CWRDM

Kerala, India
Kerala, India
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George C.,Sub Center | Jayakumar K.V.,CWRDM | James E.J.,Karunya University
Meteorological Applications | Year: 2012

Changes in streamflow in the Meenachil river basin, Kerala, are assessed at two upstream gauging stations located at Palai and Cheripad and one downstream gauging station at Peroor to understand changes in flows due to upstream urbanization. An increase of 14% in the population and 46% in the number of housing units have been observed in the entire study area during the last two decades, indicating increase in urbanization. Time series analysis of 29 years data shows an increasing trend at Peroor at 2.8% per year for total flow and 5.2% for peak flow, which indicates the effect of urban land use. There has been a decreasing trend in the flows at 2% at the upstream gauging stations of the river basin. The frequency of occurrence of flows are observed to be increasing at Peroor due to urbanization which brings down vegetation, enhances the impervious area and contributes to fast draining of stormwater. The decrease in both the flow and its frequency of occurrence at the upstream stations are due to the increase in area under plantation crops and also the soil and water conservation works attempted in the area. © 2011 Royal Meteorological Society.


Jayakumar M.,Agronomy Regional Coffee Res. Station | Surendran U.,CWRDM | Manickasundaram P.,Tamil Nadu Agricultural University
International Journal of Plant Production | Year: 2014

Field experiment was conducted for 2 seasons to study the influence of drip fertigation in combination with or without bio fertilizers on yield, plant uptake and soil fertility of Bt cotton. The treatments comprised of four levels of drip fertigation viz., 75, 100, 125 and 150 per cent of recommended dose of fertilizers (RDF, NPK) combined with and without bio fertilizers, drip irrigation with soil surface application of 100 per cent RDF and surface irrigation with soil surface application of 100 per cent RDF as control. Biofertilizers used for fertigation is azophosmet containing Azospirillum, phosphobacterium and pink pigmented facultative methylotroph. Most of the yield attributes viz., number of sympodial branches per plant, number of fruiting points, bolls per plant, plant uptake and available soil N, P and K of Bt cotton were significantly increased by the drip fertigation treatments. Application of 150 per cent RDF as drip fertigation combined with biofertigation of liquid formulation of azophosmet @ 250 ml (1012 cells ml-1) ha-1 registered the highest seed cotton yield of 3395 kg ha-1 and was significantly superior over control. Biofertigation significantly increased seed cotton yield and a progressive increase in seed yield was noticed with increasing levels of NPK fertilizer application. Application of nutrients through drip fertigation improved seed cotton yield by 43.0 per cent compared with conventional surface irrigation with soil surface application of fertilizers. The nutrient uptake pattern and post harvest soil fertility status also followed similar trend and confirmed the significance of drip fertigation with biofertilizers.


Mullakkezhil Reghunathan V.,Kerala University | Joseph S.,Kerala University | Warrier C.U.,CWRDM | Hameed A.S.,CWRDM | Albert Moses S.,Kerala State Pollution Control Board
Environmental Monitoring and Assessment | Year: 2016

Environmental carrying capacity is a measure of competence of a lake to accommodate pollution inputs without degrading water quality. In the research reported here, we identified the factors influencing the environmental carrying capacity of Vellayani Lake or VL (a typical tropical freshwater lake), Thiruvananthapuram, Kerala State, India. R-mode factor analysis is used to identify the factors controlling the carrying capacity of the lake, whereas hierarchical cluster analysis (HCA) helped to classify the lake. The carrying capacity of the lake is low with respect to alkalinity, due to ion deficiency, and is potentially reactive to sudden changes in pH. Eutrophic condition exists in the entire lake system. Acidic factor, mineralization factor, fertilizer factor (P & K), evaporation factor and organic pollution factor are the controllers of VL water quality during the pre-monsoon period. The same factors (but not evaporation factor) and an additional runoff factor control the water quality during monsoon. In the post-monsoon, the aforesaid factors (other than runoff, alkalinity) and soil erosion factor influence the water quality. Hence, managers of the lake system need to also focus on combating acidic factor during pre- and post-monsoons and runoff during monsoon. Smaller areal extent and shallow depth of VL, reduced outflow from it, less rainfall, presence of lateritic rock and soil and absence of limestone strata in the catchment are the chief elements affecting the acidic factor of Vellayani Lake. © 2016, Springer International Publishing Switzerland.


Gopinath G.,CWRDM | Swetha T.V.,CWRDM | Ashitha M.K.,CWRDM
Applied Geomatics | Year: 2014

The launch of Cartosat-1 turns into a new era for user communities of remote sensing and mapping. Generation of digital elevation model (DEM) of a particular geographic region of interest is the primary goal and advantage of Cartosat-1 mission. To generate the most accurate DEM from Cartosat-1 stereo data, 34 GCP points were used, and 122 tie points are automatically extracted with the aid of LPS-2011. Here, an attempt has been made to study the quantitative hypsometric analysis of six sub-watersheds of the Kuttiyadi River Basin (676 km2) with a humid tropical setting, using Cartosat-1 DEM. An extension, CalHypso, an add-on tool to ArcGIS 9.2, was utilized to synthesize hypsometric data from Cartosat-1 DEM which reflects the erosional signature of sub-watersheds based on geological stages of development. From hypsometric analysis, it is found that three sub-watersheds are in old stage, and the remaining three are of mature stage. © 2014 Società Italiana di Fotogrammetria e Topografia (SIFET).


PubMed | Kerala State Pollution Control Board, Kerala University and CWRDM
Type: Journal Article | Journal: Environmental monitoring and assessment | Year: 2016

Environmental carrying capacity is a measure of competence of a lake to accommodate pollution inputs without degrading water quality. In the research reported here, we identified the factors influencing the environmental carrying capacity of Vellayani Lake or VL (a typical tropical freshwater lake), Thiruvananthapuram, Kerala State, India. R-mode factor analysis is used to identify the factors controlling the carrying capacity of the lake, whereas hierarchical cluster analysis (HCA) helped to classify the lake. The carrying capacity of the lake is low with respect to alkalinity, due to ion deficiency, and is potentially reactive to sudden changes in pH. Eutrophic condition exists in the entire lake system. Acidic factor, mineralization factor, fertilizer factor (P & K), evaporation factor and organic pollution factor are the controllers of VL water quality during the pre-monsoon period. The same factors (but not evaporation factor) and an additional runoff factor control the water quality during monsoon. In the post-monsoon, the aforesaid factors (other than runoff, alkalinity) and soil erosion factor influence the water quality. Hence, managers of the lake system need to also focus on combating acidic factor during pre- and post-monsoons and runoff during monsoon. Smaller areal extent and shallow depth of VL, reduced outflow from it, less rainfall, presence of lateritic rock and soil and absence of limestone strata in the catchment are the chief elements affecting the acidic factor of Vellayani Lake.

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