The Impact of Climate Change as Well as Land-Use and Land-Cover Changes on Water Yield Services in Haraz Basin

Abstract

Water-yield assessment is crucial to effectively achieve water supply management at the basin scale. It is affected by climate change, and Land Use/Land Cover Change (LULCC). This paper quantifies the combined impact of LULCC and climate change on water yield over short and long-term periods in the Haraz basin, Iran. This basin has experienced severe forest degradation, agricultural expansion, and urbanization. Most agricultural lands are within the plains and coastal areas, and 25% of the basin is covered by forest, which includes part of the Hyrcanian conservation forests. Four scenarios to distinguish the relative portion of Land Use/Land Cover (LULC) and climate for water supply variations are considered, including real conditions at the beginning of the period (Sn1), real conditions without changes in LULC (Sn2), real conditions without climate change (Sn3), and real conditions at the end of the period (Sn4). Four study periods include 1992–2007, 2007–2016, 2016–2026 as a short term, and 1992–2026 as a long-term period. The spatial patterns of annual precipitation showed decreasing amounts in the three studied years from the northwest to the south. Water yield also reduced during the study period 1992–2007 and 2007–2016, and climate change plays an essential role in this reduction. Forecasts show that rainfall will recover in 2026 and water yield will increase in the northern sub-basins. In the long run, from 1992 to 2026, the contribution of LULCC and climate change factors to water yield are equal. The results can provide references for land use management to enhance water yield considering global climate change.

Landscape Pattern Change and Ecological Effect in a Typical Mountain–Oasis–Desert Region in the Northwest Region of China

“…In addition, population density and land-use intensity might also have contributed [42]. In contrast, the decreasing trend of the water yield and the total water conservation in our study area is different from that of Jing-Jin-Ji, China [59], Haraz Basin, Iran [60] and Mereb-Gash River Basin in the Horn of Africa [61]. The sparse vegetation of our study area might contribute to this difference.…”

Spatiotemporal Variation and Driving Factors of Water Supply Services in the Three Gorges Reservoir Area of China Based on Supply-Demand Balance

“…Their research has found that water provision services in the Tungabhadra basin are vulnerable to climate change. Emlaei et al [25] applied the InVEST annual water yield model to analyze the water supply in the Haraz Basin. Their study also explored the combined effects of land use/cover and climate change on the short and longterm water supply to provide a reference for implementing reasonable land management strategies to improve water production under climate change.…”

A Study on the Rationality of Land Use Change in the Dianchi Basin during the Last 40 Years under the Background of Lake Revolution

“…Scholars in related fields at home and abroad have undertaken a great deal of research and achieved a lot of results. For example, a series of studies were conducted on the spatio-temporal changes of land use in lake basins [4][5][6][7][8][9][10][11][12][13] and their driving factors [14][15][16][17][18][19], the impacts of land use change in lake basins [20][21][22][23][24][25][26][27][28][29] and the dynamic monitoring of lake areas [30][31][32][33]. These studies have laid an important theoretical foundation for the study of lake land use.…”