L. S. de Sousa1, X. S. Tindio1, M. T. A. Matangue1, R. M. Wambua2, B. M. Mutua3 and J. M. Raude4
1Division of Agriculture, Instituto Superior Politécnico de Gaza, Campus Politécnico de Lionde, Chókwè-Gaza Province, Mozambique
3Division of Planning, Partnerships, Research and Innovation, Kibabii University, Bungoma, Kenya; firstname.lastname@example.org
4Soil, Water & Environmental Engineering Department, Jomo Kenyatta University of Agriculture & Technology, Nairobi, Kenya; email@example.com
Chókwè Irrigation Scheme (CIS) is the biggest of its kind in Mozambique, supporting the practice of irrigated agriculture in region and contributing to food security and economic growth. The scheme faces seasonality in water flow-flux resulting from the climate variable effects. Sediment particles has accumulated over decades in the canals causing serious problem in the scheme. The lack of knowledge on the climate variables influence is the utmost limit in the site. To address these concerns, this study investigated the effect of climate variables on the performance of the scheme. Climate and hydrology data of the region were obtained from the National Meteorology Institute (INAM), Water Administration for South region (ARA-SUL) and Chókwè Hydraulic, Public Enterprises (HICEP). The effect of climate variables on the performance of CIS was found to be significant for precipitation and air temperature, which plays significant role on the water flow made available in the scheme. A need for a reference evapotranspiration model adjusted to local characteristics was found critical and therefore, a model proposed. The most relevant meteorological variable in estimating ETo for Chókwè region, was found to be the Global Solar Radiation (r=95%; r2=90%). Estimation of the ETo by the Methods Based on Solar Radiation resulted on the Hargreaves method being the best fitting (r2=94%; r=97%), and Benevides and Lopez (r2=76%; r=87%) methods proved to be better and reliable, for Methods Based on Air Temperature. These findings can play role in water flow-flux and sedimentation management and prediction.
Keywords: Climate variables, water flow-flux, sedimentation, precipitation, air temperature.