Bangladesh is losing huge food production from the Teesta catchment area due to a lack of availability of irrigation water in the dry and lean period because of unilateral water withdrawal in the upstream country, India. The area, which is directly dependent on the irrigation water of the Teesta river, is the study area for this paper. The study reveals that rice production in Dalia, Nilphamari, Sayedpur and Rangpur regions is badly affected by the irrigation water scarcity. It appears that production is particularly severely affected in Rangpur, making it a relatively more food insecure area in the Teesta basin. The major finding of this study is that more than 4.45 million metric tons of rice production have been missed from the Teesta catchment area since 2006–07, triggered by the massive irrigation failure of the Teesta Barrage Irrigation Project (TBIP) due to reduced water flow in the Teesta river. The total rice production missed in the north-western region since 2006–07 is more than the country's total rice import during 2008/09–2013/14 fiscal years and nearly one quarter of the total boro production in the 2012/13 fiscal year. This reduced food production renders the north-western part of the country a food insecure region from its own production.

## Introduction and background

Irrigation water is one of the major factors affecting agricultural production around the world. Without timely and sufficient irrigation, optimum production cannot be obtained from the available firm land. In Bangladesh, irrigation water plays a significant role in crop production, especially in drought-prone areas. The intent of this study is to examine regional food insecurity as a result of reduced food production due to irrigation water shortage in the Teesta catchment area, consequent upon reduced water flow through the Teesta river. The Teesta catchment area mostly envelops the north-western part of Bangladesh. Irrigation in the Teesta catchment is mainly based on the water of the Teesta river, which has been facing large-scale volatility over the years due to unilateral withdrawal of Teesta waters in India. In order to foster agricultural production and socio-economic development in the area, Bangladesh constructed a barrage at the Dalia-Doani point of the Teesta river. The main objective of this barrage is to provide irrigation facilities in the Teesta catchment area, with a view to ensuring the best possible production in the area. The command area of phase 1 of the Teesta Barrage Irrigation Project (TBIP) is 120,752 hectares (ha) and the cultivable area is 111,406 ha (Bangladesh Water Development Board (BWDB)). Because of scarcity of water in the dry and lean season, the irrigated area in the region is restricted to 79,378 ha. Besides, it is not possible to irrigate the entire irrigable area due to scarcity of water in the Teesta river in the boro cropping season. Thus, irrigation failure occurs and a large part of the Teesta catchment area cannot be brought under cultivation, which triggers lower food production in this region. This leads to regional food insecurity, in terms of own production, in the north-western part of Bangladesh.

The estimated catchment area of the Teesta river is 2,004 square km in the Bangladesh part, with 21 million people living in the area. Reduced water flow in the Teesta river, therefore, leads to irrigation water shortages in the dry and lean season and, as a result, desired cultivation is not possible in the irrigable area of the TBIP. Farmers outside the command area of the TBIP use groundwater for irrigation through deep tube-wells, which is much more costly. The average irrigation cost of cultivating one acre of land is nearly Bangladeshi taka (BDT) 8,000 through deep tube-wells in the Teesta basin, whereas the farmers under the TBIP pay only BDT 480 per acre of irrigation. Moreover, most of the farmers of the TBIP are resource-poor and there is no deep or shallow tube-well within the TBIP area. So, when irrigation failure occurs, farmers suffer as they do not have back-up irrigation facilities. As a result, crop production is hampered, with food production facing substantial downturn, which has been used in this study to assess the regional food insecurity from own production.

## Objective of the study

The major objective of this study is to investigate the risk of food production reduction and food insecurity in the north-western region due to irrigation water shortages in the Teesta river. The specific objectives are to:

• examine the irrigation conditions in different parts of the Teesta catchment area for those who access irrigation water from the TBIP;

• assess rice production in the boro cropping season in the Teesta catchment area in the face of water scarcity; and

• scrutinize the impact of irrigation failure on the regional food production.

## Review of literature

There is plenty of local and international literature that investigates regional food insecurity due to irrigation water shortages. These studies have addressed different aspects of food insecurity caused by irrigation failure in different countries across the world. Very scant literature is available that addresses food production and insecurity issues downstream in the context of reduced water flows in transboundary rivers.

