Showing 31 results for Climate Change
A. R. Massah Bavani, S. Morid,
Volume 9, Issue 4 (1-2006)
Abstract
In this study the impact of climate change on temperature, rainfall and river flows of the Zayandeh Rud basin under two climate change scenarios for two periods (2010-2039 and 2070-2099) are investigated. For the evaluation of future climate change impact on stream flow to Chadegan reservoir, the global circulation model (GCM) outputs of the HadCM3 model (monthly temperature and precipitation) with two scenarios, A2 and B2, are obtained and downscaled to the local level for the selected time periods. The results indicate that the annual average of precipitation decreases and temperature increases for both periods that are more pronounced for the period 2079-2099. Such that 10% to 16% decrease in precipitation and 3.2 to 4.6ºC increases in temperature can be anticipated for scenarios A2 and B2, respectively. To predict future stream flow changes due to climate change, artificial neural networks (ANNs) have been applied and trained by the several input models and architectures for rainfall-runoff simulation. The results indicate that the maximum of 5.8% decrease in the annual flows. Comparison of the two scenarios indicates the more critical situation in scenario A2 for the basin.
E. Vaseghi , A. Esmaeili,
Volume 12, Issue 45 (10-2008)
Abstract
This study used a Ricardian approach to measure the impact of climate change on Iranian wheat production and analyzed potential impacts of further climate changes. The study utilized time series data for the period 1984-2004 pooled over 17 provinces. Results showed that climate change has significant nonlinear impacts on net revenue per hectare of wheat in Iran. The results also showed that rise in temperature and reduction in rainfall by the year 2100 will cause the reduction in land value by 41 %, because of increased greenhouse gas emission.
Z Maryanji, A Sabziparvar, F Tafazoli, H Zare Abianeh, H Banzhad, M Ghafouri, M Mousavi,
Volume 12, Issue 46 (1-2009)
Abstract
Under different climatic conditions of Iran, the evaluation of evapotranspiration (ETo) models sensitivity to meteorological parameters, prior to introducing the superior performance model, seems quite necessary. Using a 35-year (1971-2005) climatological observations in Hamedan, this study compares the sensitivity of different commonly used evapotranspiration models to different meteorological parameters within the IPCC recommended variability range of 10 to 20% during the growing season (April-October). The radiation and temperature-based ETo models include: Penman-Monteith -FAO56 [PMF56], Jensen-Haise [JH1,2], Humid Turc [TH], Arid (semi) arid Turc [TA], Makkink [MK], Hansen [HN], and Hargreaves-Samani [HS]. Results indicate that all the above-mentioned ETo models show the highest sensitivity to radiation and temperature parameters. This implies that special care is required when we apply model-generated radiation and albedo parameters in such ETo models. It is predicted that by 2050, as a result of global warming, the cold semi-arid climates of Iran will cause an average evapotranspiration rise of about 8.5% in crop reference during the growing season.
R Sabohi, S Soltani,
Volume 12, Issue 46 (1-2009)
Abstract
Climate change has important effects on earth environment and human life. Therefor, investigation and study of climate change is very essential. This study investigated rainfall, temperature, relative humidity and wind variability by analyzing data for annual and monthly climatic factors collected at 13 synoptic stations (industrial cities of Iran) by using Mann-Kendall test. The results of monthly rainfall trends showed that most of synoptic stations have significant positive and negative trends in winter and spring months. About 23% and 1.7% of stations have significant negative and positive trends, respectively, in annual trend of this factor. The results of monthly number of rainy days showed the major number of significant trends occurs in spring. In autumn (September, October and November) like as summer most of the stations have no significant trends. Analyzing the annual number of rainy days trends also showed that 4 stations have significant positive trends and 2 stations negative trends. Trend of greatest daily precipitation is low throughout the year, so there is not any significant trend in winter. Annual investigations confirm the seasonal investigations. The major number of significant trends in monthly mean maximum temperature occurs in summer but there are not any significant trends in winter and March. The trend of mean minimum temperature is approximately high in all of the seasons and the major number of significant trends occurs in summer and autumn and then in spring and ultimately in winter. In annual investigation, most of the stations showed positive trends and only Oroomieh station has negative trends. Trend of mean temperature is high except for winter. Most of the stations showed positive trend, indicating increasing trends in this factor. Annual studies vertify the positive trends and about 63% of stations have significant positive trends.
