University of Amsterdam (UvA)
A case study of salinization and
agriculture in post-tsunami Aceh.
Anneke ter Schuure Arash Hoseni - 10610812 Geert van Houselt - 10738525 Omar Elmecky - 10772588 Yosta Schuuring - 10808310 The Indian Ocean tsunami of December 2004 damaged approximately 30,000 ha of rice paddies in the Aceh province of Indonesia and had drastic consequences for agricultural areas along the coast of Indonesia. The Aceh region was one of the most severe damaged agricultural areas. In this research, the effects of salinization on groundwater and soils, and the resulting consequences for the inhabitants of this area are investigated. By gathering secondary data, solutions to soil salinization and the following consequences are examined. Thereafter, several different governmental approaches are being described and the most fitting approach for this case study is selected. Words: 6752 02-06-2017
Table of contents
1. Introduction ... 3 1.1. 2004 tsunami & relevance ... 3 1.2. Problem definition ... 3 1.3. Complexity of the problem ... 4 1.4. Persistence & magnitude of the problem ... 4 1.5. Research question: ... 5 1.6. Sub-questions: 1: Why does salinization continue to impact the soils and groundwater in the Aceh region? ... 5 2. Theoretical Framework ... 5 2.1. Low permeability & drainage theory ... 5 2.2. Retention time & EC values of salt theory ... 6 2.3. Sediment theory ... 6 2.4. Salt intolerance of rice theory ... 6 2.5. Insufficient government theory ... 6 2.6. Theory integration through causally linked steps ... 6 3. Selected method and data ... 7 3.1. Study site description ... 7 3.2. Soil and crops strategy ... 7 3.3. Literature Study ... 7 3.4. Organisation method ... 8 3.5. Interdisciplinary integration ... 8 3.6. Scenario’s ... 9 4. Results ... 11 4.1. AquaCrop ... 11 4.2. Literature study ... 12 5. Conclusion, discussion and recommendations ... 15 5.1. Conclusion ... 15 5.2. Discussion ... 16 6. References ... 171. Introduction
1.1. 2004 tsunami & relevance In 2004 the third largest earthquake to be ever recorded with the longest faulting duration ever observed occurred in the Indian Ocean near the west coast of Sumatra, Indonesia (National Science Foundation, 2005). The resulting tsunami first reached the coast of northern Sumatra, where it primarily struck the Aceh region (Figure 1)(Borrero, 2005). A 15 to 30 metres high body of seawater flooded the west coast of Aceh and 6 to 12 metres high waves inundated the coast of this region (Paris et al., 2007). The tsunami affected about 37,500 ha of agricultural grounds close to the Aceh’s coastline (McLeod et al., 2010). About 30,000 ha of this area consisted of rice fields and got damaged for years, primarily due salinization of the soil (ibid.). A decrease in production of approximately 120,000 tons of rice per season was the aftermath (ibid.).This caused a major problem; it resulted in a great impact on the food security in the rural areas and on the livelihood of the local farmers (ibid).
After 600 mm of rainfall in 20 days after the 2004 tsunami the salinity of the soil reduced (Rao & Greene), but remained at such a level that crop production was affected (McLeod et al., 2010), even when more than 3000 mm of rainfall had flushed the soils in the 4 years following the 2004 Tsunami (Kume et al., 2009). The rainfall leached the salts in the soils poorly due to slow movement through the floodwaters (Velmurugan et al., 2015).
Figure 1: location of 2004 tsunami. Retrieved from: http://www.geosci.usyd.edu.au/users/prey/Teaching/Geos2111GIS/Tsunami/Images/tsunami_aceh_map.gif
1.2. Problem definition In this research the aim is to bridge the knowledge gap of the overarching problem. The main overarching problem is the salinization of the ground after a tsunami and the rehabilitation of it. This is a causal problem whereby different disciplines are needed to answer it; the cause of the problem fits another discipline than the solution. Knowledge of all the disciplines is required to understand the problem and to create realistic solutions. The different disciplines are one of the complex problems of the case and also the different systems that interact with each other.
These systems are so complex that they can’t be fully analyzed in terms of elements, variables and fixed links, only a few aspects can be analyzed. In complexity thinking, not only physical but also all living and social systems that interact with each other are considered complex systems. (Cilliers,
2005).