Hamdan & Salman (2005) conducted a study to assess the impact of irrigation water scarcity on the agricultural sector and food security in Jordan. Employing several agricultural development policies, Jordan improved its position regarding food security over the last two decades, but soaring population growth and scarcity of water have turned out to be major bottlenecks concerning agriculture and food security. The main finding of this paper is that decreasing water supply by 20% will reduce the total cultivable area by about 14%, which can feed into national food insecurity in the long run.

Ribera & McCorkle (2013) investigate the economic impact of irrigation water shortage on the Lower Rio Grande Valley (LRGV) agriculture using an input-output model. It appears from the study that the total crop production loss due to lack of irrigation water in the LRGV region was US$229.24 million during the fiscal years 2008–2012. Gram Bikash Kendra (GBK) (2012) carried out a study on water scarcity in northern Bangladesh with the aim of detecting socio-economic impacts of water shortage on agriculture and livelihoods of the concerned people in greater Rangpur and Rajshahi divisions. North-west Bangladesh had become a food surplus area, but the gains are being eroded by inadequate water availability. The study reveals that overall agricultural productivity is falling in northern Bangladesh due to a lack of irrigation facilities, inadequate rainfall in the dry season, and insufficient water flows in the rivers, mainly in the Ganges and the Teesta, caused respectively by the Farakka and Gazaldoba barrages. Rahman et al. (2010) attempted to examine the impact of dams and embankments of the north-east part of India on the north-western region of Bangladesh. This study is concerned with water shortages in 17 rivers coming to Bangladesh from across the east and north-east borders as a result of large-scale withdrawal of water in India from these rivers by building barrages. The Food and Agriculture Organization (FAO, 2012) attempted to define the risk and uncertainty of food production in the face of water crisis and develop a framework for ensuring food security. The study mentions that agriculture currently accounts for 70% of global freshwater withdrawals, and more than 90% of its consumptive use. Under the combined pressure of population growth and changes in dietary habits, food consumption is increasing in most regions of the world. It is anticipated that by 2050 an additional billion (109) metric tons of cereals and 200 million metric tons of meat will be required annually to meet growing food demand. The study discusses the driving forces behind water scarcity and its implications for coping strategies and the required policy stances. Linseley et al. (1975) define the north-west and south-west regions of Bangladesh as the areas in the Ganges basin in the Bangladesh part, which are drought-prone. Inadequate rainfall and large-scale water demands create this situation. Mirza & Hossian (2004) argue that local agriculture used to cope with this situation through irrigation from surface water sources that include the Ganges and its distributaries, ponds, and other water bodies. The people of north-west Bangladesh are now badly suffering due to scarcity of surface water due to the upstream uses and regulation (Institute of Water Modelling (IWM), 2008). Asia Foundation (2013) found that in the South-Asian region, formulation and implementation of water policies provide limited room for the expression of legitimate civil society voices and stakeholder concerns. Despite the existence of several bilateral treaties and agreements, the lack of regional cooperation and the absence of local and sub-national perspectives continue to plague sustainable development and management of transnational water resources for livelihood improvement, food security, poverty reduction, and effective adaptation to climate change impacts. The study suggests that access to information and data on Teesta water is essential and that the entire river basin be taken as a unit of analysis, as that can ensure sustainable river basin management and deliver larger socio-economic benefits to all parties involved. Asian Development Bank (ADB) (2007) shows that India withdraws nearly 75% fresh water from the Indus, the Ganges and the Brahmaputra river basins that India shares with Pakistan, Bangladesh and Nepal. Increasing water withdrawal from these transboundary river systems by India reduces the availability of water for the downstream nations. Islam & Higano (2002) find that due to inconsistent water flows, only 22% of the total TBIP area could be brought under cultivation. They contend that, if the total target area of 750,000 ha could be cultivated, the value of production, on average, would increase by up to US$230 million per year. The study also reveals that a flow of water of 8,000 cubic feet per second (cusec) in the Teesta river can produce US\$20 million worth of crops in a year.