P. Ashofteh, A. R. Massah Bouani,
Volume 14, Issue 53 (10-2010)
Abstract
Climate change has different impacts on extreme events such as flood and drought. However, in Iran there are few researches about the impacts. This research was aimed to investigate maximum annual discharge (magnitude and frequency) that may occur due to climate change in Aidoghmoush Basin during 2040-2069 (2050s). At first, monthly temperature and precipitation data of HadCM3 model under the SRES emission scenario, namely A2 , was provided for the basin. Then, these data were downscaled spatially and temporally to Aidoghmoush basin by proportional and change factor downscaling methods. Results showed that the temperature increases (between 1.5 to 4) and the precipitation varies (30 to 40 percent) in 2040-2069 compared with baseline period (1971-2000). A semi-conceptual model (IHACRES) for simulation of daily runoff was calibrated. Downscaled temperature and Precipitation for 2050s were introduced to IHACRES and daily runoff was simulated for the future. Probability distribution was fitted to maximum annual discharge series and the maximum discharge regime of the future was compared with the baseline. Results indicated that climate change affects Maximum discharge in the regime of the basin. Also, the analysis showed that the intensity of maximum discharges for the time period less than 50 does not show any significant difference but by increasing the return period, the intensity increases in future periods. Moreover, it was shown that the probability of maximum discharges with constant intensity will decrease in the future compared to the baseline.
S. Dodangeh, S. Soltani, A. Sarhadi,
Volume 15, Issue 58 (3-2012)
Abstract
This study performs trend analysis of hydroclimatic varibles and their possible effects on the water resources variability. Nonparametric Mann-Kendall and spearman tests were used to investigate trend analysis of mean annual and 24-hr maximum rainfall, flood and low flow parameters of 23 hydrometery and 18 synoptic stations in Sefid-Roud basin. The results showed that mean annual and 24-hr rainfall parameters are decreasing in few stations while most of stations representing negative trend for low flow and flood time series. Applying Sequential Mann-Kendall test revelad that this negative trend is started from 1965 to 1970 for rainfall parameters and from 1970 to1980 for flow (low flow and flood) parameters. Results show that climate change has probability affected variability of climatic variables, while changing of land use may have aslo affeteced extreme flow trends during recent decads. Therefor it can be noted that combination of climate chanege effects and human activities on water recources have affected the negative trend of hydroclimatics variables.
S. Dodangeh, J. Abedi Koupai, S. A. Gohari,
Volume 16, Issue 59 (4-2012)
Abstract
Due to the important role of climatic parameters such as radiation, temperature, precipitation and evaporation rate in water resources management, this study employed time series modeling to forecast climatic parameters. After normality test of the parameters, nonparametric Mann-Kendall test was used in order to do trend analysis of data at P-value<0.05. Relative humidity and evaporation (with significant trend, -0.348 and -0.42 cm, respectively), as well as air temperature, wind speed, and sunshine were selected for time series modeling. Considering the Autocorrelation function (ACF) and Partial Autocorrelation function (PACF) and trend of data, appropriate models were fitted. The significance of the parameters of the selected models was examined by SE and t statistics, and both stationarity and invertibility conditions of Autoregressive (AR) and Moving average (MA) were also tested. Then, model calibration was carried out using Kolmogorov-Smirnov, Anderson- Darling and Rayan-Joiner. The selected ARIMA models are ARIMA(0,0,11)*(0,0,1), ARIMA(2,0,4)*(1,1,0), ARIMA(4,0,0)*(0,1,1), ARIMA (1,0,1)*(0,1,1), ARIMA (1,0,0)*(0,1,1) for relative humidity, evaporation, air temperature, wind speed and sunshine, respectively. The fitted models were then used to forecast the parameters. Finally, trend analysis of forecasted data was done in order to investigate the climate change. This study emphasizes efficiency of time series modeling in water resources studies in order to forecast climatic parameters.
