Assessment of rainwater harvesting systems for agricultural productivity in Napak amidst climate change and socio-economic factors

Abstract

This study assessed the performance and effectiveness of rainwater harvesting (RWH) systems in supporting agricultural productivity in Napak District, Uganda, a semi-arid region increasingly affected by rainfall variability and water scarcity. The research was guided by four core objectives: (1) to evaluate the design and hydraulic performance of existing RWH systems, (2) to assess the impact of RWH systems on soil moisture retention and crop water availability, (3) to examine the socio-economic and cultural factors influencing adoption, and (4) to analyze the effectiveness of RWH systems in supporting different farming techniques and practices. Field surveys, geospatial measurements, climate data analysis, and hydrological modeling (including the SCS-CN method and unit hydrograph) were employed. Soil moisture data was collected using satellite-derived SMAP datasets and validated with community observations. A comparative agronomic analysis was conducted between RWH adopters and non-adopters to determine differences in planting cycles, crop types, and irrigation practices. Socio-economic survey results revealed that income, training, and land ownership were major enablers of adoption, while gender, cultural beliefs, and lack of awareness acted as key barriers. Results show that where actively used, RWH systems significantly improved dry-season crop production, crop diversity, and planting frequency, particularly in areas like Nakichumet. However, underutilization of systems in other locations limited their impact. Climate analysis revealed that current systems are vulnerable to changes in rainfall intensity and distribution, requiring adaptive redesign. The study recommends enhanced farmer training, integration of local RWH committees, and targeted expansion of systems in underserved areas to strengthen resilience and food security.