## Methodology and data

The purpose of the study can be fulfilled by illustrative research methods. Hence, the study is based on descriptive analysis. In order to carry out this study, secondary data have been used. The data on irrigation and production in different cropping seasons have been collected from Bangladesh Water Development Board and historical water flow of the Teesta river from Joint Rivers Commission (JRC), Dhaka.

Twelve Upazilas, namely, Dimla, Joldhaka, Kishorgonj, Nilphamari Sadar, Sayedpur, Rangpur Sadar, Taragonj, Badargonj, Gangachara, Parbotiur, Chirirbandor, and Khansama of greater Rangpur division, get irrigation water from the Teesta river through the TBIP. Data related to irrigation and production in these 12 Upazilas have been grouped into four regional data sets as Dalia, Nilphamari, Sayedpur, and Rangpur for the macroeconomic study. After that, an overall analysis has been conducted to examine the total impact of irrigation water shortages on food production in the north-western part of Bangladesh, by aggregating the data of the four regions: Dalia, Nilphamari, Sayedpur, and Rangpur.

### Study area

The Teesta river is about 117 km long in Bangladesh, finally merging with the already merged mighty rivers, Brahmaputra and Jamuna. But in the cropping period, especially in the dry season, the contribution of the Teesta to the combined flows is insignificant, due to very low flows through the river as a result of large-scale upstream withdrawal in India. Generally, all the people of the Teesta basin do not get an opportunity to use the water of the Teesta river for irrigation because, in cropping periods, only the people who are under the coverage of the TBIP can use the water of this river for cultivation. The TBIP is designed to provide an irrigation facility only in the drought-prone areas of the greater Rangpur division. That is, people who belong to areas outside of TBIP coverage cannot access Teesta waters for irrigation. The farmers covered by the TBIP are those who are primarily affected by the water crisis in the Teesta river. So, the command area of the TBIP phase 1, which covers Dalia, Nilphamari, Sayedpur and Rangpur regions, has been chosen as the relevant area for this study. Figure 1 specifies the Teesta catchment area that is at risk of substantial food production reduction due to irrigation water shortages.
Fig. 1.

Study area.

Fig. 1.

Study area.

## Results and discussion

In this section, the historical scenario of water scarcity in the Teesta river and its impacts on north-western Bangladesh are examined. Historical water flow and its relationship with the irrigation of the TBIP's command area are also investigated here. In addition, region-wise or zone-wise impacts of water shortages on irrigation and crop production are investigated.

### Irrigation water shortage and food insecurity

A country faces water stress when per capita water availability falls below 1,667 cubic meters. Water scarcity surely threatens economic development and human health and well-being when there is less than 1,000 cubic meters per capita. It is a situation of absolute water scarcity when water resources are less than 500 cubic meters per capita (Falkenmark, 1986). Most of the studies on the subject emphasize that a country is water-scarce when per capita water supply falls below the benchmark of 1,000 cubic meters. There is a link between water resources' availability and food production. If water is unavailable, water-dependent food grains cannot be produced. In this case, the country in question has to import food grains, and that is what the Middle Eastern nations do. This is not a sustainable solution in relation to ensuring food security in every country in the long run because volatility in the international food market, trade failures among the countries, uncertainty in the world food production and global markets may make it extremely difficult, even impossible, to import food grains when needed, even if money is available. The best option for food security is to enhance domestic production as much as possible in developing countries like Bangladesh.

Not only the total annual per capita water availability, for which Bangladesh is still more than adequately endowed, but also, perhaps more importantly, regional and spatial distributions of water have crucial roles to play in the context of food production. Certain areas of the country suffer from inadequate rainfall, even prolonged drought or drought-like situations, adversely impacting on food production. Moreover, transboundary rivers such as the Ganges, the Meghna, the Brahmaputra, the Teesta and others face reduced water flows in the dry season due to upstream withdrawal in India of water resources of common rivers (Rashid, 2012a).

In the Teesta catchment area, Bangladesh often fails to meet the irrigation demand in the dry and lean period due to reduced water flows in the lower Teesta floodplain, which triggers lower food production in the north-western region (Bangladesh Water Development Board (BWDB), 2014; Arfanuzzaman & Ahmad, 2015). Irrigation water shortage as a result of low flows in the Teesta obviously defines the gap between the water demand and supply in the Teesta catchment area, and that adversely impacts on food production in the region.

