# Analysis of Hydrological Characteristics of Blue Nile Basin, Nishe Watershed
## 1 Introduction  
Water is the critical and valuable natural resource for sustaining life, development, and environment in order to achieve the long-term economic and social growth. Development and management of integrated water resources are important infrastructure for sustainable development even nowadays the management is a difficult task due to internal and external influences [1]. The development of water management and hydrological models are used to recognize all the measured and physical data of hydrologic behavior. The problems of water resources managing and understanding involve complex processes and relations at the interface [2]. Watershed characterization with regard to geographic disparities in hydrological response complements modeling, as one of the challenges of hydrological modeling is the difficulty in parameterizing differences in watershed characteristics. The influence of catchment hydrology developments on watershed management depends on significant factors since it offers a basis for the development of land issues fordeveloping and securing water resources [3; 4]. The most significant characteristic in water development programs is understanding catchment and its hydrological developments to advance appropriate models for the watershed. For watershed hydrology, many models were developed [5] but the main constraint was the availability of temporal and spatial data impeding the implementation of these models especially in developing countries. The spatial distribution of weather stations is poor, with least coverage over rural areas, many non-functioning stations, inhomogeneous and missing data, and in some cases inefficient quality control systems in Africa [6]. The water resources availability is crucial for all countries especially for the areas facing the risk of drought, desertification, land use changes, and high population growth. Assessment of catchment is a precondition to understand the key processes of the hydrology. The response of a watershed in terms of its state variables and characteristics is the main challenge of hydrological modeling. Water resources management has become more vital and complicated because of conflicting demands by various stakeholders, rapid population growth, industrialization, hydropower development, irrigation, urbanization and land degradation [7]. The water balance study in such a challenge provides an understanding of the hydrologic characteristics of the watershed and used to identify changes in the main hydrological processes [3]. Hydrological models are mathematical representations of real-world hydrological processes that can be used to simulate the water balance as well as plan and manage water resources. It is an essential constituent of water resources as well as simulating the effects of watershed processes. They were developed to monitor the water resources management strategies formulation by understanding the space and time variation distributions of water resources. Water resources assessments, prediction of uncertainty analysis, calibration, and validation have been conducted with the hydrological models [8; 9]. The purpose of using hydrological modeling is used to deliver the information for management of water resources in sustainable manner for hydrological analysis. The hydrological response of watershed characterization is decisive on the capacity to manage water scarcity in areas like Blue Nile River Basin and specifically around the study area. The interactions between various hydrological processes and drivers from external sources such as land use, rainfall, soil types, and temperature variability are used to investigate the behavior of catchments. The Soil and Water Assessment Tool (SWAT) model has a capacity to simulate hydrological processes with reasonable accuracy at comparatively bigger watersheds.