scholarly journals Crop planning based on rainfall variability for Bastar region of Chhattisgarh, India

2021 ◽  
Vol 22 (4) ◽  
pp. 509-517
Author(s):  
ADIKANT PRADHAN ◽  
T. CHANDRAKAR ◽  
S.K. NAG ◽  
A. DIXIT ◽  
S.C. MUKHERJEE
Keyword(s):  
Upland Rice ◽  
Rainfall Variability ◽  
Annual Rainfall ◽  
Maximum Rainfall ◽  
Crop Planning ◽  
Monsoon Rain ◽  
Dry Spells ◽  
Small Millets ◽  
Sw Monsoon

Analysis of long-term rainfall data (1986-2018) of Bastar region revealed decreasing trend in total quantum of annual rainfall with varying frequency and distribution. The quantity of winter and summer rains decreased drastically during 2008-18 as compared to earlier two decades (1986-96 and 1997-2007). SW monsoon rain of 2008-18 was more than past two decades, whereas NE monsoon rain changed much in quantity except during 1997-2007. During 1986-96, the pre-monsoon shower was received in April, but later two decades the shower was received in May, which supports for summer ploughing and dry aerobic seeding. The cropping period almost synchronized between 22-43 standard meteorological week (SMW) reaching 93.11 mm per week as maximum rainfall. As the probability of 20 mm rainfall decreased from 75 to 50%, the crop yield got reduced by 30%. The mid-land rice with a probability of 13.47 to 16.07 mm rain per week supported growth phase during 17-21SMW. Whereas, upland rice maturing in 90-100 days could avoid dry spells, if the rice is managed by conservation furrows at the time of sowing. The summer ploughing is preferred with more than 40 mm rain in single day during March to April for mitigating dry spells. On the other hand, preparatory tillage and sowing were performed together in support of ripening niger and horsegram under probability of 75, 50 and 25% rain through crop planning. Maize and small millets reduced yield  significantly when rainfall reached 75% deficit, whereas 25% deficit rain did not affect the yields.

scholarly journals An Assessment of Drought in Mannar District, Sri Lanka

2019 ◽  
pp. 1-13
Author(s):  
Dr. K. Rajendram
Keyword(s):  
Sri Lanka ◽  
Rainfall Variability ◽  
Rainfall Anomaly ◽  
Primary Data ◽  
Annual Rainfall ◽  
Dry Spells ◽  
Recent Climate ◽  
Data Period ◽  
Recent Epoch

Due to recent climate changes and variability the frequency of occurrence and intensity of extreme climatic events such as flood, drought, etc. are increasing significantly in Sri Lanka. The main objectives of the study are to analyze the annual and seasonal rainfall variability in the last 147years from 1871-2018 with particular reference to drought and to assess the occurrence of droughts and its intensity and the impacts of drought on agriculture. For this secondary and primary data have been used. The long-term average annual rainfall of Mannar show the decreasing trend (r2= 0.0158), particularly in recent epochs higher negative anomalies of rainfall were found, as a results frequent occurrence of droughts or dry spells have been occurred. The rainfall anomaly results reveal that, out of 147years of the data period about 47years were experienced as drought and its probability is P=0.320. Accordingly, once in four to five years a drought could be possible. However, in the recent epoch of 1991-2018, higher number of droughts occurred than the any other epochs and its epochal probability is higher (P=0.40) than the normal, which indicate the effect of recent climate change.

scholarly journals Long term rainfall variability and trend analysis in lower Shivaliks of Punjab, India

MAUSAM ◽  
2021 ◽  
Vol 72 (3) ◽  
pp. 571-582
Author(s):  
NAVNEET KAUR ◽  
ABRAR YOUSUF ◽  
M. J. SINGH
Keyword(s):  
Trend Analysis ◽  
Monsoon Rainfall ◽  
Rainfall Variability ◽  
Kendall Test ◽  
Annual Rainfall ◽  
Entire Study ◽  
Seasonal Basis ◽  
Normal Rainfall ◽  
Rainy Days

