Chapter 2: Exploring the Effects of Land Use and Land Cover Change on White-Eared Kob Migration in the Gambella Region, Ethiopia

Grey Benjamin, Colin Cummings & Ellen Evangelides

To download a pdf of this chapter (975 KB), please click here

View Chapter 2 Presentation

Research Highlights

• White-eared kob undergo the second largest mammal migration in Africa.
• This report examines the effects of land cover change on the white-eared kob migration in the Gambella Region.
• The Gambella Region is rich with diverse landscapes, wildlife, and people.
• Gambella National Park, established in 1973 to protect the region’s diverse flora and fauna, currently lacks resources for management and enforcement.
• Anthropogenic factors, such as expanding human populations and large-scale agricultural development, threaten ecosystems in the Region.
• Geographic Information Systems (GIS) analyses show how white-eared kob depend on threatened ecosystems.
• Findings suggests a need for continuing land and wildlife data collection efforts and facilitating working relationships among local communities, government agencies, conservation groups, and commercial agriculture operations to improve land use practices in the Gambella Region.

Executive Summary

The Gambella Region in southwestern Ethiopia boasts an ecologically rich landscape comprised of diverse ecosystems, wildlife, and human populations. Historically, the region has remained largely unsettled, but rising human populations, ethnic conflicts, food insecurity, and foreign agricultural investments have increased competition for land. In an effort to protect its valuable ecosystems and wildlife, the Ethiopian government created the 5,000 square kilometer Gambella National Park in 1973. However, due to resource constraints, the park has largely lacked management and enforcement since its inception. As a result, both small and large-scale human developments threaten wildlife in the area today.

One key species of particular concern is the white-eared kob. This iconic antelope undergoes the second largest mammal migration in Africa, crossing the border between Ethiopia and South Sudan each year in numbers reaching 250,000 or more. Conservation organizations working in the Gambella Region have become increasingly concerned for the white-eared kob, not only for its unique trans-boundary migration, but also for the kob’s dependence on land with significant economic potential for local farmers, international agricultural investors, and regional tourism development. Anthropogenic threats to kob include, but are not limited to, growing human settlements, expanding livestock grazing, and conversion of natural habitat to commercial agricultural production. In order to ensure the uninhibited migration of this species in Gambella, more information is needed on the relationships among humans, land, and wildlife of the region.

This paper uses Geographic Information Systems (GIS) to explore the extent and type of land use and land cover change in western Ethiopia since 1984, with a focus on the possible effects of such changes on white-eared kob migrations in the Gambella Region. Drawing on a combination of satellite imagery, systematically classified aerial photographs, and detailed white-eared kob migration data, this study analyzes the movements of white-eared kob in relation to vegetation density, vegetation type, and the distribution of anthropogenic factors in the region.

Findings suggest that human development and environmental degradation may be having adverse effects on wildlife. An examination of white-eared kob migration and land cover change over time reveal that white-eared kob depend on wetland ecosystems. Further, land cover type analysis shows that savannah grasslands, wooded grasslands, and wetlands are the preferred habitat for the white-eared kob, highlighting these land types as important conservation priorities. Finally, analysis of human activity within the Gambella Region illustrates that the land is under significant anthropogenic pressure, emphasizing the need for concerted efforts toward conservation land management, incorporating the full array of local, regional, national, and international stakeholders.

1. Introduction

With the combination of extreme poverty and a rapidly growing population, which is expected to more than triple by 2050, Ethiopia is facing extraordinary strains on its natural resource base (Suddath, 2011; World Bank, 2013). Roughly 85% of the Ethiopian population resides on rural lands and makes a living from small-scale agriculture (Horne, 2011). But due to drought, famine, and food price spikes, Ethiopia has faced chronic malnutrition and food insecurity, becoming the largest recipient of food aid in the world (Horne, 2011; United States Agency for International Development (USAID), 2013). In this context, Ethiopian environmental policy – including sustainable land management – has remained a secondary priority relative to issues of poverty and human health (World Bank, 2013). With increases in the sale of public lands to foreign investors for large-scale commercial agricultural development, the Ethiopian government has tried to improve the overall economic and food security of the general population (Abbink, 2011). However, such policies and projects can threaten both human and wildlife populations that inhabit areas adjacent to large-scale agricultural development activities (Rahmato, 2011). In the Gambella Region alone, the government has made over 800,000 hectares of land – or 32% of the total land area of the region – available to investors (Horne, 2011). Such development initiatives can have, and have already had, devastating effects on the vitality of both human and wildlife populations in this area (Liu, Sinha, & Stern, 2013; Rahmato, 2011; TFCI, 2010).

Spanning more than 29,000 square kilometers – or 2.6% of the total land area of Ethiopia – the Gambella Region boasts an ecologically rich landscape comprised of diverse ecosystems, wildlife, and human populations (Gambella’s Hidden Treasures, 2012). To the east lie rugged mountain peaks and highland forests, while vast savannah grasslands and wetlands dominate the lowlands to the west (Horn of Africa Regional Environment Center and Network (HoA-REC&N), 2013). This area is also home to diverse wildlife, including the rare Nile lechwe, the endangered shoe-billed stork, and the iconic white-eared kob, which undergoes the second largest mammal migration in Africa (HoA-REC&N, 2013). It is estimated that over 250,000 white-eared kob migrate between the Boma Region of South Sudan and the Gambella Region of Ethiopia each year, making this expansive area important for biodiversity conservation (van Aarst, 2012).

Human inhabitants add to the complexity of current competition for land in the Gambella Region. In 2007, the Central Statistical Agency of Ethiopia (CSA) indicated that just over 300,000 people, representing at least six different ethnic groups, inhabit the Gambella Region, amounting to a very low relative population density of 10 individuals per square kilometer (Central Statistical Agency, 2007). As a result, the Gambella Region represents a unique cultural mosaic, permeated with natural resources and biodiversity that have remained relatively untouched over the years (HoA-REC&N, 2013).