In this research the complexity is seen in the open systems that experience external influences and can adapt to it adaptively. Think of the ecological system that can adapt to its environment that is restored by different social approaches. Also in our research, we see a non-linearity of interactions which makes it impossible to describe all the parts of the system equally, so some parts of the system will always be suppressed. Think of the natural decrease in groundwater- and soil salinity due to leaching that does not occur in a logical or linear way.
Furthermore, our research is characterized by temporality through dynamics. Salinization has always been a problem, so the core of the problem is transformed by the history, but the history is not decisive. In the next section
1.3. Complexity of the problem When this problem is going to be addressed, a few traits of complexity will emerge.
First, for the whole research in general an observer dependency is implied; this case covers multiple disciplines, and every individual within our group is limited to what they know from their own specialization. Therefore integration of disciplines on an organisational level will be required. Second, within this issue a certain non-linearity is present; the natural decrease in groundwater- and soil salinity due to leaching does not occur in a logical or linear way, which is generally the case with brackish water or saline soils (Richards, 1969). This makes it a more troublesome challenge to calculate salt levels over time after a tsunami occurs, and to determine the measurements needed to recover the soils. Third, the natural resilience that the soil ecosystems in the Aceh province hold is important to study and consider. Because, only then the artificial actions needed to bring salt levels back to standard and favourable conditions can be accurately stated. Furthermore, the resilience of a certain ecosystem is difficult to assess due to the complex interactions that drive this self-organisation, but with an adequate understanding of this natural resilience it may be possible to improve this.
Fourth, an important trait of complexity that arises is hierarchy, stating that solutions at one operational level can be ineffective when an higher level impedes them. For example, Some biological interventions for the reclamation of agricultural soils may not be feasible to get implemented by the government.
1.4. Persistence & magnitude of the problem
There are a few things causing the persistence and the magnitude of the problem.
First, the lack of adequate drainage, due to dikes around the rice paddies, and hard compressed layers in the soil, the clay pans, were believed to be the cause of a long retention time and thus a poor leaching of the salts (McLeod et al., 2010). Furthermore, sand and and clay deposition by the tsunami also reduces the leaching of salts and causes soil salinity to remain high, even after months of rainfall (Moore et al. 2006). The magnitude of the problem is significantly increased by the fact that salinization of the rice paddies soils and groundwater causes lower production rates in agriculture, due to the low salt tolerance of the rice crop varieties that are currently being cultivated at the rice paddies. (McLeod et al., 2010). Finally, the persistence of the problem maintains because the Indonesian government suffers from corruption, and lacks a sufficient amount of aid to help the inhabitants of the Aceh region (Thorburn, 2009).
A literature research identified a set of technologies or approaches to recover saline soils or to target rice cultivation on saline soils.
First, reducing infiltration capacity and improving drainage can protect the soil and groundwater from salt intrusion (Villholth et al, 2005; Hogan et al, 2006). Secondly, applying the so-called “Green manures” and/or gypsum and/or FYM on salinized soils, stimulates the reclamation of the saline soils (Vakeesan et al., 2008, and Harris & Rengasamy, 2004, and Cha-um et al., 2011). Third, gene
pyramiding, which is practically stacking favourable genes into the genome of a certain strain, by crossing existing rice varieties can bring new efficient salt tolerant species. (Gregorio et al., 2002, and Dionisio-Sese & Tobita, 1998, and Aslam et al. 1993). Fourth, genetic modification (GM) can be practiced to develop salt tolerant crop species by altering the genetic make-up of a plant. (Flowers, 2004, and Xu et al. 1996, and Bohnert & Jensen 1996, and Gerg et al. 2002)
Fifth, there are three theories in the form of governmental approaches that each give a possible scenario describing the constraints and possibilities of that approach. These approaches are neoliberalism, the bottom up approach and the top down approach.
In this research an assessment will be made on how can be dealt with the impacts of such a Tsunami as occurred in 2004, in particular with the impacts of salinized soils. To investigate this complex problem and to provide possible solutions an interdisciplinary approach is required. Thus, the experiences from the disciplines earth sciences, biology and human geography are needed to address the three different steps of which problem is divided. The focus of the earth scientists is on estimating the salt levels in these soils due to inundation of seawater and their diminution over time. These estimations of salt concentrations is needed by the biologist to investigate which, till what extend and at what time biological practices can redress or persevere these levels of salinization. Furthermore, an assessment of the different possible governmental approaches is made by the social scientist to determine the possibilities for rehabilitation and adaptation, for example, to reveal with which governmental approach a certain biological solution is feasible.