The trend analysis of historical rainfall data on monthly, annual and seasonal basis for three locations in lower Shivaliks of Punjab, viz., Patiala-ki-Rao (1982-2015), Ballowal Saunkhri (1987-2015) and Saleran (1984-2017) has been done in the present study using linear regression model, Mann Kendall test and Sen’s slope. Further, the data for annual and seasonal rainfall and rainy days has also been analyzed on quindecennial basis, i.e., for the period of 1986-2000 and 2001-2015. The analysis of data showed that annual rainfall in the region ranged from 1000 to 1150 mm. The trend analysis of the data shows that the monthly rainfall is decreasing at Patiala-ki-Rao and Saleran, however, the trend was significant for May at Patiala-ki-Rao; and in March and November at Saleran. At Ballowal Saunkhri, the decreasing trend is observed from May to October, however, the trend is significant only in August. The decrease in annual and monsoon rainfall is about 13 to 17 mm and 12 to 13 mm per year respectively at three locations in lower Shivaliks of Punjab. The highest annual (1600-2000 mm) and monsoon (1500-1800 mm) rainfall during the entire study period was recorded in the year 1988 at three locations. The decadal analysis of the data shows below normal rainfall during April to October. The analysis of the rainfall and rainy days on monthly, annual and seasonal averages of 15 year basis showed that both rainfall and rainy days have decreased during the 2001-2015 as compared to 1986-2000 during all the seasons of the year.

scholarly journals Indicator-Based Assessment of Drought in Bhilwara District, Rajasthan

2021 ◽  
pp. 141-153
Author(s):  
Gaurav Sharma ◽  
Chandra Kishor Kumar ◽  
Rishi Pathak
Keyword(s):  
Indian Monsoon ◽  
Rainfall Variability ◽  
Daily Rainfall ◽  
Rain Gauge ◽  
Annual Rainfall ◽  
Drought Frequency ◽  
Arid Conditions ◽  
Dry Spells ◽  
Water Scarce ◽  
Rainfall Departure

Management of water resources helps to sustain even in drastic conditions resulted due to unprecedented disruption in rainfall patterns. Change and irregularity in the pattern of the Indian monsoon are the outcomes of human-induced activities. Inadequate water availability affecting various sectors namely domestic, industrial, and agricultural sectors that are dependent upon it. To cope under such drastic conditions adaptability and planning prior to its occurrence plays a significant role. It is under this context, the present study investigated drought characteristics which include drought frequency and severity caused by prolonged dry spells in Bhilwara district, Rajasthan. The district falls in the water-scarce regions with arid to semi-arid conditions and with an average annual rainfall of 658.03 mm. Due to high rainfall variability, the region is frequently subsumed under drought-like conditions. Comprehensive analysis using daily rainfall data from 1973-2018 for 12 rain gauge stations in Bhilwara district has been carried out. Most of the stations were drought-prone assessed by probability analysis using Weibull’s plotting position formula. The departure analysis showed that Kotri station has a maximum drought frequency of 1 in 2 years while other stations were having a drought frequency of 1 in 3 to 4 years. Prioritization of drought-prone stations based on rainfall departure analysis helps to initiate an immediate mitigation process based on the ranking of its proneness. Asind and Bhilwara station with RDI 0.91 has maximum proneness and its calls for effective planning for drought management. Based on seasonal departure analysis it is found that 1980, 1981, 1985, 1987, 2000, 2002, 2008, 2015, and 2017 are drought years. The result has been supplemented using NDVI so that the vegetation condition can also be assessed during water stress conditions. The study highlighted that the frequency of drought has increased owing due to climate change and thus, poses serious challenges if not tackle adequately.

scholarly journals Performance of Sorghum Varieties under Variable Rainfall in Central Tanzania

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Barnabas M. Msongaleli ◽  
S. D. Tumbo ◽  
N. I. Kihupi ◽  
Filbert B. Rwehumbiza
Keyword(s):  
Crop Production ◽  
Rainfall Variability ◽  
Growing Season ◽  
Moisture Stress ◽  
Crop Failure ◽  
Rainfall Distribution ◽  
Cropping Season ◽  
Dry Spells ◽  
Semiarid Areas

Rainfall variability has a significant impact on crop production with manifestations in frequent crop failure in semiarid areas. This study used the parameterized APSIM crop model to investigate how rainfall variability may affect yields of improved sorghum varieties based on long-term historical rainfall and projected climate. Analyses of historical rainfall indicate a mix of nonsignificant and significant trends on the onset, cessation, and length of the growing season. The study confirmed that rainfall variability indeed affects yields of improved sorghum varieties. Further analyses of simulated sorghum yields based on seasonal rainfall distribution indicate the concurrence of lower grain yields with the 10-day dry spells during the cropping season. Simulation results for future sorghum response, however, show that impacts of rainfall variability on sorghum will be overridden by temperature increase. We conclude that, in the event where harms imposed by moisture stress in the study area are not abated, even improved sorghum varieties are likely to perform poorly.