M. Khoshravesh, J. Abedi-Koupai, E. Nikzad-Tehrani,
Volume 19, Issue 74 (1-2016)
Abstract
During the past few decades, the southern part of the Caspian Sea has more frequently experienced extreme climatic events such as drought and flood. Trend analysis of hydro-climatic variables was conducted using non-parametric Mann-Kendall test and regression test for Neka basin in the north of Iran. Trends of precipitation and stream flow characteristics including maximum flow, mean flow and low flow indices were analyzed at the annual, seasonal and monthly time scales from 1358 to 1391 (34 years). Results showed a general decrease in annual and winter precipitation and decrease in daily maximum precipitation, with an increased trend in daily maximum precipitation of spring season. A decreasing trend was observed in 7-day low flow in summer for all sub-basins. Annual and monthly mean flows specifically in winter in all sub-basins decreased, but annual maximum flow increased from upstream to downstream. Land use changes showed that deforestation and urbanization increased during 34 years in the mid and downstream sub-basins. The analysis showed that low flow indices and mean flows are strictly sensitive to climate change. Overall, from hydrological perspective, these results indicate that the study region is getting dryer and facing more severe drought events. The results of this study can predict future droughts to make better decisions for irrigation planning and management of water resources.
M. J. Zareian, S. S. Eslamian, H. R. Safavi,
Volume 20, Issue 75 (5-2016)
Abstract
This study investigated the effects of climate change on the evapotranspiration amount and water balance in the Zayandeh-Rud river basin. Two important weather stations; Isfahan and Chelgerd stations, located in the East and West of the basin respectively, were selected for investigation in this study. The combination of 15 GCM models were created based on the weighting method and three patterns of climate change including the ideal, medium and critical were defined. Using the proposed patterns, the effects of climate change on temperature and evapotranspiration in Isfahan station and precipitation in Chelgerd station were estimated under the A2 and B1 emissions scenarios. Two indices were considered to determine the sustainability of agricultural water consumption in the study area. Ratio of evapotranspiration in the East part of the basin to precipitation in the West part was defined as EPR index (Evapotranspiration-Precipitation Ratio), and the ratio of maximum agricultural water deficit to the amount of agriculture water need, was considered as maximum deficit index (MD). Results showed that the annual temperature would increase between 0.63-1.13°C in the eastern part of the basin. The west precipitation in the basin would reduce between 6.5-30% in the ideal to critical patterns. Summer season, showed the most amount of increase in the temperature, and winter season, showed the most amount of decrease in precipitation. The A2 emission scenario showed more temperature increase and more precipitation decrease in comparison with the B1 emission scenario and also indicated that the potential evapotranspiration would increase by 3.1 to 4.8% in the basin. The EPR index will increase between 13-52% and MD index will increase between 9-35% in Zayandeh-Rud river basin under different climate change patterns. The results revealed the imbalance between agricultural water use in eastern part and the precipitation in the western part of the basin. In other words, in these conditions, appropriate management strategies and planning should be implemented to ensure the sustainability of water resources in Zayandeh-Rud River Basin.
P. Almasi, S. Soltani, M. Goodarzi, R. Modarres,
Volume 20, Issue 78 (1-2017)
Abstract
With regard to the confirmation of climate change in most regions of the world and its effects on different parts of the water cycle, knowledge of the status of water resources is necessary for proper management of resources and planning for the future. Hence many studies have been done in different areas with the aim of analyzing the impact of climate change on hydrological processes in the upcoming periods. In present research, the effect of climate change on surface runoff in Bazoft watershed has been studied. Bazoft watershed, located in North-West of Chahar Mahal & Bakhtiari province, has significant contribution in the production of water resources of the region due to its special topographical and geographical status. In this study, climatic model – HadCM3- and A2 and B2 emission scenarios have been used to assess uncertainty in forecasting climate change. For this purpose, a statistical model –SDSM- has been applied to downscale large- scale precipitation and temperature data and hydrological model –WetSpa- has been used to simulate runoff. After calibration of the hydrological model, downscaled precipitation and temperature data in near future (2020-2050) and far future (2070-2100) periods were introduced to WetSpa model and runoff was simulated for mentioned periods. Results of this study represent suitable performance of SDSM model in downscaling climatic data, especially minimum and maximum temperature. Also, performance evaluation of Wetspa model shows proper performance of this model for runoff simulation in Bazoft watershed, so that Nash- Sutcliffe efficiency during calibration and validation was 0.63 and 0.65, respectively. Moreover, assessing the amount of predicted runoff for future periods indicates an increase in annual runoff in the Bazoft watershed under both A2 and B2 scenarios.
