scholarly journals Spatio-temporal rainfall trends in the twentieth century for Bundelkhand region, India

2017 ◽  
Vol 8 (3) ◽  
pp. 441-455 ◽  
Author(s):  
C. Jana ◽  
N. M. Alam ◽  
D. Mandal ◽  
M. Shamim ◽  
Rajesh Kaushal

Globally, climate change and extreme weather events are occurring more frequently, impacting water resources and farming systems. Therefore, spatio-temporal analysis of long-term rainfall is much needed to understand the variability of rainfall occurrence. The present study attempts to analyse spatio-temporal rainfall change scenarios in the 20th century (1901–2000) over Bundelkhand, one of the drought hit regions of India. Analysis shows that major rainfall contributed from 3 months, i.e. July, August and September. However, decreasing rainfall trend during monsoon season and increasing trend during pre-monsoon and post-monsoon season indicates the scenario of shifting rainfall from normal occurrence. This result is supported by decreasing seasonality index (SI) (1.94–1.1). The northern part of the region witnessed positive annual and monsoon rainfall trend but the southern part observed negative trend. Pettitt's test indicates 1983 is the most probable change year with 0.95 probability, after which annual and monsoon rainfall was found decreasing. Wavelet analysis revealed that extreme rainfall occurrence was observed with a periodicity of 2–16 years. However, Bundelkhand rainfall pattern depicts declining rainfall trends, heading towards a further drier phase with more irregular rainfall in the coming era. The study will serve as future reference in similar regions in the world to determine vital weather patterns which may impact farming systems.

2006 ◽  
Vol 10 (6) ◽  
pp. 797-806 ◽  
Author(s):  
E. Zehe ◽  
A. K. Singh ◽  
A. Bárdossy

Abstract. Within the present study we shed light on the question whether objective circulation patterns (CP) classified from either the 500 HPa or the 700 HPa level may serve as predictors to explain the spatio-temporal variability of monsoon rainfall in the Anas catchment in North West India. To this end we employ a fuzzy ruled based classification approach in combination with a novel objective function as originally proposed by (Stehlik and BᲤossy, 2002). After the optimisation we compare the obtained circulation classification schemes for the two pressure levels with respect to their conditional rainfall probabilities and amounts. The classification scheme for the 500 HPa level turns out to be much more suitable to separate dry from wet meteorological conditions during the monsoon season. As is shown during a bootstrap test, the CP conditional rainfall probabilities for the wet and the dry CPs for both pressure levels are highly significant at levels ranging from 95 to 99%. Furthermore, the monthly CP frequencies of the wettest CPs show a significant positive correlation with the variation of the total number of rainy days at the monthly scale. Consistently, the monthly frequencies of the dry CPs exhibit a negative correlation with the number of rainy days at the monthly scale. The present results give clear evidence that the circulation patterns from the 500 HPa level are suitable predictors for explaining spatio- temporal Monsoon variability. A companion paper shows that the CP time series obtained within this study are suitable input into a stochastical rainfall model.


2021 ◽  
Vol 21 (3) ◽  
pp. 297-306
Author(s):  
PANKAJ PANWAR ◽  
SHARMISTHA PAL ◽  
NANCY LORIA ◽  
MED RAM VERMA ◽  
N.M. ALAM ◽  
...  

Climate change impact varies across different altitudinal ranges and demands local specific management strategies for water resource and farming system management. The present study analyses spacio-temporal climate parameters across different altitudes of Himachal Pradesh a hilly state of India. Analysis shows that annually, minimum temperature has significantly decreased by -0.09°C at altitude I (350 - 400 m) while maximum temperature has significantly increased by 0.05°C at altitudes I and II (1400-1500 m) and decreased significantly by -0.08°C at altitude III (2000- 2100 m). Higher regions Altitude – IV (2900-3000 m) received lowest rainfall (746.1 mm) with 30.2 % variation. Seasonal rainfall variability was higher in post monsoon (102 - 174%) and least in monsoon (21 - 57%). Annual rainfall at altitude I is strongly irregular (PCI 20.1 to 22.3), followed by altitude – IV (PCI 15-25); altitude – II irregular (PCI 15-20) and altitude – III moderate to irregular (PCI 12 -19) rainfall. Seasonal Index values for four altitudes fall between 0.91-0.96 revealed that rainfall is irregular and markedly seasonal with longer drier season. Higher wavelet powers in altitude - I and II after 2005 suggests frequency of extreme rainfall occurrence had increased.