Recently, however, with a rise in government-supported large-scale land acquisitions for commercial agriculture development, concern for the rural livelihoods, diverse ecosystems, and rare wildlife of the Gambella Region has come to the forefront of national and international debates (Abbink, 2011; Horne, 2011, 2012; Pearce, 2011). The aforementioned white-eared kob population is of particular concern for its trans-boundary migration pattern, overall importance in ecosystem functioning, and economic potential for ecotourism development (Pearce, 2011; TFCI, 2010). In 1973, to protect this and other iconic and endangered Ethiopian species, the Ethiopian Wildlife Conservation Authority (EWCA) created the 5,000 square kilometer Gambella National Park (TFCI, 2010). Lacking specific boundaries, resources, and management, however, the Gambella National Park remains a ‘paper park,’ its boundaries having never been ratified at the federal level (TFCI, 2010). Recently, EWCA has proposed, and begun implementing, new park boundaries in hopes of overcoming its ‘paper park’ status (van Aarst, 2012). Despite the more irregular shape and slightly smaller area of the revised park boundaries, an officially recognized and physically established Gambella National Park could protect several integral species, among them being the white-eared kob, whose rarity led to the initial park proposal four decades ago (Gambella’s Hidden Treasures, 2012). To gain a better understanding of the ecology of the park, EWCA has teamed up with several other conservation organizations to form the Trans Frontier Conservation Initiative (TFCI) Task Force. The task force conducts seasonal aerial surveys to systematically collect data on the flora, fauna, and people of Gambella National Park (TFCI, 2010).

Considering all of the aforementioned socioeconomic factors, including a rise in human population (Suddath, 2011), food security crises (Horne, 2011), a diversity of ethnic groups in competition for land (Horne, 2012), and foreign investments in large scale commercial agriculture (Pearce, 2011), the Gambella Region represents a unique area for studying the effects of land use and land cover on ecosystems and wildlife. This research aims to assess the combined effect of these socioeconomic factors on the migration patterns of the white-eared kob in the Gambella Region. Specifically, we seek to answer the following research questions:

• How have historical land cover changes between 1980 and 2013 impacted areas of potentially critical white-eared kob habitat, and thus the behavior and vitality of this iconic species?
• How are current land cover types and land uses related to white-eared kob migration patterns within the Gambella Region of Ethiopia?

In addition to analyzing the effects of land cover and land use change on the white-eared kob migration in the Gambella Region, this research also explores the methodological question:

• How accurately do remote-sensing based analyses of land cover using Landsat imagery reflect on-the-ground land cover as determined by high-resolution aerial photographs?

We first outline the associations between the economic, social, environmental, and political conditions that currently define Ethiopia in general. We then narrow our focus down to the issues of large-scale land acquisitions, encroachment of human settlements, park management, and wildlife protection in the Gambella Region. With the combination of a preliminary literature review, pioneering GIS mapping and analyses, and collaboration with key stakeholders, we aim to support ongoing efforts to identify opportunities for land use management in the Gambella Region that strike a balance between the protection of white-eared kob and the social and economic opportunities offered by the Gambella Region’s vast natural resources.

2. Background

2.1. Historical Context

A long history of government-controlled land management practices have cumulatively led to the current competition for land in the Gambella Region. In the early 1970s, around the time when Gambella National Park was first established, Emperor Haile Selassie imposed an agricultural feudal system in Ethiopia defined by unequal landholdings, exploitative labor relations, and sharecropping (Devereux & Guenther, 2009). Under this system, Ethiopia was especially vulnerable to devastating famine, as seen in 1974 when a major famine crippled the country and led to the overthrow and replacement of Haile Selassie by Colonel Mengistu Derg (Devereux, Teshome, & Sabates-Wheeler, 2005). With this change of power, Ethiopia transformed into a dictatorial regime that forcefully and radically changed the system of landholdings: between 1976 and 1991, the Derg regime created an equal per capita redistribution of all farmland across rural Ethiopia (Devereux & Guenther, 2009). Although the objectives of this shift included ridding the country of unequal land control, improving agricultural productivity, and increasing rural incomes, this regime ultimately led to an era of “militarization, war and repression, the worst African famine of the twentieth century, economic stagnation and failed development programs” (Devereux et al., 2005). After an even more devastating famine in 1984, the Derg regime lost power in 1991, giving way to Meles Zenawi and the Tigray People’s Liberation Front (TPLF), which later became the Ethiopian People’s Revolutionary Democratic Front (EPRDF). Despite the transition in power, the Derg system of communal access and state ownership of land remained largely intact (Devereux & Guenther, 2009). In contrast to earlier regimes, however, Meles Zenawi and the EPRDF brought a new political objective and focus to federal land policies – economic development of the agricultural sector (Abbink, 2011).

Under Prime Minister Zenawi, the Ethiopian government created the Agricultural Development-Led Industrialization (ALDI) strategy in 1996, a top-down land management system defined by large-scale agricultural projects and investments (Abbink, 2011). This program marked the beginning of the Ethiopian government’s emphasis on the importance of commercial farming to create economic growth and improve household food security (Devereux, 2000). Initially, government policy encouraged domestic investors to cultivate land for commercial agricultural purposes, which would boost the economy and lead to improvements in smallholder agriculture (Gebreselassie, 2006). Soon, however, the Ethiopian government invited foreign investors and companies to lease large plots of lands to further boost agricultural production and exports. These foreign investors acted as stakeholders that would not be politically contentious and that had access to more capital and distinguished distribution channels. This gradual process gained momentum as a result of the global food crisis of 2007 and 2008, leading to the creation of programs such as the Plan for Accelerated and Sustainable Development to End Poverty (PASDEP), initiated in 2005 by the World Bank and other private donors (Abbink, 2011; Ministry of Finance and Economic Development (MoFED), 2006).

With issues such as poverty and food insecurity at the forefront of Ethiopian politics, the expansion of large-scale commercial agricultural practices have accelerated based on the notion that such an effort could help ensure economic benefits, contribute to poverty eradication, and provide health and food security benefits (MoFED, 2006). However, such development may threaten the vitality of indigenous communities and wildlife species (Rahmato, 2011; TFCI, 2010). The historical transition in land management policies and objectives discussed above offers some explanation for why competition for land in the Gambella Region has become ever more contentious. With the Ethiopian government increasingly invested in large-scale commercial agriculture development, consideration for smallholder farmers, land conservation efforts, and, of course, wildlife populations have at times taken second stage (Horne, 2011). The appointment of Hailemariam Dessalegn as Prime Minister in August 2012 represented a peaceful and constitutional transition of power (World Bank, 2013). With the new national leadership, as well as the rise of regionalization, which has shifted regulatory power from the federal to state and regional governments, individual Ethiopian regions now control the management schemes for parks and protected areas within their jurisdictions ( Lee & Roberts, 2012; Horne, 2011). With increased political support, international and national groups have begun to advocate for the protection of land in the Gambella Region, and the people and wildlife that it supports.

2.2. Formal Institutions

The rise of regionalization in the Ethiopian regulatory system requires expanded consideration of both the formal and informal institutions contributing to land management policies and practices in the Gambella Region. At the international level, Ethiopia is entrenched in formalized environmental treaties, strategic frameworks, and conventions that have set goals and objectives to combat environmental issues, such as land degradation (EPA, 2011; Human Development Report, 2007/2008). However, the conflicting and diverse environmental, economic, and ultimately political interests of involved nations and multinational corporations have stunted these international efforts (Amsalu, & Genremichael, 2010). In this context Ethiopia has continued its focus on large-scale agricultural projects, which may improve food security, but may also impact the long-term sustainability of land that supports several communities, wildlife, and ecosystems (Rahmato, 2011).

