Climate change cannot be a sudden thing but a gradual (slow) process. The effects of climate change on hydrologic models can be minimized by calibrating the models, periodically, with new observations. Model parameters may have to be adjusted to balance the effects of climate change on model results.

Most models are based on historic data, and as needed tweaked or adjusted to other locations after some verification and validation efforts. Historical data records of 50 years or more may include periods of drought, and wet periods including a few major storm events. Some aspects of the hydrologic cycle model better than others. Even with our dispersed streamgaging network, flood peak estimates of plus or minus 40% are not unusual. It is difficult to prove climate change effects, and what those effects might have on model, especially with short term hydrologic records, and variability as to how climate change affects various areas differently. There are numerous inputs or factors that can influence hydrology, climate being one of them. There are about 10 climate change models making various assumptions, which can be applied to help forecast rainfall, temperature and other change to specific regions. But the results are about like the hurricane models in the middle ofAtlantic Ocean, ie, going various ways and not very exact. If you can or find someone who can validate or adjust model to your area, this is a good start. When you start having several storms, droughts or decade trends that extend outside the normal frequency or severity confidence limits, and no substantial land use or other changes but consistent with compelling data on climatic change, then this will help validate climate change effects. Until then, choose one or two of the climate models with assumptions, and run those models relative to your area. Then take those estimates and apply them to your validated hydrologic model. The estimates you might expect are usually based by decade to 50 years, such as general or mean changes in temperature, rainfall, frequency of extremes, sea level change, etc. Most validated hydrologic models to your area, are not going to make changes due to climactic forecasts, unless specifically designed to. You may want to consult with hydrologist, as if the rainfall models suggest a 10% decline on average and temperatures up 3 degrees, streamflow average might decline by 20% due to increased evapotranspiration. The estimate adjustments for a specific area can become complex, and that is why I would suggest searching for any publications on climate change and hydrology specific to your physiographic region(s). Occasionally large coastal Cities have generated reports on hydrologic climate change and sea level rise, and the citations and authors, models and adjustments used could help.

Dear Dr. Aysar,

Since climatic changes effects the rate of global warming and precipitation , then certainly it would effect both surface and groundwater levels fluctuations. Furthermore, climate changes produces several global disorders like: Antarctica cap melting ,sea levels rising , hurricans impact and ocean currents disorder. Please follow the link below with my presentation concerning the climatic changes according to geophysical and astronomical points of view:

https://www.researchgate.net/publication/324248868_The_Climatic_Changes_According_to_Geophysical_and_Astron

Hope my answer would help.

Best regards

Wadhah

Change of groundwater recharge

From the changes in climate, there are significant changes in groundwater models, which lead to change of water tables, change of modeled curves in1D and tomographies in 2 and 3Dl analyses and clogging of formation pores.

Climate changes affects precipitation and global warming, of course it will affect surface and ground water fluctuations. Furthermore, climate changes produces several global disorders like: Antarctica cap melting ,sea levels rising , hurricans impact and ocean currents disorder. In this way, this will affect hydrological modelling.

The effect of climate change on hydrological models can be multifold. In surface water hydrology:

1) The statistical models used for estimating design storm analysis may need to include non-stationarity approaches and frequent updates.

2) The shape of the runoff hydrograph generated can be influenced by the changes in the temporal pattern of rainfall hyetograph. Hence, frequent calibration of hydrological models may be required even under relatively static landuse.

Hydrological models simulate the relationship between rainfall and runoff. Global (more precisely the local) warming increases the loss rates, especially the evaporation which can affects the accuracy of predictions. Still the modeler can keep the accuracy of the model by changing model parameters which needs calibration of the model periodically.

Even the climate predictions have many uncertainties, due to data used (insufficiency & unreliability and representatives) and also due to calibration and verification issues. Therefore, the hydrologists shouldn't worry too much regarding the effects of global warming on the accuracy of hydrological models.

Dear Aysar,

Relevant climatic variables for hydrology are precipitation and variables such as temperature, wind speed, humidity and radiation influencing (potential) evapotranspiration. In principle, with climate change you would expect that only these variables change and the hydrological system/ catchment modelled will remain unchanged. Then, climate change would only affect the hydrological fluxes and states in the hydrological system but not the modelled hydrological system itself.

However, since most hydrological models need to be calibrated because parameters cannot be identified based on data, measurements or literature, the estimated parameter values inherently depend on the climatic conditions under calibration. Consequently, model performance for another (validation) period is often worse than for the calibration period because of different climatic conditions. This has been shown in several studies where the split sample test and/ or the differential split sample test has been applied. Obviously, this will also be the case when applying hydrological models for climate impact studies. One way to deal with this is to explicitly incorporate the relations between parameters and climatic characteristics, see e.g. Article The influence of parametric uncertainty on the relationships...

