**4.2. CASE STUDY 2: Climate risk management of plantation crops in the humid tropic region of Kerala, India (G.S.L.H.V. Prasada Rao)**

The global economy has adversely been affected to a considerable extent due to weather related disasters which are not uncommon in the recent past. It is true in the case of the Indian economy too. The year 2010 was the warmest year ever recorded, followed by 2009 in India.

Climate model simulations indicate that a marked increase in rainfall and temperature over India could be seen during the current century. The maximum expected increase in rainfall is likely to be 10-30 percent over central India, with temperatures projected to increase between 2 and 3oC by the end of the 21st century.

More frequent storm surges and increased occurrence of cyclones in the post monsoon period, along with increased maximum wind speed are also expected along the coastal belt. As a result, the occurrence of floods and droughts, cold and heat waves and sea level rise may adversely affect the food security to a large extent across India, as seen in 2009, 2002 and 1987. Such impacts also influence plantation crops, which are predominantly grown in the humid tropics like Kerala, in the southwest of India (between latitudes 8°15`N and 12°50`N and longitudes 74°50`E and 77°30`E). The location map of Kerala is given in Fig. 6.

**Figure 6.** Location map of Kerala. Source: www.mapsofindia.com

### *4.2.1. Rainfall and thermal regimes of Kerala*

504 Risk Management – Current Issues and Challenges

welcomed more training.

through index insurance.

partnerships.

India.

would be the best way. Overall, the farmers appreciated the experience of last year and

Seasonal climate forecasts could have considerable potential to improve agricultural management and livelihoods for smallholder farmers. But constraints related to legitimacy, salience, access, understanding, capacity to respond and data scarcity have so far limited the widespread use and benefit from seasonal predictions in the Sahel region. The existing constraints reflect inadequate information services, policies or institutional processes in the region. However there is great potential to overcome these constraints. An approach is suggested that packages: i) seasonal and onset forecasts, ii) opportunity for farmers to implement strategies, and iii) insurance tools in case of extreme variable or dry years. Even when the seasonal rainfall or onset matches the forecast, poor farmers wouldn't profit if they don't have access to funds or crop varieties to implement any forecast-based strategy. And it turns out that in Kaffrine, there is often false start of the rainy season, making it imperative to provide farmers with alternatives, for example

As work with farmers in Kaffrine on the forecast continues, research is being conducted and a working group on improving prediction of intra-seasonal variability has been set up. Crop producers and seed bank will be invited into the process, to allow farmers to access suitable varieties for forecast-based strategies. There is some work on index insurance in the region, and it is planned to reach out to involve such groups in this effort. Through this approach it is hoped to gain success, avoid frustration and build long-term

**4.2. CASE STUDY 2: Climate risk management of plantation crops in the humid** 

The global economy has adversely been affected to a considerable extent due to weather related disasters which are not uncommon in the recent past. It is true in the case of the Indian economy too. The year 2010 was the warmest year ever recorded, followed by 2009 in

Climate model simulations indicate that a marked increase in rainfall and temperature over India could be seen during the current century. The maximum expected increase in rainfall is likely to be 10-30 percent over central India, with temperatures projected to increase

More frequent storm surges and increased occurrence of cyclones in the post monsoon period, along with increased maximum wind speed are also expected along the coastal belt. As a result, the occurrence of floods and droughts, cold and heat waves and sea level rise may adversely affect the food security to a large extent across India, as seen in 2009, 2002 and 1987. Such impacts also influence plantation crops, which are predominantly grown in the humid tropics like Kerala, in the southwest of India (between latitudes

**tropic region of Kerala, India (G.S.L.H.V. Prasada Rao)** 

between 2 and 3oC by the end of the 21st century.

The annual rainfall across Kerala is highly variable, averaging about 3000mm, but varying between less than 1000mm to greater than 5500mm.

Seasonally, rainfall is bimodal, due to the influence of both the summer and winter monsoons, with maximum monthly rainfall (>600mm) during the summer monsoon in June and July, and winter monsoon rainfall (200-300 mm) during October. Heavy rainfall during the summer monsoon, followed by a prolonged dry spell is a characteristic feature of the humid tropics, which is particularly prominent in the case of the northern districts, including Kasaragod, where the influence of winter monsoon is negligible (Fig. 7).

Annual average surface air temperature varies between 25 and 30°C, with a seasonal range between around 18°C in winter and 35°C in winter. The altitude across Kerala varies from below mean sea level to above 1500m, and temperature varies significantly with altitude. Accordingly, a sequence of crops is grown across the altitudinal range (see Table 3).

