Abstract:
Agriculture is an important sector of Pakistan Economy which largely depends on
water resources, and it is important to define and adopt such agricultural practices that
help in understanding the water requirement of crops and its timely supply for
effective management of crops and conservation of water resources. Therefore, the
current study aims at estimation of agricultural water balance (surplus/deficit) and
assessment of Crop Irrigation Requirement under current and future Climate Change
Scenario for Upper and Lower Jhelum Canal Command Areas. The required datasets
were Sentinel-2 imagery, climatic parameters, CMIP-6 data, and irrigation water
supply data. The climatic data and bias corrected CMIP6 data were simulated by
employing CROPWAT model and used for the estimation of monthly CWR and CIR
for the baseline (1982–2014) and future (years 2024-2048, 2049-2073 and 2074-
2099) period. By using required Irrigation data, water deficit is calculated for current
and future scenarios in both canal (UJC and LJC) command areas. Results indicated
that Tmax and Tmin showed an upward trend while precipitation showed a downward
trend across all scenarios. ETo showed gradual increase and reached to maximum
value in May and June. Minimum ET rate was observed in January. The monthly ETo
variations suggest that CWR and Irrigation requirements may be highest from April to
August and lowest from November to February. However, due to low rainfall and
increased minimum and maximum temperature from November to February, Rabi
season crop (wheat) faces severe water deficit as compared to Kharif season crops.
CWR of all crops is expected to increase in future climatic scenarios which is an
indication of amplified crop water demand for all major crops. However, water supply
remains constant in both canals. Thus, unmet demand would reach peak values in
January, and March-May in future because of comparatively low canal supplies in
these months.
