Simple water balance model and crop water demand at different spatial and temporal scales in Periya Pallam catchment of upper Bhavani basin, Tamilnadu

Reduction in agricultural water use and increasing the sustainability of water resources can be achieved by studying the water balance of the area and crop water demand. In this paper, by using a simple water balance model, Evapotranspiration, Rainfall, Runoff, Water Demand and Water Requirement different crops are estimated. The crop water requirement and crop water demand for different crops grown in the Periya Pallam Catchment of Upper Bhavani Basin, Tamilnadu, was estimated. Water balance estimation of the area reveals that out of the annual rainfall, runoff is estimated to be 129 mm, effective rainfall is 252 mm, and deep percolation is about 67 mm. The demand for water for agriculture in the study area is about 61 million cubic meters (MCM), but only 19 MCM of water is available through precipitation in the form of effective rainfall. Hence, the remaining 43 MCM of water is supplied through groundwater and other sources. The results will pave the way for sustainable crop water use planning and would achieve water security in the basin.

Evaluation of crop water demand for sustainable crop production using geospatial tools in a canal command of West Bengal

The agricultural sector is the primary consumer of water resources around the world, and the need for additional food production for growing population further exerts more pressure on water resources. In this study, crop water demand was assessed spatially and temporally for a case study area, Damodar Canal Command (DCC) using geospatial techniques. Crop evapotranspiration was estimated for all the crop seasons using reference evapotranspiration and Fraction of Vegetation cover (FV) that was used as a surrogate for crop coefficient. The reference evapotranspiration (ET ) was calculated using the FAO o Penman-Monteith method. FV was computed based on Normalized Difference Vegetation Index (NDVI) derived from MODIS satellite imagery and its value ranges from 0 to 1. The maximum and minimum reference evapotranspiration values were estimated as 8.44 and 1.88 mmday-1 in May and September, respectively during the normal year 2004. The average monthly crop water demand was maximum in May i.e. 8.08 mmday-1. Among all crop seasons, Boro season has the maximum crop water demand followed by Aus and Aman seasons with maximum ET as 496, 438 and 328 mm, respectively. Total annual crop c water demand for normal year, 2004 was estimated at 1237 mmyr-1 in the study area. Spatially and temporally distributed crop water demand estimates help the irrigation planners to devise the strategies for effective irrigation management.

Machine Learning Method for Forecasting Weather Needed For Crop Water Demand Estimations in Low-Resource Settings Using A Case Study in Morocco

Low and middle income countries often do not have the infrastructure needed to support weather forecasting models, which are computationally expensive and often require detailed inputs from local weather stations. Local, low-cost weather prediction services are needed to enable optimal irrigation scheduling and increase crop productivity for rural farmers in low-resource settings. This work proposes a machine learning approach to predict the weather inputs needed to calculate crop water demand, namely evapotranspiration and precipitation. The focus of this work is on the accuracy with which Moroccan weather can be predicted with a vector autoregression (VAR) model compared to using typical meteorological year (TMY) weather, and how this accuracy changes as the number of weather parameters is reduced.

A Practical Guide for Peach Irrigation Scheduling in Florida

The goal of this publication is to provide a practical guideline for irrigation of young (1–3 years old) and adult (>3 years old) peach trees cultivated in Florida. This document is based on field research of peach water uptake conducted by UF/IFAS. The first section describes peach tree growth stages and their respective crop water demand in central Florida. The second and third sections present practical information on preparing year-round irrigation scheduling for young and adult peach trees, respectively. More information about irrigation practices for peaches is provided in EDIS publication HS1316 (https://edis.ifas.ufl.edu/hs1316).

Historical trends in Crop Water demand over Semi-Arid region of Syria

Climate change has caused a shift in aridity, particularly in the dry regions of the world which may subsequently affect several sectors predominantly the agricultural and water resources. This research examined the climate change effects on crop water demand (CWD) in Syria over the period 1951–2010. Given the lack of observed data, this analysis relied on (GPCC) precipitation and (CRU) temperature data from 1951 to 2010. Potential Evapotranspiration (PET) at each grid was calculated using Penman-Monteith method and FAO-56 model was used to calculate the crop water demand (CWD). The analysis revealed that CWD in Syria increased from 1981 to 2010 when compared to 1951–1980.The increase in CWD has been found for all the crops except wheat, whereas the maximum changes are found during April, and May. The differences in CWD for Barley between the two periods were found to be in the range of -20 to 40 mm. A decrease in CWD observed in the south of the country. However, a rise in 0 to 20 mm range was also discovered in the north. The CWD for wheat was found to decline in most parts of the country. However, it was found to increase in the north. The increase in CWD for barley and wheat has increased agricultural water stress in the region. Several agriculture planning needs to be developed in accordance with the expected future climate changes in order to maintain the agricultural production in the region.

Future Climatic Patterns and Sustainability of Current Cropping Patterns in a Water-Scarce River Basin of Eastern India

<p>Agricultural sector, being the largest consumer of water is greatly affected by climatic variability and disasters. Most parts of the world already face an enormous challenge in meeting competitive and conflicting multi-sector water demands. Climate change has further exacerbated this challenge by putting the sustainability of current cropping patterns and irrigation practices in question. For ensuring climate-resilient food production, it is crucial to examine the patterns of the projected climate and potential impacts on the agricultural sector at a basin scale. Hence, this study was carried out for an already water-scarce basin, Rushikulya River basin (RRB), located in the coastal region of eastern India. The bias-corrected NorESM2-MM general circulation model of Coupled Model Intercomparison Project-6 (CMIP6) was used in this study under four shared socioeconomic pathway (SSPs) scenarios, namely SSP126, SSP245, SSP370 and SSP585. The projected climatic parameters and crop water demands of the basin were analyzed assuming existing cropping pattern in the future. Analysis of the results reveals a significant and rapid increase in the temperature at a rate of 0.02-0.5ºC/year during 2026-2100 under all SSPs except SSP126, whereas the rainfall is expected to increase slightly during 2026-2100 as compared to the baseline period (1990-2016), especially in the far future (2076-2100) under all the SSPs. In contrast, monsoon rainfall is predicted to decrease under SSP245 and SSP370, while a slight increase in the monsoon rainfall is evident under SSP126 and SSP585. Although the rainy days will decrease slightly in the future 25-year time window, the number of heavy rainfall events is predicted to increase by two to three times. Also, retrospective analysis of rainfall and evapotranspiration suggested an existence of rainfall deficit (rainfall-evapotranspiration) in the basin throughout the year, except during July to September. The rainfall deficit in the basin during 2026-2100 is found to remain more or less same in the non-monsoon season, except for the month of October under SSP245, SSP370 and SSP585 scenarios where deficit increases by two folds. Rainfall is expected to be in surplus by 4 to 5 times higher under all SSPs except for SSP245. As to the evapotranspiration, an insignificant increasing trend is observed under future climatic condition with only 2 to 4% rise in the crop water demand compared to the baseline period. As the basin is already water stressed during most months in a year under baseline and future climatic conditions, continuing the current practice of monsoon paddy dominant cultivation in the basin will further aggravate this situation. The results of this study will be helpful in formulating sustainable irrigation plans and adaptation measures to address climate-induced water stress in the basin.</p><p><strong>Keywords:</strong> Climate change; CMIP6; SSP; Monsoon rainfall; Temperature; Crop water demand.</p>