| Title: | Multi-dimensional evaluation of simulated small-scale irrigation intervention: A case study in Dimbasinia Watershed, Ghana |
| Authors: | Worqlul, A.W., Y.T. Dile, J.-C. Bizimana, J. Jeong, T.J. Gerik, R. Srinivasan, J.W. Richardson and N. Clarke |
| Year: | 2018 |
| Journal: | Sustainability |
| Volume (Issue): | 10(5) |
| Pages: | |
| Article ID: | 1531 |
| DOI: | 10.3390/su10051531 |
| URL (non-DOI journals): | |
| Model: | APEX & SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | model and/or data interface |
| Secondary Application Category: | irrigation impacts or irrigation BMP scenarios |
| Watershed Description: | 35 km^2 Dimbasinia River, located in the upper east Navrongo Region in northern Ghana. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | This paper studied the impacts of small-scale irrigation (SSI) interventions on environmental
sustainability, agricultural production, and socio-economics using an Integrated Decision Support
System (IDSS). The IDSS is comprised of a suite of models, namely the Soil and Water Assessment
Tool (SWAT), Agricultural Policy/Environmental eXtender (APEX), and Farm Income and Nutrition
Simulator (FARMSIM). The IDSS was applied in Dimbasinia watershed in northern Ghana using
irrigation water from shallow groundwater. The watershed has a modest amount of shallow
groundwater resources. However, the average annual irrigation water requirement exceeded
the average annual shallow groundwater recharge. It was found that the current crop yield in
Dimbasinia watershed was only ~40% of the potential crop production. This is mainly related to
climate variability, low soil fertility, and land-management practices. For example, application of
50 kg/ha urea and 50 kg/ha DAP doubled maize and sorghum yield from the current farmers’
practices. Better income was obtained when irrigated vegetables/fodder were cultivated in rotation
with sorghum as compared to in rotation with maize. Investment in solar pumps paid better dividends
and also supplied clean energy. The socio-economic analysis indicated that having irrigated dry
season vegetables will improve household nutrition. Since shallow groundwater recharge alone may
not provide sufficient water for irrigation in a sustainable manner, surface water may be stored using
water-harvesting structures to supplement the groundwater for irrigation. Integrated use of the water
resources will also reduce depletion of the shallow groundwater aquifer. We conclude that IDSS is
a promising tool to study gaps and constraints as well as upscaling of SSI. |
| Language: | English |
| Keywords: | small-scale irrigation; SWAT; APEX; FARMSIM; IDSS; Ghana |