My suggestion is to apply a combination of different methods, depending upon the local aspiration how they value their system. You can apply scenario based approaches, e.g. using different levels of emissions, its impact on ES and how these values change.

Non-market values, especially cultural values will be a challenge until people's perspectives are incorporated. I attach my papers if these are of some value. 

http://edis.ifas.ufl.edu/pdffiles/FE/FE78700.pdf

Contingent valuation might be a good option to value the lake. Climate impacts could be embedded within the "Willingness to Pay" question.

کتاب ارزشگذاری اقتصادی منابع زیست محیطی

نوشته دکتر حمید امیرنژاد

انتشارات دانشگاه ساری

Contingent Valuation would be an appropriate start point, willingness to pay vs willingness to accept, refer to Exon Valdez oil spill study attached

My suggestion is to apply a combination of different methods, depending upon the local aspiration how they value their system. You can apply scenario based approaches, e.g. using different levels of emissions, its impact on ES and how these values change.

Non-market values, especially cultural values will be a challenge until people's perspectives are incorporated. I attach my papers if these are of some value. 

I agree and support reply from @Kamaljit Kaur Sangha. It needs to tried/applied.

Maybe those papers mentioned below helps you and will give you some ideas forward even they are in totally different region.

Artell, J. 2013.  Lots of value? A spatial hedonic

approach to water quality valuation. Journal of Environmental Planning and

Management.

Janne Artell*, Heini Ahtiainen, Eija Pouta 2013. Subjective vs. objective measures in the valuation of water quality. Journal of Environmental Management 130 (2013) 288

e296

Dear Morteza,

Market and non-market values are usually measured in different ways. If you are only interested in the value (amenity, existence and non-market use values like recreation) that a society, as viewed in terms of its members, places on a natural asset then you may simply undertake an appropriately designed CV study or choice experiment. This will provide you with an estimate of the WTP or WTA of changes in lake quality based on amenity, existence, and non-market use values. CV and choice experiments measure these aspects based on 'stated preference' methods which are based on hypothetical profiles the analyst develops. Alternatively non-market use values are usually assessed using 'revealed preference' methods such as the Travel Cost Methodology (TCM). Both SP and RP may measure components of non-market use values or non-use values respectively. 

If however you want to assess market values then different approaches may be suitable. For example, if industry and agriculture require access to clean water you might be able to estimate production/profit functions for these industries including an index of water quality or quantity and then analyse these in terms of decreases in water quality and/or increases in water prices. This approach is reviewed in Vincent (2008 - see link below). McConnell and Bockstael also have a chapter on this approach in the handbook of environmental economics. This approach treats the natural asset as an intermediate demand good which contributes to a measurable market value in terms of a marketed commodity or service. Other approaches include the 'damage function' approach which may also measure the impacts of declining water quality on population health and relate this to declining labour productivity or damage to capital assets. 

If you wanted assess all of these things together then it is simply a matter of adding up the market-based costs and the non-market values being very careful to not double count. If you look at the Total Economic Value framework (easy to google) you'll be able to visualise how the approaches outlined above fit together. 

In order to undertake any of these approaches you first need to identify what the effects of climate change are going to be for the lake and the usage profiles for users of the lake over the timeframe of your analysis. 

Valuation of non-market goods is a big field taking up possibly the majority of effort in environmental economics. It would be a good idea to perhaps first look through the handbook of environmental economics to get a good overview of the broad approaches taken. A review of valuation papers in the Journal of Environmental Economics, Environmental Economics, Australian Journal of Agricultural and Resource Economics, Environmental and Resource Economics etc is also a good starting point. 

http://www.sandeeonline.org/uploads/documents/publication/744_PUB_complete_paper.pdf

Hope that helps.

-Daniel

Please @Alireza Daneshi...Can you use english language to answer? Because we want understand what you say. Thank you...

It is a good question...but I can't say something about because it isn't my tocpic, but I like understand this kind of issue. Thank you

Daniel's answer has a lot of useful information in it. For properties of the lake which affect goods and services that have some kind of market value you may be able to apply some kind of hedonic pricing approach:

http://www.ecosystemvaluation.org/hedonic_pricing.htm

For non-market goods/services as several other people have already mentioned some sort of contingent valuation method is likely to be the best approach

http://www.ecosystemvaluation.org/contingent_valuation.htm

If you want to include some wider issues into your analysis, for example, how people perceive changes in the status of the lake to be affected by and to affect  wider socio-economic variables perhaps a cognitive mapping approach would be beneficial.  There are a number of good case studies relating to water issues.  One of the best is from Turkey:

http://www.sciencedirect.com/science/article/pii/S030438000300543X

But also concerning water policy in Europe:

https://www.researchgate.net/publication/223646563_Mapping_public_participation_in_the_Water_Framework_Directive_A_case_study_of_the_Pinios_River_Basin_Greece

Article Mapping public participation in the Water Framework Directiv...

This an important are of study since you are attempting I hope you will be able to produce good information for the future research.

As far as methodology is concern, I feel indirect methods for assessment of positive and negative effects of interaction between biotic and abiotic agents operative in and around the study area need to be quantified. very high level modeling or methodology need not to be apply, simple surrogate measures if possible use so that information get disseminated to those who directly or indirectly responsible for cause.

Best wishes

Dear Morteza,

As I concur with the answers from colleagues above,  I am suggesting that you have the climate data around Lake Urmia for a decade  or more and  correlate how these values have been changing with changing climate. I attach my work on direct values in one of Ramsar site in Tanzania, also I tried to value wildlife values with changing climate in the the book on experiences of climate change adaptation in Africa by Walter Leah Filho -Link.springer.com/.../10.1007%2F978-3...

Wishing you all the best