Can the geology of an area have an effect on the quality of water that drains through it?
Dear Bodi;
it is a nice question about the geology of the watershed area; the geology of that particular area have direct impact on the quality of the water which is drain over a period of time; physical, chemical and the biology of the particular area determine the initial quality after the drops reaches the earth surface.
physical nature provides the amount of holding, infiltration rate, etc
chemical nature provides all combinations to the drops via seeping
biology takes water for their survival and increase the aesthetic view as well as improves the holding nature.
Yes it can; catchment geology can change all kinds of physiochemical attributes of the water, e.g. pH, dissolved solid contents and hardness. Which attributes do you think of in particular?
The geology of the watershed sure can effect the quality of that water source mainly the hardness and the alkalinity. Iron is also important in the composition of water and comes from waterbed rocks. One can not conradict.
Nils, I was looking at the nutrient concentration for example nitrate and phosphorus in the different creeks which drain through a geological formation in the watershed.
Does anyone know if there will be more nutrient concentration in the hyporheic zone than the surface water or is it the other way around?
I am not a specialist on nutrients in particular. In the short term it is likely that ecological factors dominate nutrient concentrations, but in the longer term, lithology determines denitrification rates (Beusen, A.H.W., Slomp, C.P., Bouwman, A.F., 2013. Global land-ocean linkage: direct inputs of nitrogen to coastal waters via submarine groundwater discharge. Environ. Res. Lett. 8, 6, doi: 10.1088/1748-9326/8/3/034035.) and phosphorus is mobilized by chemical weathering from rocks (Hartmann, J., Moosdorf, N., Lauerwald, R., West, A.J., Hinderer, M., 2014. Global chemical weathering and associated P-release - the role of lithology, temperature and soil properties. Chemical Geology 363, 145-163, doi: 10.1016/j.chemgeo.2013.10.025.) - a process which actually has changed substantially with climate change in the past 150 years (Goll, D.S., Moosdorf, N., Hartmann, J., Brovkin, V., (in press). Changes in chemical weathering and associated phosphorus release since 1850: implications for the land carbon sink. Geophysical Research Letters, doi: 10.1002/2014GL059471.).
I would in general assume that nutrient concentrations are higher in the hyporheic zone, but that should depend on the local situation and I am certainly not a specialist for this topic.
Best regards,
Nils
The geology of the catchment has a high effect on water quality . Natural sources of nitrate has been linked to geology in some California Catchment (see Nature 395, 785-788 22 October 1998). The nature of soil are highly dependand of the geology in the area, and thus the quality of runnof.
Quality of water is effected by mainly two reasons :
1. Natural (2) anthropogenic
Natural is related with geological strata in which mineral-water interaction is important.
When water flow in any of the exposed rocks of the watershed it react with them. If rock react with water certainly the water quality changes. For example if the country rock is limestone then the reaction probability is very high. Many time the rain water make carbolic acid (mild acid) it also react with rocks and get contaminated.
Yes. Primarily by the lithology of the area, the resident time of water to intreract with rocks, climatic conditions etc. Secondly the water quality can be modified by the anthropogenic activities in an area. It interacts with soil, pesticides, fertilizers used, manure, waste water generated, any dams and watershed related structures present in the upstream directions etc.
Geology of a watershed is the primary factor responsible for controlling the natural chemistry and thereby, the quality of groundwater. Water percolating through the subsurface comes in contact with the soil particles and lithounits, and thus gets influenced by the constituent minerals. Ionic constituents in groundwater like calcium, magnesium, sodium, potassium, carbonates, chlorides and many others including minor and trace elements are all derived due to water-rock interaction. Another important constituent influenced by geology is the TDS (Total Dissolved Solids). This is not only controlled by the type of rock making up the aquifer, but also by its nature (weathering). Rock types like schistose formations contribute higher quantum of solids due to their brittle nature and mineralogy. Others like limestone/dolomite are responsible for higher concentration of calcium and carbonates. In contrast, compact rocks like granitoids/basalts forming aquifers contribute far lesser TDS to the groundwater. Another important factor governing groundwater quality is its residence time. Greater the residence time, greater is the scope for dissolving of a mineral.
Mr. Bodi, If you check my profile you will find several papers that deal with your questions.
Geology of the water shed area is one of the important parameter for influencing the water quality of that region. In this regard a large number of publications are already available.
The water composition depends on the interaction between rocks. Minerals with Pb, F, As and other metals can be soluted and change the composition. Some of them can be toxic or interfer in animals/humans metabolism. Ph, dissolved oxigen an eH can influence in the solubility of these metals in water.
There is two types of water (1) surface ( 2) ground water. The ground water has more significance towards geological strata, soil and water percolation system. How much water is going deep and also water- rock interaction. Contact period water such interaction. Geo hydrological conditions and chemical kinetics play very important role. Water table , overburden have also impact.
If you are only interested in nitrate and phosphorus, both of these are rare in rocks. The nitrates in California that you mentioned are associated with desert areas.
Well,
The question leads to search in sediment transport hydrology tagged to hydrogeology, surface geological survey and hydrochemistry.
Sincerely
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