### Reasons behind irrigation water shortages in the Teesta basin

Water scarcity depends on geographical location, nature of a river, pattern of water flow, climatic conditions, and human actions. Broadly, the reasons for water scarcity can be divided into two types: natural and anthropogenic. Natural causes sometimes play a decisive role in water scarcity in a river. One possible reason in our case may be the receding of Himalayan glaciers, which would eventually lead to water shortages in the region during lean periods. Then, extreme climatic conditions in the Teesta basin such as lower rainfall in Sikkim, high temperature and environmental changes can cause the river basin to dry and groundwater supply may decline drastically. But, in the present context, natural occurrences are not contributing significantly to water scarcity in the Teesta river. If these were the reasons for the water crisis, the entire Teesta catchment area (North Bengal and West Bengal) could face water scarcity, not only the Bangladesh part. However, it is the case that the Bangladesh part experiences critical shortages of water, while this is not so in the Indian part of the catchment area (Arfanuzzaman, 2015).

Anthropogenic reasons basically refer to the human activities, such as control, diversion and withdrawal of water from the main river by constructing infrastructures for these purposes, which may result in water scarcity downstream of the river catchment area. In the case of the Teesta, when India constructed the Gazaldoba barrage and a series of dams upstream, Bangladesh began to get reduced water flow in its part (Rashid, 2012b). As a downstream country, Bangladesh is certainly now affected by the extraction and diversion of the Teesta river water by India through the Gazaldoba barrage. Consequently, Bangladesh is getting very low water flow in its part and fails to attain the purpose of the TBIP as well as to meet the country's irrigation demand in the north-western region.

According to the Convention on the Law of the Non-Navigational Uses of International Watercourses (1997), if a project or other measures are planned in an international watercourse in a country that may have a significant adverse impact upon another country or countries sharing the same watercourse, the country in which the measures are planned must timely notify the other country or countries of its planned actions. If a notified country believes the planned measures would be a breach of the articles 5 or 7, a process of consultations and, if necessary, negotiations may be initiated to find an equitable resolution of the situation. However, it appears that India has not informed Bangladesh officially about their upstream plans of infrastructure building for water regulation activities in the Teesta river. As a result, Bangladesh has not been able to respond in terms of jointly finding an appropriate solution, and now suffers not only from water scarcities in the Teesta, but also from data and information gaps in relation to upstream activities in India.

Neither India nor Bangladesh has ratified this convention. However, its major thrust of equity, fairness, and no harm to be caused by any intervention in a common river by a co-riparian has been enshrined [Preamble and Clause IX] in the 30-year 1996 Ganges [Water Sharing] Treaty between Bangladesh and India.

### Historical water flow in the Teesta river

Water becomes a rare commodity in the dry season in the Bangladesh part of the Teesta river due to unilateral withdrawal and diversion of water by the upstream country, India. In greater Rangpur and Dinajpur regions, temperature is usually high compared to other parts of Bangladesh. In fact, for proper agricultural activities and to increase the moisture of the soil, more irrigation is needed in the TBIP area; but, from Figure 2, it can be seen that water flow is volatile in the dry season in the Teesta river. Wirsing & Jasparro (2007) also found that India is increasingly diverting more water to Gazaldoba at the expense of downstream Bangladesh.
Fig. 2.

Average water flow in Teesta river during dry season. Source: Joint Rivers Commission (JRC).

Fig. 2.

Average water flow in Teesta river during dry season. Source: Joint Rivers Commission (JRC).

Figure 2 shows that water flow has been in downward drift since 2001 in the lower Teesta basin as well as in the Bangladesh part. In 2002 and 2010, the water flow in the Teesta unexpectedly reached a low of nearly 500 cusec. It seems that in 1996 the water flow was about 6,500 cusec but, after that, this flow was never observed in the Teesta river due to the intense control on the river waters by India, which led to massive irrigation failure in north-western Bangladesh. Accordingly, a larger part of cultivable land has had to be kept unutilized, resulting in substantially lower food production in the area. The downward-sloping linear trend line and three-year moving average of the water flow also indicate declining water flow in the Teesta over the years.