scholarly journals Trend Analysis of Rainfall Variability in Western Agro Climatic Zone of Tamil Nadu

2017 ◽  
Vol 12 (1) ◽  
pp. 181-187 ◽  
Author(s):  
S Kokilavani ◽  
R Selvi ◽  
S Panneerselvam ◽  
Ga Dheebakaran
Keyword(s):  
Tamil Nadu ◽  
Rank Order ◽  
Rainfall Variability ◽  
Climatic Zone ◽  
Annual Rainfall ◽  
Time Variability ◽  
Rainfall Analysis ◽  
North East ◽  
South West Monsoon

An analytical examination was done to work out the unevenness in point location and time to time variability in rainfall at Coimbatore and Erode district of Western agro climatic zone of Tamil Nadu (India) for 100 years (1916-2015). Simple descriptive statistics along with Co-efficient of Variation (CV) were worked to understand the rainfall variability. The long term mean seasonal and annual rainfall analysis showed that South West Monsoon (SWM) rainfall observed was (176.9 mm) & (257.9 mm) and North East Monsoon (NEM) of (336.9 mm) & (323.3 mm) and annual rainfall of (674.8 mm) & (764.4 mm) at Coimbatore and Erode respectively. The CV for seasonal and annual rainfall showed high dependability status by recording appropriate threshold level of CV for seasonal and annual rainfall. The time series rainfall data for 100 years were divided into ten year period and the correlation was carried out for the SWM and NEM using Spearman’s rank-order correlation. The results indicated the correlation between two monsoons for Coimbatore (0.14) and for erode (0.07) which indicates that there was less relation between SWM and NEM. Major emphasis was given to analyse annual and seasonal (SWM and NEM) rainfall time sequence over an extensive time gap to identify probable trend and to measure their implication. For Coimbatore and Erode districts, in both the monsoon seasons and annual analysis revealed an increasing trend for long term (100 years-1916-2015) period.

scholarly journals Spatial analysis of rainfall variability and rainfed rice crop using GIS Technique in West Bengal (India)

MAUSAM ◽  
2021 ◽  
Vol 68 (2) ◽  
pp. 287-298
Author(s):  
P. K. SINGH ◽  
L. S. RATHORE ◽  
D. V. BHASKAR RAO ◽  
K. K. SINGH ◽  
A. K. Baxla ◽  
...  
Keyword(s):  
West Bengal ◽  
Rainfall Variability ◽  
Crop Productivity ◽  
Rice Crop ◽  
Annual Rainfall ◽  
Mean Annual Precipitation ◽  
Growth Stages ◽  
Kharif Season ◽  
Dry Spells ◽  
The Mean

The rainfed areas receive mean annual precipitation in range of 500-1500 mm with high degree of variability and are beset with problems of mid-season drought and associated impacts on the crop productivity. In this paper, analysis of weekly, monthly, annual rainfall and weekly rainfall probabilities in relation to crop productivity has been carried out for all the stations of the study area in West Bengal where rain-fed agriculture is predominant.  However, duration of dry spells and its probabilities, climatic derivatives like commencement and cessation of rainy season, length of growing period (LGP) and estimates of water balance parameters have been carried out, in respect of all blocks in the identified three districts in West Bengal. The mean productivity during kharif season indicated that, highest productivity values of 3 to 3.5 t/ha are noticed in the block of central districts of Burdwan, Bankura, Birbhum, Hoogly districts.  Perhaps, irrigation facilities in these districts might have helped in arriving at such high productivity rates.  Low productivity of 1 to 1.5 t/ha have been noticed in two to three blocks of South 24-Paraganas and in Jalpaiguri districts. The productivity levels of northern districts, viz., Jalpaiguri, Coochbehar, West Dinajpur, South 24-Paranagas vary from 1.5 to 2.0 t/ha. The lowest productivity of 11.28 q /ha in Jaldha and 14.89 q /ha in Manbazar in 1996 can be due to heavy rainfall conditions in June and again in August. The mean productivity pattern of rice crop during kharif season in identified districts was analyzed with respect to occurrence of number of dry spells at different growth stages and average MAI values. The productivity was also related to monthly rainfall (July) and correlations have been mentioned for Jaldha block (0.22) and Manbazar block (0.64). The highest productivity of 2-3 t/ha are recorded in hot sub-humid to humid regions of West Bengal where LGP vary from 150 to 200 days. From the study of the probability of dry and wet spells and MAI during different crop phenophases, the most vulnerable phases can be identified in each region.  

