INTRODUCTION
Soil erosion by water threatened the food security and environmental
protection of the globe (Lieskovský & Kenderessy 2014). The sub-Saharan
African countries, including Ethiopia, are the most affected by soil
erosion (Israel et al., 2020; Terefe et al., 2020). Globally, soil
erosion affects about 10 million hectares of cultivated land each year,
with Africa accounting for 65 percent of the damage (Vlek et al., 2008;
Pimentel, 1995). In Ethiopia, the amount of soil loss reported about 2
billion t yr-1. The annual average soil loss from
cultivated fields is about 100 t ha-1 (FAO, 1986;
Bewket & Sterk 2002).
Gumara River watershed is one of the major tributaries to Lake Tana and
the Blue Nile river basin (Setegn et al., 2008). The watershed
attributes extreme soil erosion, high runoff and the highest rainfall
intensity (Belayneh et al., 2019; Fazzini et al., 2015). Different
researches were completed to quantify the rate of soil erosion in the
watershed. According to Easton et al. (2010), the predicted soil loss
from Gumara watershed was about a maximum of 84 t ha-1yr-1. A study conducted by Belayneh et al. (2019) and
Zimale et al. (2017), reported that an average soil loss rate of 42 and
49.2 t ha-1 yr-1, respectively.
Wubie & Assen (2019) showed the soil degradation index (SDI) in the
watershed was in the range of -236 to -364%, indicating that the area
is subjected to high soil erosion. To reverse this trend, the Ethiopian
government with the help of non-governmental organizations started a
large-scale watershed development program (WDP) to increase agricultural
productivity, and reduce soil erosion. The program focused on the
construction of the physical structure in the highlands for the last two
decades. However, the rate of soil erosion was not decreasing (Abate et
al., 2015).
The effectiveness of conservation measures over longer periods evaluated
as not effective, especially in the sub-humid and humid monsoonal
climates (Yeraswork, 2000; Mhiret et al., 2020). Whereas, in the
semi-arid highlands of the Tigray region, the implemented measures were
effective in reducing soil erosion and increasing water storage (Nyssen
et al., 2009). In humid highlands, sediment concentrations in the major
rivers showed an increasing trend (Abate et al., 2016). According to
Haile et al., (2006), the failure was related to the poor design of soil
and water conservation practices (SWCP). Watershed planners lack
knowledge of the hydrological processes and the landscape location
(Guzman et al., 2017b, Bayable et al., 2016). In areas like Ethiopia
where SWC was implemented in community mobilization, the standards of
conservation measures were influenced by inadequate expert follow-up,
lack of farmers’ technical skill, and poor community participation
(Sinore et al., 2018; Zimale et al., 2017; Reij et al., 1996).
The livelihood of smallholder farmers largely dependent on the long-term
viability of WDP. The success of development projects largely determined
by community participation and commitment. Participation is a group
effort to establish long-term management requirements, identify
objectives, determine potentials, technology selection and policies, and
monitor and analyze outcomes (Johnson et al., 2001). Community
participation promotes long-term watershed management activities (Lubell
& Fulton 2007). However, government-sponsored conservation efforts,
have taken a top-down approach, failing to understand the needs,
concerns, and traditions of local people. The local people who were
worried about and motivated to take action must have built up WDP from
the bottom-up (Mullen & Alison 1999). Conservation programs failed to
produce immediate results benefiting the poor farmer, making it hard to
invest in long-term impacts. The objective of this research was,
therefore, to better understand the general approaches used in the
implementation of SWCPs in watersheds and the design of WDP in the
Gumara watershed, to efficiently maintain soil erosion to the downstream
water bodies.