Figure 3 shows the lowest water flow year by year in the Teesta. The amount of the lowest water flow was recorded as 4,500 cusec in 2001 but, after that, it declined steeply. Besides, the linear trend line and three-year moving average of the water flow also indicate the downward trend in water flow in the Teesta river up to 2011. Since then, there has been some improvement, but it still remains less than half of the lowest flow as of 2001.
Fig. 3.

Lowest recorded historical water flow in the dry season. Source: Water Monitoring Station, Dalia Point.

Fig. 3.

Lowest recorded historical water flow in the dry season. Source: Water Monitoring Station, Dalia Point.

If Figures 2 and 3 are compared, it would appear that the trend of water flow is almost the same in each of the two figures. Clearly, therefore, the lowest water flow in a year prevails in the whole dry season in most of the years. Very low flow at one time or the other may occur for one reason or another, which may not inflict much harm. But if it occurs during the whole season, water deprivation and its adverse effect on food production can be, and have been, severe in the area under study.

### Trend of regional food production in Teesta catchment area

All three types of rice, namely, aus, aman and boro are cultivated in the Teesta catchment area, where irrigation water is supplied from the Teesta river through the canal network of the TBIP. Initially, supplementary irrigation was provided in aus and aman seasons in the TBIP area. Later, from 2006–07 cropping year, the irrigation facility was extended to the boro season. During aus and aman cropping periods, sufficient water is in fact available in the Teesta river; but, in the boro season, there is scarcity of water in the river, which adversely affects the boro cultivation in the Teesta catchment area as well as north-western Bangladesh. Moreover, rainwater is also used as a source of irrigation in aus and aman periods, which is totally unavailable during the boro season. Thus, boro production is extremely reliant on the water of the Teesta river. Hence, when irrigation failure occurs, production of boro is hampered. Against this backdrop, this study examines the impact of irrigation water shortages on boro production in different areas of the Bangladesh part of the Teesta basin.

Figure 4 shows that, after 2005–06, boro production in all regions started increasing rapidly except in Rangpur. After experiencing a considerable drop, production in Nilphamari, Sayedpur and Rangpur began rising steadily and that continued up to 2011–13, but a steep fall occurred with effect from 2012–13 crop year due to a crisis of irrigation water in the Teesta river. It is notable that boro production in Rangpur experienced large ups and downs over the years, compared to other regions. In 2009–10 and 2013–14, boro production was the lowest in this region. Among the regions, relatively higher production of 607,848 metric tons was achieved in Nilphamari and the lowest production of 410,176 metric tons was achieved in Rangpur during 2006–07 to 2013–14, implying that the Rangpur region is the worst affected.
Fig. 4.

Trend of boro production in different regions. Source: Authors' estimation based on data collected from BWDB. Production in thousand metric tons.

Fig. 4.

Trend of boro production in different regions. Source: Authors' estimation based on data collected from BWDB. Production in thousand metric tons.

### Extent of irrigation failure in the Teesta catchment area

A massive irrigation failure emerged in the Teesta catchment area due to scarcity of water in the Teesta river. Table 1 specifies the irrigation failure in boro season since the 2006–07 cropping year. It is seen that irrigation failure in the boro cropping period was about 85%. Then it declines gradually from the 2007–08 cropping period, i.e. irrigation water availability improves, with the failure rate down to 24.7% in 2012–13. But, in 2013–14, the failure increased sharply to 65.3%. Since there is no alternative source of irrigation in the boro season, irrigation water shortages from the Teesta river make the boro production highly vulnerable.

Table 1.

Percentage of irrigation failure in boro season due to water scarcity in the Teesta catchment area.

Cropping year Irrigation target (ha) Irrigation failure (%)
2006–07 18,450 85.74
2007–08 33,311 44.06
2008–09 44,000 62.93
2009–10 48,000 45.85
2010–11 46,000 42.05
2011–12 46,500 36.82
2012–13 67,000 24.75
2013–14 70,000 65.34
Cropping year Irrigation target (ha) Irrigation failure (%)
2006–07 18,450 85.74
2007–08 33,311 44.06
2008–09 44,000 62.93
2009–10 48,000 45.85
2010–11 46,000 42.05
2011–12 46,500 36.82
2012–13 67,000 24.75
2013–14 70,000 65.34

Source: Authors' calculation based on data collected from BWDB.

