Hydrological Effects Of Climate Change Research Articles

Climate and landform interact to control the source and transport of nitrate in Pacific Northwest rivers

The hydrological effects of climate change are documented in many regions; however, climate-driven impacts to the source and transport of river nutrients remain poorly understood. Understanding the factors controlling nutrient dynamics across river systems is critical to preserve ecosystem function yet challenging given the complexity of landscape and climate interactions. Here, we harness a large regional dataset of nitrate (NO3–) yield, concentration, and isotopic composition (δ15N and δ18O) to evaluate the strength of hydroclimate and landscape variables in controlling the seasonal source and transport of NO3–. We show that hydroclimate strongly influenced the seasonality of river NO3–, producing distinct, source-dependent NO3– regimes across rivers from two mountain ranges. Riverine responses to hydroclimate were also constrained by watershed-scale topographic features, demonstrating that while regional climate strongly influences the timing of river NO3– transport, watershed topography plays a distinct role in mediating the sensitivity of river NO3– dynamics to future change.

Impacts of climate change and fruit tree expansion on key hydrological components at different spatial scales

Assessing how fruit tree expansion and climate variability affect hydrological components (e.g., water yield, surface runoff, underground runoff, soil water, evapotranspiration, and infiltration) at different spatial scales is crucial for the management and protection of watersheds, ecosystems, and engineering design. The Jiujushui watershed (259.32 km2), which experienced drastic forest changes over the past decades, was selected to explore the response mechanisms of hydrological components to fruit tree expansion and climate variability at different spatial scales (whole basin and subbasin scale). Specifically, we set up two change scenarios (average temperature increase of 0.5°C and fruit tree area expansion of 18.97%) in the SWAT model by analyzing historical data (1961∼2011). Results showed that climate change reduced water yield, surface runoff, and underground runoff by 6.75, 0.37, and 5.91 mm, respectively. By contrast, the expansion of fruit trees increased surface runoff and water yield by 2.81 and 4.10 mm, respectively, but decreased underground runoff by 1 mm. Interestingly, the sub-basins showed different intensities and directions of response under climate change and fruit tree expansion scenarios. However, the downstream response was overall more robust than the upstream response. These results suggest that there may be significant differences in the hydrological effects of climate change and fruit tree expansion at different spatial scales, thus any land disturbance measures should be carefully considered.

Assessing the Effects of Climate Change on Middle Rio Grande Surface Water Supplies Using a Simple Water Balance Reservoir Model

Abstract The middle Rio Grande is a vital source of water for irrigation in the region. Climate change is impacting regional hydrology and is likely to put additional stress on a water supply that is already stretched thin. To gain insight on the hydrologic effects of climate change on reservoir storage, a simple water balance model was used to simulate the Elephant Butte–Caballo Reservoir system (southern New Mexico). The water balance model was forced by hydrologic inputs generated by 97 climate simulations derived from CMIP5 global climate models, coupled to a surface hydrologic model. Results suggest that the percentage of years that reservoir releases satisfy agricultural water rights allocations over the next 50 years (2021–70) will decrease relative to the past 50 years (1971–2020). The modeling also projects an increase in multiyear drought events that hinder reservoir management strategies to maintain high storage levels. In most cases, changes in reservoir inflows from distant upstream snowmelt is projected to have a greater influence on reservoir storage and water availability downstream of the reservoirs than will changes in local evaporation and precipitation from the reservoir surfaces.

Controlled drainage under two climate change scenarios in a flat high-latitude field

Abstract This simulation study focused on the hydrological effects of climate change and controlled drainage operated with subsurface drains and an open collector ditch in an agricultural field. The objective was to understand the potential of controlled drainage and open ditch schemes for managing groundwater levels and field water balance in climate conditions projected to take place in Finland during the 21st century with representative concentration pathways 8.5 and 2.6. A methodological aim was to find ways to condense hourly hydrological results to understand future changes in field hydrology. During the historical reference interval (1970–2005), controlled drainage caused 17–36 cm higher mean groundwater levels and decreased the mean annual drain discharge by 11–23% compared to conventional subsurface drainage. Controlled drainage was projected to increase groundwater levels by additional 1–4 cm in the future compared to its effect on drainage during the reference interval. The effect on annual drain discharge did not change significantly. The open collector ditch lowered groundwater tables and diminished the effect of controlled drainage on groundwater levels in the vicinity of the ditch. Controlled drainage was shown to remain an effective method for countering early summer drought and reducing drain discharge.