Hacquetia ◽  
2014 ◽  
Vol 13 (1) ◽  
pp. 205-213 ◽  
Author(s):  
Christakis Evangelou ◽  
Maria Yiakoulaki ◽  
Vasilios Papanastasis

Abstract Grazing animals explore different forage resources to satisfy their daily nutrient needs, following specific spatial and temporal patterns throughout the year. In this study four different flocks of sheep and goats (two of each species) were selected to record their spatial location with a handheld GPS during spring, summer and winter. At the same time, three animals in each flock were followed to study their grazing activities by direct observation. These data with the time information and a detailed land use map were manipulated in a GIS to assign animal activities to different forage resources. Sheep and goats were travelling long distances (7.5 km and 9.0 km, respectively) to satisfy their nutritional needs throughout the year. They were found to graze in two main forage resources, rangelands (grasslands, shrublands and forest ranges) and agricultural land (fallow land, stubble fields and temporary pastures). Both grazer species spent significantly less time (P≤ 0.05) feeding in rangelands (38.9% & 18.1%) than in agricultural land (63.6% & 53.4%) during spring and summer. It appears that a heterogeneous landscape is necessary for supporting extensive farming systems of small ruminants since rangelands and agricultural land complement each other in providing forage throughout the year.


2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Fasiha Safdar ◽  
Muhammad Fahim Khokhar ◽  
Muhammad Arshad ◽  
Iftikhar Hussain Adil

Monsoon rainfall is the principle source of fresh water essential for agricultural practices and human sustenance in the Indian subcontinent during summer. This study is primarily designed to analyse the extent of rainfall and temperature variations in Pakistan over the northern monsoon belt by using satellite and ground-based observations. The satellite gridded data for rainfall are acquired from Tropical Rainfall Measuring Mission (TRMM) along with rainfall and temperature data from 15 ground stations of Pakistan Meteorological Department (PMD). Data were analysed to identify changes in climatic parameters and spatiotemporal shift in monsoon precipitation in Pakistan. Analysis shows that there is significant correlation between TRMM and PMD datasets. Decrease in monsoon rainfall is observed during the last two decades. A more pronounced decrease is observed in monsoon rainfall during the years 2010–2017, i.e., 17.58 mm/year accompanied by 0.18°C increase in temperature. A southward spatial shift in monsoon rainfall occurrence (rainfall ≥2.5 mm/day) is observed while an eastward shift in moderate to heavy monsoon rainfall is identified. This study may be helpful for an agricultural country like Pakistan which is heavily dependent on monsoon rainfalls for assessing the impacts of changing monsoon season and to adapt towards changing climate.


2018 ◽  
Vol 6 (2) ◽  
pp. 104
Author(s):  
Nurnabi Meherul Alam ◽  
Chayna Jana ◽  
Dhananjay Barman ◽  
Bhavika Sharma ◽  
Deepak Singh ◽  
...  

MAUSAM ◽  
2022 ◽  
Vol 46 (4) ◽  
pp. 377-382
Author(s):  
S. K. SUBRAMANIAN ◽  
V. N. THANKAPPAN

The rainfall during southwest monsoon season over Tamilnadu is quite significant from the point of view of water storage in major reservoirs as northeast monsoon rainfall, which is about half of the annual rainfall, is not stable enough due to its large interannual variability. The southwest monsoon rainfall, on the other hand, is more stable. The north-south oriented trough over Tamilnadu and adjoining Bay togetherwith upper air cyclonic circulation/trough in lower tropospheric levels account for three fourths of significant rainfall occurrence during southwest monsoon season. Rainfall during southwest monsoon and northeast monsoon seasons was found to be independent with a small negative correlation of -0.18. This shows that the southwest monsoon rainfall may not be of much use to predict the pattern of northeast monoon rainfall over Tamilnadu.  


2009 ◽  
Vol 129 (10) ◽  
pp. 1778-1784
Author(s):  
Yasuaki Uehara ◽  
Keita Tanaka ◽  
Yoshinori Uchikawa ◽  
Bong-Soo Kim

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