### Impact on rice production in the entire region under study

The impacts of Teesta river-based irrigation failure are translated into significant reduction of food production in this river-dependent area. Yearly reduction of rice production in the boro season in the Teesta catchment area is shown in Table 2. If the irrigation target is met in the TBIP area, no loss or damage occurs. It emerges that in 2007–8, 2010–11 and 2011–12, actual irrigation exceeds the irrigation target in TBIP areas. Subsequently, additional crop production was achieved in these cropping periods.

Table 2.

Estimated loss of production due to irrigation water shortage.

Cropping year Production damage Production loss Total production failure
2006–07 46,325.5 664,956.5 711,282
2007–08 −72,130.5 568,360 496,229.5
2008–09 94,737.5 498,881.5 593,619
2009–10 32,630 472,881.5 505,511.5
2010–11 −26 485,881.5 485,855.5
2011–12 −23,751 482,631.5 458,880.5
2012–13 47,235.5 349,381.5 396,617
2013–14 276,341 329,881.5 606,222.5
Total 401,362 3,852,855.5 4,254,218
Cropping year Production damage Production loss Total production failure
2006–07 46,325.5 664,956.5 711,282
2007–08 −72,130.5 568,360 496,229.5
2008–09 94,737.5 498,881.5 593,619
2009–10 32,630 472,881.5 505,511.5
2010–11 −26 485,881.5 485,855.5
2011–12 −23,751 482,631.5 458,880.5
2012–13 47,235.5 349,381.5 396,617
2013–14 276,341 329,881.5 606,222.5
Total 401,362 3,852,855.5 4,254,218

Production in metric tons.

Source: Authors' estimation based on data collected from BWDB.

The loss due to irrigation failure is estimated on the basis of cultivable area remaining uncultivated. That is, the amount of boro land that has had to be kept uncultivated due to irrigation failure is reflective of the loss in the boro season. It has been estimated, using the cultivated land and a standard yield rate, that the boro production failure (production loss + damages to crop) was over 0.7 million metric tons in 2006–7, which is the highest amount of loss during the years under review. The lowest production failure in the boro season was about 0.4 million metric tons in 2012–13. The total loss of boro production, in the years under consideration, is estimated at over 4.25 million metric tons. Clearly, the total loss of rice production is enormous, which indicates a high food-security risk, from own production, in the area under study, due to irrigation water shortages in the Teesta catchment area.

Figure 5 shows the overall trend of production failure in the boro season in the Teesta catchment region. It can be seen from the Figure that boro production failure is similar in the first and last of the years under consideration, while it declined, increased and then declined again in the years in-between. The two-year moving average line also indicates similar movements.
Fig. 5.

Trend of food production loss in boro season.

Fig. 5.

Trend of food production loss in boro season.

### Productivity level in different cropping seasons

It can be seen from Table 3 that agricultural productivity in the Teesta catchment area is much higher in areas that get adequate irrigation water from the TBIP, compared to the area outside the command area of the TBIP. It happened for two reasons, basically. The area close to the Teesta river is more fertile and farmers can use limitless water from the canal for irrigation at a fixed cost, which is much lower compared to deep tube-well-based irrigation.

Table 3.

Productivity of different crops in the Teesta catchment area.

Irrigated Non-irrigated
Name of crops yield (m.tons/ha) yield (m.tons/ha) Productivity loss (%)
Kharif-ii aman season Hybrid aman 6.5 8.33
Hyv. aman 25
T-aman 3.75 25
Rabi boro season Hybrid boro 6.5 7.69
Hyv. boro 20
Wheat 4.25 3.7 14.86
Kharif-i aus season Hybrid aus 20
Hyv.-T-aus 4.5 12.5
Irrigated Non-irrigated
Name of crops yield (m.tons/ha) yield (m.tons/ha) Productivity loss (%)
Kharif-ii aman season Hybrid aman 6.5 8.33
Hyv. aman 25
T-aman 3.75 25
Rabi boro season Hybrid boro 6.5 7.69
Hyv. boro 20
Wheat 4.25 3.7 14.86
Kharif-i aus season Hybrid aus 20
Hyv.-T-aus 4.5 12.5

Source: Authors' calculation based on data collected from BWDB. Note: Rabi (November–February); Kharif-i (March–June); Kharif-ii (July–October).