Introduction to the Special Collection

Unsustainable management of groundwater basins has led to groundwater depletion, with impacts to human and environmental systems that will be exacerbated by the hydrologic effects of climate change. Increasing inflows to groundwater basins through managed aquifer recharge (MAR) is a mechanism that can help bring aquifers into sustainable balance, yet in spite of significant physical potential, MAR remains underused. Increasing emphasis on the technical aspects of MAR has served to improve knowledge of the science needed to implement MAR. However, water managers often express anecdotally that institutional elements are equally important determinants, challenges, and potential drivers of MAR. In this special collection, we examine the institutional elements that enable, or gate progress on, MAR by presenting and comparing examples of successful MAR implementation from around the United States. The case studies depict the deep connection between water management objectives of MAR and institutional contexts and design. The motivations for MAR in these case studies fall into four broad categories: water supply risk management, groundwater banking, addressing interconnected groundwater and surface water, and recharge for broader aquifer or environmental benefits. In each case study, these water management objectives help determine key managerial and administrative issues that need to be addressed and accordingly the institutional shape of a MAR project. Ultimately, empirical efforts such as this special section may help demystify this process and enable more rapid adoption and diffusion of MAR.

Application of non-conventional soft computing approaches for estimation of reference evapotranspiration in various climatic regions

Evapotranspiration (ET) is a fundamental element in the hydrological cycle and plays a vital role in simulating hydrological effects of climate change. Accurate estimation of reference evapotranspiration (ETo) plays a significant role in the field of hydrometeorology and agrometeorology. There are many direct or indirect methods that are employed for estimation of ETo. Furthermore, soft computing approaches are also used to solve complex problems of estimation in various disciplines. The application of the soft computing techniques for estimating evapotranspiration has only been limited to few approaches including artificial neural network, fuzzy logic, and genetic algorithm. This study is conducted to apply non-conventional soft computing approaches for estimating ETo which include single decision tree (SDT), tree boost (TB), and decision tree forest (DTF). Monthly meteorological data spanning over 30 years (1987 to 2016) for six different cities located in arid, semi-arid, and humid regions of Pakistan is used for the estimation of ETo in this study. Seventeen input combinations comprising of various climatic parameters were developed to evaluate the impact of different parameters. A total of 306 models were developed using the SDT, TB, and DTF approaches for all six selected cities of Pakistan. The results of the developed models are then compared with ETo calculated by the standard method of modified Penmen equation. The TB modeling technique is found to perform best for various cities located in different climatic zones of Pakistan. Only two climatic parameters, the mean temperature and wind velocity, are found to be sufficient for efficient ETo prediction. To further validate the results, the outcome of the study was applied on some other climatic regions located in the USA, New Zealand, and China. Finally, it is concluded that these non-conventional approaches can also be considered superior alternatives to the available methods of estimating ETo.

Mechanistic simulations predict that thermal and hydrological effects of climate change on Mediterranean trout cannot be offset by adaptive behaviour, evolution, and increased food production

Streamflow is a main driver of fish population dynamics and is projected to decrease in much of the northern hemisphere, especially in the Mediterranean region, due to climate change. However, predictions of future climate effects on cold-water freshwater fish populations have typically focused only on the ecological consequences of increasing temperatures, overlooking the concurrent and interacting effects of climate-driven changes in streamflow regimes. Here, we present simulations that contrasted the consequences of changes in thermal regime alone versus the combined effects of changes in thermal regime and streamflow for resident trout populations in distinct river types with different sensitivities to climatic change (low-altitude main river vs. high-altitude headwaters). We additionally assessed the buffering effect of increased food production that may be linked to warming. We used an eco-genetic individual-based model that integrates the behavioural and physiological effects of extrinsic environmental drivers –temperature and flow– with intrinsic dynamics –density-dependence, phenotypic plasticity and evolutionary responses – across the entire trout life cycle, with Mediterranean brown trout Salmo trutta as the model species. Our simulations indicated that: (1) Hydrological change is a critical dimension of climate change for the persistence of trout populations, in that neither river type supported viable populations under strong rates of flow change, even under scenarios of increased food production. (2) Climate-change-related environmental change most affects the largest, oldest trout via increased metabolic costs and decreased energy inputs. In both river types, populations persisted under extreme warming alone but became dominated by younger, smaller fish. (3) Density-dependent, plastic and evolutionary changes in phenology and life-history traits provide trout populations with important resilience to warming, but strong concurrent shifts in streamflow could exceed the buffering conferred by such intrinsic dynamics.