At the national level, federal and state governments in Ethiopia have numerous formally defined objectives related to land management and protection (Gessesse, 2010). Overall, the national regulatory framework regarding environmental protection, as represented by the 1995 Constitution of the Federal Democratic Republic of Ethiopia, illustrates national focus on environmental protection with conditions such as:

• Government shall endeavor to ensure that all Ethiopians live in a clean and healthy environment;
• The design and implementation of programs and projects of development shall not damage or destroy the environment;
• People have the right to full consultation and to the expression of views in the planning and implementations of environmental policies and projects that affect them directly; and
• Government and citizens have the duty to protect the environment (Constitution of the Federal Democratic Republic of Ethiopia, 1995).

However, the 1995 Constitution may not reflect the on-the-ground practices in regions such as Gambella. As an area with high potential for ecotourism and commercial agriculture development, the Gambella Region may represent an area prone to human activity and development projects that may impact the environment.

With this in mind, current collaboration between international and national – and government and non-government – institutions working in the Gambella Region highlights that some groups consider protecting and managing vulnerable areas a priority In the “Sustainable Development of the Protected Area System of Ethiopia (SDPASE) Mid-Term Evaluation in 2012,” the Ministry of Culture and Tourism reported that the interest in Gambella, and in the National park in particular, “has accelerated since the scale of the white-eared kob has become apparent” (Williams & Tefera, 2012).

Specifically, the Ethiopian Wildlife Conservation Authority (EWCA), a formal institution operating on a national level and housed in the Ministry of Culture and Tourism (MoCT), works to “scientifically conserve and manage Ethiopian wildlife and its habitats in collaboration with communities and stakeholders for the ecological, economical, and social benefits of the present generation, and pass to the next generation as a heritage” (Ethiopian Wildlife Conservation Authority (EWCA), 2012). EWCA works to protect wildlife in sanctuaries and national parks, such as Gambella National Park. Further, EWCA has worked with Addis Ababa University (AAU) and several other organizations to establish the Trans Frontier Conservation Initiative (TFCI) Task Force to assess, develop, and implement a strategic land management plan for the Gambella Region (TFCI, 2010; van Aarst, 2012).

Two of these other organizations include the African Parks Network, a nonprofit that works to enhance long-term management of national parks through economic initiatives (African Parks, 2013), and the Horn of Africa Regional Environment Centre and Network (HoA-REC&N), an international NGO that works directly in Djibouti, Ethiopia, Kenya, Somalia, South Sudan, and Sudan to advocate for environmental conservation and management of natural resources (HoA-REC&N, 2013). In addition to its involvement in the TFCI, HoA-REC&N is leading an effort known as the Ecosystem Management & Conservation Programme to create a strategic land management plan that will offer benefits to all stakeholders linked to the Gambella Region.

The institutional composition of this collaboration highlights the complexity of interests – environmental, economic, and social – in the Gambella Region. With this multi-level approach (Table 1), these institutions are currently working to manage, protect, and utilize the Gambella Region’s communities, wildlife, and economic opportunities, respectively.

Table 1. Partner institutions contributing land use planning in the Gambella Region, Ethiopia.

Institution	Level/Type	Organizational Focus within Gambella
Ethiopian Wildlife Conservation Authority (EWCA)	National/Government	Wildlife protection and park management
African Parks Network	International/NGO	Economic sustainability and tourism
Horn of Africa Regional Environment Centre and Network (HoA-REC&N)	International/NGO	Land use and development plans to ensure biodiversity conservation, wildlife protection, and further institutional capacity

2.3. Informal Institutions

Informal institutions, such as local communities, provide another lens for framing natural resource management and conservation in the Gambella Region. Often, informal institutions represent the unwritten rules, norms, values, and belief systems that permeate local communities and culture (North, 1991). In the Gambella Region, the presence of six major ethnic groups – Nuer, Anuak, Majangere, Opo, Komo, and the general category “Highlander” (referring to Ethiopians from the Central Highlands) – as well as many Sudanese refugees, creates cultural and ethnic differences that have led to conflicts regarding use and management of land (Horne, 2012; Sewonet, 2003). Groups in the area are known to use traditional systems to administer and manage land, including the establishment and understanding of boundaries based on local customs, and resolving land conflicts using community forums (Horne, 2012). However, with the presence of multiple ethic groups, traditional management systems often conflict with one another, such as those that have been documented between the Nuer and Anuak since the 20^th century. With groups inhabiting the same area, they have historically worked together to create reciprocal relationships solve conflicts internally. However, with the population and demand for land rising, coupled with the fact that power over the land lies in the hands of the local administrations, the historically-established “conflict resolution mechanisms” between elders have started to disappear (Sewonet, 2003).

However, some researchers believe that collaboration of these groups remains a viable option for successful conservation and land management efforts. Specifically, Tessema, Lilieholm, Ashenafi, & Leader-Williams (2010) used focus groups and household surveys to learn about the opinions that a sample of local communities in Ethiopia have regarding nearby wildlife and protected areas of land, finding that most participants in the study supported the existence of both (Tessema, Lilieholm, Ashenafi, & Leader-Williams, 2010). Although local support for land conservation and wildlife protection may exist within Ethiopia, the story may very well be different within the Gambella Region, not only due to its culturally diverse inhabitants, but also the fact that the Ethiopian government considers the land “unused” or “underutilized” (Horne, 2012). The effective management and protection of the land in the Gambella Region will depend highly on the cooperation of all formal and informal institutions. As outlined in the Trans Frontier Conservation Initiative (TFCI) Task Force Aerial Survey Report (2010), competition for land in the form of human settlements, wildlife populations, and commercial agriculture enterprises in the Gambella Region highlights the need for this collaborative effort.

This research ultimately seeks to understand the relationships between the aforementioned formal and informal institutions by identifying how the behaviors and decisions of these groups and agencies affect the use of land in the Gambella Region and how that, in turn, affects the migrations of white-eared kob. Demonstrated through thorough preliminary research, as well as through aerial photo and GIS analyses discussed in the next section, the white-eared kob is a frequent inhabitant of this region of Ethiopia. With this in mind, the kob offers a unique and compelling opportunity to explore the relationship between the environment and society, and for an array of stakeholders to work together to create an effective land and wildlife (i.e., white-eared kob) management plan for the Gambella Region.

