Climatic Characterization of Punjab State Using Geographic Information System

Agro-climatic characterization in spatial domain can play a great role in site specific suitability of sustainable agricultural crop production. Climatic characterization for Punjab in the past involved manual integration of data. As a result, large amount of data could not be handled easily. This led to the loss of information on spatial variability. Modern tools such as Geographic Information System (GIS) has been providing newer dimensions to effectively monitor and manage the database in spatial domain. The enormous growth of agriculture and land use/land cover change coupled with increased intensity of surface irrigation in this part of the country and the change in global climate contributing factors have led to change in climate at various places of Punjab in the last decades. Thus in the changing climatic and land use scenario, the present investigation was planned and an attempt has been made for creation of spatial database and zoning of agro-climatic resources (thermal and LGP zone) of Punjab in spatial environment using GIS approach. This zoning approach divided Punjab into five zones for temperature and seven zones for Length of Growing Period (LGP). These newly drawn zones reflect that the average annual temperature of the state varies from 21–26^oC, with LGP ranging from & 60 to 180 days. Temperature and LGP variation in the entire state depicted a reverse trend, being maximum temperature in south-western part with lowest LGP while lowest temperature being recorded in the northern most parts with highest LGP. Amongst all thermal zones, area under T₃ (23–24⁰C) zone was highest (58% of total geographical area) followed by T₄ (24–25 ⁰C) and the least area was under T₁ (21–22⁰C). Similarly, the state has highest area (29.5%) where LGP varies from 120–140 days (L₃ zone) followed by L₄ (100–120 days) and L₅ (80–100 days). Less than 1% of the total area of the state has LGP of >160 days (L₁ zone). Overlaying of thermal and LGP layers further resulted into 7 thermal-LGP zones. Maximum area of the state (36% of TGA) was under Z₃ (temperature is 23–24 ⁰C & LGP is 120–140 days) zone followed by Z₄ and Z₅ zones.