In conclusion, although theoretically climate change should not directly affect hydrological models, it does indirectly through calibration under different climatic conditions than the future climatic conditions and we should take this into account when assessing climate impacts.

Best wishes,

Martijn

I agree with George answer above,... From the changes in climate, there are significant changes in groundwater models, which lead to change of water tables, change of modeled curves in1D and tomographies in 2 and 3Dl analyses and clogging of formation pores. .

Dear Aysar Alawadi, perhaps one big issue regarding the effect of what is considered Climate Chance on groundwater is that groundwater has not been subject to be separated into the water (flow system) that is sensitive to such changes. For this issue, I will refer you and the readers to the following publication; should a need in discussing such paper rises I will be most willing to try to answer any queries, do get from Mexico saludos,joel

Carrillo-Rivera, JJ y Cardona, A; 2012. Groundwater Flow Systems and Their Response to Climate Change: A Need for a Water-System View Approach. American Journal of Environmental Sciences 8(3), pp 220-235. Science Publications. ISSN: 1553-345X, SNIP (2012): 0.85.

Following answers

You have generated some good discussion. In areas where snow is an important aspect of the hydrologic cycle, the impacts of climate change on snow hydrology is complicated. The two dominant effects will be more rainfall events than snow events. Rainfall intensity is greater than snow melt rates, so peak runoff rates and runoff amounts will likely increase from these events.

The second major impact is that the snowpack will likely be less. This has two implications. The first is that snowmelt fed streams will have flows diminish much earlier in the summer, likely impacting downstream water users. The second implication is that in those climates where rain falling on snowpack causes most flood events, we may see decreased flooding because the snow available to melt may be less.

Both of these winter processes, however, will be site specific, so hydrologic models need to have good snow accumulation and melt routines to predict what will happen for a given site.

As stated above, warmer climates with greater vapor pressure deficits will result in greater evapotranspiration rates if soil water is available, and greater evaporation rates from oceans may result in greater precipitation patterns on the landscape. The magnitude of such counteracting impacts, and the effects on surface and groundwater processes will be site specific, so it is not really possible to generalize. As with snowmelt, enhanced hydrologic models will be needed to evaluate site-specific conditions.

A final, more complex change in future climates is that dry spells will be longer, and wet spells will be wetter. Exactly how much the length of dry spells will increase, or how much wetter the wet spells will be are not really known. These effects will be the subject of research in the coming century as climate and hydrologic researchers try to understand the ever changing climates that we will be experiencing.

good question, following

The climate change have negatively effect on hydro logical model , for example the sun and the rain off has effect on surface and ground water .

Climate change has multiple effects on hydrological models in such away that it affects the forcing data of the model such as precipitation, temperature and other climatic variables. Hence, climate change might have positive or negative effect on the output of the hydrological model as the climate variables are the key driving factor for the hydrology. It is a more general question to put specific answers and its effect on the hydrological model depends on the area of study. So, I would recommend the answers from William and Martijn.

Best,

In addition to my previous answer, I think it is important to distinguish two effects of climate change here. The impact of climate change on hydrological models (model structure, spatial and temporal discretization, parameters, etc.) and the impact of climate change on the hydrology (fluxes, states). My previous answer (and I think also the question of Aysar) is about the first effect. A general answer regarding the second effect is hard to give, since the impact of climate change on hydrology will depend on many factors such as the time period of climate change, the RCP scenario(s) being used, the GCMs (and RCMs) being employed, the specific hydrological variable of interest (and its spatial and temporal characteristics) and obviously the characteristics and location of the study area.

Climate change really

Climate change multiple affect on hydrological processes.

Hemos dirigido una Tesis Doctoral en la Universidad de La Coruña, España. En la misma en Dr. Luis Lenzi analizaba el efecto del Cambio Climático en la Respuesta Hidrológica en una serie de 30 años históricos simulados con el modelo Matemático de transformación Luvia/Caudal en la Cuenca del Arroyo Feliciano de la República Argentina, de 8700 kilómetros cuadrados.

Comparó los valores observados en la serie histórica con los estimados por el modelo, los que permitieron determinar los valores de los parámetros de ajuste.

Posteriormente se adoptó uno de los escenarios, que para el área en estudio, que asume un incremento del 20% de las precipitaciones.

La simulación de la serie histórica con un incremento del 20% de las precipitaciones genera incrementos de hasta casi un 50% de los caudales estimados en la sección de control. Ello se transforma en un alerta para el recalculo de las obras civiles (puentes, etc)

Hi,

The effect of climate change on hydrological models?

Or

The effect of climate change on outputs from hydrological models?

Or

The effect of climate change on the forcing data used for the hydrological modelling ẹ.g. Temperature, precipitation, evapotranspirstion, lulc etc?

I think your question is very broad, perhaps you should narrow it down.

Are you interested in any hydrological variable or any part of the hydrological output e.g. Base flow, highflows etc?

