Projected and Observed Aridity and Climate Change in the East Coast of South India under RCP 4.5.

A Ramachandran,Dhanya Praveen,R Jaganathan,K Palanivelu

doi:10.1155/2015/169761

A Ramachandran, Dhanya Praveen + Show 2 more

Open Access

https://doi.org/10.1155/2015/169761

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Abstract

In the purview of global warming, the present study attempts to project changes in climate and quantify the changes in aridity of two coastal districts in south India under the RCP 4.5 trajectory. Projected climate change output generated by RegCM 4.4 model, pertaining to 14 grid points located within the study area, was analyzed and processed for this purpose. The meteorological parameters temperature and precipitations were used to create De Martonne Aridity Index, to assess the spatial distribution of aridity. The original index values ranged from 13.7 to 16.4 mm/°C, characterizing this area as a semidry climate. The outcome from the changed scenario analysis under RCP 4.5 showed that, during the end of the 21st century, the aridity may be increased more as the index values tend to reduce. The increasing trend in the drying phenomenon may be attributed to the rising of mean annual temperatures.

Highlights

Altering climate is a complex phenomenon which has intricate implications
Assessing the changing patterns of aridity is a serious matter of concern in the context of global climate change
There is a high degree of certainty that global climate change, land use developments, and land cover changes will lead to an accelerated decline in water availability and biological production in dry lands [3, 6]

Summary

Introduction

Altering climate is a complex phenomenon which has intricate implications. Arid and semiarid regions of the world are highly sensitive to human-induced climate and/or land transformation [1]. Scientific reports have already indicated that global warming is likely to pose a defining challenge on most of the economic sectors in India that are driven by climate such as water resources, agriculture and allied services, biodiversity, and forests [17] In this context, the present study focuses on projecting the changes in the spatial distribution of climate and aridity conditions of two coastal districts of South India using De Martonne aridity indices that determine the climatic conditions of a place based on temperature and precipitation. The study region, Chengalpet (erstwhile known by this name), covers present Thiruvallur and Kancheepuram coastal districts of Tamil Nadu, South India (Figure 1) It is located in the northeast agroclimatic zones of Tamil Nadu between the latitudes 12∘0󸀠 and 13∘40󸀠N and 79∘0󸀠 to 80∘20󸀠E longitude. These areas were known as “Erie Mavattam” (Lake District) earlier as the ancestors had constructed a series of tanks across the river basins and had good practices for harvesting the rainwater for irrigation purposes

Data Analysis and Models

Results and Discussion

Conclusions