As for the joint model, different flood severity were considered in this combined model (floods of or longer
than one day, 10 days, 15 days, 20 days, 30 days, and 50 days).
Nutrition indicators
Table 25 displays the results of the DiD tests for the nutrition indicators.
The effect of flood events on these nutrition indicators was mixed. In particular while the relationship in the months directly following the flood were by positive values in the zlen (stunting) indicator, the values
of the coefficients decline rapidly over time and become negative around five to seven months –see for instance the coefficients of the zlen_30_days test, which passes from 0.074 at the period directly after the event down to -0.067 after nine-month-, suggesting a slow degradation of the stunting situation in these communities, compared to the non-affected communities. This degradation does not lead to any statistically significant level however.
The impact of flood events on the zwfl (wasting) indicators shows a clearer pattern: the difference was either negative or became negative after three to five months. In fact the five-month lagged period had the lowest coefficient values and these are all statistically significant (p<0.001 for the five tests: zlen_all to zlen_50 days). Values remained negative after this 5-month period and were statistically significant for the events of lower intensity. This pattern is in line with what had been observed with the joint models and the individual-events tests.
Drought events seem to have negative effects on both zwfl and zlen. For the zlen (stunting) indicators
the effect appear to be lagged and was significant at five and nine month lags, while for the zwfl (wasting) indicator the drought effect begins immediately and lasts for up to seven months where it reaches a level of statistical significance for the events longer than 15 days. The strong positive effect of drought on zwfl at nine months is difficult to explain, but it could be due to a reduction in illness such as diarrhoea27.
The results also indicate that drought seems to have little effect on maternal BMI. A negative trend starts just after the event, and lasts up to five months, but none of the values are statistically significant. There is in contrary some evidence of positive (and significant) effect for medium flood events (15 and 20 days) on BMI, but the statistical significance is not maintained across models and is therefore difficult to interpret.
Both child and maternal dd show statistically significant positive values with strong flood events (20 days and above) which start straight after the event and last up to 7 months.
Here again these are quite difficult to interpret at first sight. They suggest that the level of dietary diversity
for both children and mothers are statistically higher in communities that are affected by flood than in non-affected communities. This is in agreement with the results that were showed in the joint-events models.
For drought some initial negative values in both children and maternal dd can be observed just after the events but these are not significant.
Instead some positive and significant values are recorded around seven to nine months, especially once only severe flood events are controlled for.
Food security and price food indicators
Table 26 displays the results of the DiD tests for the food security and food price indicators. The overall trend is relatively clear: for FL (food loan), and the three price indicators (rice, oil and food basket price indicators, PO, PR and PBF) the occurrence of drought or flood results in higher prices and a greater number of food loans, generally starting either just after the event or at the latest two months after.
Most of these trends are statistically significant and remain so for up to the nine month-lag period. However, coefficients decrease as time passes
27 Overall events the prevalence of diarhoea decreased in the period in which a drought began as well as in L1, L2, and L4. This held true in both the individual and combined drought models.
by. This trend is clear in particular in the case of the PO indicator (see e.g.
the coefficient values decreasing from 6.224 to 1.052 or from 9.218 to 1.303 between the time of the event and the nine-month lagged period for PO 30 days under flood and drought respectively). For food loan (FL) the coefficient increases with the severity of the flood in particular around five month after the event (see for instance the coefficient values that
Table 25. Flood drought combined models(a) – nutrition indicators
zlen all zlen 10 days zlen 15 days zlen 20 days zlen 30 days zlen 50 days coef p-value coef p-value coef p-value coef p-value coef p-value coef p-value flood event
+3m +5m +7m +9m drought event +3m increase from 0.139 to 1.037 for the
five-month lag period), while for drought the overall trend is positive across the whole series of tests, with statistically significant values observed for all cases just after the event and at the three-month lagged period.
For FE (food expenditure), the trend is similar to the other indicators discussed just above (i.e. broadly positive coefficients) although not
as strong especially in the case of flood where the effect stops to be significant after 5 months. It is however still possible to observe an increase in the coefficients for the period just after the event: the longer the flood the higher the FE coefficient, suggesting that after a flood event households’ food expenditures not only increases but are also influenced by the severity (length) of the flood.
zwfl all zwfl 10 days zwfl 15 days zwfl 20 days zwfl 30 days zwfl 50 days coef p-value coef p-value coef p-value coef p-value coef p-value coef p-value flood event
+3m +5m +7m +9m drought event +3m BMI all BMI 10 days BMI 15 days BMI 20 days BMI 30 days BMI 50 days coef p-value coef p-value coef p-value coef p-value coef p-value coef p-value flood event
+3m +5m +7m +9m drought event +3m
Child dd: all drought event +3m drought event +3m Legend: Only statistically significant p-values are indicated (in bold), other non-significant p-values are omitted. Coefficient values highlighted in light red indicate cases for which the DiD test suggests a worsening situation in relation to nutrition, that is, a lower zlen, zwfl, BMI, child dd or maternal DD in the affected (treatment) communities, compared to the non-affected (control) communities. Dark red values indicate cases where the worsening of the nutritional situation is statistically significant.
zlen: Length/Height for age z-score; zwfl: weight for Length/Height z-score; BMI: Maternal body mass index; dd: Child dietary diversity; DD: Maternal dietary diversity. The notation +3m; +5m, +7m, and +9m refer to 3-month, 5-month, 7-month, and 9-month lagged periods respectively, while
‘drought event’ and ‘flood event’ refer to the period during or just after the event.
(a) The following variables were also included in the models (but not shown in the table) to control for individual and household effects: age and sex of child; mother age and education; livelihood strategies (farmer; labour; transport; salary; business); family size; birth order; source for drinking; use of latrine –see definitions in section 2.5.2.
Table 26. Flood drought combined models(a) – food security and food price indicators drought event +3m drought event +3m
PR all drought event +3m drought event +3m
PFB all PFB 10 days PFB 15 days PFB 20 days PFB 30 days PFB 50 days coef p-value coef p-value coef p-value coef p-value coef p-value coef p-value flood event
+3m +5m +7m +9m drought event +3m Legend: Only statistically significant p-values are indicated (in bold), other non-statistically p-values are omitted. Coefficient values highlighted in light red indicate cases for which the test suggests a worsening situation in relation to food security, that is, a higher FL, FE, PR, PO, or PFB in the affected (treatment) communities, compared to the non-affected (control) communities. Dark red values indicate cases where the worsening of the food security or food price situation is statistically significant.
FL: food loan; FE: food expenditure; PR: rice price; PO: soybean oil price; PBF: price of food basket. The notation +2m; +4m, +6m, and +8m refer to 2-month, 4-month, 6-month, and 8-month lagged periods respectively, while ‘drought event’ and ‘flood event’ refer to the period during or just after the event.
(a) The following variables were also included in the models (but not shown in the table) to control for individual and household effects: age and sex of child; mother age and education; livelihood strategies (farmer; labour; transport; salary; business); family size; birth order; source for drinking; use of latrine –see definitions in section 2.5.2.