DISTRICT CLIMATE:
Climatic condition of Dhemaji district

The district receives a good amount of rainfall throughout the year, with maximum down pour during May to August and minimum during November to February. The number of maximum and minimum rainy days also follows similar trend. This data indicates prevalence of moisture stress condition during the major part of the year and thereby the farmers are practicing their tested traditional practices due to fear of failure. The rainfall data for last 10 years:


Month 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
January 77 24.2 24.2 54.2 6.3 0 11.2 28.7 8.4 .75
February 160 87.26 73.34 40.49 40.68 5.12 13.09 2.44 0.5 75.5
March 262 41.55 14.81 50.49 129.86 215.34 203.78 49.53 118.82 100.32
April 289 159.21 244.13 140.68 127.32 399.04 176.77 233.87 154.3 150.62
May 492 450.13 521.54 247.64 227.73 279.44 188.25 429.12 230.57 210.55
June 892.7 617.5 641.19 462.11 509.27 614.6 340.36 377.34 384.02 381.19
July 708.84 575.83 828.56 734.33 522 699.48 637.91 827.92 508.18 246.61
August 459.67 566.26 395.8 591.1 817.55 699.65 452.29 345.92 300.41 625.1
September 162.93 269.14 223.72 301.05 140.89 467.79 405.29 605.13 190.48 213
October 80.2 173.46 144.25 160.86 141.04 71.78 36.06 168.11 82.33 11
November 45.7 77.91 17.78 17.78 28.34 41.43 10.04 12.44 0 13.2
December 0 13.56 0 0 10.17 13.97 12.7 18.54 0 0

 



Topography:
The district is in a strategic location where steep slope of Eastern Himalayas abruptly drop forming a narrow valley, which widens towards the western side. Numerous drainage systems originating from the hills of Arunachal Pradesh flow through this narrow valley ending at the mighty river Brahmaputra. In general, the slope of the triangular district drops from northern and eastern corners towards south and western sides. After the confluence the three mighty rivers i.e. Dihing, Dibang and Lohit from their hilly course to the valley exert tremendous impact of peak runoff at the eastern most corner of Dhemaji district, making the district vulnerable to annual flooding. After the great earthquake in 1950 the Brahmaputra riverbed is rising continuously due to deposition of sand carried down from upstream. This has led to the formation of a saucer shaped low-lying zone in the plains of the district. Physiographically, the area can broadly be divided into three district units:


  • Piedmont zone: The foothill zone near the northern and eastern parts adjacent to Arunachal Pradesh
  • Active flood plain: Near the river Bramhaputra and other major tributaries.
  • Low-lying alluvial belt: Covering the middle plain zone i.e. the saucer shaped built up zone. Innumerable beels and swampy areas are common features.

  • The general and average soil character of cultivable land in these districts is mainly alluvial and composed of mixture of sand (coarse to fine) and clay in varying proportions. The general geochemical characteristic of the soil is highly acidic. However, new alluvial soils formed due to inundation of land by river at intervals contain more percentages of fine sand fine silt and are less acidic. Such soils are often neutral and even alkaline. Large expanse of low-lying land characterized by heavy clayish soil with a high percentage of nitrogen is good for rice cultivation. Abundant rainfall and excessive humidity through out the year also greatly favour cultivation of rice in the district .The soil around the Subansiri and Ranganadi rivers are sandy coated with silt which is good for cultivation of winter crops, such as raga, and mustard, potato etc. Out of the total geographical area, 9.08% area is of clay soil, 20.24% of clay loam, 4.42% of alluvial, 20.61% of sandy soil and 45.65% of sandy loam soil type.

    The soils of this district can be broadly classified into three different zones viz. The foothill soils, active flood plain soils near the river Bramhaputra and the low-lying marshy lands. On the basis of rainfall, physiography, soils, floods etc., 5 agro-ecological situations (AES) were identified with an aim to study and analyze the problem, prospects and the needs of the farmers.


  • Foothill (AES-I)
  • Low and Flood affected (AES-II)
  • Sand deposited area (Coarse) (AES-III)
  • Medium land (AES-IV)
  • Sand deposited area (Fine silt) (AES-V)

  • The AES-IV (Sand deposited area (Fine sand)) is having the highest area visually 156682 ha (52%) followed by AES-II (Low and Flood affected) with 63275 ha (21%), AES-I (Foothill) with 61769 ha (20.5%), AES-III (Sand deposited area (Coarse)) with 10546 ha (3.5 %) and AES-V (Sand deposited area (Fine silt)) with 9039 ha (3.0%).