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Since rainfall is abundant during the monsoon season, surplus water during the first crop season leads to waterlogging which is detrimental to crop growth. In comparison, the second and third crops often suffer from soil moisture stress, and crop failure is a common phenomenon if irrigation is not assured. Erratic rainfall distribution during the monsoon, coupled with failure of the northeast monsoon, may result in drying up of surface reservoirs during summer, which are the major water resources in the region. In recent years, meteorological droughts during the monsoon and summer droughts are not uncommon

across Kerala, with the summers of 1983 and 2004 particularly prominent (Fig. 8).

**Figure 8.** Water deficit in Kerala from Sept to May 1982-83 and 2003-04.

The prolonged summer droughts, coupled with high temperature and low atmospheric humidity, in Kerala during 1983 and 2004 adversely affected production of many plantation crops, particularly rainfed coconut palms, arecanut, cardamom, coffee and black pepper and as a result the economy of the state was impacted. For example, monthly nut yield declined by up to 50 per cent (depending on management practices) in the year following drought, cardamom yield reduced by 30 per cent in Idukki dristrict and several black pepper gardens were wiped out in Wayanad district. Cocoa yield was also adversely affected due to high temperature in the absence of soil moisture. The impacts of these droughts on the agriculture and economy of Kerala highlighted the need to manage the risks posed by climate variability and change in this region, including other climate hazards such as floods, cold temperatures and heat waves). Various measures are now in place and being developed to pro-actively manage these risks, particularly at local levels. In the next section two of these measures are highlighted: 1) Scarce water resource management specifically through effective management of irrigation; and 2) Weather forewarning and dissemination.

*4.2.2. Impact of summer drought on plantations* 

**Figure 7.** Mean weekly rainfall and pan evaporation at RARS, Pilicode, Kasaragod District, Northern Kerala, India.


**Table 3.** Altitudinal sequence of crops in Kerala.

Since rainfall is abundant during the monsoon season, surplus water during the first crop season leads to waterlogging which is detrimental to crop growth. In comparison, the second and third crops often suffer from soil moisture stress, and crop failure is a common phenomenon if irrigation is not assured. Erratic rainfall distribution during the monsoon, coupled with failure of the northeast monsoon, may result in drying up of surface reservoirs during summer, which are the major water resources in the region. In recent years, meteorological droughts during the monsoon and summer droughts are not uncommon across Kerala, with the summers of 1983 and 2004 particularly prominent (Fig. 8).

**Figure 8.** Water deficit in Kerala from Sept to May 1982-83 and 2003-04.

#### *4.2.2. Impact of summer drought on plantations*

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Kerala, India.

Low land

High land

High land 

High ranges

Megatherms

Mesotherms

Microtherms I

Microtherms II

Microtherms III

below mean sea level to above 1500m, and temperature varies significantly with altitude.

**Figure 7.** Mean weekly rainfall and pan evaporation at RARS, Pilicode, Kasaragod District, Northern

**(amsl) Crops** 

pepper

pepper

Cardamom

100 -500 m Rubber, coconut,

500-1000 m

1000-2500

m

0 -10 m Coconut, arecanut and cashew

10 -100 m Coconut,cocoa arecanut, rubber,

black pepper

cashew and black

cashew, arecanut and

Coffee (arabica), rubber, arecanut and black

Tea, Coffee (arabica) and

**Class Region Temperature conditions Altitude** 

throughout the year

Mid land Moderate temperature

temperature relatively low

temperature low

year

**Table 3.** Altitudinal sequence of crops in Kerala.

High to Moderate temperature

throughout the year, winter

Moderate to Low temperature throughout the year, winter

Low temperature throughout the

Low temperature throughout the year, winter temperature is occasionally goes below 0°C

Accordingly, a sequence of crops is grown across the altitudinal range (see Table 3).

The prolonged summer droughts, coupled with high temperature and low atmospheric humidity, in Kerala during 1983 and 2004 adversely affected production of many plantation crops, particularly rainfed coconut palms, arecanut, cardamom, coffee and black pepper and as a result the economy of the state was impacted. For example, monthly nut yield declined by up to 50 per cent (depending on management practices) in the year following drought, cardamom yield reduced by 30 per cent in Idukki dristrict and several black pepper gardens were wiped out in Wayanad district. Cocoa yield was also adversely affected due to high temperature in the absence of soil moisture. The impacts of these droughts on the agriculture and economy of Kerala highlighted the need to manage the risks posed by climate variability and change in this region, including other climate hazards such as floods, cold temperatures and heat waves). Various measures are now in place and being developed to pro-actively manage these risks, particularly at local levels. In the next section two of these measures are highlighted: 1) Scarce water resource management specifically through effective management of irrigation; and 2) Weather forewarning and dissemination.