The main goal of this research is to provide sufficient answers on the following research question and sub-questions:
1.5. Research question:
How can impacts of the salinization of farmlands after a tsunami in the Aceh region of Indonesia be mitigated?
1.6. Sub-questions: 1: Why does salinization continue to impact the soils and groundwater in the Aceh region? 2: What are the possible biological solutions to recover or adapt to salinized soils?
3: What kind of governance type is the best for the recovery of the salinized farmlands of the Aceh region after a tsunami?
2. Theoretical Framework
The problem that is being investigated during this research is analysed by selecting relevant information concerning this project, and are formulated as theories. These theories each propose a mechanism or make a certain statement that help to create a clearer picture of the overall problem. As has been said above, the overall problem can be divided in three different steps and each sub-question, also stated above, addresses one of these steps. Also, the theories described below each address only one step of the problem. 2.1. Low permeability & drainage theory To start off, the low permeability & drainage theory states that impermeable clay pans in the soils underlying the rice fields reduce the vertical movement of the seawater due to small pore spaces inthe silty loam and clay layers. This causes reduced leaching rates and therefore they contribute to an increasing salinity (Mcleod et al. 2010). However, Mcleod et al. does not describe the advantages of the clay pans. The clay pans do protect the groundwater from salt water intrusion. Furthermore, the clay layers can be easily removed after inundation. Moreover, the dikes that are being used to keep water in the rice paddies also cause a low drainage (ibid). 2.2. Retention time & EC values of salt theory The retention time & EC values of salt theory describes that as the cultivation of rice largely depends on standing water, the rice paddies tend to have a long retention time for the inundated sea water. The resistant clay pan and dikes that prevent drainage, enhances the retention time and soil salinity over time. After the 2004 tsunami flooded the Aceh region of Indonesia, EC values were up to 50% higher when inundated areas had a retention time of 6 days compared to 3 days (Mcleod et al. 2010). 2.3. Sediment theory The sediment theory aims to describe the fact that a tsunami not only causes sea water inundation but also brings large amount of sediments like clay and sand. These depositions change the soil horizons and features. The sandy sediments deposited by a tsunami consist of badly sorted sand and soil clast units (Moore et al. 2006). These sediments reduce the percolation rates of water and decrease the ability of the soil to leach salts (Food and Agricultural Organization, Saline soils and their management). 2.4. Salt intolerance of rice theory The salt intolerance of rice theory claims that when a soil gets too salinized, the production of rice and other agricultural crops will be negatively affected (McLeod et al., 2010). This is under the assumption that the crops are not, or harder to be, cultivated under saline conditions. Then, when the damage to an agricultural system is too severe, social impacts like food security will become an issue that is to be addressed (McLeod et al., 2010). For this theory the assumption is made that a developing country, like Indonesia, is being considered and that the crop production is meant for local distribution. 2.5. Insufficient government theory The insufficient government theory describes that Indonesia is considered a developing country and suffers on a large scale from corruption and lacks a sufficient amount of aid to help the inhabitants of the Aceh region (Thorburn, 2009). 2.6. Theory integration through causally linked steps As has been said above, the overall problem can be divided in three different steps and each sub-question, also stated above, addresses one of these steps. Also these theories each address only one step of the overall problem (Figure 2).
Figure 2: Schematic picture of how the theories are integrated through the different causally linked steps they each address.
3. Selected method and data
3.1. Study site description During this research the Aceh region in Indonesia will be investigated. The Aceh region has been heavily damaged by the 2004 tsunami and agricultural soils showed high salinity even 5 years after the tsunami (Marohn et al. 2012). Many aspects of our research will rely on a case study, this will mainly be the 2004 tsunami. 3.2. Soil and crops strategy By modelling in AquaCrop different soils and crops can be impeded in a model. To make an AquaCrop model data about soil types in the Aceh region of Indonesia will be needed. Travelling to the Aceh region to collect soil samples is not feasible, however, secondary data such as scientific articles and journals can be used. Based on collected secondary data, two soil types can be collected to for this research: Entisols and Inceptisols. These soil types can be used to create a model in AquaCrop. For each soil, first the initial position is established, this is the natural state, in which no salt or O horizon is added. After that, for each soil a second state is established in which high amounts of salt and clay (O horizon) are added. To estimate the effect of precipitation on leaching and groundwater salinization also water is added. By addition of large amounts of salt and clay to soils, the damage to crops and soils can be calculated. Additionally, specific secondary data such as soil characteristics will be used in the AquaCrop model. The outcome of the AquaCrop model would be of a significant use when conducting research about the effects of a higher salinity in soils on crops. To stay critical, a comparison should be made between our results and outcomes of the used scientific articles and journals. 3.3. Literature Study Furthermore, information about effects on crops, social effects and effects on soils will be gained through a literature study. Different scientific articles and journals will be studied. Furthermore, information from each discipline is needed to study other disciplines. Hence, an interdisciplinary approach is needed in the literature study.