3. Methods

This study uses Geographic Information Systems (GIS) to examine land cover and land uses over time in the Gambella Region, with a focus on the migration routes of the white-eared kob. Data include United States Geological Survey (USGS) Landsat satellite-based remote sensing images, aerial photographs of land cover and land uses in the region, global position system (GPS) collaring data of migrating white-eared kob, and regional boundary layers from DIVA_GIS and the Ethiopian Mapping Agency (EMA).

Geospatial data for land cover were obtained via the USGS Landsat program. Since the early 1970s, the National Aeronautics and Space Administration (NASA) has sponsored the Landsat program, providing freely available 30 meter by 30 meter resolution satellite imagery of the earth’s surface (United States Geological Survey (USGS), 2013). Past studies have deployed satellite imagery and aerial photographs to analyze change in temporal remotely sensed data (de Mûelenaere et al., 2012). Our research used similar tools to assess the accuracy of remote-sensing based analyses and analyze land use change and type.

A team from HoA-REC&N, working under the Ecosystem Management and Conservation Program in the Gambella Region, provided much of the raw land cover and wildlife data for this report. This team conducted an aerial survey in the dry season of the Gambella Region between April and May of 2013. These systematic reconnaissance flights used specified transects, flight altitude, and speed to assure consistency (van Aarst, 2013). Among these photographs, the project partners coded 218 images as a key for classifying vegetation type. Further, this research team also supplied GPS collar data of current white-eared kob migration patterns in the Gambella Region. All data were analyzed using ESRI ArcMap 10.1 and the open-source statistical software package R. Specific analyses undertaken are summarized in sections 3.1 through 3.3.

3.1. Landsat Satellite Imagery & NDVI Processing

First we downloaded scenes from Landsat to create clear and cloud free maps of the Gambella Region in both the wet and the dry seasons across three time periods (see Appendix I for Landsat satellite imagery data tables). For the dry season, scenes range from February to April, and for the wet season, scenes range from November to December. The three time periods were specified as follows: 1984-1986, 1999-2002, and 2012-2013. To cover the entire Gambella region, we needed six scenes of data per year and season.

Next, we used the data processing software RStudio to calculate the Normalized Difference Vegetation Index (NDVI) for all Landsat data (see Appendix II for detailed Landsat satellite imagery and NDVI processing). NDVI is an indicator of green biomass and tree density on a piece of land, which helps understand the overall extent and density of vegetation in the region. To accomplish this, NDVI combines the energy absorbed by chlorophyll in the red sector of the electromagnetic spectrum (RED) with the opposing energy deflected by the internal structure of leaves in the near-infrared (NIR). NDVI then calculates this difference as an estimate of vegetation greenness using the following formula:

NDVI = (NIR-RED)/(NIR+RED)

This calculation yields a range of pixel values from -1 to 1; typically, negative values represent the absence of vegetation and positive values represent vegetation presence (Martinuzzi et al., 2008). Using ArcMap 10.1, we then mosaicked these processed NDVI layers into a single map for the wet or dry seasons in 1984-1986 (Appendix III; Figure 1), 1999-2002 (Appendix IV; Appendix V), and 2012-2013 (Figure 2; Appendix VI).

Finally, with detailed NDVI Landsat data for the region across three time periods, raster subtractions yielded changes in vegetation cover across time periods. By incrementally subtracting these layers, the increases and decreases in vegetation cover became evident. Figure 3 reveals substantial vegetation gain (shown in green) in many places. The 1980s were years of severe drought in Ethiopia, and thus some vegetation gain can be seen throughout the region (Bewket & Conway, 2007). Widespread annual rainfall differences also account for some of this slight vegetation gain throughout the region. Despite this, significant vegetation loss (shown in red) is present both in the east, along forest edges, and in the west, with increased human presence. Some of this loss is likely due to forest clearing for agricultural purposes (e.g. along river edges). In some places, however, these large-scale agricultural developments are misleading in that they appear as vegetation gain. As shown in the top inset of Figure 3, although this area appears green, representing vegetation gain, it is an example of forested land cleared for agricultural operations. See Appendix VII for further detail on the raster subtraction process.

3.2. Assisted Automated Land Cover Classification

Following this NDVI map generation and subtraction, our second step was to classify land cover by coding high-resolution aerial photographs of the Gambella Region for vegetation density and type. A preliminary dataset, provided by HoA-REC&N, included 218 pre-coded photographs, illustrating the key vegetation types of the region. After training student coders in the identification of land cover in these pre-coded photographs, we were able to classify 1,477 photographs, first by land cover density and then by land cover type. Figure 4 depicts the location of these photographs in relation to Gambella National Park.

To systematically code each photograph, we used a binary coding scheme, assigning a value of “1” to any photograph depicting a certain land cover density or type, and a value of “0” to any photograph not depicting that land cover density or type. Beginning with land cover density, we coded each photograph for one of four density categories: open grassland, savannah grassland, wooded grassland, and woodland (Table 2). Figure 5 presents sample photographs of the four density categories. We coded photographs as open grassland if they depicted landscapes with less than 5% tree cover and as woodland if the photo showed more than 80% of tree cover.

Table 2. Tree-cover density classification.

Next, to further characterize land cover type, we coded all wooded grasslands and woodlands as one of ten land type categories. These categories consist of combinations of the following tree species found in the Gambella Region: Acacia, Balanites, Boswellia, Kigelia-Ficus, Tamarindus, and Ziziphus. Table 3 lists the number of photographs coded as each of the four density categories and Table 4 lists the number of photographs coded as each of the 11 land cover types, based on tree species.^[1]

Table 3. Summary of aerial photograph land-cover density coding.

Table 4. Summary of aerial photograph land-cover type coding.

After manually classifying the 1,477 photographs by land cover density and type, we created an automated land cover classification scheme for the region. Using ArcMap 10.1, we geo-referenced the manually classified photographs as points. As illustrated in Figure 6, we then used ArcMap 10.1 to conduct an assisted automated classification of Landsat scenes using the coded points to estimate the probable land cover types across the entire region. See Appendix VIII for further detail on the training and creation of the assisted automated classification scheme.

3.3. Manual Anthropogenic Factor Classification and Mapping

After classifying land cover in the Gambella Region, our third step was to code for anthropogenic activity on the land, and in turn its effect on the white-eared kob. In 1,462 of the aerial photographs, we coded burned land, human settlements, human presence, roads, cattle/livestock, indigenous agriculture, and/or commercial agriculture (Table 5). We then used ArcMap 10.1 to geo-reference the coded photographs onto a map of the Gambella Region. We then observed and analyzed the locations of five out of the seven anthropogenic factors in relation to Gambella National Park and white-eared kob migration patterns in order to better understand the impact humans are having on wildlife in the area. See Appendix X for detailed instructions on mapping anthropogenic factors in relation to white-eared kob migration.