A Monthly-Step Water Balance Model to Evaluate the Hydrological Effects of Climate Change on a Regional Scale for Irrigation Design

AbstractCurrent and ongoing changes in the climate are typified by a rise in global temperatures. Climate change can have a dramatic impact on the water cycle. The aim of this paper was to develop a model based on Thornthwaite-type monthly water balance estimations. The main goals were to calibrate the model parameters using a remote sensing-based evapotranspiration dataset. The calibrated model was used for projection on the basis of four climate model datasets (remo, dmihirham5, smhirca.bcm, knmiracmo2). The four main projection periods were: 1980-2010, 2010-2040, 2040-2070, and 2070-2100. The advantage of this model is its robust structure. It can be applied if temperature and precipitation time series are available. The key parameter is the water storage capacity of the soil (SOILMAX), which can be calibrated using the actual evapotranspiration data available. If the physical properties of the soil are known, the maximal rooting depth is also projectable. The model can be primarily used at the catchment level or for areas without additional amounts of water from below. For testing the model, a mixed parcel of land that is used as a cornfield near Mosonmagyaróvár and a small, forest-covered catchment near Sopron were successfully used as the datasets. Furthermore, we determined the water stress with the calculation of the relative extractable water (REW), soil water deficit (SWD), and the water stress index (IS).

A model for the spatial distribution of snow water equivalent parameterized from the spatial variability of precipitation

Abstract. Snow is an important and complicated element in hydrological modelling. The traditional catchment hydrological model with its many free calibration parameters, also in snow sub-models, is not a well-suited tool for predicting conditions for which it has not been calibrated. Such conditions include prediction in ungauged basins and assessing hydrological effects of climate change. In this study, a new model for the spatial distribution of snow water equivalent (SWE), parameterized solely from observed spatial variability of precipitation, is compared with the current snow distribution model used in the operational flood forecasting models in Norway. The former model uses a dynamic gamma distribution and is called Snow Distribution_Gamma, (SD_G), whereas the latter model has a fixed, calibrated coefficient of variation, which parameterizes a log-normal model for snow distribution and is called Snow Distribution_Log-Normal (SD_LN). The two models are implemented in the parameter parsimonious rainfall–runoff model Distance Distribution Dynamics (DDD), and their capability for predicting runoff, SWE and snow-covered area (SCA) is tested and compared for 71 Norwegian catchments. The calibration period is 1985–2000 and validation period is 2000–2014. Results show that SD_G better simulates SCA when compared with MODIS satellite-derived snow cover. In addition, SWE is simulated more realistically in that seasonal snow is melted out and the building up of "snow towers" and giving spurious positive trends in SWE, typical for SD_LN, is prevented. The precision of runoff simulations using SD_G is slightly inferior, with a reduction in Nash–Sutcliffe and Kling–Gupta efficiency criterion of 0.01, but it is shown that the high precision in runoff prediction using SD_LN is accompanied with erroneous simulations of SWE.

Simulated impact of climate change on hydrology of multiple watersheds using traditional and recommended snowmelt runoff model methodology

For more than two decades researchers have utilized the snowmelt runoff model (SRM) to test the impacts of climate change on streamflow of snow-fed systems. SRM developers recommend a parameter shift during simulations of future climate, but this is often omitted. Here we show the impact of this omission on model results. In this study, the hydrological effects of climate change are modeled over three sequential years with typical and recommended SRM methodology. We predict the impacts of climate change on water resources of five subbasins of an arid region. Climate data are downscaled to weather stations. Period change analysis gives temperature and precipitation changes for 55 general circulation models which are then subsampled to produce four future states per basin. Results indicate an increase in temperature between 3.0 and 6.2 °C and an 18% decrease to 26% increase in precipitation. Without modifications to the snow runoff coefficient (cS), mean results across all basins range from a reduction in total volume of 21% to an increase of 4%. Modifications to cS resulted in a 0–10% difference in simulated annual volume. Future application of SRM should include a parameter shift representing the changed climate.

