The Influence of Land Use Change toward Hydrological Aspect at Upper Site

1Firman Hidayat

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Abstract:

The Impact of land-use change not only give some benefit to community but also can cause problem, namely: erosion, sedimentation, flooding and other. Erosion will cause silting of reservoirs, reducting irrigation channel capacity, and disrupt electrical power generation systems. High erosion, flooding in the rainy season not only have a negative impact on the biophysical aspects of natural resources and the environment but also the social aspects of the economic impact on the community. Several cases of changes in land use in some watersheds in Indonesia is presented with a discussion of the causal relationship of hydrological aspects, especially regarding the carrying capacity of the watershed and the frequency of flooding. Hydrology and run off characteristics of a number of primary rivers in Indonesia (Java) presented by using of land that increase timely. Related with that case the research will be taken. The objective is, to analisys influence of land use change to hidrological aspects. at Mahat Hulu watershed, located in the Lima Puluh kota district that 15 years old (1995-2010) deforestation has taken significantly. In 1995 Watershed has Forest area approximarely 50.9% and in 2010 decrease into 28% or from 14523 ha (1995) decrease to 7981 ha (2010) but mix garden increased from 17.1% (1995) to 43.8% (2010) or 4889 ha (1995) to 12508 ha (2010), Consequently, such as runoff increased, flooding, and drought during the dry season, high erosion and sedimentation as well as a decline in productivity and income of farmers. In this case, special aspect that research, were the influence of land use changes on the hydrological aspects such as coefficient of annual and seasonal runoff, and fluctuations. The method used quantitative and multiple regression test. Result of analysis are deforestation will increases coefficient run off, and fluctuations discharged. Coefficient runoff from 20% in the 1999-2002 to 24% in 2007-2010 and fluctuation of discharged (KRS) also increased from 2.4-5.5 (1999- 2002) to 5.9-10.7 (2007-2010) indicating DAS is critics. Results of multiple regression test showed a close correlation between the variables (0.9) the formula is C (%) = 975 - 11.2 htn - 15.3 kbn cpr - 10.9 smk blkr + 0.43 tgln dan R-Sq = 42.4%, for the stepwise regression test showed that forest area influence to run off. It can be showed from the equation is CRO = 31.5 - 0.370 htn, , R-Sq = 5.3% Its mean, run off will increased cause by forest area decreased.

Keywords:

Hydrology, Erosion, Sedimentation, Runoff.

Paper Details
Month3
Year2020
Volume24
IssueIssue 5
Pages1261-1276