Table 5. Summary and definition of anthropogenic factor coding for aerial photos of Gambella.

From the many anthropogenic factors coded, we selected five to analyze the relationship of each with the white-eared kob migration patterns in the Gambella Region.

• Human Presence
• Human Settlements
• Burning
• Commercial Agriculture
• Cattle/Livestock

3.4. White-Eared Kob Migration Data

A final step was to explore the relationships between land cover changes and white-eared kob migration patterns as measured by collaring data. HoA-REC&N supplied migration data for one white-eared kob individual collared with a GPS tracker between April and October 2013. We used these data to represent the migration trends of the white-eared kob population in this part of the Gambella Region. To view the movements of this white-eared kob over the seven-month period, we used ArcMap 10.1 to geo-reference the migration data as points onto a map of the region. To see where the white-eared kob spent most of its time, we generated a density layer of the migration points (Figure 7). The darker purple areas in Figure 7 represent areas the white-eared kob visited most often (see Appendix IX for further detail on the density generation process).

Finally, we overlaid this migration density layer with the NDVI results, the assisted land cover classification scheme, and the anthropogenic factor maps to compare white-eared kob migration to land cover change, vegetation type, and anthropogenic threats.

4. Results/Findings

4.1. Vegetation Cover (NDVI) and White-Eared Kob Migration

The conversion of land in the Gambella region has largely accelerated in the past three decades. This conversion has been seen though the thinning of forest edges and a decrease in the extent and diversity of overall tree cover. The raster subtraction below (Figure 8) shows the NDVI change in vegetation cover from the dry season to the wet season of 2012/2013. Of main importance in this map is the density of green pixels on the right half of the frame. This area represents the Duma wetland, which undergoes a large-scale, annual hydrologic change. Here, the dark green rendering of this area is a result of vegetation growth during the wet season, while the red throughout the entire extent represents rivers and wetland flooding. This wetland occupies a large portion of the white-eared kob migration route, thus heightening its overall importance.

While this expansive wetland is in a state of continuous hydrologic fluctuation throughout the year, external factors could introduce disorder at any time, thus altering hydrologic cycle (Hirpo, 2011; Lemma, 2012; Pal & Akoma, 2009; Yalew et al., 2013). Disruption to this cycle would not only affect the land itself, but may also project adverse effects on the white-eared kob. Possible results of this include diminishing the area’s suitability for this mammal’s migration route and the abrupt alteration of critical resources on which the white-eared kob rely (Lemma, 2012). Through this, the link between the white-eared kob and this wetland becomes clearer.

From Figure 8, water sources appear to be indicative of white-eared kob migration patterns. These patterns roughly follow the rivers in the area that stem from the wetland, which serve as a dependent replenishing resource for the white-eared kob throughout their movement. The relationship between these rivers and the wetland highlight the importance of this critical habitat, as a disturbance to the wetland’s hydrologic cycle would extend far into the surrounding area.

4.2. Forest/Land Cover Type and White-Eared Kob Migration

Figure 9 displays the assisted automated land cover classification scheme based on coded aerial photographs and Landsat 8 satellite data for April 2013. This scheme has also been scaled to the extent of the white-eared kob migration route, honing in on the main area of interest (see Appendix VIII for full land cover classification scheme). Within the area of interest, the four largest land cover types represented are savannah grassland, open grassland, Tamarindus Acacia wooded grassland, and Acacia wooded grassland. All remaining land types comprise the “other” category on Figure 9. Finally, the white areas within this map represent cloud cover, for which limited reliable data are available.

As seen below, white-eared kob appear to prefer savannah grasslands (in orange) and wooded grasslands (in gray), while seeming to avoid open grasslands and Tamarindus Acacia wooded grasslands. The large cluster of savannah grassland in this map also represents the previously mentioned Duma wetland. The distribution of white-eared kob across these land types suggests that savannah grasslands, wetlands, and Acacia wooded grasslands may be key targets in land conservation efforts.

4.3. Anthropogenic Factors and White-Eared Kob Migration

4.3.1. Human Presence

Figure 10 shows that human presence, in the form of people, roads, vehicles, agricultural sites, and more permanent settlements, is widespread in the area surrounding Gambella National Park. Human presence appears to be most concentrated just north of the park and in the non-park land extending inward from the east. There are some instances of human presence inside the park, but mostly to the west, south, and along the northernmost border. Overall, our research suggests that white-eared kob may avoid human presence along migration routes.

4.3.2. Human Settlements

Human settlements include permanent huts or dwellings with thatched or metal roofs. They range in size from as few as one, to as many as hundreds of huts arranged in a large village. Figure 11 reveals the location of human settlements as coded from the aerial photographs in the area around Gambella National Park. The highest concentration of human settlements is located in the peninsular area extending into the park from the east. Some settlements are located along the edges of the park and in the western and southern portions of the park. The line of settlements extending west to east across the north of the region likely follows the path of a major road. Compared to the individual white-eared kob movements, human settlements seem to be on the brink of encroaching onto preferred migration paths. Considering human population in the Gambella Region is growing, villages are likely to expand outwards, possibly further impinging on white-eared kob migration routes. Lastly, because settlements are relatively permanent, as opposed to temporary or transient sites of human activity, they represent areas where human impact could be severe in the long term.

4.3.3. Burning

Although human presence and human settlements follow similar geographic patterns, other anthropogenic factors cover the Gambella Region more extensively. An example of this is burning, which includes land either currently (visible flame or smoke) or previously burnt in a fire (ash-ridden land). Burning stems from both human activities and natural causes, and thus has an extensive presence in the Gambella Region.

As shown in Figure 12, the distribution of burning or burnt land is relatively consistent throughout the area in which the photographs were taken. Although the clusters of burning are denser in areas of human activity surrounding Gambella National Park, burning is also found explicitly within its boundaries. Further, the figure illustrates that the white-eared kob in this region tend to avoid areas of burning or burnt land. This pattern can be explained by the possible obstruction of migration pathways and destruction of food sources due to this anthropogenic and/or natural factor.