scholarly journals Rare ground data confirm significant warming and drying in western equatorial Africa

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8732 ◽  
Author(s):  
Emma R. Bush ◽  
Kathryn Jeffery ◽  
Nils Bunnefeld ◽  
Caroline Tutin ◽  
Ruth Musgrave ◽  
...  
Keyword(s):  
Rainfall Variability ◽  
Climatic Variability ◽  
Central Africa ◽  
Dry Season ◽  
Annual Rainfall ◽  
Weather Patterns ◽  
Evergreen Forests ◽  
Total Annual Rainfall ◽  
Equatorial Africa

Background The humid tropical forests of Central Africa influence weather worldwide and play a major role in the global carbon cycle. However, they are also an ecological anomaly, with evergreen forests dominating the western equatorial region despite less than 2,000 mm total annual rainfall. Meteorological data for Central Africa are notoriously sparse and incomplete and there are substantial issues with satellite-derived data because of persistent cloudiness and inability to ground-truth estimates. Long-term climate observations are urgently needed to verify regional climate and vegetation models, shed light on the mechanisms that drive climatic variability and assess the viability of evergreen forests under future climate scenarios. Methods We have the rare opportunity to analyse a 34 year dataset of rainfall and temperature (and shorter periods of absolute humidity, wind speed, solar radiation and aerosol optical depth) from Lopé National Park, a long-term ecological research site in Gabon, western equatorial Africa. We used (generalized) linear mixed models and spectral analyses to assess seasonal and inter-annual variation, long-term trends and oceanic influences on local weather patterns. Results Lopé’s weather is characterised by a cool, light-deficient, long dry season. Long-term climatic means have changed significantly over the last 34 years, with warming occurring at a rate of +0.25 °C per decade (minimum daily temperature) and drying at a rate of −75 mm per decade (total annual rainfall). Inter-annual climatic variability at Lopé is highly influenced by global weather patterns. Sea surface temperatures of the Pacific and Atlantic oceans have strong coherence with Lopé temperature and rainfall on multi-annual scales. Conclusions The Lopé long-term weather record has not previously been made public and is of high value in such a data poor region. Our results support regional analyses of climatic seasonality, long-term warming and the influences of the oceans on temperature and rainfall variability. However, warming has occurred more rapidly than the regional products suggest and while there remains much uncertainty in the wider region, rainfall has declined over the last three decades at Lopé. The association between rainfall and the Atlantic cold tongue at Lopé lends some support for the ‘dry’ models of climate change for the region. In the context of a rapidly warming and drying climate, urgent research is needed into the sensitivity of dry season clouds to ocean temperatures and the viability of humid evergreen forests in this dry region should the clouds disappear.

scholarly journals Spatial and Temporal Assessment of Rainfall Variability using GIS Approach in Trichy District of Tamil Nadu

2021 ◽  
Vol 16 (3) ◽  
pp. 890-897
Author(s):  
P. Ponnuchakkammal P. Ponnuchakkammal ◽  
B. Violet Joy ◽  
P. Aravind ◽  
A. Raviraj A. Raviraj
Keyword(s):  
Tamil Nadu ◽  
Hydrological Cycle ◽  
Rainfall Variability ◽  
Geographical Information ◽  
Annual Rainfall ◽  
Maximum Rainfall ◽  
North East ◽  
South West ◽  
South West Monsoon ◽  
West Monsoon

Precipitation is one of the transportation components in hydrological cycle. The magnitude of precipitation swings with time and space. Majorly India receives precipitation in the form of rainfall. Precipitation plays a key role in the rainfed agriculture. The present study deals with the rainfall characteristics of Tiruchirappalli district, Tamil Nadu. Seasonal rainfall data from eighteen rain gauge stations (1971-2012) have been taken for analysis of seasonal and annual rainfall pattern of Tiruchirappalli district. Mean rainfall of the district is about 696 mm. The highest rainfall of 1247 mm recorded in the year 2005 and the lowest precipitation of 227 mm recorded in the year 1976. About 48 percent and 35 percent of the rainfall received in North East and South West Monsoon, respectively. Spatial rainfall distribution was studied with the help of Kriging interpolation technique and respective maps were prepared with Geographical Information System. The percentage departure of annual rainfall is classified under the category of excess, normal and large excess category. South East and central part of Tiruchirappalli receives moderate to low rainfall. North East parts of Tiruchirappalli district such as pullambadi, Lalgudi and nearby areas received maximum rainfall during North East Monsoon and South West Monsoon. In winter season Manapparai and Vaiyampatti region received more rainfall while in summer season Thottiam and Mayanur area received more rainfall. The two major highlighted crops in Trichy district are Banana and Onion. Tiruchirappalli district is one of the Banana growing belts in Tamil Nadu. Spatial distribution of rainfall maps will be helpful to form a crop plan for different crops to increase the agricultural productivity of Tiruchirappalli district and to ensure the food security.

