Long term (approximately 10 years) monthly maximum and minimum temperatures were collected from six meteorological stations falling in the


Suggested Suitable Landuse

Agro-Ecological Zoens |

Figure 2 : Flow diagram of the method for agro-ecological zoning

Figure 2 : Flow diagram of the method for agro-ecological zoning western Himalayas. However, monthly rainfall data for eight years were collected from eleven rain gauge stations within the study area. The details about location of meteorological and rain gauge stations are shown in Table 1. Digital elevation data with one-kilometer grid size was taken from Global Digital Elevation Model (USGS GDEM) and geometrically registered in UTM projection. Validation and accuracy check for digital elevation data derived from Global DEM was done with spot height observation from Survey of India toposheets on 1:250000 scale. A close agreement was observed between spot height observations and Global DEM based elevation data (R2 = 0.98). Long term monthly and annual averages of mean temperatures of six meteorological stations were regressed against corresponding elevation using MICROSTA statistical software (Table 2). A good agreement was also observed between annual mean temperature and elevation (annual mean temperature = 24.443 - 0.0045 X elevation, R2 = 0.97). Similarly long term average annual rainfall recorded at different rain gauge stations were regressed against elevation for developing rainfall - elevation relationship (annual rainfall = 515.1 + 0.3843 X elevation, R2 = 0.75) representing the region under study. The empirical relations thus developed were used to utilize inherent spatial quality of digital elevation model in GIS environment for depicting spatial variation in normal monthly and annual mean temperatures as well as annual rainfall condition over Kumaon region. These monthly spatial distribution of mean temperatures were used for computation of spatial potential evapotranspiration (PET) based on Thornthwaite (1948) as:

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