4.3.4. Cattle/Livestock

Cattle and livestock represent another anthropogenic factor contributing to the present condition of the land in the Gambella Region. The region ranked fourth in the country in terms of livestock density in 2005, at about 17 topical livestock units – equal to 250 kilograms of live weight – per square kilometer (TLU/km²) (SOS Sahel Ethiopia, 2008). Unlike burning, the locations of cattle and livestock are found generally in the areas of human presence (Figure 13). This can be explained by the dietary and commodity purposes that these animals serve for individuals and communities; cattle and livestock provide both food and economic security for inhabitants of the Gambella Region (Jabbar, Negassa, & Gidyelew, 2007; Jabbar & Negassa, 2008; Tschopp, Aseffa, Schelling, & Zinsstag, 2010). As both population and economic incentives for raising cattle and livestock continue to grow, the land in and around human settlements may become more degraded due to grazing. Cattle herders may likely be forced to expand beyond their settlements and villages, leading to a vicious cycle in which degrading land becomes the cost of improving the living standards of local communities and families (Jabbar et al., 2007; Tschopp et al., 2010).

4.3.5. Commercial Agriculture

Commercial agriculture represents any signs of large-scale industrial agricultural production, including large blocks of irrigated fields, commercial tractors, and other heavy machinery for clearing large tracts of land. Figure 14 depicts the location of commercial agriculture sites around Gambella National Park. While there are few sites in the area, research suggests government investments in commercial agriculture in the Gambella Region are an emerging trend, expected to increase significantly in the near future (Pearce, 2011). Similarly, although there are few commercial agricultural sites coded from the aerial photographs, the size of each operation is substantial and their effects on neighboring land and water resources are far-reaching. Most notably, several commercial agriculture sites are located just on the outskirts of Gambella National Park. These could potentially impede the migration of the white-eared kob just to their south and west. They could also potentially drain valuable water resources from the Duma wetland, effecting its fragile wet and dry season cycles or even the white-eared kob migration (Hirpo, 2011; Lemma, 2012; Pal & Akoma, 2009; Yalew et al., 2013;).

Taken together, Figures 11-14 provide a comprehensive illustration of human activity that may be affecting the migration and habitat of the white-eared kob in the Gambella Region.

5. Discussion

This research used complementary methods to explore the relationships between land cover change over time, land type, and anthropogenic factors and white-eared kob in the Gambella Region of Ethiopia. Generally, prior research has shown that kob migration patterns reflect changes in the distribution of food and water sources, especially in savannah areas (Fryxell & Sinclair, 1988). In addition, studies concluded that the availability of food and water, which depend on the length of the dry and wet seasons and on the associated frequency of drought and flooding, ultimately dictate the vitality and survival of the kob species (Fryxell, 1987). Fryxell went on to claim that kob tend to inhabit areas situated near water supplies because these areas tend to have a strong presence of grass and that even moderate droughts can lead to population decline for the kob due to damage to this primary food source. Finally, kob have shown to prefer grasslands with low levels of rainfall because these areas face less of a threat to surface flooding (Fryxell & Sinclair, 1988).

Consistent with these past findings, the present research suggests that white-eared kob prefer savannah grasslands and wooded grasslands in the Duma wetland and travel along, and in the vicinity of, water sources. But while Fryxell and Sinclair showed that the ecosystem and habitat of the white-eared kob is one threatened by natural droughts and floods 30 years ago, the Gambella Region now faces those same natural threats coupled with an increased presence of human activity. With the encroachment of human activity, as characterized by the anthropogenic factors considered in this study, the land that the white-eared kob depend on in the Gambella Region may be more threatened than ever before. Given that the migration patterns of kob depend on access to food, water, and uninhibited migratory channels, all of which may be impacted by both natural and anthropogenic factors, these findings help identify key habitats as target areas for white-eared kob conservation efforts.

Here we see an opportunity for our research to add to the consideration of the effects of land cover change and anthropogenic factors on the kob population’s movements and vitality. Generally, the research methods used in this study not only confirm the findings of previous researchers, but also highlight the role that GIS and spatial analysis can play in land and wildlife management efforts. Although the provided GIS tracking data only applied to 2013, and thus limited our ability to analyze historic trends of kob movement, the results of this research clearly illustrate the behavior of kob in relation to the land and anthropogenic factors in the Gambella Region.

With the predicted rise in population, human activity may increase in the region and encroach on the boundaries of Gambella National Park (Suddath, 2011). The fact remains that the Gambella Region represents an area rooted in human-wildlife competition for land. Land and livelihoods will always be thoroughly connected for both the human inhabitants and the white-eared kob of the Gambella Region, leading to the inherent competition. With this in mind, cooperation among inhabitants of the Gambella Region could be a successful strategy for ensuring that the land remains protected.

6. Policy Recommendations

Based on the findings, this study makes several policy suggestions that align with existing recommendations from both Ethiopian government agencies and scientific literature. First, these findings strongly support the ongoing efforts of the Trans Frontier Conservation Initiative (TFCI), comprised of EWCA and HoA-REC&N, which has been conducting yearly aerial surveys of the Gambella Region since 2009. The goal of these surveys is to collect data on the distribution of wildlife and human activities in the region to aid mapping analyses such as those conducted in this report. The TFCI 2009/2010 Task Force Aerial Survey Report recommends, and this study wholly supports, continuing and expanding these survey efforts (TFCI, 2010). Specifically, our study recommends continuing annual wet and dry season aerial surveys as our results reveal that assisted automated land cover classification schemes based on aerial photographs accurately depict actual land cover. Further, our study recommends continuing and expanding wildlife collaring and GPS tracking efforts. Continuing to collect migration data on white-eared kob in different areas of the region, as well as across international borders, would allow for greater analysis of the impacts of land cover and human activity on this species.

Past survey efforts (TFCI, 2010) reveal that white-eared kob migrate seasonally between the Boma Region of South Sudan and the Gambella Region, highlighting the need for increasing collaring efforts of trans-boundary migrations. These data would also allow land and wildlife researchers to gain a better understanding of migration directionality, rate of movement, and length of time spent in particular locations. Officials could use this information to prioritize land management decisions. Lastly, to complement aerial surveys, the TFCI study recommends conducting systematic ground transects on foot and from vehicles. Ground transects could yield more accurate information about biodiversity and human activity, especially in densely forested areas difficult to survey from the air (TFCI, 2010).

This study also emphasizes the need for improving on-the-ground management of the Gambella National Park. Results show human activity is encroaching on park boundaries, posing potential threats to important landscapes and wildlife that the park is designed to protect. Therefore, we recommend that park managers demarcate the official park boundary and establish patrols along its borders. The systematic ground surveys recommended above could act as patrols for the protection of wildlife and biodiversity within the park (TFCI, 2010). Lastly, involving local community members in the management, enforcement, and surveying of the park could serve several conservation needs. For one, local communities could provide the labor force needed to patrol the boundaries of the park. Second, including locals in management decisions could improve the relationship between park managers and farmers, pastoralists, and families living along the edges of the park, hopefully encouraging effective conservation and natural resource-use practices. Third, studies of local community-based conservation and agroecology have shown that local knowledge can better reflect ecological and social processes than conventional knowledge (Altieri, 2004; Goldman, 2003). The knowledge possessed by local inhabitants of the Gambella Region could better guide surveying efforts in the park.

