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This study assessed the impacts of climate change on diversion water requirements for irrigation system planning and development in the Philippines. Representative sites with high potential for irrigation development were selected from each of the four climatic types in the country. Cropping calendars were developed based on evapotranspiration and...
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... e research on the deterministic model of crop planting structure optimization at home and abroad includes singleobjective models and multiobjective models. e singleobjective models generally aim to maximize the economic benefits of the whole irrigation area, and the calculation method generally adopts the linear programming method [15]. e single-objective model is relatively simple, but it fails to achieve the overall development of negotiation and coordination between decision-makers and models [16,17]. ...
... x gm equal to 1 means that the gate of the branch canal/ bucket canal is opened. e constraint functions are expressed in equations (15) and (16). ...
The agriculture sector is the backbone of the economies of many Asian countries such as India, China, and Bangladesh. The agriculture sector can contribute a major share to the GDP of such countries where the main occupation of the citizens is agriculture or the dependency of the citizens is mainly on the agricultural productivity. It is important to study the potential areas of agricultural economic resource development. The existing methods are not efficient enough to map the potential areas of agricultural productivity with economic resource development, and hence, it has motivated us to study the aspects which impact the economic resource development based on agricultural productivity. There are numerous factors such as low productivity, high irrigation amount, high labor charges, low proportion of planning optimization, and low crop yield that should be considered to study the correlation between economic development and agricultural productivity. Firstly, the spatial relationship of potential areas of agricultural economic resources development is analyzed in this paper. Secondly, the multiobjective linear programming model is proposed. Based on this multiobjective model, the optimal matching model for potential areas of agricultural economic resource development is constructed, and the improved genetic algorithm is used to solve the model to realize the optimal matching of potential areas of agricultural productivity and economic resource development. The experimental results show that the proposed method has high economic benefit, low irrigation amount, and high proportion of planning optimization with high crop yield.
... The FAO developed CropWAT program which was used to estimate the diversion water requirement in the potential service areas. Alejo et al. (2021) provided information on how CropWAT estimates net irrigation requirement and detailed estimation method of diversion water requirement. This part of the present study employed their method in estimating DWR wherein a 70% irrigation application efficiency was considered, which is the typically accepted value for water resources planning. ...
... Compared to the DWR in the baseline period, climate change is seen to consistently increase the DWR across scenarios. Climate change will cause a doubling of diversion water requirements of future irrigation systems in the Philippines (Alejo et al. 2021). Across all scenarios, diversion water requirement in the site will increase with RCP and towards the late twenty-first century. ...
Considering changes in irrigation planning and development due to climate change is necessary to avoid system failure. This study demonstrated that changes in dependable flow and diversion water requirements in the future due to climate change will reduce potential irrigable areas. Climate change were based on the published projected climate in the study area. The dependable flow derived from successfully calibrated and validated Soil and Water Assessment Tool (SWAT) model streamflow simulations and the diversion water requirements based on the CROPWAT estimations of irrigation scheme were used to assess the potential irrigable areas. Substantial reductions in potential rice production areas (-4% to – 39%) were largely due to dwindled dependable flow (-1% to -25%) and an increase in diversion water requirement (+ 7% to + 26%). Reduction in potential irrigable area was projected during dry and normal years and may worsen towards the late twenty-first century under the worst-case climate scenario. Swelling of rivers during wet years will increase stream flows and potential irrigable areas but may also pose a danger of flooding. The development of water storage structures is necessary to reduce the adverse impacts of too much water during the wet years. Crop calendars should also be retrofitted to optimize the use of available rainfall during dry and normal years and climate-proof future irrigation systems. The results showed that it is necessary to incorporate climate change in irrigation planning and development. The methodologies described here could be used to climate-proof future irrigation systems in other areas in the Philippines and other countries.
... In the Philippines, typhoons, La Niña and other climate change effects are among the constraints in rice GY production (Alejo et al., 2021, Stuecker et al., 2018. Also, Philippines has variable rice farming climate conditions like types I and III with most months are dry season while types II and IV with most months are rainy season (PAGASA, 2014). ...
... E1 and E2 were defined in Cantila et al. (2019), E3 was set-up during October 2018 to January 2019 at Philippine Rice Research Institute (PhilRice)-Midsayap Experimental Station (MES), Midsayap, Cotabato, and E4 was set-up during April to July 2019 at Pigcawayan, Cotabato ( Figure 1). E1, E2, E3, and E4 were within the SOCCSKSARGEN region with type IV climate condition (Alejo et al., 2021, PAGASA, 2014. The meteorological data of the tested environment was obtained using a climate toolbox (Hegewisch and Abatzoglou, 2020). ...
... In GY gap analysis, rice varieties planted during dry season had 64.5% GY advantage (average in two years) over the varieties planted during rainy or wet season (Yang et al., 2008). In 2019, the rice bowl regions in the Philippines, Central Luzon and Cagayan Valley (most areas are dry season) (Alejo et al., 2021, PAGASA, 2014 produced 3.73 and 2.66 million metric tons (MMT) of rice, respectively, almost twice higher than 1.34 MMT in SOCCSKSARGEN region (most areas are rain-prone) (PSA, 2020). ...
The stability of high yielding hybrid rice varieties is very important to meet food security. The grain yield(GY) stability of 13 hybrid rice varieties in multi-environment with type IV climate condition (E1, E2,E3, and E4) was analyzed using genotype main effects and genotype x environment interaction (GGE).Combined analysis of variance showed environment and genotype by environment (GxE) interaction which accounts45% and 28% of the total variation, respectively, as the main factors influencing the GY significantly (p < 0.005). GGE biplots were generated using the two interaction principal components (PC1 and PC2) which accounts a total of 92.4% of the GxE effect for GY. GGE biplot analysis identified best performing genotypes for a specific environment like M1(Mestizo 1), M60 (PAC 801), and M55 (Mestizo 55) at E1 andE2, M60 and M6 (SL-8H) at E3, and M6 at E4. M1 was ranked as top 1, M60 as top 2, M6 as top 3, and M55 as top 4 in four tested environments with a mean GY of 7.48, 7.40, 6.93, and6.86 t/ha, respectively. Therefore, M1, M60, M6, and M55should be recommended to rice farm areas of SOCCSKSARGEN and other places in the Philippines with type IV climate condition such as Davao regions.
The proportion of agricultural water consumption is continuously decreasing due to increased competition for water resources by urban, industrial, and agricultural users. Drip irrigation is more efficient in terms of water and energy utilization. These considerations are critical in view of the ongoing struggle for water resources among various consumers due to water scarcity. Some of the most critical criteria in the effective design and maintenance of drip irrigation systems are the shape and size of the volume of wet soil beneath the emitter. Hence several statistical models were constructed in this research to estimate the dimensions of wetting patterns, which are critical for designing an optimal drip irrigation system. The Nash-Sutcliffe efficiency (NSE), coefficient of correlation (CC), and root mean square error (RMSE) criteria were used to assess the models' performance. The results showed that the Polynomial model was the most accurate for horizontal advance, with 0.94, 0.93, and 1.33 (cm) values for CC, NSE, and RMSE, respectively. For vertical advance, the logarithmic model showed 0.96, 0.96, and 0.72 (cm) values for CC, NSE, and RMSE. Thus, in the absence of a wetting pattern and under identical conditions, these models can be utilized to generate synthetic horizontal and vertical advances data.