Simulation of the Runoff in a Short-Term Scale and Assessing the Hydrologic Effects of Climate Change in the Zarinerood Basin (As Part of the Orumyeh Lake Great Basin)

Snowmelt has a significant effect on rivers outflow in Western Iran. Occasionally, in some areas about 90% of runoff result from melting snow. Access to accurate and timely information for measuring the volume of available water resources is necessary. It is important to plan and design programs for drought-resistance and flood prevention as fundamental issues in Iran. The water balance (WB) model was used to estimate daily runoff produced by melting snow, without reliance to satellite images, from October to February (2005-2006) in the Zarinerood basin. This model uses available data and information in the basin to provide the possibility of estimating daily runoff in the short-term. For this purpose, the watershed was divided into three elevation zones and in each zone, an index station was determined. Using the water balance model, runoff was estimated from each station producing the outlet runoff in the basin. To calculate model accuracy, the correlation coefficient (R2) and root mean square error (RMSE) were estimated as 0.62 and 0.003, respectively. These results showed that the accuracy of the model to estimate daily runoff was acceptable. Therefore, the calibration of this model endorses its use in similar basins. It has been shown that increasing temperature has affected on snow-melt period as shifting it from spring and early summer to winter in North-west Iran. It results to increasing runoff rates in the snow-melt season and therefore this region encounters intensive drought and flood.

Determinants of vulnerability to the hydrological effects of climate change in rural communities: evidence from Nepal

The vulnerability of communities in the Himalayas to water stress caused by climate change depends on changes in the availability of water as well as how it is used. There has been little work done to reconcile these drivers of water stress in the Himalayas. This paper evaluates how climate change may affect water availability in two Nepalese mountain communities, Panglin and Tallo Lorpa, and assesses whether these changes drive vulnerability to water stress. First, estimates of hydrological change are made based on climate model output and hydroclimatological theory. Household surveys, focus group discussions and participatory rural appraisal techniques are used to assess vulnerability and adaptive capacity in each community. Finally, the expected effects of climate change on water availability are linked to findings on the communities’ vulnerability to these changes. The results show that both communities are vulnerable to changes in water availability under climate change, but this vulnerability is small in comparison to adaptation opportunities. However, the ability to appropriate benefits from these opportunities is constrained, and it is the extent of this inhibition that determines vulnerability. These findings demonstrate that Malthusian interpretations may be inappropriate in the Himalayas, and highlight the importance of the constraints to climate change adaptation.

Toward a comprehensive assessment of the combined impacts of climate change and groundwater pumping on catchment dynamics

Under increasing anthropogenic pressure, it is becoming increasingly important to evaluate the combined hydrologic effects of climate change and groundwater overexploitation. Climate change impact studies traditionally rely on scenario projections, provided by General Circulation Models (GCMs) that are transformed via downscaling and bias correction and used to drive hydrological models. The potential impacts of climate change are then assessed by comparing the historical and projected hydrological responses. This approach assumes that downscaled GCM simulations can function as surrogates for the corresponding actual values (represented by observations or reanalysis fields), which implies a kind of stochastic equivalence. In this work we apply the concept of Stochastic Equivalence to evaluate the validity of the response of a hydrological model driven by GCM simulations that are downscaled to generate high-resolution spatially distributed rainfall fields. We then use this approach to assess the combined effects of projected climate change and groundwater pumping in the Upper Guadiana basin in Spain. Our results suggest that very significant decreases in availability of water for the future can be expected throughout the year, but most notably during a 3-month longer, extended hotter and drier summer season; overall, the soil moisture and actual evapotranspiration are reduced by 20%, recharge is reduced by 50%, and aquifer related responses (runoff generation, groundwater–surface water exchange, wetlands and streamflow) are reduced by 60%.

Stability of model performance and parameter values on two catchments facing changes in climatic conditions

Hydrological models are often used for studying the hydrological effects of climate change; however, the stability of model performance and parameter values under changing climate conditions has seldom been evaluated and compared. In this study, three widely-used rainfall–runoff models, namely the SimHYD model, the HBV model and the Xin’anjiang model, are evaluated on two catchments subject to changing climate conditions. Evaluation is carried out with respect to the stability in their performance and parameter values in different calibration periods. The results show that (a) stability of model performance and parameter values depends on model structure as well as the climate of catchments, and the models with higher performance scores are more stable in changing conditions; (b) all the tested models perform better on a humid catchment than on an arid catchment; (c) parameter values are also more stable on a humid catchment than on an arid catchment; and (d) the differences in stability among models are somewhat larger in terms of model efficiency than in model parameter values.

