PREDICTION OF PADDY IRRIGATION REQUIREMENTS BY USING STATISTICAL DOWNSCALING AND CROPWAT MODELS: A CASE STUDY FROM THE KERIAN IRRIGATION SCHEME IN MALAYSIA

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Nuramidah Hamidon ◽  
Sobri Harun ◽  
M. A Malek ◽  
Tarmizi Ismail ◽  
Noraliani Alias

With an average rainfall of 2500mm per year, Malaysia has abundant water resources but climate change coupled with drought, urbanisation and pollution sometimes causes water stress. Global warming has changed the local climate, threatening agricultural activities with particular impact on paddy production systems. To ensure availability of sufficient irrigation water for growing crops, there is a need to estimate future irrigation water requirements in the face of the complex dynamic resulting from global warming. The current study was therefore carried out to estimate paddy irrigation water requirements based on future climate trends by using SDSM and CROPWAT Models at the Kerian Irrigation Scheme, Perak, Malaysia. The application of the SDSM model revealed that both temperature and rainfall will increase in the future. Meanwhile the CROPWAT model predicted that the annual irrigation requirement will slightly decrease for period between 2010-2069 and increase for years 2070-2099 even though crop evapotranspiration (ETcrop) is predicted to increase in future for rise in temperature for year 2010 to 2099. This integration of SDSM and CROPWAT models produced better simulations of crop water requirement and irrigation requirement. Therefore, it can assist the reservoir’s operating management team in giving effective and proficient response to climate changes in the future.

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2006
Author(s):  
Mirza-Junaid Ahmad ◽  
Kyung-Sook Choi

Conceptualizing the implications of climate change for crop evapotranspiration (ETc) and subsequent net irrigation water requirement (NIWR) is critical to sustaining Pakistan’s agriculture and food security. In this article, future ETc, NIWR, and design water requirements (DWR) were projected for the rice–wheat system of Punjab, Pakistan. Consistently increasing temperatures signify an impending hotter transition in the future thermal regime, accompanied by a substantial increase in monsoon rainfall. Future climate warming accelerated ETc and NIWR, which were compensated by 2–5 and 1–2 additional irrigations during the rice and wheat seasons, respectively. Future rice and wheat required 13–18 and 2–5 irrigations per season, respectively. Effective rainfall increments did not compensate for the warming-driven higher ETc and NIWR because of uneven and erratic rainfall distribution. Rainfall occurrence and the duration of peak irrigation demand were mismatched, resulting in surplus rainwater availability during the future rice season. The results suggest that DWR for 5- and 10-year return period droughts during the baseline period (965 and 1000 mm, respectively) should be revised to accommodate the additional 100–200 mm of irrigation water per season; otherwise, the study area will face an acute water shortage in the future.


2018 ◽  
Vol 11 (2) ◽  
pp. 402-419
Author(s):  
Na Fu ◽  
Xiaoyu Song ◽  
Lu Xia ◽  
Lanjun Li ◽  
Xiaogang Liu

Abstract This study aimed to identify the future changes in water requirements (ETc) of flue-cured tobacco by comparing estimated ETc values in the future with previous usage. This will provide a basis for estimating irrigation requirements, and help improve agricultural water use efficiency in the future. The Penman–Monteith equation and the single-crop efficient method were used to calculate the flue-cured tobacco ETc, net irrigation requirement (IR) and net irrigation requirement index (IDI) for the period 1956–2015, and the four Intergovernmental Panel on Climate Change (IPCC) AR5 emission scenarios were used to estimate ETc for two future periods (2046–2065 and 2081–2100) in the central Yunnan Province, China. The results showed that the IDI gradually decreased, along with the growth of flue-cured tobacco. The ETc, IR and IDI values increased with latitude in central Yunnan Province. Furthermore, the variations in the ETc over the whole growth period in the mid-21st century and late-21st century also tended to increase with latitude. In addition, based on the influence of climate variation on the ETc as assessed by a principal component analysis, precipitation was the main factor affecting flue-cured tobacco growth. This study contributes to the establishment of suitable irrigation systems for flue-cured tobacco at every growth stage in central Yunnan Province.


2019 ◽  
Vol 10 (2) ◽  
pp. 61-68
Author(s):  
Hanan Shalsabillah ◽  
Khairul Amri ◽  
Gusta Gunawan

The Irrigation Area of Air Nipis is located in Regency of South Bengkulu at Bengkulu Province with irrigation area 3.116 Ha. Planning and management of irrigation systems is one of the important steps to determine the irrigation water requirement as a whole. The purpose of this research is aim to analyze the water requirement to get value prediction of minimum and maximum irrigation water requirement in irrigation area of Air Nipis using the CROPWAT Version 8.0 method. Irrigation water requirements obtained from CROPWAT Version 8.0 are based on climate data, soil data and plants.The parameters that were reference plant evapotranspiration, effective rainfall, soil treatment, soil data, and plants. The results of the research showed that the maximum irrigation requirement for calculation using CROPWAT 8.0 software occurred in the first 10 days of December (14,49 m3/sec), while the minimum irrigation water requirements for CROPWAT 8.0 occurs in mid to end March (0,04 m3/sec).


2015 ◽  
Vol 7 (1) ◽  
pp. 39-51 ◽  
Author(s):  
Ali Fares ◽  
Ripendra Awal ◽  
Samira Fares ◽  
Alton B. Johnson ◽  
Hector Valenzuela

The impact of potential future climate change scenarios on the irrigation water requirements (IRRs) of two major agricultural crops (coffee and seed corn) in Hawai'i was studied using the Irrigation Management System (IManSys) model. In addition to IRRs calculations, IManSys calculates runoff, deep percolation, canopy interception, and effective rainfall based on plant growth parameters, site specific soil hydrological properties, irrigation system efficiency, and long-term daily weather data. Irrigation water requirements of two crops were simulated using historical climate data and different levels of atmospheric CO2 (330, 550, 710 and 970 ppm), temperature (+1.1 and +6.4 °C) and precipitation (±5, ±10 and ±20%) chosen based on the Intergovernmental Panel on Climate Change (IPCC) AR4 projections under reference, B1, A1B1 and A1F1 emission scenarios. IRRs decreased as CO2 emission increased. The average percentage decrease in IRRs for seed corn is higher than that of coffee. However, runoff, rain canopy interception, and deep percolation below the root zone increased as precipitation increased. Canopy interception and drainage increased with increased CO2 emission. Evapotranspiration responded positively to air temperature rise, and as a result, IRRs increased as well. Further studies using crop models will predict crop yield responses to these different irrigation scenarios.


2021 ◽  
Author(s):  
Liang Guo ◽  
Laura Wilcox ◽  
Massimo Bollasina ◽  
Steven Turnock ◽  
Marianne Lund ◽  
...  

<p>The occurrence of severe haze events remains a serious problem in Beijing. Previous studies suggested that the frequency of weather patterns conducive to haze may increase with global warming. The new Shared Socioeconomic Pathways (SSPs) cover a wide range of uncertainties in aerosol and greenhouse gases emissions. Global and Chinese aerosol emissions are projected to decrease in most SSPs, while increases in greenhouse gases and global warming will continue for the rest of the century. The future, therefore, remains unclear.</p><p>We quantified the air pollution over Beijing and associated weather patterns using multiple indices calculated from the SSPs</p><p>We show that the occurrence of weather patterns conducive to the formation of haze significantly increases by the end of the century due to increases in greenhouse gases. Aerosol reductions also cause an increase in their occurrence, but reduce the severity of haze, and overall reducing aerosol emissions will be beneficial.</p>


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