat satellite images over the period of 2013–2019, the number (6683) and total area (4529 km2) of giant aufeis fields (area ≥ 0.1 km2) were estimated for the territory of North-Eastern Eurasia. The contribution of aufeis runoff to river streamflow in different seasons was calculated for 58 hydrological gauges (area 523–526,000 km2). The contribution of aufeis and glaciers to water balance is compared. The aufeis resources vary from 0.4 to 4.25 km3 (or 3.7–11 mm) for individual basins of large rivers. They are at least 10.6 km3 in total or 5 mm of water depth on average for the study area. Aufeis annual runoff varies from 0.3 to 29 mm (0.1–22%, average 3.8%), with the share in winter runoff amount about 6–712% (average 112%) and the spring freshet 0.2–43% (average 7.1%). In general, the aufeis runoff exceeds the glacial runoff. The dynamics of aufeis formation are directly related to winter runoff, whose changes are observed in different parts of the cryosphere. The presented results are relevant for studying the impact of climate change on the hydrological cycle and its components in the permafrost regions of the Northern Hemisphere.

Stormwater runoff reduction simulation model for urban flood restoration in coastal area.

Urban floods caused by expanding impervious areas due to urban development and short-term heavy precipitation adversely affect many coastal cities. Notably, Seoul, one of the coastal cities that experiences acute urban floods, suffers annually from urban floods during the rainfall season. Consequently, to mitigate the impacts of urban floods in Seoul, we established flood-vulnerable areas as target areas where green infrastructure planning was applied using the Stormwater Runoff Reduction Module (SRRM). We selected the Gangdong, Gangbuk, and Dobong districts in Seoul, Korea, all of which demonstrate high flood vulnerability. Analyses in reducing the runoff amount and peak time delay effect were estimated by model simulation using the SRRM. The reduction in peak discharge for the whole area occurred in the following order: Gangdong district, then Gangbuk district, and lastly Dobong district. In contrast, the reduction in peak discharge per unit area was most prominent in Gangbuk district, followed by Dobong and Gangdong districts. However, the delay effect was almost identical in all target areas. Based on the simulation results in this study, we planned green infrastructure, including green roofs, infiltration storage facilities, and porous pavement. We believe that the results of this study can significantly enhance the efficiency of urban flood restoration and green infrastructure planning in coastal cities. Supplementary InformationThe online version contains supplementary material available at 10.1007/s11069-022-05477-7.

A Comparative Evaluation of Using Rain Gauge and NEXRAD Radar-Estimated Rainfall Data for Simulating Streamflow

Ascertaining the spatiotemporal accuracy of precipitation is a challenge for hydrologists and planners for flood protection measures. The objective of this study was to compare streamflow simulations using rain gauge and radar data from a watershed in Southern Ontario, Canada, using the Hydrologic Engineering Center’s event-based distributed Hydrologic Modeling System (HEC-HMS). The model was run using the curve number (CN) and the Green and Ampt infiltration methods. The results show that the streamflow simulated with rain gauge data compared better with the observed streamflow than the streamflow simulated using radar data. However, when the Mean Field Bias (MFB) corrections were applied, the quality of the streamflow results obtained from radar rainfall data improved. The results showed no significant difference between the simulated streamflow using the SCS and the Green and Ampt infiltration approach. However, the SCS method is reasonably more appropriate for modeling the runoff at the sub-basin-scale than the Green and Ampt infiltration approach. With the SCS method, the simulated and observed runoff amount obtained using rain gauge rainfall showed an R2 value of 0.88 and 0.78 for MFB-corrected radar and 0.75 for radar only. For the Green and Ampt modeling option, the R2 value for the simulated and observed runoff amounts were 0.87 with rain gauge, 0.66 with radar only, and 0.68 with MFB-corrected radar rainfall inputs. The NSE values for rain gauge input ranged from 0.65 to 0.35. Overall, three values were less than 0.5 for streamflow for both the methods. For seven radar rainfall events, the NSE was greater than 0.5, with a range of very good to satisfactory. The analysis of RSR showed a very good comparison of stream flow using the SCS curve number method and Green and Ampt method using different rainfall inputs. Only one value, the 2 November 2003 event, was above 0.7 for rain gauge-based streamflow. The other RSR values were in the range of “very good”. Overall, the study showed better results for the simulated runoff with the MFB-corrected radar rainfall when compared with the simulations obtained using radar rainfall only. Therefore, MFB-corrected radar could be explored as a substitute rainfall source.

Pervasive alterations to snow-dominated ecosystem functions under climate change

Climate change projections consistently demonstrate that warming temperatures and dwindling seasonal snowpack will elicit cascading effects on ecosystem function and water resource availability. Despite this consensus, little is known about potential changes in the variability of ecohydrological conditions, which is also required to inform climate change adaptation and mitigation strategies. Considering potential changes in ecohydrological variability is critical to evaluating the emergence of trends, assessing the likelihood of extreme events such as floods and droughts, and identifying when tipping points may be reached that fundamentally alter ecohydrological function. Using a single-model Large Ensemble with sophisticated terrestrial ecosystem representation, we characterize projected changes in the mean state and variability of ecohydrological processes in historically snow-dominated regions of the Northern Hemisphere. Widespread snowpack reductions, earlier snowmelt timing, longer growing seasons, drier soils, and increased fire risk are projected for this century under a high-emissions scenario. In addition to these changes in the mean state, increased variability in winter snowmelt will increase growing-season water deficits and increase the stochasticity of runoff. Thus, with warming, declining snowpack loses its dependable buffering capacity so that runoff quantity and timing more closely reflect the episodic characteristics of precipitation. This results in a declining predictability of annual runoff from maximum snow water equivalent, which has critical implications for ecosystem stress and water resource management. Our results suggest that there is a strong likelihood of pervasive alterations to ecohydrological function that may be expected with climate change.

Hidrogeologi daerah BRG berdasarkan kondisi hidrologi untuk mengetahui prediksi kesetimbangan Airtanah (Groundwater)

The rapid increase in groundwater exploitation in various sectors in Indonesia has caused preparations in the form of concrete steps that must be faced, especially reducing the impacts caused. The BRG area is an area known as an area in Geological Conditions the existence of intrusions that may result in retained groundwater flows and are productively small and even rare and in addition to that also in terms of environmental conditions of areas surrounded by large industries in the amount of very large groundwater use. Groundwater intake activities impacted the drawdown of groundwater levels. This study in cased the Water Balance conditions of the BRG area groundwater. This study employs hydrology variable to determine groundwater balance. Variables of Rainfall (CH in mm/yr), Evapotranspiration (ET in mm/yr), Infiltration (R in mm/yr) and Run Off (RO in mm/yr). Balance of Groundwater is based on a general formula of Capacity (S). Capacity (S) is directly proportional to Rainfall (CH) as Inflow and Total amount of Evapotranspiration (ET), Infiltration (R) and Run Off (RO) as Outflow. The study revealed that the inflow and outflow of water in BRG area are balanced. The results of the Hydrological Variables of the study area are as follows: Rainfall (CH) is of 8302 mm/yr average value, Evapotranspiration (ET) is of 2726,6 mm/yr average value, Infiltration (R) is of 2,02 x 107 mm/yr and Run off (Ro) 1316,3 mm/yr. The result of Groundwater Water balance is a negative value (Inflow &lt; Outflow). Hydrological calculations decreased in each year for the last 4 years the observation data showed the negative values were getting greater, as follows: (a) the first year -4.01 x 107, (b) the second year -5.63 x 107, (c) the third year -3.10 x 107, (d) the fourth year -4.72 x 107.