Modelling the Climatic Variability in the Niger Delta Region: Influence of Climate Change on Hydrology

With substantial variations to flood occurrence predicted as a result of climate change it becomes significant to investigate how global hydrological models process climate-forcing data. The paper presents reasonable analyses of projected hydrological effects of climate change on the Niger Delta region, Nigeria. Runoff simulated represent the present and future flood risk for the catchment of the River Niger using Global Hydrological Models (GHMs) from EU WATCH project driven by three GCMs. The simulated discharges are compared with the monthly gauge measurement along the River Niger from the Global Runoff Data Centre (GRDC). A period of (1970-2050) was chosen to understand the climatic variability across the Niger Delta region. The GHMs under Special Report on Emissions Scenarios A2 scenario were used to provide future climate scenarios over the Niger River. The hydrological models from EU WATCH project were used to calculate flood extents for different model outputs. The simulation shows clears trends of increased in river discharge over the catchment although uncertainty cannot be over role. Considering the future climate suggests that river flow from the basin could be substantially increased, especially in the long term when compare to the reference period. It is not applicable to formulate precise recommendations for management of runoff in the Niger Delta region as Todd highlighted that the degree of uncertainty in future projections of river flow is consider as a constrained towards developing applicable adaptation activities. The rationale behind this work is the need to understand in clear terms the climate change threats on the Niger Delta region; this will form a practical basis for developing adaptation strategies to manage future climate risks.

Hydrologic effects of climate change in a sub-basin of the Western Bug River, Western Ukraine

Today, integrated water resources management (IWRM) is an important approach for sustainable management and protection of catchment areas. One of the core challenges for a successful IWRM program is the assessment of climate change impacts on the quantity and quality of water resources as well as related socioeconomic sectors. In this context, the climate impact on the hydrology of the catchment “Inflow Reservoir Dobrotvir” situated in Western Ukraine was investigated. The results of the regional climate model CCLM (COSMO—Climate Limited-area Modeling) were used to evaluate the climate conditions for two 30-year future periods in the framework of the future emissions scenarios A2 and B1 as laid out by the IPCC. Based on the projected climatic conditions, a hydrologic impact study was conducted using the Soil Water Assessment Tool (SWAT). Signals of possible future climate and future water budgets were analyzed having the period 1961–1990 as a reference for current climatic conditions. Climatic and hydrologic indices were calculated to assess possible risks and opportunities for the water management sector. In a more generic manner, the implications of climatic changes for the sectors of agriculture, forestry, ecology, energy business and human health were examined with respective literature. Increasing temperatures, declining summer rainfalls and a decreasing climatic water balance were the primary simulated results for the period 2071–2100. These meteorological conditions lead to decreasing soil water content as well as decreasing runoff and groundwater recharge through nearly all seasons. Reduced water yields may affect the energy sector, water supply and water quality negatively. Water stress, especially in summer, might cause declining yields in agriculture and forestry. By contrast, rising temperatures will lead to an extended growing season, which represents an opportunity for higher agricultural and silvicultural yields. However, rising temperatures may also cause indirect effects such as higher risks of pest infestation and germs, which can have a negative impact on a variety of the evaluated socioeconomic sectors. In this work, the impact of possible future scenarios on climate and hydrology as well as resulting risks and opportunities have been identified to serve as a basis for further investigations.

Impacts of climate change on water resources in Spain

Impacts on water resources produced by climate change can be exacerbated when occurring in regions already presenting low water resources levels and frequent droughts, and subject to imbalances between water demands and available resources. Within Europe, according to existing climate change scenarios, water resources will be severely affected in Spain. However, the detection of those effects is not simple, because the natural variability of the water cycle and the effects of water abstractions on flow discharges complicate the establishment of clear trends. Therefore, there is a need to improve the assessment of climate change impacts by using hydrological simulation models. This paper reviews water resources and their variability in Spain, the recent modelling studies on hydrological effects of climate change, expected impacts on water resources, the implications in river basins and the current policy actions. Editor Z.W. Kundzewicz Citation Estrela, T., Pérez-Martin, M.A., and Vargas, E., 2012. Impacts of climate change on water resources in Spain. Hydrological Sciences Journal, 57 (6), 1154–1167.