#### *4.2.3. Climate risk management*

**Scarce water resource management – irrigation**: Management of irrigation during the summer months under scarce water resources is one of the key tools available for managing the adverse impacts of summer drought on crops. Various methods can be used to assess the irrigation requirements for different crops and time periods throughout a season, e.g. estimate weekly water deficit/surplus by taking the difference between weekly rainfall and open pan evaporation, or through calculations of potential evapotranspiration.

Improving Climate Risk Management at Local Level –

**% increase over pretreatment yield** 

**Whether significant over pretreatment yield** 

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**Difference in yield (A – B)** 

**Post-treatment yield (1991-97) (B)** 

T1 103 122 19 18.4 S T2 103 112 9 8.7 S T3 94 107 13 13.8 S T4 87 120 33 37.9 S T5 92 115 23 25.0 S T7 91 95 04 4.4 S T6 60 82 22 36.7 S

**Agro climatic zonation**: Based on climate variables such as precipitation and potential evapotranspiration, the agro climatic zonation can be delineated using the water balance techniques. Such agro-climatic zonation if delineated on crop wise, climatic risks can be mitigated to a considerable extent. In the case of cardamom across the Western Ghats, Zone I & II are superior when compared to that of Zone III, where climate risk is high in terms of high temperature, prolonged dry spells and less length of crop growing season (Fig. 9). Similarly, cashew can be extended from northern districts of Kerala to south of Maharastra along the West Coast and North of Tamil Nadu to Orissa along the East Coast and inland areas away from the Coast. However, tea mosquito bug incidence along the West Coast and cyclones along the East Coast are the constraints for obtaining better cashew production. Similarly, simulation models can very well be used to simulate production potential of various crops in a given watershed area through which the climate risk can be minimized with proper crop management practices. In addition, agroadvisory service based on weather forecasting will go a long way in sustenance of crop production. Another multidisciplinary project launched by the Government of India, that is FASAL, is a classical example to help in GIS based watershed planning in

**Weather forewarning and dissemination**: A reliable and clearly disseminated weather forecast is a very important tool for forewarning crop managers of potential

**Treatment** 

**Pre-treatment yield (1976-89) (A)** 

T1- Irrigating the palms @450l/palm/week during December and January T2- Irrigating the palms @ 450l/palm/week from December to February T3 – Irrigating the palms @450l/palm/week from December to March T4 – Irrigating the palms @ 450l/palm/week from December to April T5 – Irrigating the palms @ 450l/palm/week from December to May T6 – Irrigating the palms as per climatic water balance procedure

(150 l/palm/week in December, 200 l/palm/week in January, 300 l/palm/week in February,

350 l/palm/week in March, 400 l/palm/week in April, 450 l/palm/week in May) **Table 5.** Duration of soil moisture stress on coconut yield of WCT.

Agriculture as a part of climate risk management.

In the RARS, Pilicode location of Kerala, the irrigation requirement for coconut was estimated using the FAO's CROPWAT decision support tool for estimating crop irrigation water requirements based on soil, climate and crop data (see: http://www.fao.org/nr/ water/infores\_databases\_cropwat.html). According to CROPWAT, the monthly average irrigation requirement for coconut in this region varied from 1106 litres/palm/month in December to 1488 litres/palm/month in April. The total irrigation requirement from December to May was estimated as 7807 litres/palm (Table 4). These values have provided guidance to coconut growers in the region on the general amount of irrigation water required to improve yield during average summer months.


ETo-Reference evapotranspiration; 0.75-Crop coefficient; r-Radius of coconut basin in m2

**Table 4.** Estimated irrigation requirements for coconut in the RARS, Pilicode location of Kerala.

More detailed seasonal irrigation advice to coconut growers has been provided by field experiments in which coconut palms were either irrigated at a rate 450 litres/palm/week for differing periods between December and May, or irrigated according to a climatic water balance approach, or not irrigated (Table 5). Results showed that the yield improved in all the irrigated treatments when compared to that of pre-treatments yield or no irrigation, as a result of reduction in the duration of water stress. Irrigation applied as per the climatic water balance approach (T6) showed one of the largest percentage yield increases, indicating that the preferred irrigation treatment for coconut yield is as required during the whole summer.

