**3.3. Chamrajnagar (Semiarid)**

From Table 2, it is noticed that Chamrajanagar shows the arid climate category in 15 years of the study period. The years such as 1993, 1997, 1998 and 1999 displayed subhumid climates. The climatic types of this region are the good representative of climatic features over the study

**Figure 7.** Variation of IM and NDVI – Belgaum

period. In the case of semi arid region of Chamrajnagar, the variability of IM and NDVI is better as compared with the humid and dry subhumid regions (Figure 8). The overall IM is varied from -10% in the year 1984 to a maximum of 44% during the year 1998 for the south west monsoon season. Accordingly NDVI, also varied from 0.26 to a high value of 0.42 in the year 1996. The values of NDVI are less in this region than previously mentioned areas but the trends of IM are NDVI were positive with slopes of 0.824 and 0.002 for IM and NDVI respectively along with the standard deviations of 11.5 and 0.05. The correlation of these two data sets is 0.42 at 0.05 level of significance which infers the good agreement of IM and NDVI. From this analysis, it can be noticed that the deficiency of moisture which is represented by IM in this study was well reflected by low NDVI values and adequate moisture conditions are supported by the moderate vegetation conditions.

**Figure 8.** Variation of IM and NDVI – Chamrajanagar

#### **3.4. Gulbarga (Arid)**

All the years of study period are dominated by the arid category for this region. The compar‐ ison of IM and NDVI yielded good results in the arid region of selected test sites (Figure 9). The interannual variability was found to be very high both in IM and NDVI where as IM varied from -77% during August of 1982 to zero value during September month in the years 1983 and 1992 with the corresponding NDVI values of 0.055 and 0.127 respectively. The time series plot for IM and NDVI for the total south west monsoon season display the one to one linear agreement where the trends of both were highly increasing than other test regions (Figure 8). The slopes of the trends were 1.68 and 0.007 respectively. The standard deviations of 14 and 0.05 infer that the interannual variability of IM is more than NDVI from which it can be noticed that the vegetation over a region may not respond immediately to the rainfall/available moisture despite there is a dependence of vegetation on rainfall/available moisture. The time series plot of IM and NDVI (Figure 10) shows that the maximum of amount of moisture of-12% have seen in the year of 1998 with the NDVI value of maximum NDVI of 0.269 that is recorded during the entire study period. The correlation in this case is +0.64 which is at 0.01 level of significance which shows the strong agreement between IM and NDVI.

**Figure 9.** Variation of IM and NDVI – Gulbarga

period. In the case of semi arid region of Chamrajnagar, the variability of IM and NDVI is better as compared with the humid and dry subhumid regions (Figure 8). The overall IM is varied from -10% in the year 1984 to a maximum of 44% during the year 1998 for the south west monsoon season. Accordingly NDVI, also varied from 0.26 to a high value of 0.42 in the year 1996. The values of NDVI are less in this region than previously mentioned areas but the trends of IM are NDVI were positive with slopes of 0.824 and 0.002 for IM and NDVI respectively along with the standard deviations of 11.5 and 0.05. The correlation of these two data sets is 0.42 at 0.05 level of significance which infers the good agreement of IM and NDVI. From this analysis, it can be noticed that the deficiency of moisture which is represented by IM in this study was well reflected by low NDVI values and adequate moisture conditions are supported by the

All the years of study period are dominated by the arid category for this region. The compar‐ ison of IM and NDVI yielded good results in the arid region of selected test sites (Figure 9). The interannual variability was found to be very high both in IM and NDVI where as IM varied from -77% during August of 1982 to zero value during September month in the years 1983 and 1992

moderate vegetation conditions.

**Figure 7.** Variation of IM and NDVI – Belgaum

102 Environmental Change and Sustainability

**Figure 8.** Variation of IM and NDVI – Chamrajanagar

**3.4. Gulbarga (Arid)**

**Figure 10.** Time series of IM and NDVI for southwest monsoon

The study commenced with the retrieval of IM values from the water balance model on monthly basis over different selected test regions those represent the various climatic types such as humid, dry sub humid, semi arid and arid. The knowledge of different climatic types enables us to understand the climatology of the test regions during the study period. Since these climates were derived from the IM values, they replicate the status of the moisture content available which is very essential input to decide the crops fate. The comparison study of IM with the satellite derived NDVI shown very interesting features of sensitivity of NDVI with IM over different climatic types. The study inferred the poor correlation such that no linear and significant relation of IM with NDVI over humid and dry subhumid regions. The reason for this could be the plenty of available moisture over these regions and even temporary pertur‐ bations of land surface conditions may not affect the crops/agriculture. The relation grown up to strong when the comparison closes from semi arid to arid regions. Especially, Gulbarga, arid region displayed very strong relation of IM with NDVI which unraveled the poor/good vegetative conditions associated with low/high values of IM. The correlation of +0.65 is a good supporting factor to say that the relation is substantial. The overall analysis of the present study suggested that the relation of IM with NDVI is very strong and it is of immense use for the studies of drought monitoring in the arid areas as compared with the other climatic types.