Functional aquatic ecosystems, inland fisheries and the Millennium Development Goals

AbstractFreshwater allocation in an environment of increasing demand and declining quality and availability is a major societal challenge. While biodiversity and the needs of local communities are often in congruence, the over‐riding necessity of meeting national demands for power, food and, increasingly, mitigation of the hydrological effects of climate change, often supersedes these. Sophisticated models of ecosystem function to establish environmental flows are difficult to implement and consequently have generally failed to reduce rates of biodiversity and habitat loss, resulting in disenfranchisement of local communities resulting from dam construction and water abstraction for industry and agriculture. There are no agreed standards upon which a fairer allocation of resources can be made and thus a pragmatic approach to the resolution of these conflicts is clearly needed. While having generally negative impacts on biodiversity and traditional lifestyles, creation of new infrastructure and active management generates national economic growth and much‐needed employment. Intensification of usage in watersheds already expropriated for human enterprise can spare land needed for the biodiversity that will fuel adaptation for the future. Taking advantage of a range of mitigation technologies and building their cost into the investment plans for water management infrastructure can improve the cost/benefit ratio of water control infrastructure and may be a more practical and efficacious approach to the valuation of fisheries and the maintenance of other essential services from functional aquatic ecosystems.

Climate change impact on the hydrology of Spencer Creek watershed in Southern Ontario, Canada

Summary This study is for the assessment of climate change impact on the future hydrology of Spencer Creek watershed located in Southern Ontario, Canada under the A2 scenario of the Special Report on Emissions Scenarios (SRES). The study is particularly concerned with changes in the climate variables and the seasonal and interannual flow regimes of the study area. The analysis also addresses the annual exceedance probability of extreme precipitation, temperature and flow events. Potential hydrologic effects of climate change were assessed for the Spencer Creek by imposing changes in precipitation and temperature derived from the North American Regional Climate Change Assessment Program (NARCCAP) climate simulations between 2040 and 2069. The climate models results were used as input to three hydrological models to produce projections of Spencer Creek watershed discharges. The results were compared to the observed discharges between 1989 and 2008. Notwithstanding the variability between the different regional climate model and hydrological model projections that envelop the future climate scenarios and the hydrological modeling uncertainties, all future simulations show an increase in the average interannual discharge, but also a noteworthy change in the seasonal distribution of the discharges. While the former is mainly attributed to the average annual precipitation, which tends to increase, the change in seasonal distribution of discharges is in line with the temperature increase of the winter and spring seasons that results in earlier snowmelt. Important changes were found in the annual exceedance probability (recurrence interval) of the extreme precipitation, temperature and runoff events.

Identification of the effective water availability from streamflows in the Zerafshan river basin, Central Asia

Summary Quantitative estimates of the hydrologic effects of climate change are essential for understanding and solving potential transboundary water conflicts in the Zerafshan river basin, Central Asia. This paper introduces an identification of runoff generation processes and a detection of changes in hydrological regimes supporting Mann–Kendall trend analysis for streamflows. By this, the effective available and future water resources are identified for the Zerafshan. The results for the subbasins in the upper Zerafshan and for the reference station at the upper catchment outlet indicate that glacier melt is the most significant component of river runoff. The Mann–Kendall trend analysis confirms the regime analysis with the shift in the seasonality of the discharge. Furthermore, the results of the Kendall–Theil Robust Line for predicted long-term discharge trends show a decreasing annual discharge. The experience gained during this study emphasizes the fact that the summer flood, urgently required for the large irrigation projects downstream in Uzbekistan, is reduced and more water will be available in spring. Additionally, following the estimation of future discharges in 50 and 100 years the hydrological changes are affecting the seasonal water availability for irrigation. This analysis highlighted that water availability is decreasing and the timing of availability is changing. Hence, there will be more competition between upstream Tajikistan and downstream Uzbekistan. Planned projects within the basin might have to be reconsidered and the changed scenario of water availability needs to be properly taken into account for long-term basin scale water management.