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T1- Irrigating the palms @450l/palm/week during December and January

T2- Irrigating the palms @ 450l/palm/week from December to February

T3 – Irrigating the palms @450l/palm/week from December to March

T4 – Irrigating the palms @ 450l/palm/week from December to April

508 Risk Management – Current Issues and Challenges

**Scarce water resource management – irrigation**: Management of irrigation during the summer months under scarce water resources is one of the key tools available for managing the adverse impacts of summer drought on crops. Various methods can be used to assess the irrigation requirements for different crops and time periods throughout a season, e.g. estimate weekly water deficit/surplus by taking the difference between weekly rainfall and open pan evaporation, or through calculations of potential

In the RARS, Pilicode location of Kerala, the irrigation requirement for coconut was estimated using the FAO's CROPWAT decision support tool for estimating crop irrigation water requirements based on soil, climate and crop data (see: http://www.fao.org/nr/ water/infores\_databases\_cropwat.html). According to CROPWAT, the monthly average irrigation requirement for coconut in this region varied from 1106 litres/palm/month in December to 1488 litres/palm/month in April. The total irrigation requirement from December to May was estimated as 7807 litres/palm (Table 4). These values have provided guidance to coconut growers in the region on the general amount of irrigation water

**(ETo x 0.75)** 

**Table 4.** Estimated irrigation requirements for coconut in the RARS, Pilicode location of Kerala.

More detailed seasonal irrigation advice to coconut growers has been provided by field experiments in which coconut palms were either irrigated at a rate 450 litres/palm/week for differing periods between December and May, or irrigated according to a climatic water balance approach, or not irrigated (Table 5). Results showed that the yield improved in all the irrigated treatments when compared to that of pre-treatments yield or no irrigation, as a result of reduction in the duration of water stress. Irrigation applied as per the climatic water balance approach (T6) showed one of the largest percentage yield increases, indicating that the preferred irrigation treatment for coconut yield is as required during the whole summer.

December 3.79 2.84 1106 January 3.95 2.96 1154 February 4.56 3.42 1204 March 5.01 3.76 1464 April 5.26 3.95 1488 May 4.76 3.57 1391 Total 7807

ETo-Reference evapotranspiration; 0.75-Crop coefficient; r-Radius of coconut basin in m2

**Irrigation requirement (1) (πr2h)** 

required to improve yield during average summer months.

**Month ETo (mm) Water requirement (mm)**

*4.2.3. Climate risk management* 

evapotranspiration.

T5 – Irrigating the palms @ 450l/palm/week from December to May

T6 – Irrigating the palms as per climatic water balance procedure

(150 l/palm/week in December, 200 l/palm/week in January, 300 l/palm/week in February,

350 l/palm/week in March, 400 l/palm/week in April, 450 l/palm/week in May)

**Table 5.** Duration of soil moisture stress on coconut yield of WCT.

**Agro climatic zonation**: Based on climate variables such as precipitation and potential evapotranspiration, the agro climatic zonation can be delineated using the water balance techniques. Such agro-climatic zonation if delineated on crop wise, climatic risks can be mitigated to a considerable extent. In the case of cardamom across the Western Ghats, Zone I & II are superior when compared to that of Zone III, where climate risk is high in terms of high temperature, prolonged dry spells and less length of crop growing season (Fig. 9). Similarly, cashew can be extended from northern districts of Kerala to south of Maharastra along the West Coast and North of Tamil Nadu to Orissa along the East Coast and inland areas away from the Coast. However, tea mosquito bug incidence along the West Coast and cyclones along the East Coast are the constraints for obtaining better cashew production. Similarly, simulation models can very well be used to simulate production potential of various crops in a given watershed area through which the climate risk can be minimized with proper crop management practices. In addition, agroadvisory service based on weather forecasting will go a long way in sustenance of crop production. Another multidisciplinary project launched by the Government of India, that is FASAL, is a classical example to help in GIS based watershed planning in Agriculture as a part of climate risk management.

**Weather forewarning and dissemination**: A reliable and clearly disseminated weather forecast is a very important tool for forewarning crop managers of potential

weather hazards. The India Meteorological Department is constantly working to improve forecast skill and help disseminate the forecast in a suitable form to aid farm level decisions.