It seems that different types of rice cultivated in the TBIP areas are more productive than in non-irrigated areas of the Teesta basin. In the boro season, productivities of hybrid boro and hyv. boro are respectively 7.69%, and 20% higher in the TBIP areas than in those areas of the Teesta catchment that do not get irrigation water from the TBIP.

Productivity is also significantly higher in aus and aman seasons in the irrigated areas, compared to non-irrigated areas of the Teesta basin. In the irrigated areas, productivity of boro is relatively higher than that for both aman and aus crops. But boro cultivation is hampered in the Teesta catchment area due to water shortages in the Teesta river during the dry season.

It is now evident that if the non-irrigated areas can be brought under the TBIP network, production from this area will increase, provided that irrigation water can be ensured. However, under the present circumstances, the TBIP fails to meet its irrigation target in the dry season due to water scarcity in the Teesta river. If sufficient water is available in the dry season, more food grains can be produced in Dalia, Nilphamari, Sayedpur and Rangpur regions, compared to other regions in the Teesta basin, which do not get Teesta river water directly for irrigation from the TBIP irrigation network. Finally, it may be suggested that, since productivity of boro is comparatively higher than that for aus and aman crops, if boro production is hampered due to lack of irrigation water, the magnitude of loss per unit of land will be higher in the boro season than in other cropping seasons.

## Concluding remarks

The study indicates that a large part of the Teesta catchment area is adversely impacted significantly by irrigation water shortages. The areas in the north-western part of Bangladesh that are directly reliant on the Teesta river's water are mostly affected by Teesta water shortages. It emerges that rice production in Dalia, Nilphamari, Sayedpur and Rangpur is hampered substantially due to irrigation failure in the TBIP commend area. The north-western region of Bangladesh is known as the rice basket of the country, which is under the risk of significant food production reduction due to water crisis in the Teesta river. The people of the north-western region mainly depend on aman and boro production. There is no irrigation water shortage in the aman season but, in the case of boro, lack of irrigation water has emerged as a major constraining factor.

The total rice production missed in the north-western region since 2006–07 due to irrigation failure is more than the country's total rice import during fiscal years 2008–09 to 2013–14, and nearly one quarter of the total boro production in the 2012–13 fiscal year. The north-western region of Bangladesh is drought-prone and the Teesta is the only big river for irrigation water in the Teesta catchment area as well as other parts of the north-western region. Against this backdrop, a fair Teesta water sharing agreement is necessary that will ensure sustained water flow in the Teesta river in the Bangladesh part during the dry and lean period. Through such an agreement, irrigation failure can be minimized in the TBIP area and regional food production increased.

In addition to complete loss, crop damage also occurs due to irrigation shortfall, which also devastates the farmers, particularly subsistence farmers. Hence, in order to reduce crop damage, appropriate adaptation policies and actions should be taken. In order to lessen regional food insecurity, Bangladesh may take some immediate measures until the Teesta water sharing agreement is signed and implemented. Coping options in the context of crop losses and crop damage could be explored and, if available, should be undertaken to reduce losses and damage in the meantime.

Since there is no alternative source of water for agricultural production in the Bangladesh part of the Teesta catchment area, Bangladesh should keep the diplomatic pressure, on the basis of strategic mutual benefits, on India for an equitable Teesta agreement, which is now at an advanced stage of finalization. To meet the irrigation water demand in the dry season, deep tube-wells may be used to an extent, but that may cause the groundwater table to dip, and providing tube-well irrigation is much more costly. Since the north-western part of Bangladesh is relatively economically backward, farmers of this region may not able to bear the increased cost of alternative irrigation. Hence, this is not a sustainable option.