Sh. Kouhestani, S, Eslamian, A. Besalatpour,
Volume 21, Issue 1 (6-2017)
Abstract
This study aims to investigate the changes of minimum and maximum temperature variables under the impact of climate change for time period of 2015-2100 in the Zayandeh-Rud River Basin. The outputs of 14 Global Climate Models (GCMs) under three green-house emission scenarios (RCP2.6, RCP4.5, and RCP8.5) are employed from the Fifth Assessment Report (CMIP5) of Intergovernmental Panel on Climate Change (IPCC). A novel statistical downscaling method using a Bayesian Relevance Vector Machine (RVM) is used to project the impact of climate change on the temperature variables at regional scale. The results of the weighting average of the GCMs show that the various models have different accuracy in the projecting the minimum and maximum temperatures in the study area. The results demonstrate that the MIROC5 and CCSM4 are the most reliable models in projecting the maximum and minimum temperatures, respectively. The highest increase for both maximum and minimum temperatures was obtained in winter.
On the annual basis, the maximum temperature will increase by 0.18-0.76 °C and 0.25-1.67 °C, respectively, in the near and long-term future periods under different emission scenarios. The annual minimum temperature will increase by 0.28 to 0.82 °C and 0.24-1.56 °C, respectively, in the near and long-term future periods. In a general view, changes in maximum temperature will be slightly higher than minimum temperature changes in the future.
Dr. S. Akhavan, N. Delavar, Dr. A. M. Mehnatkesh,
Volume 21, Issue 2 (8-2017)
Abstract
The aim of this study was to investigate the climate change impacts on some factors affecting rainfed wheat growth such as effective rainfall, planting date and length of growing season in four stations located in Chaharmahal and Bakhtiari province. Firstly, it is necessary to predict future (2046-2065) climatic conditions. For this purpose, the output of HADCM3 general circulation model was used under three scenarios of A1B, A2 and B1. The data were downscaled by LARS-WG model. After simulating the climatic parameters in mention period, the effective rainfall during the wheat growing season was calculated by Food and Agriculture Organization method. Also, the optimum planting date was defined according to the date of the first rain (at least 10 mm in case of continuing for next days). The wheat's growth stages were determined by Growing Degree Days method. The results indicated a rise in temperature for four stations. On average, it is expected that the annual temperature increase by 1.8°C compared with the baseline period (2010-1990). Total annual precipitation in Shahrekord, Koohrang and Borujen will decrease 2.2, 7.8 and 3.6 per cent respectively. About Lordegan it will increase by 2.7 per cent. Also, the results showed that in three stations of Shahrekord, Koohrang and Borujen, the amount of effective rainfall in November will increase compared to baseline, but in Lordegan it will reduce. So, in the first three stations, in most years, planting date was obtained earlier than baseline, but in Lordegan it was later than baseline. The Length of growing season will reduce in Shahrekord, Borujen and Lordegan stations, 12 days on average and in Koohrang about 13 days.
S. M. Sajjadi, H. R. Safavi, O. B. Haddad,
Volume 22, Issue 3 (11-2018)
Abstract
In this study, the WEAP model was used for the simulation and the Gravitational Search Algorithm (GSA) was applied as the optimization model. Due to the necessity of multiple simulations in the optimization process to achieve the optimal solution, the linkage of simulation and optimization models was done in the MATLAB software environment. To evaluate the performance, hedging policies achieved in the base period were investigated for the near future period under climate change. The results showed the poor state of aquifers under the baseline scenario; also, the continuation of the current management caused the Zayandehrood river basin to experience significant problems. So management of water resources using conjunctive hedging policies could improve the situation. The use of conjunctive hedging rules showed 11 percent increase in the group sustainability index for demands, in comparison with the baseline scenario. Also, according to the group sustainability index for the resources, applying the conjunctive hedging policies could increase the sustainability of surface water and groundwater resources as much as 5.2 and 6 percent, respectively, relative to the baseline scenario. The results also indicated the better performance of conjunctive hedging policies in comparison to the baseline scenario policies.