To help ensure that the rise of commercial agriculture does not endanger the livelihoods of local farmers, existing literature (Abbink, 2011; Altieri, 2004) recommends, and our study supports, facilitating cooperation between local communities and large commercial agriculture operations. Cooperative efforts could include large commercial operations selling certified seeds to small farmers and introducing imported technology to the broader community. Further, these large operations could rent farm equipment to local farmers and teach them their proper use and innovative farming techniques. They could also export smallholder farm products, granting locals greater access to markets and increasing the value of their products (Abbink, 2011). Overall, it is important that local communities do not lose their land or livelihoods, for if they do they would likely move to more marginal lands, further threatening ecosystems and wildlife in the region. Our results show a presence of commercial agriculture on the northern border of the Gambella National Park boundary, thus supporting the recommendation for cooperation between commercial agriculture operations and local communities to protect white-eared kob.

Lastly, based on our findings and existing reports (TFCI, 2010; Zbicz, 2003), this study recommends trans-boundary cooperation between the governments and institutions of Ethiopia and South Sudan to ensure the uninhibited migration of white-eared kob and other wildlife in the area. Our study shows the importance of protecting these vast migration corridors, which we hope will spark collaboration between the two nations. While this research solely focuses on a domestic migration route within the Duma wetland, other migration routes do exist, including one between Ethiopia and South Sudan (van Aarst, 2012), famous for being the second largest mammal migration in Africa. Emerging information on trans-boundary white-eared kob migration reveal the importance of pursuing cooperative conservation planning between Ethiopia and South Sudan. However as Zbicz (2003) observes, while international organizations are major contributors to trans-boundary cooperation, ultimately it is the daily efforts of those on the ground that ensure its sustained success.

As an area of Ethiopia that provides security for both human and wildlife populations, the Gambella Region appears to be a target area for conservation. However, competition for land in this region has resulted in unchecked development and degradation. Our research offers new methods, analyses, and recommendations to ensure that degradation becomes opportunity – opportunity to protect; opportunity to grow; and opportunity to manage with enduring confidence. Focusing on the long-term health of the Gambella Region is one way to reciprocate all that it provides. A holistic land management plan, designed and implemented through the cooperative efforts of all stakeholders in this region, could ensure and sustain the vitality of the landscape upon which both human and wildlife populations depend.

7. References

 

Abbink, J. (2011). “Land to the foreigners”: economic, legal, and socio-cultural aspects of new land acquisition schemes in Ethiopia. Journal of Contemporary African Studies, 29(4), 513–535.

African Parks. (2013). African Parks Network.

Altieri, M. A. (2004). Linking ecologists and traditional farmers in the search for sustainable agriculture. Frontiers in Ecology and the Environment, 2(1), 35–42.

Amsalu, A., & Genremichael, D. (2010). An Overview of Climate Change Impacts and Responses in Ethiopia in 2009 (pp. 215–232). Addis Ababa. Retrieved from http://www.ffe-ethiopia.org/pdf/Ethiopian_Environment_Review.pdf.

Bewket, W., & Conway, D. (2007). A note on the temporal and spatial variability of rainfall in the drought-prone Amhara region of Ethiopia. International Journal of Climatology, 27(11), 1467–1477.

Central Statistical Agency: Population Census Commission. (2007). Population and Housing Census Report: Gambella Region. Retrieved from http://www.csa.gov.et/newcsaweb/images/documents/surveys/Population and Housing census/ETH-pop-2007/survey0/data/Doc/Reports/Gambella_Statistical.pdf.

Constitution of the Federal Democratic Republic of Ethiopia. (1995). Constitution of the Federal Democratic Republic of Ethiopia. Retrieved from http://www.refworld.org/docid/3ae6b5a84.html.

De Mûelenaere, S., Frankl, A., Haile, M., Poesen, J., Deckers, J., Munro, N., … Nyssen, J. (2012). Historical Landscape Photographs for Calibration of Landsat Land Use/Cover in the Northern Ethiopian Highlands. Land Degradation & Development, n/a–n/a.

Devereux, S. (2000). Food Insecurity in Ethiopia: A discussion paper for the Department for International Development (DFID), (October).

Devereux, S., & Guenther, B. (2009). Agriculture and Social Protection in Ethiopia Agriculture. Retrieved from http://www.future-agricultures.org/pdf files/Social_Protection/Working Paper No SP03 – Agriculture & Social Protection in Ethiopia.pdf.

Devereux, S., Teshome, A., & Sabates-Wheeler, R. (2005). Too Much Inequality or Too Little? Inequality and Stagnation in Ethiopian Agriculture. Institute of Development Studies, 36(2), 121–126.

DIVA-GIS. (n.d.). Retrieved from http://www.diva-gis.org/.

EPA. (2011). Ethiopian Environmental Protection Authority. Retrieved from http://www.epa.gov.et/default.aspx.

Ethiopian Mapping Agency: Geo-Information for Sustainable Development. (2009). Ethiopian Mapping Agency. Retrieved from http://www.ema.gov.et/.

Ethiopian Ministry of Culture and Toursim. (2013). Ecotourism potentials in Ethiopia. Retrieved from http://www.tourismethiopia.gov.et/English/Pages/EcotourismpotentialsinEthiopia.aspx.

Ethiopian Wildlife Conservation Authority (EWCA). (2012). Ethiopian Wildlife Conservation Authority. Retrieved from http://www.ewca.gov.et/.

Fryxell, J. M. (1987). Food limitation and demography of a migratory antelope, the white-eared kob. Oecologia, 72(1), 83–91.

Fryxell, J. M., & Sinclair, A. R. E. (1988). Seasonal migration by white-eared kob in relation to resources. African Journal of Ecology, 26, 17–31.

Gambella’s Hidden Treasures. (2012). Gambella’s hidden treasures. Ethiopia: HoA-REC/N and EWCA. Retrieved from http://www.youtube.com/watch?v=HrZ-WWotCr0.

Gebreselassie, S. (2006). Intensification of Smallholder Agriculture in Ethiopia: Options and Scenarios. Prepared for the Future Agricultures Consortium Meeting at the Institute of Development Studies, 1–26.

Gessesse, B. (2010). Review of Land Degradation and Land Management in Ethiopia up to 2008/09 (pp. 187–208).

Goldman, M. (2003). Partitioned Nature, Privileged Knowledge: Community-based Conservation in Tanzania. Development and Change, 34(5), 833–862.

