Claim Missing Document
Check
Articles

Found 2 Documents
Search

Assessment of the soil erosion and sedimentation levels of selected Small Water Impounding Systems (SWIS) in Nueva Ecija, Philippines Camania, Denver C.; Almerol, Carolyn Grace; Malamug, Vitaliana U.; Castillo, Claire Marie M.; Fabula, Jonathan V.; Sacdalan, John Paulo C.; Badua, Sylvester A.; Reños, Erwin B.; Samson, Richard V.
Journal of Degraded and Mining Lands Management Vol. 13 No. 2 (2026)
Publisher : Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15243/jdmlm.2026.132.9717

Abstract

The Philippines was able to implement around 740 small water impounding systems (SWIS) from 1974-2021, which reportedly irrigated a service area of more than 27,000 hectares, benefiting about 26,600 farmers. Unfortunately, these projects are facing an alarming sedimentation problem due to soil erosion at upstream watersheds. It was observed that limited studies have been undertaken for the past 10 years that investigate the status of SWIS, especially the governing relationship between soil erosion and reservoir sedimentation. The present study was driven by these problems to provide a picture of its current levels of severity and its effects on the project itself. The six (6) selected sites were situated in the north-western portion of Nueva Ecija province, namely Villa Isla, Mangandingay, Villa Boado, Maasin, Tibag II, and Alalay Grande SWIS. The soil erosion component of the study was evaluated using the Modified Universal Soil Loss Equation (MUSLE) and Quantum Geographic Information System (QGIS). While the sediments deposited at the SWIS reservoir were measured using the Real-Time Kinematic (RTK) equipment. It was found out that these sites were now experiencing soil erosion from slight to moderate, 3.21 t/ha/year, to extremely high, 100.35 t/ha/year. In effect, the level of sedimentation within the reservoirs reached the intensity from slight to high with values ranging from 2.20-26.11 t/ha/year. Thus, recording an average reservoir storage loss of 702.86 m3/year or 2.86%/year which equated to average remaining useful life of 37.01 years, at 100% capacity of the reservoir.
Development of MUSLE-based models for the prediction of sediment deposits of Small Water Impounding Systems (SWIS) in Nueva Ecija, Philippines Camania, Denver C.; Almerol, Carolyn Grace S.; Malamug, Vitaliana U.; Castillo, Claire Marie M.; Fabula, Jonathan V.; Sacdalan, John Paulo C.; Badua, Sylvester A.; Reños, Erwin B.; Samson, Richard V.
Journal of Degraded and Mining Lands Management Vol. 13 No. 2 (2026)
Publisher : Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15243/jdmlm.2026.132.10013

Abstract

The estimation of sediments within the reservoir is important during the engineering design and operational phase of the small water impounding system (SWIS). Most of the existing sediment prediction models were developed from a certain number and group of reservoirs (or watersheds) with known attributes, making them of limited use. The present study was conducted to develop localized sediment prediction models that are based on Modified Soil Loss Equation (MUSLE) and suited to the characteristics of SWIS. The data from the recent soil erosion and sedimentation study in six (6) SWIS in Nueva Ecija, namely Villa Isla, Mangandingay, Villa Boado, Maasin, Tibag II, and Alalay Grande SWIS, were utilized in model development. The manual linearity analysis was employed to generate regression coefficient factors (CFs) and models by determining the sites with a greater relationship in terms of measured sediment deposits and MUSLE factors. There were about 19 regression CFs with 15 models, possessing 1-2 independent variables, developed from different land uses and watersheds. The LS factor, having the strongest relationship to soil erosion, was used in tandem with other MUSLE factors to form models with 2 independent variables. The study found an exceptional performance of the developed MUSLE-based models in terms of R2, residual, and mean absolute percentage error (MAPE). The models with 2 independent variables achieved a perfect performance with R2 of 1.0, while no residuals and errors were recorded. The models with 1 independent variable performed well with R2, residual, and MAPE of 0.8036-0.9893, 0.00-2.43, and 7.41-41.05%, respectively.