Comparing fixed and flexible stocking as adaptations to inter-annual rainfall variability in the extensive beef industry of northern Australia

2016 ◽  
Vol 38 (1) ◽  
pp. 85 ◽  
Author(s):  
Lester Pahl ◽  
Joe Scanlan ◽  
Giselle Whish ◽  
Robyn Cowley ◽  
Neil MacLeod
Keyword(s):  
Carrying Capacity ◽  
Rainfall Variability ◽  
Full Range ◽  
Herd Size ◽  
Annual Rainfall ◽  
Northern Australia ◽  
Beef Industry ◽  
Growing Seasons ◽  
Stocking Rates

Many beef producers within the extensive cattle industry of northern Australia attempt to maintain a constant herd size from year-to-year (fixed stocking), whereas others adjust stock numbers to varying degrees annually in response to changes in forage supply. The effects of these strategies on pasture condition and cattle productivity cannot easily be assessed by grazing trials. Simulation studies, which include feedbacks of changes to pasture condition on cattle liveweight gain, can extend the results of grazing trials both spatially and temporally. They can compare a large number of strategies, over long periods of time, for a range of climate periods, at locations which differ markedly in climate. This simulation study compared the pasture condition and cattle productivity achieved by fixed stocking at the long-term carrying capacity with that of 55 flexible stocking strategies at 28 locations across Queensland and the Northern Territory. Flexible stocking strategies differed markedly in the degree they increased or decreased cattle stocking rates after good and poor pasture growing seasons, respectively. The 28 locations covered the full range in average annual rainfall and inter-annual rainfall variability experienced across northern Australia. Constrained flexibility, which limited increases in stocking rates after good growing seasons to 10% but decreased them by up to 20% after poor growing seasons, provides sustainable productivity gains for cattle producers in northern Australia. This strategy can improve pasture condition and increase cattle productivity relative to fixed stocking at the long-term carrying capacity, and its capacity to do this was greatest in the semiarid rangeland regions that contain the majority of beef cattle in northern Australia. More flexible stocking strategies, which also increased stocking rates after good growing seasons by only half as much as they decreased them after poor growing seasons, were equally sustainable and more productive than constrained flexibility, but are often impractical at property and industry scales. Strategies with the highest limits (e.g. 70%) for both annual increases and decreases in stocking rates could achieve higher cattle productivity, but this was at the expense of pasture condition and was not sustainable. Constrained flexible stocking, with a 10% limit for increases and a 20% limit for decreases in stocking rates annually, is a risk-averse adaptation to high and unpredictable rainfall variability for the extensive beef industry of northern Australia.

Climatic variability and change over southern Africa: a reflection on underlying processes

1997 ◽  
Vol 21 (1) ◽  
pp. 23-50 ◽  
Author(s):  
S.J. Mason ◽  
M.R. Jury
Keyword(s):  
Southern Africa ◽  
Southern Oscillation ◽  
Rainfall Variability ◽  
Climatic Variability ◽  
Sea Surface ◽  
Annual Rainfall ◽  
Eastern Equatorial Pacific ◽  
Moisture Fluxes ◽  
Sea Surface Temperature Anomalies

Quasi-periodicities in annual rainfall totals over southern Africa have been identified; in particular, an approximately 18-year cycle may be related to interdecadal variability in sea-surface temperatures in the eastern equatorial Pacific and central Indian Oceans. A 10-year cycle along the south coast is related to variability in standing wave 3. Atmospheric anomalies associated with wet and dry years can be related to changes in the frequency, intensity and persistence of important rainfall-producing weather systems and highlight the significance of the strength of the continental heat low and the preferred locations and amplitudes of the westerly troughs. El Niño Southern Oscillation events and sea-surface temperature anomalies in the Indian and South Atlantic Oceans can influence both the tropical and the temperate atmospheric circulation and moisture fluxes over the subcontinent and thus are significant influences on rainfall variability. Evidence for long-term climatic change is not as definitive as in the Sahel, although there are indications of desiccation in some areas since the late-1970s. Increases in temperatures are of approximately the same magnitude as the hemispheric trends and may be attributable to the enhanced greenhouse effect.

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