Hirpo, L. A. (2011). Climate change and wetland resources vulnerability: Impacts on livelihoods and opportunities for enhancing in Ethiopia (pp. 50–58).

Horn of Africa Regional Environment Center and Network (HoA-REC&N). (2013). Welcome to HoA-REC&N. Retrieved from http://www.hoarec.org/.

Horne, F. (2011). Understanding Land Investment Deals in Africa: Country Report: Ethiopia (pp. 1–58). Oakland. Retrieved from http://www.oaklandinstitute.org/sites/oaklandinstitute.org/files/OI_Ethiopa_Land_Investment_report.pdf.

Horne, F. (2012). “Waiting Here For Death:” Forced Displacement and “Villagization” in Ethiopia’s Gambella Region (pp. 1–120). New York. Retrieved from http://www.hrw.org/sites/default/files/reports/ethiopia0112webwcover_0.pdf.

Human Development Report 2007/2008. (n.d.). Status of major international environmental treaties (pp. 314–317).

Jabbar, M., & Negassa, A. (2008). Livestock ownership, commercial off-take rates and their determinants in Ethiopia (pp. 1–40). International Livestock Research Institute. Retrieved from http://books.google.com/books?hl=en&lr=&id=zDnNqgL2NZgC&pgis=1.

Jabbar, M., Negassa, A., & Gidyelew, T. (2007). Geographic distribution of cattle and shoats populations and their market supply sheds in Ethiopia. Discussion paper No. 2. Improving Market Opportunities. International Livestock Research Institute (ILRI).

Lee, L., & Roberts, C. (2012). A Delicate Balance: Land Use Planning in the Gambella Region of Ethiopia. In Environmental Policy Update 2012: Development Strategies and Environmental Policy in East Africa (pp. 1–32). Retrieved from https://moodle.colby.edu/pluginfile.php/36200/mod_resource/content/2/CH4_A-Delicate-Balance-Land-Use-Planning-in-the-Gambella-Region-of-Ethiopia.pdf.

Lemma, E. (2012). Remote sensing and GIS based wildlife corridor suitability for Nile Lechwe Species in Gambela National Park, Ethiopia. Retrieved from http://etd.aau.edu.et/dspace/bitstream/123456789/4712/1/Eyassu Lemma.pdf.

Liu, W., Sinha, A., & Stern, R. (2013). Unheard Voices: The Rights Impact of Land Investments on Indigenous Communities in Gambella. The International Human Rights Clinic (IHRC) at New York University School of Law in collaboration with The Oakland Institute, 1–17.

Martinuzzi, S., Gould, W. A., Gonzalez, O. M. R., Martinez, A., Maldonado, P. C., Pérez-buitrago, N., & Caban, J. J. F. (2008). Mapping tropical dry forest habitats integrating Landsat NDVI, Ikonos imagery, and topographic information in the Caribbean Island of Mona. Revista de Biologia Tropical, 56(June), 625–639.

Ministry of Finance and Economic Development (MoFED). (2006). Ethiopia: Building on Progress: A Plan for Accelerated and Sustained Development to End Poverty (PASDEP) (2005/06-2009/10) (Vol. I, pp. 1–267). Addis Ababa. Retrieved from http://www.afdb.org/fileadmin/uploads/afdb/Documents/Policy-Documents/Plan_for_Accelerated_and_Sustained_%28PASDEP%29_final_July_2007_Volume_I_3.pdf.

North, D. C. (1991). Institutions. Journal of Economic Perspectives, 5(1), 97-112.

Pal, S., & Akoma, O. C. (2009). Water Scarcity in Wetland Area within Kandi Block of West Bengal: A Hydro-Ecological Assessment. Ethiopian Journal of Environmental Studies and Management, 2(3), 1–12.

Pearce, F. (2011). Agribusiness Boom Threatens Key African Wildlife Migration. Yale Environment 360. Retrieved September 24, 2013, from http://e360.yale.edu/feature/agribusiness_boom_threatens_key_african_wildlife_migration/2377/.

Rahmato, D. (2011). Land to Investors: Large-Scale Land Transfers in Ethiopia Addis Ababa. Forum for Social Sciences, 1–36.

Sewonet, A. (2003). Breaking the Cycle of Conflict in Gambella Region (pp. 1–7).

SOS Sahel Ethiopia. (2008). Pastoralism in Ethiopia: Its Total Economic Values and Development Challenges (p. 33). Retrieved from http://data.iucn.org/wisp/documents_english/TEV/TEV Ethiopia Final_JD.pdf.

Suddath, C. (2011, June). Census Update: What the World Will Look like in 2050. Time. Retrieved from http://content.time.com/time/nation/article/0,8599,2080404,00.html.

Tessema, M. E., Lilieholm, R. J., Ashenafi, Z. T., & Leader-Williams, N. (2010). Community Attitudes Toward Wildlife and Protected Areas in Ethiopia. Society & Natural Resources, 23(6), 489–506.

Trans Frontier Conservation Initiative (TFCI) Task Force. (2010). Aerial Survey Report: Gambella Reconnaissance 2009 & Census 2010, 1–33.

Tschopp, R., Aseffa, A., Schelling, E., & Zinsstag, J. (2010). Farmers’ Perceptions of Livestock, Agriculture, and Natural Resources in the Rural Ethiopian Highlands, 30(4), 381–390.

United States Agency for International Development (USAID). (2013). Food Assistance Fact Sheet: Ethiopia. Retrieved from http://www.usaid.gov/ethiopia/food-assistance.

United States Geological Survey (USGS). (2013). Landsat. Retrieved from http://landsat.usgs.gov/index.php.

Van Aarst, S. (2012). Protected Areas Delineation and Land Use Planning – Gambella Case. Ethiopia: University Water Sector Partnership. Retrieved from http://www.thewaterchannel.tv/hn/component/hwdvideoshare/viewvideo/1392/ecosystem/protected-areas-delineation-and-land-use-planning-gambella-case.

Williams, S., & Tefera, Z. (2012). Sustainable Development of the Protected Area System of Ethiopia (SDPASE). Addis Ababa.

World Bank. (2013). Ethiopia Overview. World Bank. Retrieved October 3, 2013, from http://www.worldbank.org/en/country/ethiopia/overview.

Yalew, S., Zaag, P., Van Der Mul, M., Uhlenbrook, S., Teferi, E., & Van, A. (2013). Coupled hydrologic and land use change models for decision making on land and water resources in the Upper Blue Nile basin, 15.

Zbicz, D. C. (2003). Imposing Transboundary Conservation. Journal of Sustainable Forestry, 17(1-2), 21–37.