Dear oluwafemi, you may consider the two parts you mentioned above, but I think the first part is very important to have a good understanding about the behavior of the models .

As the new technologies being inducted with passage of time, hydrological modelling will go on improving in spatial and temporal accuracy for prediction of various hydrological parameters but not as such because of climate change...! And in fact some one ...rightly asking....

is the climate changing ...???

Follow

Article Eco-Hydrological Footprint of a River Basin in Western Ghats

The effect of climate change on hydrological models and processes.

Good question I will follow answer

The climate changes have negatively effect on hydrological model due to effect on the surface and ground water.

Good day,

Of course, it highly depends on the type of your "hydrological model". We in a study in west of Iran understood that climate change and forest mortality can significantly reduce the amount of rainfall reaching the forest floor (i.e. throughfall water). We used Sparse Gash model which is used to predict forest canopy rainfall interception. Therefore, I advice to have a "goal" at first, and the see what happen if climate change and affect. We must notice that the effect of climate change depends on the parameter we want to discover.

Regards,

Omid,

Yes. It highly effected of the spatial distribution of hydrological processes.

Hi,

Article Climate and hydrological models to assess the impact of clim...

Thanks a lot Marjan, I think it is helpful paper

Nice discussion by all the RG colleagues.

Climatic effects on the hydrological models are enormous. Both the atmospheric and solid earth hydrological models are affected by climatic changes. For instance, the VES model curve in dry condition may be similar in shape with that of wet season. However, the values of resistivity in dry condition are less when compared to wet condition.

Nice discussion dr. Nyakno jimmy George thanks.

Climate change cannot be a sudden thing but a gradual (slow) process. The effects of climate change on hydrologic models can be minimized by calibrating the models, periodically, with new observations. Model parameters may have to be adjusted to balance the effects of climate change on model results.

Prema Hettiarachchi , that is a good point. Although often assumed to be independent on climate and climate change, hydrological model parameters are estimated under particular climatic conditions and probably will not completely be determined by catchment characteristics (e.g. soil type, slope, land use) alone but also by the climatic conditions of the calibration period. In addition, model parameters might compensate for errors in the input data, output (calibration) data and model structure. Therefore, hydrological model parameters might need to be estimated (calibrated) for distinctive time slices.

Obviously for the climate change impact assessments, other approaches need to be used since calibration of model parameters cannot be done. For instance, historical climatic conditions similar to project future climatic conditions might be found, which can serve as calibration conditions for the future.

Nice discussion Dr. Prema Hettiarachchi thanks...

Hi,

I agree marjan salari.

It depends of models. Many of them are not sensitive well enough. Second crucial factor is geological, hydrogeological and geomorphological setting of the individual catchment. This is very hard problem, firstly for modeler.

I recommend dear Dr. Ognjen Bonacci answer.

Good day, here firstly it has to be clearly defined which is the scenario used as reference about climate change as defined by the IPCC; second there is a need to identify which are the hydrological models of interest (surface water or groundwater), where are they located; then with these data some discussion could be started and some lines of inquire been proposed... do get from Mexico saludos,jjoel carrillor

Interesting question! Following answers

There is one great problem with hydrological modelling. Some people, especially young scientists (without field experience) believe in models lake in good. No one model is perfect because of fact that climatological-hydrogeological-ecological-geophysical-etc., etc. interactions vary in space and time very fast and extremely different in different landscapes. Due to this we are not able to precisely assess effects of climate changes on the non-perfect hydrological models. Second problem is that we do not know precisely development of climate changes in future.

Thanks a lot Dr.Ognjen. your answer clarified significantly the question.

https://www.sciencedirect.com/science/article/pii/S2405880717300158 plz see this site

Hello,

Hydrologic models provide a framework to investigate the relationships between climate and water resources and there are several models available for different analysis. However, calibration of models are important for climatic conditions of the calibration period.

I agree@ Yohan Mahagamage

There have been many studies of climate-change effects on hydrology and water resources which usually consist of three steps: (1) use of general circulation models (GCMs) to provide future global climate scenarios under the effect of increasing greenhouse gases, (2) use of downscaling techniques (both nested regional climate models, RCMs, and statistical methods) for “downscaling” the GCM output to the scales compatible with hydrological models, and (3) use of hydrologic models to simulate the effects of climate change on hydrological regimes at various scales.

I think your question needs to be more precise. Do you mean the effects of climate change on groundwater resources, please read this Article Effects of Climate Change on Groundwater Resources (Gaza Str...

Thanks a lot eng salah

for me if data collect are in the same space, climate change could be minimize in the models.

It's very interesting question you can read this good paper

Climate and hydrological models to assess the impact of climate change on hydrological regime: a review

Kour, R., Patel, N. & Krishna, A.P. Arab J Geosci (2016) 9: 544. https://doi.org/10.1007/s12517-016-2561-0

Article Climate and hydrological models to assess the impact of clim...