The following steps square measure taken within the overall assessment
(i) Identification
(ii) Data assortment
(iii) Prediction
(iv) Assessment allow us to discuss them one by one with some specific examples.
Let us discuss them one by one with some specific examples.
1) Identification of Impact Areas
Depending upon the project underneath study there square measure such a large amount of areas over that the impact assessment could also be created. a number of them square measure common and may be sometimes applied on all comes.
Water Resource Project
Let us contemplate them for a water resource project. it’s a dam, reservoir, canal and therefore the distribution system etc. The dams have giant|an outsized|an oversized} impact on the atmosphere as generally they’re terribly large.
Population :
When a dam is made to store water an outsized reservoir is formed on its upstream. This reservoir could also be generally unfold in kilometers. therefore the land or forest or habitation submerged underneath this water is lost for ever.
Meteorology :
As an outsized reservoir is made or a canal passes through an areaity|a vicinity|a part|a section} local microclimatic changes occur. Presence of water vapour is most significant. the most temperature comes down and minimum temperature will increase. range of hot days can cut back. Stretch of extreme temperature also will cut back. Nights are hotter. because the wetness will increase there could also be native showers.
Permanent presence of clouds can stay. In dam (Egypt) 5000 sq. km square measure of reservoir is there therefore permanent clouds square measure fashioned giving daily some showers.
Water resources :
As it may be a water resource project clearly the water resource on upstream facet shall increase therefore there’s a positive impact on upstream facet. The down stream of the stream shall face water shortage. however the general impact is positive as a dam prevents the recent sweet surface water to be ultimately mixed with the saline water of the ocean. therefore the web balance is positive.
Floods and droughts :
The main purpose of constructing a dam is safety against floods. A dam stores the rain at the time of storm inflicting floods and relieves it throughout the year as per the demand. notably in summers once there’s no rain and therefore the stream is additionally dry, irrigation will be done through the canal system. therefore the impact is positive on each floods and droughts and if quantification is completed, most marks in favor of the project shall be on this basis.
Water quality :
In the reservoir the water stands still therefore because of deposit the silt and different settle ready impurities relax. Water becomes clear because the murkiness reduces therefore it’s a positive impact on water quality from cosmetic purpose of read or drinkable purpose of read. From irrigation purpose it’s a negative purpose because the silt is usually helpful for crops. The second quality parameter is dissolved element. Water takes D.O. from the air and it gets mixed in it relying upon the deficit and therefore the temperature etc.
Water work and salinity :
Generally, the reservoirs aren’t settled on fully proof base. The canals even have oozing inspite of all efforts. This water goes down and if the soil is proof it comes back on the surface and stands still there solely. This permanent storage of water within the root zone of plants is understood as water work.
Water supply and sanitation :
The water resource project actually will increase the facility on the upstream facet. This water is employed primarily for irrigation and conjointly for drinkable offer. although the amount of water used for drinkable offer is extremely less compared to the irrigation water generally it should be a lot of vital as an example in desert areas.
Drainage :
As the facility to the cities will increase the waste water (sewage) comes on the streets. With less water and fewer biodegradable pollution it may be managed in room gardens and therefore the open drains.
Soil :
The soil is affected primarily by 2 ways that
a) Fertility :
With the lots of irrigation water farmers take 2 to 3 crops during a year. because of over utilization of land the fertility of soil reduces.
b) Soil erosion :
Soil erosion: Soil erosion: Soil erosion: Soil erosion: multiplied farming operations, like cultivation, loosens the soil that successively gets simply worn by flowing water or the wind storms.
Land use :
The land use pattern changes drastically. The lots of irrigation water will increase farming and cultivation. The grasslands and land for grazing of kine conjointly comes underneath cultivation (agriculture).
2) Data assortment
After the identification of impact areas the information assortment is completed. Following steps square measure taken within the information collection:
(a) Environmental reconnaissance mission
(b) Preliminary survey
(c) careful survey
(a) Environmental reconnaissance :
In the initial or reconnaissance mission survey the subsequent indicative list is prepared:
(i) Name of business
(ii) class of business (small scale, medium or significant industry)
(iii) Input and output of the business
(iv) Specific water demand
(v) Waste characteristics like hydrogen ion concentration, B.O.D5, C.O.D, total dissolved solids, total suspended solids et al..
(b) Preliminary survey :
In this the bottom line survey (scoping) is completed. For this purpose census information, district lexicon, maps revealed by numerous agencies (like the G.T. Sheets revealed by the survey of Asian country Department, Irrigation atlas etc.) square measure obtained.
C) careful survey :
In this the sector level measurements of crucial time and site square measure done. The impact square measureas are known and specific to those areas study is formed by assortment of samples testing and observations.
Prediction
Prediction means that giving advanced info. Prediction could also be qualitative nearly as good, bad, high, low etc. or quantitative. Quantitative modeling is completed for depiction the method and finish results. it should be exhausted following ways that
Mathematical modeling
• applied mathematics modeling
• Regional
• Physics primarily based the constraints in prediction square measure uncertainty and inadequacy of knowledge. The prediction techniques square measure
• Modeling (empirical, applied mathematics, mathematical)
• Superimposition
• Transposition
