The base map of Tiruchirappalli was drawn from the Survey of India (SOI) Toposheets Nos. 58 J/9, 10, 13 and 14. The city lies between the latitudes 10° 43' 40''- 10° 53' 00'' North and the longitudes 78° 38' 14'' - 78° 48' 50'' East (Figure 1). The Cauvery delta starts to form 16 km west of the city where the river splits into two the Cauvery and the Kollidam to form the island of Srirangam.

The topography of Tiruchirappalli city is relatively flat and its average elevation is 88 metres from mean sea level. Some isolated hillocks are rising beyond the surface, the topmost of which is the Rockfort.  Its estimated age is 3,800 million years and it is marked as one of the ancient rocks in the world. Other famous hillocks include the Golden Rock, Khajamalai, Uyyakondan Thirumalai and Thiruverumbur.

The river Cauvery and its distributary Kollidam facilitate Tiruchirappalli city also the city is fertilised by the Uyyakondan, Kudamuritti and Koraiyar canals. The land adjacent to the Cauvery River, which crosses Tiruchirappalli city from west to east, consists of fertile alluvial soil deposits on which crops such as paddy, banana and sugarcane are cultivated and in dry soil, finger millet and maize are cultivated nearby.  Further south, the surface is enclosed by poor quality black soil. A belt of cretaceous rock known as the Trichinopoly group extends to the northeast and the southeast of the city. There are layers of Achaean rocks, granite and gneiss covered by a thin bed of conglomeratic laterite. 

The current study is based on secondary data sources. The crimes, which have been reported and registered in the FIRs of police stations, were collected from the City Crime Records Bureau (CCRB) Tiruchirappalli City Commissioner of Police Office, for the years 2012 to 2017. Only those crimes against women (Rape, Dowry Death, Molestation, Kidnapping, Cruelty by Husband, Dowry Prohibition Act, 1961 and POCSO Act, 2012) totaling 345 as classified by CCRB have been incorporated by factor analytical technique with basic data from Census of India 2011 population, sex ratio, literacy ratio, and work participation rate collected from the City Municipal Cooperation.

About 11 variables for the crime against women have been used to extract the factors by using statistical factor analysis. Based on the eigen-values and cumulative percentage of variance, four components have been identified. Based on those components, the variables were mapped and analyzed by adopting geoinformatics to understand the correlation between demographic parameters and crime occurrences in Tiruchirappalli City.

Figure 1

Factor analysis was conducted on the crime against women in Tiruchirappalli city to determine the factors that best represent the data. Simple component analysis was carried out to study the Eigenvalues for all scales. Reliability of the factors was decided by counting Cronbach alpha coefficients. All factors were found to have a reliability of 0.853 which is greater than 0.60 (α>0.60).

The results of the factor analysis on the crime against women in the study area were found to have four factors. The cumulative variance explained by the above factors was found to be 82.06%.

The overall significance of the correlation matrix with Bartlett’s test, considering the data in this research, the correlations, when taken overall, are significant at the 0.000 level according to Table 1 which is 149.102 for the crime against women in Tiruchirappalli city.

Data on these 11 variables for each of the 18 police stations have been entered and analysed using SPSS 19.0 version to extract factors by using the Varimax method. The output of the factor analysis is obtained by Principal Component Analysis and specifying the interpretation. There are two stages in factor analysis. Stage-I is the factor extraction process, where the objective is to recognize the number of factors that are to be extracted from the data. The most popular method is known as principal component analysis. There is also a rule of thumb based on the computation in Eigenvalue to determine how many factors to extract. The greater the Eigenvalue of a factor is the more amount of variance explicated by the factor. Since four factors were taken out in which 82.06% of the variance was explained. It is found that the four factors acted together account for 82.06% of the total variance (Table 2 ). Hence, the number of variables is reduced from eleven to four underlying factors.

The first component accounts for 38.11% of the variance while the second component accounts for 16.63% of the variance, the third component accounts about 14.49% of the variance and the fourth component explains 12.83% of the variance.

The analysis shows that the crimes against women variables such as cruelty by husband, rape, crimes under Dowry Prohibition Act 1961, crimes under POCSO Act and dowry death have loading of 0.986, 0.957, 0.946, 0.892 and 0.597 on factor 1 indicating that it is a combination of these five variables and are called ‘Gender Component’. AWPS Cantonment, Fort and Srirangam come under the very high category; AWPS Golden Rock comes under high category; Cantonment, Sessions Court, Golden Rock, Ariyamangalam, Palakkarai, Gandhi Market and Government Hospital police stations belong to medium category; and the remaining Edamalaipattipudur, K.K. Nagar, Airport, Fort, Srirangam, Thillainagar and Woraiyur police stations belong to low category (Figure 2).

Figure 2

The exploration shows that the crime against women variable of kidnapping has the loading of 0.711 and the demographic parameter of literacy ratio has the loading of 0.772 on factor 2 indicating that it is a combination of these two variables and are called ‘Personal Crimes and Literacy Component’. K.K. Nagar, AWPS Golden Rock and Government Hospital police stations come under the high category; Cantonment, Sessions Court, AWPS Cantonment, Golden Rock, Airport, Fort, Palakkarai, AWPS Fort, Srirangam and Woraiyur police stations belong to medium category; and the remaining Edamalaipattipudur, Ariyamangalam, Gandhi Market, Thillainagar and AWPS Srirangam police stations belong to low category (Figure 3).

The crime against women variable molestation has the loading of 0.878 and demographic parameter of the total population has the loading of 0.730 on factor 3 indicating that it is a combination of these two variables and are called ‘Molestation and Total Population Component’.

Fort, AWPS Fort, Srirangam and AWPS Srirangam police stations come under the very high category; Edamalaipattipudur and Woraiyur police stations come under high category; Sessions Court, K.K. Nagar, Golden Rock, Airport, AWPS Golden Rock, Thillainagar police stations belong to medium category; and the remaining Cantonment, AWPS Cantonment, Ariyamangalam, Palakkarai, Gandhi Market and Government Hospital police stations belong to low category (Figure 4).

The demographic parameter of work participation rate and sex ratio have the loading of 0.299 and 0.943 on factor 4 indicating that it is a combination of these two variables and are called ‘Work Participation and Sex Ratio Component’.

Palakkarai and Woraiyur police stations belong to very high category; K.K. Nagar, Fort, Gandhi Market and Srirangam police stations belong to high category; Cantonment, Edamalaipattipudur, AWPS Cantonment, Ariyamangalam, AWPS Fort, Government Hospital and AWPS Srirangam police stations belong to medium category; and Sessions Court, Golden Rock, Airport, AWPS Golden Rock and Thillainagar police stations belong to low category (Figure 5).