1. Analysis of spatio-temporal variations and change point detection in pan coefficients in the northeastern region of India.
- Author
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Srilakshmi, Mandru, Jhajharia, Deepak, Gupta, Shivam, Yurembam, Ghanashyam Singh, and Patle, Ghanshyam T.
- Subjects
SPATIO-temporal variation ,CHANGE-point problems ,TREND analysis ,WATER supply ,AGRICULTURAL water supply ,WATER in agriculture ,EVAPOTRANSPIRATION ,SPATIAL variation - Abstract
Evapotranspiration (ET), one of the key components of the hydrological system, plays a major role in the water availability assessment in a region. ET is a complex process, and calculating ET from reference evapotranspiration (ET
0 ) is one of the popular methods, where pan evaporation (EPan ) value is converted to ET0 by multiplying the EPan value with the pan coefficient (Kp ) value. The Kp value depends on the climatic factors; hence, the determination of Kp varies for different regions. This paper investigates the spatial and temporal variation of the Kp values for the northeastern region (NER) of India having diverse topography and climatic conditions. Observed EPan data and ET0 calculated for ten selected stations of the eco-sensitive region NER of India were used for calculating the Kp values in monthly, seasonal, and annual timescales. Spatial variation of the Kp was identified by interpolation method, and temporal trends in the Kp values were identified by using the parametric method (Linear regression test) and non-parametric (Mann-Kendall test (MK)) after the pre-whitening of the time series. The average monthly Kp values in the NER of India varied from 0.788 in March at Umiam to 2.462 in July at Gangtok, whereas the annual Kp varied from 0.978 at Imphal to 1.822 at Gangtok. The seasonal Kp was found to be high during monsoon (1.401) and low during post-monsoon (1.017). Trend analysis shows that Kp was found to be increasing in annual, pre-monsoon, and monsoon seasons, whereas decreasing trends in Kp were found during winter and post-monsoon in the NER. The spatial distribution of Kp depicted that the values were found high in the northwest region and low in the remaining parts of the NER of India. The spatial distribution of trends and their magnitudes were found to be decreasing in the northwest and some parts of the northeast and southwest, whereas increasing trends were found in the central and southern parts of the NER. Results of Pettit's test for change point analysis observed that all but four stations of the NER witnessed the change point after 1990. Assessment of the Kp could be helpful for the estimation of actual evapotranspiration in the region, which further could be useful for water management in agriculture and other water sectors. [ABSTRACT FROM AUTHOR]- Published
- 2022
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