The findings of this study strengthen the socio-economic case, particularly in relation to food security, from the point of view of Bangladesh, for an equitable Teesta sharing agreement to be expeditiously signed and implemented.

The rights of lower riparians must be respected, which can be achieved through strengthened cooperation between the countries concerned. Otherwise, growing water scarcity and degradation in the lower riparians are likely to increase tensions between the concerned upper and lower riparians. Indeed, this applies to India and Bangladesh, not only with respect to the Teesta, but also concerning other major transboundary rivers.

In so far as the Teesta is concerned, an agreement has been in sight for some time now. India has assured Bangladesh that it will happen soon. When it happens, the scope of mutually beneficial cooperation between the two countries will further widen, which is already flourishing in the wake of the passing of the Land Boundary Agreement between the two countries in the Indian Parliament in May 2015, with instruments of implementation already exchanged since.

## Acknowledgements

The study is a part of Master's thesis of the Master of Environmental Economics program, which is carried out at Dhaka School of Economics, University of Dhaka. The authors are deeply indebted to BWDB and JRC for providing supporting data and information related to the study.

## References

References
Arfanuzzaman
Md.
(
2015
).
Teesta Agreement: facts, disputes and Bangladesh's game plan
.
The Daily Star
.
(accessed 7 June 2015)
.
Arfanuzzaman
Md.
Q. K.
(
2015
).
.
Daily Prothom-alo
.
(accessed 6 April 2015)
.
Asia Foundation
(
2013
).
Political Economy Analysis of the Teesta River Basin
.
Working paper. San Francisco, CA 94104
,
USA
.
(
2007
).
Country Profile – India. Water Knowledge Center Statistics. Available at:
.
(
2014
).
Annual Report, Teesta Barrage Project
.
Ministry of Water Resources, GoB
,
.
Falkenmark
M.
(
1986
).
Fresh water – time for a modified approach
.
Ambio
15
(
4
),
192
200
.
FAO
(
2012
).
Coping With Water Scarcity: An Action Framework for Agriculture and Food Security
.
FAO Water Report Series 28, 00153, Rome, Italy
.
Gram Bikash Kendra (GBK)
(
2012
).
,
.
Hamdan
M. R.
Salman
A.
(
2005
).
Impact of Irrigation Water Scarcity on the Socioeconomics of Agricultural Sector and Food Security in Jordan
.
CIHEAM
,
USA
.
Institute of Water Modelling (IWM)
(
2008
).
Executive summary
.
.
Islam
M. F.
Higano
Y.
(
2002
).
Equitable Sharing of International Waters: A Proposal for Optimal Utilization of the Teesta River
.
Working Paper
,
Institute of Agricultural and Forest Engineering, University of Taskuba
,
Japan
.
Linseley
R. K.
Kohler
M. A.
Paulhus
J. L. H.
(
1975
).
Hydrology for Engineers
,
2nd edn
,
McGraw-Hill Book Company
,
New York
.
Mirza
M. M. Q.
Hossian
M. A.
(
2004
).
. In:
The Ganges Water Diversion: Environmental Effects and Implications
.
Mirza
M. M. Q.
(ed.).
,
The Netherlands
, pp.
177
196
.
Rahman
M. M.
Rahman
M. R.
M.
(
2010
).
Establishment of dams and embankments on frontier river of north east part of India: impact on north-western region of Bangladesh
.
Journal of Science Foundation
8
(
1
).
Rashid
H.
(
2012a
).
India's proposed river linking mega project
.
The Daily Star
.
(accessed 7 March 2012)
.
Rashid
H.
(
2012b
).
Teesta water issue: a few hard facts
.
The Daily Star
.
(accessed 11 January 2012)
.
Ribera
L. A.
McCorkle
D.
(
2013
).
Economic Impact Estimate of Irrigation Water Shortages on the Lower Rio Grande Valley Agriculture
.
Study Report
.
Texas A&M AgriLife Extension Service
,
Texas, USA
.
Wirsing
R. G.
Jasparro
C.
(
2007
).
River rivalry: water disputes, resource insecurity and diplomatic deadlock in South Asia
.
Water Policy
9
,
231
251
.