S. Nikkhoo Amiri, M. Khoshravesh, R. Norooz Valashedi,
Volume 23, Issue 4 (12-2019)
Abstract
Today, the rising surface temperature of the planet and its effects on the water cycle have attracted the attention of many researchers. The aim of this study was to investigate the effect of climate change on the Tajan (the upstream of Shahid Rajaei dam) catchment area. In order to study the output of CanESM2 model, the SDSM method was used to estimate the magnitude of the data. Flow discharge changes in Shahid Rajaei Dam were simulated using the weather data of Kiasar synoptic station and the temperature and precipitation changes were simulated using the climate scenarios of RCP2.6 and RCP8.5 for the 2016-2066 period. Also, the effect of different scenarios on the outflow of the Soleiman Tangeh hydrometric station was evaluated by SWAT hydrologic model. The results showed that the annual precipitation would be decreased by 58% and the air temperature would be increased by 14% under RCP2.6 scenario. Also, in the RCP8.5 scenario, precipitation would be decreased by 59.5% and the temperature would be increased by 21%. Peak discharge for RCP2.6 and RCP8.5 scenarios would be increased by 4% and 5.7%, respectively, and the average annual discharge might be decreased by 16% and 16.5% in the future period (2016-2066). Therefore, it can be planned by the investigation of conditions for cropping patterns in the downstream to consider the environmental impacts for future periods.
A. Alinezhad, A. Gohari, S. Eslamian, Z. Saberi,
Volume 23, Issue 4 (12-2019)
Abstract
The evaluation of climate change impact on hydrological cycle includes uncertainty. This study aimed to evaluate the uncertainty of climate change impact on the Zayandeh-Rud Reservoir inflow during the future period of 2020-2049. The outputs of 22 GCM models were used under the three emission scenarios including RCP2.6, RCP4.5 and RCP8.5. The Bayesian Model Averaging (BMA) was used as the uncertainty analysis for weighting the 22 GCM models based on their ability to simulate the baseline 1990-2005 period. Results showed that different GCM models had different abilities in estimating climatic and hydrological variables and the application of uncertainty analysis in climate change studies could be necessary. The monthly temperature in the upstream of Zayandeh-Rud reservoir could be raised by 0.85 to 1 ◦C; also, the precipitation might be increased by 2 to 3 percent. The high flow during winter season will increase under climate change, while the spring and autumn seasons’ low flows are expected to reduce. Additionally, the annual reservoir inflow may decrease by 1 to 8 percent, showing the necessity for change in Zayandeh-Rud reservoir’s rule curve and allocation of water resources.
S. Janatrostami, H. Mahmoudpour,
Volume 23, Issue 4 (2-2020)
Abstract
One of the main sources of greenhouse gas (GHG) emissions is the use of energy for groundwater pumping. Reducing energy consumption is very important to achieve the environmental sustainability and decrease the climate change impacts. In this paper, the amount of greenhouse gas emissions from groundwater pumping in the Guilan’s aquifers was investigated. Firstly, groundwater depletion and the types of pumps for water pumping were examined in the current condition; then, the values of consumed energy, GHG emissions and climate change indicator of the current condition were estimated. The primary investigations showed that 55 percent of wells in the studied region had a diesel engine pump, while 51.3 percent of the required energy for groundwater pumping was supplied by electric pump. Calculated total GHG emissions and the value of climate change indicator in the current condition were equal to 8.98 and 7.59 Milion kg CO2 eq , respectively. In order to achieve environmental sustainability and energy security, scenarios of replacing electric pumps and applying solar energy were examined. The results of the scenarios showed that diesel fuel wells had no significant effect on the reduction of greenhouse gas emissions, but the use of solar energy reduced them. GHG emissions, in comparison with the base scenarios, were decreased by 44.4% in June, July and August, respectively, by applying the scenario of using the solar pump in agricultural section. Therefore, it is preferred to apply policies in future planning to use renewable energies such as solar energy instead of diesel and electricity energy.
Z. Ebrahimikhusfi,
Volume 24, Issue 1 (5-2020)
Abstract
The purpose of this study was to analyze the temporal variations of dust phenomenon and its relationship with the climatic elements in Yazd city, located near one of the critical centers of dust production in the center of Iran. For this purpose, the Dust Storm Index was first calculated. After the standardization of precipitation, temperature, maximum wind speed, average wind speed, relative humidity and, dust storm index, the co-linearity effect between variables was calculated by using inflation variance factor. Then, several regression models were prepared based on the optimal Ridge parameter. The performance of the models was evaluated based on the determination coefficient, F value and Root Mean Square Error. Finally, by using the most accurate model, the impact of climate parameters on the dust events changes was determined. The results showed that the incidence of dust events in the spring was more than the rest of the year. Based on the optimal model (Model 12), it was found that the main factor influencing the dust storm index variations in different seasons was the surface winds speed. It was also shown that 39%, 25%, 46% and 31% of dust storm index changes in winter, spring, summer, and autumn were due to the interaction of the five climatic parameters studied in this study.
