Analysis of morphological change of lentic water bodies by using spatial vulnerability index (SVI) in Tarai region of Rapti river plains, India

Figures & data

Figure 1. Rivers, lakes, and ponds in the Rapti river plain.

Figure 2. Lakes in 1969 and 2019 in the study site.

Figure 3. Lakes transformation into large pond and disappeared lakes within 50 years (1969–2019).

Table 1. Change in area of lakes within 50 years (1969 – 2019).

Status of reduction in lake extent	Lakes in 1969	Lakes in 2019	Disappeared lake in 2019	Lake transformed into large pond in 2019
No. of lakes	75	46	12	17
Area of lakes in hectares	5776.50	3552.80	544.10	130.90

Figure 4. Lakes transformed into different extent; current lakes, large ponds and disappeared lakes within 50 years (1969 – 2019) in Tarai region.

Table 2. Transformation of lake into large pond within 50 years (1969 – 2019).

Transformation of lake into large pond Within 50 years (1969 – 2019)	Reduced extent in percent	No. of lake
Very small lake to Large pond	Below 50	5
Very small lake to Large pond	50–70	10
Very small lake to Large pond	Above 70	2

Figure 5. Change in identifiable nomenclature of lakes within 50 years (1969 to 2019).

Figure 6. Spatial vulnerability index of alive lakes during 50 years (1969 – 2019).

Figure 7. Regression analysis between reduced lake extent (50 years) and morphometric parameters of lakes in Tarai region.

Table 3. Spatial vulnerability index of alive lakes during 50 years (1969–2019).

Percent of spatial vulnerability Index (SVI) of lake	Number of lakes needs to restoration	Reduction of lake extent in hectare within 50 years)	Status of restoration
Below 29.26	13	311.20	Least
29.26–53.31	25	619.90	Moderate
Above 53.31	8	290.0	High

Data availability statement

Data will be made available if asked and required.