it the soil is wet, collect soil sample and then analyse soil characteristics.  We can also remove water from soil through separation technique and analyse its characteristics.

hi

kindly refer my papers, not to consider 2-16pdf 

Natural variation in hydrochemistry is typically caused by rock -water interactions or soil-water interaction, climate, presence or not of coastal brackish water and more.  Some processes or keywords are:

redox reactions

dissolution-precipitation

cation exchange

weathering

surface-groundwater interaction

see papers in Applied Geochemistry or Journal of Exploration Geochemistry, or Hydrological Processes by many different authors including Enrico Dinelli (soil composition) myself (water chemistry in coastal aquifer and river basin).

The learned scientists Md. Susan Verghese and Pauline Mollema have given good material to learn.

Dear Ebrahim, 

Your question needs further clarification. You mention "..chemical characteristics of water flows in the catchment area of a road". Are you interested in the derived chemical parameters nearby road areas? Cause if so, the parameters are significantly restiricted to solely anthropogenic (e.g. Pb, Na, Cl etc). This has nothing to do with geogenic processes as those mentioned by the previous colleagues. 

If you be more explicit maybe i can help more.

cheers

Dear Evangelos,

I am looking for some reference in which the chemical composition of the run-off in a catchment area was discussed. No matter this catchment area is located nearby a road, a river or anything else. 

It is clear that rain water is not chemically pure, and when this water flows toward thalwege in the catchment area, its chemical composition will change. I am looking for a research that addresses this matter. However, it is clear that a lot of parameters may control this matter, such as the geology of the catchment area.

Thanks for your time.

Dear Ebrahim,

Now it is clearer to me. The factors that affect run-off geochemistry are  - in their vast majority – anthropogenic due to leaching of accumulated contaminant loads (e.g. nutrients, municipal and mining wastes, agrochemicals etc). This is due to the fact that surface run-off is a relatively speedy process compared to processes occurring in vadose and saturated zone (e.g.  (bio)geochemical process). Normally the widely known geochemical process like redox reactions, precipitation, complexation, ion-exchange, dissolution etc which play an important role in groundwater chemistry, need time in order to be active, hence their contribution is insignificant to run-off hydrogeochemistry.  I guess you may find several references in literature (e.g. scopus or sciencedirect) if you put as keywords, surface run-off and hydrogeochemistry.

Good luck to your research.

Evangelos