S. Zandifar, Z. Ebrahimikhusfi, M. Khosroshahi, M. Naeimi,
Volume 24, Issue 3 (11-2020)
Abstract
The occurrence of wind erosion and the spread of dust particles can be regarded as one of the most important and threatening environmental factors. Climate change and the frequency of droughts have played an important role in exacerbating or weakening these events. The primary objective of the present study was to investigate the trend of changes in four important climatic elements (precipitation, temperature, wind speed and relative humidity) and dust storm index (DSI) in Qazvin city using the Mann-Kendall pre-whitened test and to determine the relationship between them based on the multiple linear regression method. Assessment of the meteorological drought status based on two standardized precipitation index and standardized precipitation, as well as the evapotranspiration index and analysis of their effect on activity level of dust events, was the other objective of this study in the study area. For this purpose, after preparing and processing the climatic data and calculating the dust storm index, the trend of changes and the relationship between climatic parameters and dust events were investigated. The results showed that the changes of trend in the annual precipitation and relative humidity in Qazvin city were increasing, while the trend of annual changes in the wind speed and the mean air temperature was a decreasing one. Investigation of the monthly changes in the dust events also showed that there was a sharp decrease in the occurrence of wind erosion and the spread of domestic dust particles only in July. On a seasonal scale, with the exception of winter that has been reported without trends, in other seasons, the intensity of these events was significantly reduced. The effect of the meteorological drought on wind erosion was estimated to be 11% at the confidence level of 99%. In general, these findings indicate a decreasing trend of land degradation and desertification caused by wind erosion in Qazvin.
H. Fathizad, M. Tavakoli, M. A. Hakimzadeh Ardakani, R. Taghizadehmehrjardi, H. Sodaiezadeh,
Volume 24, Issue 4 (2-2021)
Abstract
The purpose of this research was to investigate the trend of annual changes in Yazd station's meteorological parameters including minimum and maximum average daily temperature and average daily precipitation (1961-2005), as well as the predicted annual mean of these parameters in the three upcoming thirty years of the 2040s, 2070s and 2100s, by the SDSM model, under RCP2.6, RCP4.5, RCP8.5, A2, and B2 scenarios. Accordingly, by using the coefficient of determination and the MAE, R2, RMSE indicators, we evaluated the data generated by the SDSM model in comparison with the observed data in the base period. The lowest value of R2 based on the calibration and validation of the mean values of observed and simulated SRES was obtained for precipitation (86 and 80%). In terms of the R2 evaluation index, the accuracy of the small-scaled results of the minimum and maximum average temperature values was more than that of the average precipitation; however, in terms of the MAE and RMSE evaluation indicators, the accuracy of the small-scaled results of the average precipitation was higher than that of the minimum and maximum average temperature values. Subsequently, HadCM3 large-scale climatological data was used to predict the future periods (2010-2100). The results indicated that the temperature was raised in all months and seasons and the precipitation was decreasing in most of them, thereby confirming that the climate was changing in the studied region.
S. Moghim, J. Rahmani,
Volume 25, Issue 1 (5-2021)
Abstract
Improper water managements and overuse of surface water and groundwater mainly for agricultural purposes in Iran have led to the drying of many rivers and groundwater. Climate change adds an extra pressure on the water resources. These changes indicate the necessity of adjustment in water management plans. This study used hydroclimatic variables including precipitation and temperature in Urmia Plain to find appropriate crops that needed the minimum irrigation water. In addition, the best time for planting each crop is determined. To find the proper crops for the region, the daily water, as required for each crop, was calculated based on climate condition, crop type, and crop growth stage. The results indicates that grape could be the best crop for the region. In addition, early planting (e.g. in spring) reduced the irrigation water needed due to more rain and soil moisture in spring than summer, which could provide crop water requirement. On the other hand, the increased temperature in spring could satisfy heat units required for the fully grown plants like barley.