3.4. Organisation method As mentioned in the theoretical framework, this research requires an integration technique to asses all the different disciplines. An integration involves modifying or redefining related concepts in different disciplines to bring out a common meaning. This research aims to use an organisation integration technique. This technique organises and arranges causal links between different disciplines. All the disciplines combine and influence each other under an umbrella of organisational behaviour. Hence, This research aims to integrate the different disciplines and theories using the organisation method, where the different theories from different disciplines are linked together in an causal, almost chronological structure (Figure 3); a salt water-flood causes salinization of the soils and groundwater of the Aceh region, subsequently, this has an impact on agriculture in the form of a decrease in crop yield, and therefore food security in the Aceh region becomes at risk because it largely depends on local distribution of the rice, which makes it a social problem. Hence, by describing all the theories and redefining them within the separate disciplines, links can be generated using the organisation method to integrate the disciplines as a whole. Figure 3: visualisation of the organisation method used in this research 3.5. Interdisciplinary integration First, this research covers multiple disciplines, and every individual discipline within our group is limited to what they know form their own specialization. Therefore integration of the disciplines on an organizational level will be required. Where the different theories from different disciplines are identified, redefined and linked together in an overarching, almost chronological structure (figure 2). Therefore, each group member conducted its own literature study, from which theories were collected. These theories then are linked together in a framework from which the assessment follows. This assessment evaluates on how can be dealt with the impacts of salinized soils after a tsunami such as occurred in 2004. Figure 4 (next page) provides a visualization of the causal links after a tsunami occurs in a chronological structure described next. First, the problem definition is given. At location first the characteristics should be interpreted, both
physical and social, from which the initial conditions are determined. Where the amount of salinization influences the social characteristics of the region (food security). After which, different solutions for adaptation and mitigation are offered. “Green manures” decrease the amount of salinization, where GM and tolerant breeding just adapt to it. Finally, the social applicability of the solutions should be considered. Where social and political support influence the amount of participation of stakeholders, as does the economic feasibility. 3.6. Governmental approaches To answer the third sub-question there are three different scenarios described based on three different types of governance. The three different types of governance are linked with each other and al describe a different way of governance. In the results the different governmental approache are linked with the findings of other disciplines, that for each discipline resulted from the use of secondary data; literature reviews of scientific articles, which will create the three scenarios that can occur. By linking the multiple fields of interest and discussing scenarios, the theories can be linked to one another to provide an answer to the main question. First the three different types of governance are discussed. Finally, these governmental approaches are the tool for creating scenarios to answer the third sub-question by creating scenarios. The three types of governance that were found during the literature research are neoliberal, adaptive and inclusive governance. According to Folke et al. (2005), governance is about building circumstances to rule and shared force or organizations of social coordination. Also, governance is about what people are in the society making decisions and share power involving the systems and actions. Karpouzoglou (2016) describes governance as the process of re-answering created pacts and outlining a policy for sustainability. The first type of governance described is ‘adaptive governance’. According to Chaffin (2016) adaptive governance is a large growing concept in the past 18 years. Adaptive governance is a way of resource management in a system that is highly adaptable that allows for rules to be sharpened based on assessments conducted in a certain field of knowledge. This creates adaptive governance of social-ecological systems where social sciences and physics interact with each other (Dietz, 2003). Adaptive governance suggests the decentralization of the authority rights and power-sharing that improves participation. This doesn’t mean that the decentralization certainly results in an adaptive authority therefore are first social networks needed (Folke et al., 2005). Furthermore, Folke et al., (2005) describes that leaders can play a crucial role for adaptive governance, think of governing conflicts, collecting and creating knowledge, and connecting different stakeholders. The issue is that individuals most of the time also evolve opinions about ecosystem management and social networks, but the problem is that these individuals are not able to manage due to a lack of knowledge. When leaders have shortcomings, it can result to stillness in the social-ecological systems. Adaptive governance aims on knowledge and experimentation and it links development and governmental organization for co-operating to find solutions for conflicts according to natural resources and ecosystem management (ibid
