Abstract
This paper focuses on the scope of conjunctive management in the Lower Indus part of the Indus Basin Irrigation System (IBIS), and the contribution this could make towards food security and socio-economic development. The total Gross Command Area (GCA) of the Lower Indus is 5.92 Mha, with a cultivable command area (CCA) of 5.43 Mha, most of which is in Sindh Province. There is a limited use of groundwater in Sindh (about 4.3 Billion Cubic Meter (BCM)) for two reasons: first, there is a large area where groundwater is saline; and second, there is a high surface irrigation supply to most of the canal commands, e.g., average annual supply to rice command is 1723 mm, close to the annual reference crop evapotranspiration for the area, while there is an additional annual rainfall of about 200 mm. These high irrigation allocations, even in areas where groundwater is fresh, create strong disincentives for farmers to use groundwater. Consequently, areas are waterlogged to the extent of 50% and 70% before and after the monsoon, respectively, which contributes to surface salinity through capillary rise. In Sindh, about 74%–80% of the available groundwater recharge is lost in the form of non-beneficial evaporation. This gives rise to low cropping intensities and yields compared to fresh groundwater areas elsewhere in the IBIS. The drought of 1999–2002 has demonstrated a reduction in waterlogging without any corresponding reduction in crop yields. Therefore, in order to efficiently meet current water requirements of all the sectors, i.e., agriculture, domestic and industrial, an ab initio level of water reallocation and efficient water management, with consideration to groundwater quality and its safe yield, in various areas are recommended. This might systematically reduce the waterlogged areas, support greater cropping intensity than is currently being practiced, and free up water for horizontal expansion, such as in the Thar Desert.
Highlights
The Indus Basin Irrigation System (IBIS) is described as the world’s single largest “mega”irrigation system—covering a total area of 17.2 Mha
The IBIS consists of The Indus River, itself falling to Arabian Sea, and the tributaries Kabul, Jhelum, Chenab, Ravi, Beas and Sutlej
Managing surface irrigation in an extensive system such as that in Sindh, with extremely long canals, a flat gradient, pre-dominant saline groundwater and widespread alkaline and saline soils is a huge and daunting challenge, to say the least, and in the management of the canal system in Sindh some things have not gone well. This is because water management on a scientific basis has never been evaluated for the Lower Indus area
Summary
The Indus Basin Irrigation System (IBIS) is described as the world’s single largest “mega”. Irrigation system—covering a total area of 17.2 Mha. The IBIS consists of The Indus River, itself falling to Arabian Sea, and the tributaries Kabul, Jhelum, Chenab, Ravi, Beas and Sutlej. With increased supplies from Mangla and Tarbela reservoirs, agricultural water supply has improved greatly, but, at the same time, this has contributed towards increased recharge of the groundwater This increased recharge was utilized for supplementing crop water requirements in Punjab. A World Bank paper [4] pointed out that “the realistic water requirements of the canals are required to be re-calculated, keeping in view of various factors under the present situation” This means that water allowances are, required to be revised [5]. The current situation of increasing water demands, calls for integration of water demand and supply across and within all the water use sectors In this context, this paper demonstrates for the. Lower Indus that the groundwater has considerably higher potential that it is largely unexplored, due to ample availability of canal water and, in several areas, the high salt content
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