Improving Climate Risk Management at Local Level –

**% increase in net return over non-AAS farmers** 

**% increase over in yield over non-AAS farmers** 

Techniques, Case Studies, Good Practices and Guidelines for World Meteorological Organization Members 511

Paddy 3.7 3.0 19.0 30.0 Banana 31.8 27.9 12.2 11.5 Coconut\* 13460 11025 18.1 13.2

Banana 22.8 20.5 10.1 7.9

Banana 31.3 29.3 6.4 11.9

Banana 25.3 22.4 11.2 7.1

Banana 27.8 24.5 11.8 12.3

Banana 24.5 21.6 11.9 10.0

Kharif 2004 Paddy 2.8 2.6 7.1 31.6

Rabi 2004-05 Paddy 3.0 2.7 7.5 34.1

Kharif 2005 Paddy 2.7 2.5 6.5 38.5

Rabi 2005-06 Paddy 3.3 2.9 13.6 36.0

Kharif 2006 Paddy 2.8 2.5 9.0 29.4

Rabi 2006-07 Paddy 3.2 2.9 9.4 34.7

Adaptation strategies and awareness raising are particularly important for managing the risks posed by climate variability and change, not only on crops but also across all sectors that are sensitive to weather and climate. Various agroclimatic techniques have been used in the Kerala region of India to effectively manage some of the risks posed by climate to crop productivity. Expansion and further development of such techniques will be vital for the continued sustenance of agricultural production in humid tropical regions and particularly monsoonal regions. As pointed out by Prof. M.S. Swaminathan "India's strength lies in its ability to manage monsoons" instead of saying "Indian agriculture is a gamble of the

**4.3. CASE STUDY 3: Climate risk management through structural adjustment and regional relocation: A case of rice industry in Australia (S. Mushtaq, G.** 

Climate change poses significant challenges to the Australian agricultural sector due to likely increased climate variability and increased frequency of extreme events. Climate change projections suggest that the southern part of Australia will generally become drier, while there is a likelihood of increased rainfall and the frequency and intensity of extreme

**Season Crop Yield (t/ha)** 

**Table 6.** Impact of AAS on crop yields from 2003-04 to 2006-07.

**Cockfield, N. White, and G. Jakeman)** 

Rabi 2003-04

\* nuts/ha in the case of coconut

*4.2.4. Lessons learned* 

monsoon".

To improve dissemination of weather forecasts in a timely manner to agricultural villages, Village Resource Centres that are linked online to an Agro Advisory Service (AAS) have been established (under the ISRO programme) across the Kerala region. AAS' base their advice on the latest weather forecasts and agricultural expertise. The economic impact of a weekly AAS based on medium range weather forecasting has been assessed for different crops and regions (Table 6). This showed that the percentage increase in yield varied from 6.4 – 19 per cent depending upon the crop in the case of AAS farmers compared to the non-AAS farmers. Furthermore, it indicated that seasonal crops need intensive advisory, followed by less intensive for biennials and perennials.

**Figure 9.** Agroclimatic zones of cardamom across the Western Ghats.

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\* nuts/ha in the case of coconut

510 Risk Management – Current Issues and Challenges

followed by less intensive for biennials and perennials.

**Figure 9.** Agroclimatic zones of cardamom across the Western Ghats.

decisions.

weather hazards. The India Meteorological Department is constantly working to improve forecast skill and help disseminate the forecast in a suitable form to aid farm level

To improve dissemination of weather forecasts in a timely manner to agricultural villages, Village Resource Centres that are linked online to an Agro Advisory Service (AAS) have been established (under the ISRO programme) across the Kerala region. AAS' base their advice on the latest weather forecasts and agricultural expertise. The economic impact of a weekly AAS based on medium range weather forecasting has been assessed for different crops and regions (Table 6). This showed that the percentage increase in yield varied from 6.4 – 19 per cent depending upon the crop in the case of AAS farmers compared to the non-AAS farmers. Furthermore, it indicated that seasonal crops need intensive advisory,

**Table 6.** Impact of AAS on crop yields from 2003-04 to 2006-07.

### *4.2.4. Lessons learned*

Adaptation strategies and awareness raising are particularly important for managing the risks posed by climate variability and change, not only on crops but also across all sectors that are sensitive to weather and climate. Various agroclimatic techniques have been used in the Kerala region of India to effectively manage some of the risks posed by climate to crop productivity. Expansion and further development of such techniques will be vital for the continued sustenance of agricultural production in humid tropical regions and particularly monsoonal regions. As pointed out by Prof. M.S. Swaminathan "India's strength lies in its ability to manage monsoons" instead of saying "Indian agriculture is a gamble of the monsoon".
